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The Technological Indispensability Hypothesis: An Addendum to ‘Bound in Shallows’

Is there a single technology that can take us from being capable of reaching space to actually building an infrastructure system-wide? Or at least getting to a tipping point that makes the latter possible, one that Nick Nielsen, in today’s essay, refers to as a ‘space breakout’? We can think of game-changing devices like the printing press with Gutenberg’s movable type, or James Watt’s steam engine, as altering — even creating — the shape and texture of their times. The issue for space enthusiasts is how our times might be similarly altered. Nick here follows up an earlier investigation of spacefaring mythologies with this look at indispensable technologies, forcing the question of whether there are such, or whether technologies necessarily come in clusters that enforce each other’s effects. The more topical question: What is holding back a spacefaring future that after the Apollo landings had seemed all but certain? Nielsen, a frequent author in these pages, is a prolific writer whose work can be tracked in Grand Strategy: The View from Oregon, and Grand Strategy Annex.

by J. N. Nielsen

1. Another Hypothesis on a Sufficient Condition for Spacefaring Civilization
2. The Nineteenth Century and the Steam Engine
3. The Twentieth Century and the Internal Combustion Engine
4. The Twenty-First Century and the Energy Problem
5. The World That Might Have Been: Accessible Fission Technology
6. Nuclear Rocketry as a Transformative Technology
7. Practical, Accessible, and Ubiquitous Technologies
8. The Potential of an Age of Fusion Technology
9. Indispensability and Fungibility
10. Four Hypotheses on Spacefaring Breakout

1. Another Hypothesis on a Sufficient Condition for Spacefaring Civilization

Civilization is the largest, the longest lived, and the most complex institution that human beings have built. As such, describing civilization and the mechanisms by which it originates, grows, develops, matures, declines, and becomes extinct is difficult. It is to be expected that there will be multiple explanations to account for any major transition in civilization. At our present state of understanding, the best we can hope to do is to rough out the possible classes of explanations and so lay the groundwork for future discussions that penetrate into greater depth of detail. It is in this spirit that I want to return to the argument I made in an earlier Centauri Dreams post about the origins of spacefaring civilization.

The central argument of Bound in Shallows was that, while being a space-capable civilization is a necessary condition of being a spacefaring civilization, an adequate mythology is the sufficient condition that facilitates the transition from space-capable to spacefaring civilization. According to this argument, the contemporary institutional drift of the space program and of our civilization is a result of no contemporary mythology being readily available (or, if available, such a mythology remains unexploited) to serve as the social framework within which a spacefaring breakout could be understood, motivated, rationalized, and justified.

In the present essay I will consider an alternative hypothesis on the origins of spacefaring civilization, again building on the fact that we are, today, a space-capable civilization that has not as of yet, however, experienced a spacefaring breakout. The alternative hypothesis is that a key technology is necessary to great transitions in the history of civilization, and that a key technology is like the keystone of an arch, which when present constitutes a stable structure that will endure, but, when absent, the structure collapses. Successful civilizations see a sequence of key technologies that are exploited at a moment of opportunity that allows civilization to internally revolutionize itself and so avoid stagnation. I will call this the technological indispensability hypothesis.

There are many key technologies that could be identified—the bone needle, agriculture, written language, the moveable type printing press—each of which represented a major turning point in human history when the technology in question was exploited to the fullness of its potential. We will take up this development relatively late in the history of civilization, beginning with the steam engine as the crucial technology of the industrial revolution, and therefore the technology responsible for the breakthrough to industrialized civilization.

[Indian & Primose Mills steam engine, built in 1884, in service until 1981]

2. The Nineteenth Century and the Steam Engine

The nineteenth century belonged to steam power, which both built upon previous technological innovations as well as laying the groundwork for the large-scale exploitation of later technologies. But it was steam power that enabled the industrial revolution, which was an inflection point in human agency, both in terms of human ability to reshape our environment and the human ability to harness energy for human use on ever-greater scales. Without the rapid adoption and large-scale exploitation of steam engine technologies for shipping, railways, resource extraction, and industrial production as the model for industrialized civilization, later technological developments (like the internal combustion engine or the electric motor) probably would not have been so effectively exploited.

Almost two hundred years of continuous development built on prior technologies from the earliest steam devices (not counting earlier steam turbines such as that of Hero of Alexandria, which was not a stepping stone to later developments building on this technology) to James Watt’s steam engine. A series of inventors, starting in the early seventeenth century—Giovanni Battista della Porta (1535-1615), Jerónimo de Ayanz y Beaumont (1553-1613), Edward Somerset, second Marquess of Worcester (1602-1667), Denis Papin (1647-1713), Thomas Savery (1650-1715), and Jean Desaguliers (1683-1744)—created steam-powered devices of increasing efficiency and utility. And, of course, while James Watt’s steam engine was the culmination of these developments, it was not an end point of design, but the point of origin of exponential technological improvements that followed.

The technology of the steam engine, then, could be construed as a key technology that enabled the industrial revolution. Previous labor-saving technologies—not only earlier forms of the steam engine as implied by the evolution of that technology, but also water mill and windmill technology known since classical antiquity—were limited by their inefficiency and by the sources of energy they harvested. The steam engine, once understood, was capable of increasing efficiency both through improved design and precision engineering, and it allowed human beings to tap into sources of energy sufficiently plentiful and dense that powered machine works could, in principle, be installed at almost any location and be operated continuously for as long as fuel could be supplied (which supply was facilitated by the energy density of the fuel, first coal for steam technologies, then oil for the internal combustion engine).

About fifty years after Watt’s later iterations of his steam engine design, Sadi Carnot published Réflexions sur la puissance motrice du feu et sur les machines propres à développer cette puissance (Reflections on the Motive Power of Fire and on Machines Fitted to Develop that Power, 1824), and in so doing systematically assimilated steam engine technology to the conceptual framework of science. It was this scientific understanding of what exactly the steam engine was doing that made it possible to improve the technology beyond the limits of tinkering (or what we might today call “hacking”). As we shall see, however, the full exploitation of a transformative technology seems to require both scientific development and practical tinkering.

In regard to my thesis in Bound in Shallows, mythologies present in the Victorian age that enabled the exploitation of steam technology could include the belief in human progress and belief in the distinctive institutions of Victorian society. To take the latter first, in The Victorian Achievement I argued that the ability for Victorian England to keep itself intact despite the wrenching changes wrought by the industrial revolution was key to the success of the industrial revolution: “[Victorian civilization] achieved nothing less than the orderly transition from agricultural civilization to industrialized civilization.”

At the same time that a civilization must internally revolutionize itself in order to avoid stagnation, it must also provide for continuity by way of some tradition that transcends the difference between past, present, and future. The ideology of Victorian society made this possible for England during the industrial revolution. A sufficiently large internal revolution that fails to maintain some continuity of tradition could result in the emergence of a new kind of civilization that must furnish itself with novel institutions or reveal itself as stillborn. If the population of a revolutionized civilization cannot be brought along with the radical changes in social institutions, however, the internal revolution, rather than staving off stagnation, simply becomes an elaborate and complex form of catastrophic failure in which a society approaches an inflection point and cannot complete the process, coming to grief rather than advancing to the next stage of development.

It has become a commonplace of historiography that nineteenth century Europe, and Victorian England in particular, believed in a “cult of progress”; the studies on this question are too numerous to cite. A revisionary history might seek to overturn this consensus, but let us suppose this is true. If belief in progress distinctively marked the nineteenth century engagement with the earliest industrial technologies, we can regard this as an antithetical state of mind to what Gilbert Murray called a “failure of nerve” [1], and as such a steeling of nerve may have been what was necessary for a previously agricultural economy to find itself rapidly transformed into an industrialized economy and to survive the transition intact.

At this point, we can equally well argue for the indispensability of technology or the indispensability of mythology in the advent of a transformation in civilization, but now we will pass over into further developments of the industrial revolution. After the age of the steam engine, the twentieth century belonged to the internal combustion engine burning fossil fuel. It was the internal combustion engine that drove technological and economic modernity first revealed by steam technology to new heights.

[The Wärtsilä-Sulzer RTA96-C internal combustion engine]

3. The Twentieth Century and the Internal Combustion Engine

The key technology of the twentieth century, and the successor technology to the steam engine, was the internal combustion engine. The first diesel engine was built in 1897, and the diesel engine rapidly found itself employed in a variety of industrial applications, especially in transportation: shipping, railroads, and trucking. Two-stroke and four-stroke gasoline engines converged on practical designs in the late nineteenth and early twentieth century and began to replace steam engines in those applications where diesel engines had not already replaced steam.

The internal combustion engine has a fuel source that can be stored in bulk (also true for steam engines), and it is scalable. The scalability of the internal combustion engine often goes unremarked, but it is the scalability that ensured the penetration of the internal combustion engine into all sectors of the economy. An internal combustion engine can be made so small and light that it can be carried around by one person (as in the case of a yard trimmer) and it can be made so large and powerful that it can used to power the largest ships ever built. [2] The internal combustion engine is sufficiently versatile that it can be dependably employed in automobiles, trucks, trains, ships, power generation facilities, and industrial applications.

While it would be misleading to claim that the internal combustion engine was revolutionary to the degree that the steam engine was revolutionary, it would nevertheless be accurate to say that the internal combustion engine allowed for the expansion and consolidation of the industrialized civilization made possible by the steam engine.

The internal combustion engine proliferated at a time when the belief in the institutions of societies undergoing industrialization weakened and arguably has never recovered, so that it would be difficult to argue that the ongoing industrial revolution was driven by a distinctive mythology, whereas the continued development and refinement of the crucial technologies of industrialization continued to advance even as the core mythologies of industrializing societies were questioned as never before. At this point, technology looks more indispensable to ongoing industrialization than does mythology.

The experience of the First World War was a turning point both in technology and social change. I have called the First World War the First Global Industrialized war; for the first time, the war effort was existentially dependent upon fossil fuel powered trains, trucks, motorcycles, aircraft, and tanks, which transformed the experience of combat, so that German soldiers thereafter spoke of the “frontline experience” (Fronterlebnis). Even while all traditional warfighting seemed to vanish as being irrelevant (heroic cavalry charges no longer carried the day or turned the tide), a new kind of industrialized war experience appeared, and we can find this experience not merely described but celebrated by Ernst Jünger in Storm of Steel, Copse 125, and other works.

The war led to the destruction of many political regimes in Europe that had endured for hundreds of years, and saw the appearance of radical new regimes like Soviet Russia, which emerged from the wreckage of Tsarist Russia, which could trace its origins back almost a millennium. Whether these ancient regimes were the victims of a mythology that catastrophically failed in the midst of industrialized warfare, or whether the failed regimes brought down traditional mythologies with them, is probably a chicken-and-egg question. But even as ancient regimes and their associated mythologies failed, technology triumphed, and with technology there arose new forms of human experience, the principal driver of which new experiences was continued technological innovation.

[Reactor dome being lowered into place at Shippingport Atomic Power Station in Pennsylvania]

4. The Twenty-First Century and the Energy Problem

Both steam engines and internal combustion engines exploited the energy of fossil fuels. What economists would call the negative externalities of the trade in fossil fuels that grew in the wake of the adoption of the internal combustion engine included the “resource curse,” which marred the political economy of many nation-states that possessed fossil fuels, and extensive pollution resulting from the extraction, refining, transportation, and consumption of fossil fuels. No one could have guessed, at the beginning of the twentieth century (much less at the beginning of the nineteenth century), the monstrosity that fossil fueled internal combustion engines would become, and, by the time our civilization was utterly dependent upon the internal combustion engine, it was too late to do anything except to attempt to mitigate the damage of the entire energy infrastructure than had been created to fuel our industries.

Having realized, after the fact, the dependency of industrialized civilization upon fossil fuels, we find ourselves and our society dependent upon industries that have high energy requirements, but lacking the technology to replace these industries at scale. We are trapped by our energy needs.

I am not going to attempt to summarize the large and complex issues of the advantages and disadvantages of energy alternatives, as countless volumes have already been devoted to this topic, but I will only observe that an abundant and non-polluting source of energy is necessary to the continued existence of technological civilization. We can have civilization without abundant and non-polluting sources of energy, but it will not be the energy-profligate civilization we know today. If energy is non-abundant, it must be rationed; and if energy is polluting, we will gradually but inevitably poison ourselves on our own wastes. Both alternatives are suboptimal and eventually dystopian; neither lead to future transformations of civilization that transcend the past by attaining greater complexity.

Just as there are those who argue for the continuing exploitation of fossil fuels without limit, and who appear to be prepared to accept the consequences of this unlimited use of fossil fuels, there are also those who argue for the abandonment of fossil fuels without any replacement, so that our fossil fuel dependent civilization must necessarily come to an end. Among those who argue for the abolition of energy-intensive industry, we can distinguish between those who advocate the complete abolition of technological civilization (Ted Kaczynski, John Zerzan, Derrick Jensen) and those who look toward a kind of “small is beautiful” localism of “eco-communalism” [3] that would preserve some quality of life features of industrialized civilization while severely curtailing consumerism and mass production.

Human beings would accept sacrifices on this scale, including sacrificing their energy demands, if they believed their sacrifice to be meaningful and that it contributed to some ultimate purpose (or what Paul Tillich called an “ultimate concern”). In other words, a sufficient mythological basis is necessary to justify great sacrifices. We have seen intimations of this level of ideological engagement and call to sacrifice with the most zealous environmental organizations, such as Extinction Rebellion — the “Red Brigade” protesters present themselves with a theatricality that is certain to attract some while repelling others; I personally find them deeply disturbing—which cultivates a quasi-religious intensity among its followers. It is unlikely that those who came to maturity within a technological civilization fully understand what the implied sacrifices would entail, but that is irrelevant to the foundation of the movement; if the movement were to be successful, the eventual regret of those caught up in it would not arrest the progress of a new ideology that sweeps aside all impediments to its triumph.

The proliferation of environmental groups since the late twentieth century (the inflection point is often given as being the publication of Rachel Carson’s Silent Spring in 1962) demonstrates that this is a growing movement, but it is not clear that the most zealous groups can seize the narrative of the movement and become the focus of environmental activism. If, however, individuals were inspired by a quasi-religious zealotry to sacrifice energy-intensive living, we cannot rule out the possibility that the intensity of environmental belief could pave the way, so to speak, toward a transformative future for civilization that did not involve energy resources equal to or greater than those in use at present.

Energy resources equal to or greater than those in use today are crucial to any other scenario for the continuation of civilization. In the same way that eight billion or more human beings can only be kept alive by a food production industry scaled as at present, and to tamper with this arrangement would be to court malnutrition and mass starvation, so too eight billion human beings can only be kept alive by an energy industry scaled as at present, and to tamper with this arrangement would be to court disaster. This disaster could be borne if everyone possessed a burning faith in the righteousness of energy sacrifice, but in planning for the needs of mass society we may need to eventually recognize mass conversion experiences, but such cannot be the basis of policy; there is no way to impose this kind of belief.

One of the persisting visions of a solution for the energy problem of the twenty-first century is widely and cheaply available electricity that can be used to power electrical motors that would replace the fossil fueled engines that now power our industrialized economy. Throughout the nineteenth century dominance of the steam engine and the twentieth century dominance of the internal combustion engine, electric motors were under continual development and improvement. Electric motors came into wide use in industrial applications in the twentieth century, and into limited use for transportation, especially in streetcars when electrical power could be supplied by overhead lines. This can and has been done for longer distance electric railways as well, but the added infrastructure cost of not only laying track, but also constructing the electrical power distribution lines limited electrical train development. For ships and planes, electrical power has not been practicable to date. Only now, in the twenty-first century, are electrical technologies advancing to the point that electrical aircraft may become practical.

The problem is not electrical motors, but the electricity. Providing electricity at industrial scale is a challenge, and we meet that challenge today with fossil fuels, so that even if every form of transportation (automobiles, buses, trucks, shipping, trains, aircraft, etc.) were converted to electrical motors, the electricity grid supplying the electrical needs for these applications would still involve burning fossil fuels. A number of well-heeled businesses have recognized this and installed solar power panels on the roofs of their garages so that their well-heeled employees can plug in their electric cars while they work. This is an admirable effort, but it is not yet a solution for transportation at the scale demanded by our civilization.

If the electrical grid could either be developed in the direction of highly distributed generation with a large number of small electricity sources feeding the grid (which could well be renewables), or a continuation of the centralized generation model but without the fossil fuel dependency of coal, oil, and natural gas generating facilities, the use of electricity as the primary energy for industrial processes could be achieved with a minimum of compromises (primarily those compromises entailed by the difficulty of storing electricity, i.e., the battery problem). What would replace centralized generation if fossil fuel use were curtailed? There is the tantalizing promise of fusion, but before this technology can supply our energy needs, it would have to be shown to be practicable, accessible, and ubiquitous, which is an achievement above and beyond proof-of-concept for better-than-break-even fusion. At present, there seem to be few alternatives to nuclear fission.

The twenty-first century energy problem is the problem of the maintenance of the industrialized civilization that was built first upon steam engines and then upon the internal combustion engine; it is partially a problem of the direction our civilization will take, but it is not a problem of managing a transformative technology and the social changes driven by the introduction of a transformative technology. The initial introduction of powered machinery was such a transformative technology, but the ability to continue the use of powered machinery is no longer transformative, merely a continuation of more of the same.

It is as though we find ourselves, in the early twenty-first century, groping in the dark for a way forward. There is no clear path for the direction of civilization (which would include a clear path to energy resources commensurate with our energy-intensive civilization), and no consensus on defining a clear path forward. This absence of a clear path forward can be construed as a mythological deficit, or as the absence of a crucial technology. Here, I think, the balance of the argument favors a mythological deficit, because we possess nuclear technology, but no mythology surrounds the use of nuclear technology that would rationalize and justify its use at industrial scale—or, at least, no mythology sufficiently potent to overcome the objections to nuclear power.

[The unbuilt Clinch River Breeder Reactor Project (CRBRP)]

5. The World That Might Have Been: Accessible Fission Technology

One of the potential answers to the twenty-first century energy problem is nuclear power, but nuclear power is one of many nuclear technologies, and nuclear technologies taken together, had they been exploited at scale, might have been a transformative technology, both for the maintenance of industrialized civilization without fossil fuels, as well as for the transformation of our planetary industrialized civilization into a spacefaring civilization. Submarines and aircraft carriers are now routinely powered by fission reactors, and it would be possible to engineer fission reactors for railways and aircraft. Ford once proposed the Nucleon automobile, but this level of fission miniaturization is probably impractical. But the nuclearization of our infrastructure has stagnated. Once ambitious plans to build hundreds of nuclear reactors across the US were scrapped, and instead we find new natural gas generating plants under construction.

Darcy Ribeiro wrote of a “thermonuclear revolution” as one of many technological revolutions constituting civilizational processes that are, “…transformations in man’s ability to exploit nature or to make war that are prodigious enough to produce qualitative alterations in the whole way of life of societies.” [4] But if we do recognize thermonuclear technologies as revolutionary, we cannot identify them as having fulfilled their revolutionary function because of the stagnation of nuclearization. The promise and potential of nuclear technology never really got started, despite plans to the contrary.

While there were plans for the nuclear industry to be a major sector of the US economy, and these plans were largely derailed by construction costs that spiraled due to regulation, the nuclear industry thus conceived and thus derailed was always to be held under the watchful eye of the government and its nuclear regulation agencies. After the construction of nuclear weapons, it was too late to put the nuclear genie back in the bottle, but if the genie couldn’t be put back in the bottle, it could be shackled and placed under surveillance. The real worry was proliferation. If fissile materials become easily available, other nation-states would possess nuclear weapons sooner rather than later, and the post-war political imperative was to bring into being a less dangerous world. A world in which nuclear weapons were commonplace would be a far more dangerous world than that which preceded the Second World War, so that despite the division of the world by the Cold War, the one policy upon which almost all could agree was the tight control of fissile materials, hence the de facto constraints placed upon nuclear science, nuclear technology, and nuclear engineering. [5]

The human factor in technological development is essential, as in mythology. The details of a mythology may speak to one person and not another. So, too, a particular technological challenge may speak to one person and not to another. For those who might have had a special bent for nuclear technologies, their moment never arrived. At least two generations, perhaps three generations, of scientists, technologists, and engineers who would have dedicated their careers to the emerging and rapidly changing technology of nuclear rocketry and the application of nuclear technology to space systems, had to find another use for their talents. These careers that didn’t happen, and lives that didn’t unfold, can never be measured, but we should be haunted by the lost opportunity they represent. And perhaps we are haunted; this silent, unremarked loss would account for institutional drift and national malaise (i.e., stagnation) as readily as the absence of a mythology.

Even benign nuclear technologies that do not directly involve fissionable materials have suffered due to their expense. When funding for the SSC was cancelled (after an initial two billion had been spent), an entire generation of American scientists have had to go to CERN in Geneva because that is where the instrument is that allows for research at the frontiers of fundamental physics. There is only this single facility in the world for research into fundamental particle physics at the energy levels possible at the LHC. The expense of nuclear science has been another strike against its potential accessibility. Funding for scientific research is viewed as a zero-sum game, in which a new particle accelerator is understood to mean that another device does not get funded. Sabine Hossenfelder’s tireless campaign of questioning the construction of ever-larger particle accelerators takes place against this background of zero-sum funding of scientific research. But if science were growing exponentially, as industry grew exponentially during the industrial revolution, there would be few (or, at least, fewer) conflicts over funding scientific research.

Not only are nuclear technologies politically dangerous and expensive, nuclear technologies are also physically dangerous; extreme care must be taken so that nuclear materials do not kill their handlers. The “demon core” sphere of plutonium, which was slated to be the core of another implosion nuclear weapon (tentatively scheduled to be dropped August 19, but the Japanese surrendered on August 15), was responsible for the deaths of Harry Daghlian (due to an incident on 21 August 1945) and Louis Slotin (due to an incident on 21 May 1946) as they tested the core’s criticality. Fermi had warned Slotin that he would be dead within a year if he failed to maintain safety protocols, but apparently there was a certain thrill involved in “tickling the dragon’s tail.” The bravado of young men taking risks with dangerous technology is part of the risk/reward dialectic. Daghlian and Slotin were nuclear tinkerers, and it cost them their lives.

Generally speaking, industrial technologies are dangerous. The enormous machines of the early industrial revolution sometimes failed catastrophically, and took lives when they did so. Sometimes steam boilers exploded; sometimes trains jumped their tracks. Nuclear technologies are subject to dangers of this kind, as well as the unique dangers of the nuclear materials themselves. Because of this extreme danger—partly for reasons of personal safety, and partly for reasons of proliferation, which can be understood as social safety—nuclear reactors have developed toward a model of sealed containers that can operate nearly autonomously for long periods of time. [6] This limits hands-on experience with the technology and the ability to tinker with a functioning technology in order to improve efficiency and to make new discoveries.

There is a kind of dialectic in the development of technology since the development of scientific methods, such that the most advanced science of the day allows for new technological innovations, but once the technological innovations are made available to industry, thousands, perhaps tens of thousands or hundreds of thousands of individuals using the technology on a daily basis leads to a level of familiarity and practical know-how, which can then be employed to fine tune the use of the technology, and sometimes can be the basis of genuine technological innovations. Scientists design and build the prototypes of the technology, but engineers refine and improve the prototypes in industrial application, and this is a process more like tinkering than like science. So while the introduction of scientific method in the development of technology results in an inflection point in the development of technology (which is what the industrial revolution was), tinkering does not necessarily disappear and become irrelevant.

Because of the dangers of nuclear technologies, there is very little tinkering that goes on. Indeed, I suspect that the very idea of “nuclear tinkering” would send shudders down the spine of regulators and concerned citizens alike. And yet, it would be nuclear tinkering with a variety of different designs of nuclear rockets that would lead to a more effective and efficient use of nuclear technologies. As we noted with the steam engine, incremental improvements were made throughout the seventeenth and eighteenth centuries until the efficiency of James Watt’s steam engine became possible, and most of this was the result of tinkering rather than strictly scientific research, as the science of steam engines was not made explicit until Carnot’s book fifty years after Watt’s steam engine. In the case of nuclear technology, the fundamental science was accomplished first, and only later was that science engineered into specific nuclear technologies, which may be one of the factors that has limited hands-on engagement with nuclear technologies.

[Phoebus 1 A was part of the Rover Program to build a nuclear thermal rocket.]

6. Nuclear Rocketry as a Transformative Technology

Suppose that, for any spacefaring civilization, the key and indispensable technology is nuclear rocketry, or, we can say more generally, nuclear technology employed in spacecraft. Whether nuclear technology is employed in nuclear rockets, or in order to deliver megawatts of power in a relatively small package (e.g., to power an ion thruster), the use of nuclear fission could be a key means of harnessing of energies on a scale to enable space exploration with an accessible technology.

In what way is nuclear technology accessible? Human civilization has been making use of nuclear fission to generate electrical power (among other uses) for more than fifty years, all the while as research into nuclear fusion has continued. Nuclear fusion is proving to be a difficult technology to master. A century or two may separate the practical utility of fission power and fusion power. In historiographical terms, fission and fusion technologies may find themselves separated each into distinct longue durée periods — an Age of Fission and, later, an Age of Fusion. That means that nuclear fission technology is potentially available and accessible throughout a period of history during which nuclear fusion technology is not yet available or accessible.

How much could be achieved in one or two hundred years of unrestrained development of nuclear fission technology and its engineering applications? With an early spacefaring breakout, this could mean one or two hundred years of building a spacefaring civilization, all the while refining and improving nuclear fission technology in a way that is only possible when a large number of individuals are involved in an industry, with, say, two or more nuclear rocket manufacturers in competition, each trying to derive the best performance from their technology.

We know that the ideas were available in abundance for the exploitation of nuclear technology in space exploration. The early efflorescence of nuclear rocket designs has been exhaustively catalogued by Winchell Chung in his Atomic Rockets website, but this early enthusiasm for nuclear rocketry became a casualty of proliferation concerns. However, the imagination revealed early in the Atomic Age demonstrates that, had the opportunity been open, human creativity was equal to the challenge, and had this industry been allowed to grow, to develop, and to adapt, the present age would not have been one of stagnation.

In a steampunk kind of way, a spacefaring civilization of nuclear rocketry would in some structural ways resemble the early industrialized civilization of steam power. The nineteenth century industrial revolution was made possible by enormous machinery—steamships, steam locomotives, steam shovels (which made it possible to dig the Panama Canal), etc. A technological civilization that projected itself beyond Earth by nuclear rocketry would similarly be attended by enormous machinery. While fission reactors can be made somewhat compact, there are lower limits to practicality even for compact reactors, so that technologies enabled by the widespread exploitation of fission technology would be built at any scale that would be convenient and inexpensive. Nuclear powered spacecraft could open up the solar system to human beings, but these craft would likely be large and require a significant contingent of engineers and mechanics to keep them functioning safely and efficiently, much as steam locomotives and steamships required a large crew and numerous specializations to operate dependably.

[The bone needle, the moveable type printing press, and the steam engine]

7. Practical, Accessible, and Ubiquitous Technologies

We can summarize the technological indispensability hypothesis such that being a space-capable civilization is a necessary condition of being a spacefaring civilization, but a crucial spacefaring technology is the sufficient condition that facilitates the transition from space-capable to spacefaring civilization. What makes a spacefaring technology a sufficient condition for the transition from space-capable to spacefaring civilization is its practicality, its accessibility, and its ubiquity. A practical technology accomplishes its end with a minimum of complexity and difficulty; an accessible technology is affordable and adaptable; ubiquitous technologies are widely available with few barriers to acquisition. Stated otherwise, practical technologies don’t break down; accessible technologies can be repaired and modified; ubiquitous technologies are easy to buy, cheap, and plentiful.

Given the technological indispensability hypothesis, we can account for the drift of contemporary technological civilization by the absence of a key technology that would have allowed our civilization to take its next step forward, and we can further identify one technology—nuclear rocketry—as the absent key technology that, had it been exploited at the scale of steam engines in the nineteenth century or internal combustion engines in the twentieth century, would have resulted in a spacefaring breakout, and therefore a transformation of civilization.

None of this is inevitable, however. The mere existence of a technology is not, in itself, sufficient for a technology to transform a society. Some technologies, probably most technologies, are not intrinsically transformative. Of those technologies that are transformative, not all of these technologies have the potential to be practical, accessible, and ubiquitous. Of those technologies that are socially transformative and are practical, accessible, and ubiquitous, not all are sufficiently widely adopted to result in a transformational impact.

The list of technologies I cited earlier—among them, the bone needle, moveable type printing, and the steam engine—all were technologies that were transformative as well as being practical, accessible, and ubiquitous. The bone needle allowed for sewing form-fitting clothing during the last glacial maximum, therefore making it possible for human beings to expand across the entire surface of Earth. Movable type printing made books and pamphlets inexpensive and resulted in the exponential growth of knowledge; without inexpensive books and journals, the scientific revolution would not have made the impact that it did. Steam engines made the industrial revolution possible.

However, the existence of the technology alone is not sufficient; stated otherwise, it is not inevitable that a technology that is transformative will have the social impact that some of these technologies have had. The Chinese independently developed moveable type printing, and while this technology was in limited use, it did not revolutionize Chinese society. Chinese society stagnated in spite of possessing movable type printing technology. There are many possible explanations for this, first and foremost, the Chinese language itself may have required too many characters for movable type printing to be as effective a technology as it was for languages employing phonetic symbols with a smaller character set. In other words, the transformative technology of movable type printing may not have been practical and accessible using the Chinese character set; clearly it did not achieve ubiquity.

The example of the role of the Chinese language [7] in idea diffusion points to the possibility that a sequence of technologies (language is a technology of communication) may have to unfold in a particular order, with a civilization at each developmental juncture adopting a particular key technology (for linguistic technology, this might be a syllabary or a phonetic script), in order for later transformative events in civilization to occur. Formulated otherwise, transformative changes in civilization, like the industrial revolution, or a spacefaring breakout if that were to occur, may be metaphorically compared to inserting a key into the lock, such that each successive tumbler must be positioned in a particular way in order to finally unlock the mechanism.

In light of the above, we can reformulate the technological indispensability thesis such that a key spacefaring technology is the sufficient condition that facilitates the transition from space-capable to spacefaring civilization, but this crucial spacefaring technology must supervene upon the adoption of earlier technologies that facilitate and serve as the foundation for later spacefaring technology. We can call this the strong technological indispensability hypothesis, as it refers to technology alone as the transformative catalyst in civilizational change. The fact that the existence a technology alone does not inevitably result in its industrial exploitation once again points to the role of social factors—what I would call a sufficient mythological basis for the exploitation of a technology. In a weak formulation of the technological indispensability hypothesis, a sequence of technologies must be available, but it is a mythological trigger that leads to their exploitation. Here technology is still central to the historical process, but it must be supplemented by mythology. If we take this mythological supplement to be the sufficient condition for a spacefaring breakout, then we are back at the argument I made in Bound in Shallows.

We needn’t, of course, focus on any single causal factor, such as technology. It may be both the absence of a key technology and the absence of a key mythology. Just as the absence of a mythology may have been a factor that kept the technology from being exploited, the absence of the technology may have been a factor in limiting the mythological elaboration of its role in society. Much that I have written above about technology could be applied, mutatis mutandis, to mythology: a key mythology may need to develop organically out of previous mythologies, so that if a particular mythological tradition is absent, or develops in a different way, it cannot become the mythology that would superintend the expansion of a civilization beyond Earth. Moreover, these developments in technology and mythology may need to occur in parallel, so that it is like two keys inserted into two locks, each lining up each successive tumblers in a particular orientation—like launching a nuclear missile.

[Princeton Plasma Physics Laboratory, PFRC-2]

8. The Potential for an Age of Fusion Technology

Can we skip a stage of technological development? Can we make the transition directly from our fossil-fueled economy to a fusion-based economy, without passing through the stage of the thermonuclear revolution? Or should we regard the development of fusion technologies to be an extension of, and perhaps even the fulfillment of, the thermonuclear revolution?

Part of the promise of fusion is that it does not require fissile materials and so does not fall under the interdict that cripples the development of fission technologies, but fusion technology is not without its dangers; the promise of fusion technology is balanced by its problems. One can gain an appreciation of the complexity and difficulty of fusion engineering from a pessimistic article by Daniel Jassby, “Fusion reactors: Not what they’re cracked up to be,” which, in addition to discussing the problems of making fusion work as an energy source, also notes that the neutron flux from deuterium-tritium fusion could be used to enrich uranium 238 into plutonium 239, so that fusion does not eliminate the nuclear proliferation problem (although, presumably, continued tight control of uranium could obtain similar non-proliferation outcomes as is today the case with fission). Of course, for every pessimist there is an optimist, and there are plenty of optimists for the future of fusion.

While fusion technology would not necessarily involve fissionable material, and therefore would facilitate the construction of nuclear weapons to a lesser degree than fission technologies, the capabilities that widespread exploitation of fusion technology would put into the hands of human beings would scarcely be any less frightening than nuclear weapons. In this sense, the problem of nuclear weapons proliferation is only a stand-in for a more general problem of proliferation that follows from any technological advance, as any technology that enhances human agency also enhances the ability of human beings to wage war and to commit atrocities. Biotechnology, for example, also places potentially catastrophic powers into the hands of human beings. Nuclear weapons finally pushed human agency over the threshold of human extinction and so prompted a response—international non-proliferation efforts—but this problem will re-appear whenever a technology reaches a given level of development. Will each successive technological development that pushes human agency over the threshold of human extinction provoke a similar response? And is this a mechanism that limits the technological development of civilizations generally, so that this can be extrapolated as a response to the Fermi paradox?

It may be possible that humanity skips the stage of development that would have been represented by the widespread exploitation of thermonuclear technology (here understood as fission technologies), but this skipping a stage comes with an opportunity cost: everything that might have been achieved in the meantime through thermonuclear technologies is delayed until fusion technologies can be made sufficiently practical, accessible, and ubiquitous. But because of the severe engineering challenges of fusion, the mastery of fusion technology will greatly enhance human agency, and as such it will eventually suggest the possibility of human extinction by means of the weaponization of fusion technologies, and so bring itself under a regime of tight control that would ensure that fusion technologies never achieve a transformative role in civilization because it never becomes practical, accessible, and ubiquitous.

[Mercury-vapor, fluorescent, and incandescent electrical lighting technologies]

9. Indispensability and Fungibility

The technological indispensability hypothesis implies its opposite number, which is the technological fungibility hypothesis: no technology, certainly no one, single technology, is the key to a transformative change in civilization. But what does it mean for a technology to be one technology? Are there not classes of related technologies? How do we distinguish technologies or classes of technologies?

One could argue that some particular technology is necessary to advance a civilization to a new stage of complexity, but that the nature of technology is such that, if one technology is not available (i.e., some putatively key technology is absent), some other technology will serve as well, or almost as well. If we cannot build nuclear rockets due to proliferation concerns, then we can build reusable chemical rockets and ion thrusters and solar sails. Under this interpretation, no single technology is key; what matters is how effectively some given technology is exploited.

Arguments such as this appear frequently in discussions of the ability of civilization to be rebuilt after a catastrophic failure. Some have argued that our near exhaustion of fossil fuels means that if our present industrialized civilization fails, there will be no second chance on Earth for a spacefaring breakout, because fossil fuels are a necessary condition for industrialization (and, by extension, a necessary condition for fossil fuel technologies like steam engines and internal combustion engines that are key technologies for industrialization). We have picked the low-hanging fruit of fossil fuels, so that any subsequent industrialization would have to do without them. [8]

In order to do justice to the technological fungibility hypothesis it would be necessary to formulate a thorough and rigorous distinction between technologies and engineering solutions to technological problems. This in turn would require an exhaustive taxonomy of technology. Is electric lighting a technology, while mercury-vapor lamps and fluorescent bulbs are two distinct engineering solutions to the same technological problem, or do we need to be much more specific and identify incandescent light bulbs as a single technology, with the different materials used to construct the filament being distinct engineering solutions to the technological problems posed by incandescent bulb design? If the latter, is electrical lighting then a class of technologies? Should we distinguish fungibility within a single technology (i.e., the diverse engineering expressions of one technology) or within a class of technologies? Without such a technological taxonomy, we are comparing apples to oranges, and we cannot distinguish between technological indispensability and technological fungibility.

These arguments about the fungibility of technology in industrialization also points to a parallel treatment for mythology: mythologies, too, may be fungible, and if a given mythology is not available in a culture, another could serve the same function as well.

[Wilhelm Windelband, 1848-1915]

10. Four Hypotheses on Spacefaring Breakout

We are now in a position to distinguish four hypotheses for an historiographical explanation for a spacefaring breakout, and, by extension, for other macrohistorical transformations of civilization (beyond a narrow focus on spacefaring mythology and spacefaring technology):

  • The Mythological Indispensability Hypothesis: a key mythology is a sufficient condition for a transformation of civilization.
  • The Mythological Fungibility Hypothesis: some mythology is a sufficient condition for a transformation of civilization, but there are many such peer mythologies.
  • The Technological Indispensability Hypothesis: a key technology is a sufficient condition for a transformation of civilization.
  • The Technological Fungibility Hypothesis: some technology is a sufficient condition for a transformation of civilization, but there are many such peer technologies.

Each of these hypotheses can be given a strong form and a weak form, yielding eight permutations: strong permutations of the hypotheses are formulated in terms of a single cause; weak permutations of the hypotheses are formulated in terms of multiple causes, though one cause may predominate.

I began this essay with the assertion that civilization is the largest, the longest lived, and the most complex institution that human beings have built. This makes maintaining any hypothesis about civilization difficult, but not, I think, impossible. We cannot grow civilizations in the laboratory, and we cannot experiment with civilizations in any meaningful way. However, we can learn to observe civilizations under controlled conditions, even if we cannot control what will be the dependent variable and what the independent variable.

History is the record of controlled observation of civilization (or an implicit attempt at such), but history leaves much to be desired in terms of scientific rigor. Explicitly coming to understand history as a controlled observation of civilization would require a transformation of how history is pursued as a discipline. The conceptual framework required for this transformation does not yet exist, so we cannot pursue history in this way at the present time, but we can contribute to the formulation of the conceptual framework that will make it possible to pursue history as the controlled observation of civilization in the future.

This process of transforming the conceptual framework of history must follow the time-tested path of the sciences: making our assumptions explicit, making the principles by which we reason explicit, employing only evidence collected under controlled conditions, and so on. Another crucial element, less widely recognized, is that of formulating a conceptual framework that employs concepts of the proper degree of scientific abstraction, something I have previously discussed in Scientific Knowledge and Scientific Abtraction. This latter is perhaps the greatest hurdle for history, which has been understood as a concretely idiographic form of knowledge, in contradistinction to the nomothetic forms of knowledge of the natural sciences. [9]

In a future essay I will argue that history is intrinsically a big picture discipline, so that it must employ big picture concepts, which would make of history the antithesis of the idiographic. Moreover, there is no extant epistemology of big picture concepts (which we can also call overview concepts) that recognizes their distinctiveness and theoretically distinguishes them from smaller scale concepts, and this means that a transformation of history is predicated upon the formulation of an adequate epistemology that can clearly delineate a body of historical knowledge. In order to assess the hypotheses formulated above, it will be necessary to supply these missing elements of historical thought.


[1] I discussed Gilbert Murray on the failure of nerve in an earlier Centauri Dreams post, Where Do We Come From? What Are We? Where Are We Going?

[2] The largest internal combustion engine is the Wärtsilä-Sulzer RTA96-C; one of the remarkable things about this engine is how closely it resembles the construction of an internal combustion engine you would find in any conventional automobile.

[3] The Tellus Institute describes eco-communalism as follows: “… the green vision of bio-regionalism, localism, face-to-face democracy, small technology, and economic autarky. The emergence of a patchwork of self-sustaining communities from our increasingly interdependent world, although a strong current in some environmental and anarchist subcultures seems implausible, except in recovery from collapse.”

[4] Darcy Ribeiro, The Civilizational Process, Washington: Smithsonian Institution Press, 1968, p. 13.

[5] I have previously examined this idea in Trading Existential Opportunity for Existential Risk Mitigation: a Thought Experiment, where I posed the choice between the exploitation of nuclear technologies or the containment of nuclear technologies as a thought experiment.

[6] The newest reactor under development for the next class of US nuclear submarines, the S1B reactor, will be designed to operate for 40 years without refueling.

[7] Civilizations can and have changed their languages in order to secure greater efficiency in communication, and therefore idea diffusion. Mainland China has adopted a simplified character set. Both Japanese Kanji characters and traditional Korean characters were based on traditional Chinese models; the Japanese developed two alternative writing systems, Katakana and Hiragana (both of which are premodern in origin); the Koreans developed Hangul, credited to Sejong the Great in 1443. Under Atatürk, the Turks abandoned the Arabic script and adopted a Latin character set. Almost every civilization has adopted Hindu-Arabic numerals for mathematics.

[8] I have addressed this in answer to a question on Quora: If our civilization collapsed to pre-Industrial; do we have sufficient resources to recover (repeat the Industrial Revolution) to high tech? Or do we need to get into space on this go?

[9] On the distinction between the idiographic and the nomothetic cf. Windelband, Wilhelm, “Rectorial Address, Strasbourg, 1894,” History and Theory, Vol. 19, No. 2 (Feb., 1980), pp. 169-185.


Comments on this entry are closed.

  • Dmitry Novoseltsev September 25, 2020, 9:09

    I suppose (https://i4is.org/wp-content/uploads/2019/11/Principium27-print-1911280846-comp.pdf, pp. 4-6), the power of heat engines – steam or internal combustion – in one form or another is possible on any planet where there is a free oxidizer in the atmosphere (it is assumed that intelligent beings capable of creating a technical civilization must be animals that can actively move, and they need an oxidizer). At the same time, it does not necessarily require fossil fuel reserves, but can develop as a related branch of agriculture and forestry. Including in this case, space rockets can be created on a particular chemical fuel.
    And practical nuclear power is the result of a lucky combination of circumstances (or unfortunate, from the point of view of the inhabitants of post-war Japan), thanks to which fissile materials in the earth’s crust are available for industrial production. But it is not irreplaceable for space flights, because alternative technologies are also possible.
    I also believe (https://i4is.org/wp-content/uploads/2017/12/Principium19.pdf, pages 27-35, https://i4is.org/wp-content/uploads/2018/12/Principium23.pdf, pp. 38-42), that most of the practical problems of space civilization, including the most ambitious (up to level IV on the extended Kardashev scale – the creation of many artificial universes and migration between them) can be solved by devices with external energy sources based on light sails.

    • Nick Nielsen September 25, 2020, 15:53

      Thanks for the links to your articles in Principium.

      I agree that there are most likely alternative pathways to industrialization and to spacefaring technologies, and probably many more such pathways that we can imagine, given that our own civilization is our only data point on technological development. In the above I called the possibility of alternative pathways to technological development the “technological fungibility hypothesis.”

      The difference between technological indispensability and technological fungibility is essentially the difference between a narrowly defined technological breakthrough and a class of related technologies. In the approach you outlined, there are a class of technologies by which a society can industrialize, and a class of technologies by which a civilization can achieve a spacefaring breakout. I am completely on board with this.

      Best wishes,


  • Dmitry Novoseltsev September 25, 2020, 9:38

    And a small remark. Soviet Russia did not appear out of nowhere after the World War I. In the initial approximation, this event can be considered a Progressive reformation in the Orthodox world – similar to the Protestant reformation in the Catholic world. This reformation was much later and therefore more radical, which not only eliminated state and religious institutions that were inadequate for the modernist technical civilization of the World War I, but also replaced the anthropomorphic Creator of the Abrahamic religions with impersonal “objective laws of development”. But on a large scale of time, this civilization has largely preserved continuity. No complex civilizational formation appears “suddenly”, it is the result of the evolution of previous forms.

    • Alex Tolley September 25, 2020, 12:44

      You know your Russian history far better than I. However, isn’t the wider context that there was a push for democracy in Europe that culminated in the failed revolutions of 1848. Yet, despite failure, democracy did gain political power over the ensuing decades. In Russia, the ascendency of Alexander III and after his assassination, by Nicholas II, both reactionary autocrats overturning the earlier democratization, who wanted to keep the ideas of European democracy at bay, ultimately resulted in the 1917 October Revolution that was as transformative of Russian society as the French Revolution of 1792 to French society, but longer-lived, (unless you consider Stalin as equivalent to Napoleon).
      If so, then Soviet Russia is partially built on the changes in European society that came before it.

  • torque_xtr September 25, 2020, 10:55

    I recall a wonderful calculation which shows that even with direct-exhaust nuclear salt rockets, millions of tons could be lifted above Earth’s atmosphere before it becomes 10% more radioactive than present. With more advanced rockets, the numbers are in billions of tons even accounting for reasonable accident rates of mature technology. There also is a quasi-steady state, when further rise of radioactivity is balanced by decay of short- and medium-lived products, and the corresponding Earth-to-LEO traffic is orders of magnitude higher than current. Of course there is localized damage from accidents, but… with right mythology, it could be amortized to great extent.

    We can lift every human into space by nuclear rockets without doing much damage to environment!

    • Nick Nielsen September 25, 2020, 15:28

      My assumption is that these numbers could be improved with mass adoption of the technology, which would mean the problem solving skills of a large number of individuals brought to bear on the difficulties that nuclear technologies involve. There is a sense in which this problem solving activity gives those who solves problems a purpose, and a sense of accomplishment when they do solve the problem. These are not insignificant factors.
      Best wishes,

    • Mike Serfas September 25, 2020, 15:41

      If a human weighs a tenth of a ton, boosting millions of tons to space would translate to tens of millions of humans, less if the intent is to offer life support or housing to the emigrants after their disposition.

    • Alex Tolley September 25, 2020, 16:09

      If the system is 100% reliable with no failures, hiccups, misfires, or other fissile burps. Then there is the issue of managing the fissile material with the attendant security needs and police state development. While the emitted radiation levels average over the Earth may be low, one can be sure that the launch site and surrounding area will be unapproachable by humans.

      In the real world, piss poor engineering, cost-cutting measures, unexpected conditions (e.g. the tsunami at Fukushima), black-market sales of nuclear material, and potentially terrorist use or sabotage, will make this approach far too risky to even contemplate execution. If you want such nuclear rockets, they should be confined to space and the surfaces of sterile worlds and moons.

      • Spaceman September 26, 2020, 11:23


        One thing that I find frustrating in these discussions is the huge gap between the energy density of chemical rocket fuel and the energy density of nuclear fissile material. What are your thoughts on the possibility that we might someday slightly bridge this gap by creating a better chemical fuel that has a higher energy density than the fuels that are currently in use for rocketry? Have you heard of “metallic hydrogen”? Metallic hydrogen is thought to occur naturally in the cores of some Jovian planets. Apparently, in the last few years there has been a trickle of reports from at least one scientific group stating that the elusive metallic hydrogen was finally created using a high pressure diamond anvil apparatus. Some calculations suggest that metallic hydrogen could be the “ultimate chemical fuel” leading to possibly an order of magnitude improvement in the velocity to which we could propel our space vehicles. There is something especially poetic about the idea of using a fuel that may be found at the core of Jupiter to open up the solar system! :-)

        Some caveats are that the use of metallic hydrogen for fuel would depend on whether or not the material, once created using a high pressure apparatus, would remain stable at STP. In any case, what are your thoughts on the possibly of a revolutionary new chemical fuel, as the ‘chemical space’ of yet-to-be synthesized compounds is huge. Also, with machine learning and quantum computers on the horizon, might it still be plausible that we could pull a revolutionary rocket fuel out of the vast, unexplored chemical landscape!?




        • Alex Tolley September 26, 2020, 15:41

          I am not a rocket expert. I do know that there are chemical propellants that are more energetic than current ones, but they are extremely toxic as they are fluorine based. The increased Isp is hardly worth even thinking about.

          Regarding metallic hydrogen. It would indeed be a wonder propellant. However, there are reasons to doubt it can remain stable at STP. That it must be created in a diamond anvil suggests that if it was stable, the pressures could be released and there would be a tiny speck of the material. That would be a major science story. This paper suggests that a metastable state cannot exist at STP. On the Lifetime of Metastable Metallic Hydrogen.
          Fusion drives and even anti-matter seem more probable to me.

        • Mike Serfas September 26, 2020, 16:22

          The most intriguing possibility that I am aware of is induced gamma emission from nuclear isomers. In theory, nuclei can store tremendous amounts of energy, and might be triggered to release it. In practice, it doesn’t seem to have reproduced well. See https://muonray.blogspot.com/2016/08/the-hafnium-isomeric-gamma-ray-weapon.html for an interesting blog on it. Note, of course, that since we’re talking about a tremendously powerful and highly concealable explosive, it is possible we’re not seeing all the results.

          More fancifully, I daydream that “metatope power systems” might one day safely cascade gamma rays from common long-lived isotopes through a series of intermediates, so as to “make change” from radioactivity into a harmless and useful stream of electrical free energy.

        • torque_xtr September 27, 2020, 7:45

          The bound for specific impulse of chemical rockets is dictated by the nature of chemical bond. It’s energy, in general, cannot be higher than ionization potentials of component atoms, and it is divided by their mass. So, as you absolutely cannot get a compound with bonding energy of 10 eV per atom, and a powerful oxidizer which is lighter than oxygen, you cannot get a fuel pair with Isp much higher than current record of 550 s. Hydrogen is the exception, because it does not have a ballast of inert electrons and their corresponding nucleons. Conversion of metastable form of hydrogen can yield a very high Isp without any redox reactions. But the metastability rules apply to it, too. The more is the fraction of chemical bond energy you want to use, the less remains for kinetic barriers for decomposition of initial reagents, and the less stable they are. The article uses metallic-to-molecular transition energy release close or equal to that for recombination of atomic hydrogen, but in reality, it should be much lower for any chance of metastability to exist. (as a former chemist) I have the intuition than even 1000 s for metallic-hydrogen based propulsion is way too high. And making even a stabilized alloy in the required quantities would be next to impossible. Remember, you have to squeeze it in the DAC grain by grain to millions of bars! The catalytic route is also severely limited because the energies involved are very high, and will tend to destroy or transform any added compound.

          Maybe in the entire phase-space of chemistry do exist some feasible routes to industrial quantities of metallic hydrogen-based compounds. For RTSC, it is worth to try, but for rockets it would be like trying to make conventional railways supersonic and use them for routine transportation. It could be more daunting task than building direct-exhaust thermonuclear rocket, but much less effective. Practicality and accessibility issues outweigh even the exponent in Tsiolkovsky equation. So I believe that CH4/O2 is the ultimate fuel pair of chemical rockets.

          • Brett P Bellmore September 27, 2020, 14:18

            AND, if you did manage to produce some sort of stabilized metallic hydrogen, the first time a cosmic ray penetrated the tank, your rocket would blow up.

            I think the search for higher ISP fuels for launching from Earth is kind of pointless, because we’re approaching the traffic level at which non-rocketry solutions, launch loops, rotovators, mass drivers, start to be cost effective.

            Better propellants would be useful in space, though.

      • torque_xtr September 27, 2020, 7:50

        Of course, I wrote this bearing in mind that local effects and risks would be very high for current society. And maybe for many of the high-tech alternatives. But this is for us; less war-like species would find it more acceptable. Especially if they have (like Trisolarans :-) some form of transferring their identities from one body to another.

        I forgot another thing, but here it comes again. The space exploration map varies widely with planetary home system architecture. While for us nuclear rockets may not be indispensable technology, for others they are. If we lived on a super-earth with escape velocity of 20 km/s and under ten times-thicker atmosphere (which is common across the galaxy), we would have no other choice. With a hot jovian in place of Mercury, we would got a mighty natural slingshot next to us (and a jewel of rarely imagined beauty in twilight skies), causing no one to seriously consider space sails and high-Isp rockets for centuries. And placing higher barrier for spacefaring-to-interstellar transition. On the other hand, exo-Martian dwellers in an orange dwarf system would not even care for nuclear rockets. Why launch them if folks can build SSTO in their garage? We may be lucky in some sense – if we become spacefaring, for us it will be not too far from becoming interstellar.

  • Henry Cordova September 25, 2020, 12:18

    I find it difficult to disagree with anything in this remarkable essay, but
    I must nevertheless interject a note of caution. I will limit my criticism to two items in particular.

    1) To start with, I have my own unease with the Victorian Progress Myth. It not only promotes and enforces the new technologies made available in the late 18th century, it conveniently ignores or justifies the social conditions that made them possible, not to mention the ones it created. Mass industrialization required vast numbers of impoverished workers driven off the land in order to toil in the satanic urban mills. No matter how dismal the living conditions of the English peasant might have been, he did not willingly flock to London and Birmingham and trade them in for industrial servitude. He had no choice. The farm worker, the inheritor of an ancient, rich and stable agrarian culture with its own traditions, institutions and even rights; now found himself struggling to survive in a nightmare world over which he had no experience, little control and scarce benefit.

    There were other problems, too. The Mercantilism and laissez-faire Capitalism of this new environment required not only cheap labor, but vast markets and limitless raw materials, too. And this led to colonialism, imperialism and war. Sure, the Romans had all that too, and they didn’t have steam, but they had slaves. Same difference.

    Eventually, England, and the rest of Europe, paid a price for this Industrial Revolution: the Great War, a huge slaughter which, in retrospect, was fought for absolutely no good reason other than colonial rivalry. The economic devastation of this conflict led directly to cultural decline, Fascism and Communism, and an untouched New World superpower with a whole continent’s resources (including fossil fuels) to bring to the table. America may have greatly benefited from the Industrial Revolution, but it never paid the full price of admission.

    2) We are, indeed, “space enthusiasts”, or we wouldn’t be sharing Centauri Dreams. We are impatient to go interstellar, or even interplanetary, and we are desperate to come up with simple reasons why we haven’t, or villains we can blame for not having done so. And to be honest, some of our reasons are purely emotional. But as in our politics, there are always demagogues ready to exploit those emotions for their own purposes.

    If you really need a reason why space technology hasn’t fully caught on yet, maybe its precisely the Victorian constellation of Resources, Markets, Labor and Capital that needs to be blamed. There are no resources there so valuable that the energy costs of retrieving them isn’t prohibitive. There is no one there we can recruit as labor, or who will buy our produce, Therefore there is no return on investment to make it attractive to our financial and industrial power centers.

    Our past successes in space were driven by military rivalry, national prestige and clever science lobbies who were able to disguise their projects in those terms. Even the money making space missions (earth resources, communications, navigation) had to be subsidized and kick started by taxpayer dollars.

    Right now, unless some breakthrough technology can arise which will lower our space exploration costs by several orders of magnitude, its unlikely we will be able to justify too many more adventures in space, even purely scientific ones. In an age of declining wealth and rising costs, there will be two voices increasingly arguing against it., one on the Left, and one on the Right.

    “There are too many problems down here for us to be wasting resources out there.”

    “What’s in it for me?”

    • kph September 25, 2020, 14:18

      Agree with the eloquent, critical response. Am hopeful of a leap forward technology such as a space elevator or a discovery which prompts a space exploration mythology.

      • Dave Abbe September 25, 2020, 16:23

        If a apace elevator would work, it would work better on Mars than on Earth. With effectively the same day length on both worlds, the distance from the surface to aero synchronous orbit is much shorter than to geosynchronous orbit, and Mars surface gravity is only about .34 Earths surface gravity, so the required strength of the tether would be much less.

        However, when folks talk of the required tether strength they usually only consider the strength for the tether to support itself, and the weight of the elevator car. Unfortunately, the physics requires the tether to provide the lateral force to accelerate the horizontal speed of the elevator car from the speed with which the surface of the Earth rotates ( about 1,000 MPH) to the speed with which a satellite in geosynchronous orbits, which is about 5 times as fast. Worse, the vector of the lateral force the tether would have to apply to the elevator car would result in much much much higher forces it the tether.
        I suppose that if the lateral force was supplied by a reaction drive (chemical rocket, or at best once in vacuum perhaps an ion drive supplied with electrical power by conductors in the tether) then it might work, with the tether only supporting the vertical weight of the elevator car.

        And think of the environmental impact statement and public hearings required to construct such a thing on Earth! Not to mention the liability insurance!

      • Bryan Kelly September 26, 2020, 10:25

        Perhaps someone will come along with an idea such as light-pumping metamaterials for space travel.

        • Robert September 26, 2020, 12:36

          Someone has. That is physicist Jack Sarfatti. He theorizes that meta materials can be used to realize low energy Alcubierre Warp drive technology for hyper fast but still sub-light speeds at very low cost in energy and of course, no ejection of matter.

          • Bryan Kelly September 27, 2020, 9:35

            If I am not mistaken, he proposes trapping light, not pumping it.

            • Robert September 27, 2020, 17:31

              He calls it a Frohlich pump but what’s important is he thinks the physics of a low energy warp drive can actually be realized at low energy in certain metamaterials. He says real world data from Military encounters with ‘Tic-Tac’s’ prove it.

    • Alex Tolley September 25, 2020, 16:25

      Mass industrialization required vast numbers of impoverished workers driven off the land in order to toil in the satanic urban mills. No matter how dismal the living conditions of the English peasant might have been, he did not willingly flock to London and Birmingham and trade them in for industrial servitude. He had no choice. The farm worker, the inheritor of an ancient, rich and stable agrarian culture with its own traditions, institutions and even rights; now found himself struggling to survive in a nightmare world over which he had no experience, little control and scarce benefit.

      Scholarship suggests this is not the case [1]. It was the unskilled poor poor who most benefitted from the industrial revolution through rising wages. Yes industrial slums and factories were appalling places to live and work to our modern eyes, but we tend to have a far too rosy view of country life of peasants. People moved to the cities because there was a benefit to be had in the lives of the workers.

      I have little doubt that in a another century people will think our lives were terrible compared to theirs, yet somehow we largely seem to accept our conditions. Some people would even like to make those conditions harsher again.

      1. “A Farewell to Alms: A Brief Economic History of the World” G. Clark (2007) (See especially ch 14: Social Consequences)

      • Henry Cordova September 26, 2020, 0:55

        I’d be careful about citing “A Farewell to Alms” as a source. Even the title hints strongly it has an ideological axe to grind. Perhaps a bit too Ayn Randish for my squishy Liberal sensibilities…

        To be fair, I didn’t read Clark, (its available online as a pdf) but I did read several scholarly reviews of it and the book appears, to say the least, controversial. I found his idea of prosperity, work ethic and middle class values propagating through a population genetically (yes, in a biological, Darwinian fashion!) particularly disturbing. Survival of the richest? It all sounds vaguely fascist to me. “Yes dear, those people are just different from us. They were born that way. Its in their blood.”

        But then again, to be fair, perhaps I (and his critics) misunderstood his thesis. Its why I’ve always preferred the physical sciences to the social ones. Its too easy for an articulate speaker to be mistaken for a perceptive one.

        At any rate, those who are interested can Google the man, his books and his critics. They can decide for themselves.

        • Alex Tolley September 26, 2020, 15:31

          Fair point about his views. The book was recommended many years ago by the heterodox economist Prof. Bradford DeLong.

          However, we have a contemporary version with the rapid industrialization of China. AFAIK, peasants in the country are not leading comfortable but poor lives, and the exodus from the land to the industrial cities is willing, even if work conditions can be so poor that companies like FoxConn have to prevent suicides, and other companies treat their workers like indentured slaves. We know wages in China are rapidly increasing and domestic consumption increasing, which is an analogous situation to the British industrial revolution.

          • Henry Cordova September 26, 2020, 21:53

            The social sciences are not physics, all research and analysis in those fields is highly subjective. You can prety much find whatever facts you need to prove whatever you want. And no, I’m not being critical, its just the nature of the field. Still, the opinions of an informed and intelligent man are always of value, even if they can’t be formally proven or disproven, or even if they contradict themselves or can be shown to be biased. The interpretations of someone you disagree with totally can still be of great value.

            Although results in the social sciences cannot be verified formally by observation or experiment, this does not imply they are irrelevant. On the contrary, these are things that really matter because they affect our lives directly. The hard sciences can sometimes be a bit too abstract to be truly useful. Does it really matter how many quarks can dance on the head of pin? I have found nuggets of immense value even from such people as Jesus, Karl Marx, the Unabomber and Hunter S. Thompson. It doesn’t mean I have to accept their entire programs uncritically.

            Fiction, which makes no claim of psychological or social truth, can still provide some pretty valid insights. What sincere but troubled adolescent has not seen himself in Prince Hamlet, and what old man has not profited by contemplating Lear or Prospero,–or even Falstaff?

            • Gary Wilson September 27, 2020, 15:37

              “I have little doubt that in a another century people will think our lives were terrible compared to theirs, yet somehow we largely seem to accept our conditions. Some people would even like to make those conditions harsher again.” I would be very careful about making predictions about the future 100 years from now. Resource depletion, ecosystem degradation, overpopulation, demagoguery, fascism, xenophobia etc. are all on the rise. The future looks bleak indeed without genuine effort to change the path forward. Democracy, although imperfect is worth preserving. It is a becoming a threatened species worldwide. Beware who you vote for. We are going to be tested here in Canada soon as well. Not only does China abuse its labour force, it also abuses minorities to an even greater extent. Whatever is being offered as government in China is not Communism, but rather autocracy and dictatorship enforced with military power.

              • Alex Tolley September 27, 2020, 17:16

                I agree. The world a century hence could be quite bad. We may not even be able to [easily] control pathogens which would be a real setback. I won’t see that world, but I hope for the best, although I can see that we may well end up with a dystopia.

    • Patient Observer September 25, 2020, 20:15

      Thank you for expressing important points far more convincingly and interestingly than my aborted effort to do the same.

      The Fermi Paradox does come to mind. One possible conclusion is that there is no possible transformative technology for a space breakout.

      Finally, regarding the failure of fission power to be a transformative technology, those in the wheel house of Western civilization may not be inclined to allow another transformation of the world. Better to shut down the game while they are still ahead. Deindustrialize and finalicalize the economy seems to be the order of the day.

      And, it may be far too early to assume that fission power has run its course. Russia, China and much of the non-Western world seem to be refining the technology and bringing to parts of the world not under Western influence.

      • Dave Abbe September 26, 2020, 14:36

        I read that the actual fuel requirement to lift a human to low Earth orbit is about equal to that to fly from the USA to Australia. The main difference in cost is due to currently (before Musk) having to through the craft away and build another one. (Might have been mentioned in one of Robert Zubrin’s books.)

        Robert Heinlein mentioned that once you are in low Earth orbit you are half way to anywhere.

        I never checked the math on either assertion, but if so there is plenty of room left for fission power, either rockets or ion drives, for the longer portion of any interesting trip. And there are a lot of trips from the USA to Australia every year, so I don’t see Earth to orbit as being a show stopper.

        • Alex Tolley September 26, 2020, 21:30

          But if Australia was nothing but a big desert with nothing else to see, nowhere to stay, and little to do but bake, I doubt there would be many trips there. Maybe a few more than the old British prison ships going to Botany Bay. LEO is not that different today, but even more deadly to visit. The view is better, but what else is there to do, especially in what amounts to be in a basic amenities cruise ship?

          • Dave Abbey September 27, 2020, 13:50

            So… I’m thinking atomics from LEO to the more intersection places, and with much shorter travel times than chemical rockets.

            Of course, if there are no interesting places to go, then we don’t need access to LEO either!

            • Alex Tolley September 27, 2020, 17:03

              I still like the old BIS separation of spacecraft types – spaceplane, dedicated Earth-Moon transport and lander, and the interplanetary ships. (All 3 are depicted in 2001: A Space Odyssey, and frequently described in Clarke’s fiction.) Nuclear spacecraft can have any number of designs, from nuclear thermal to electric engines powered by nuclear reactors. NTRs have an Isp about 2x chemical rockets only. We need a lot better performance for real deep space missions, like the Discovery mission to Jupiter in the movie 2001. Higher performance requires greater exhaust velocities which in turn requires more energy. That means larger reactors or larger solar PV arrays, or hotter and higher pressures engines. The faster the ship, the more energy is needed both to accelerate and decelerate compared to low energy transfer orbits. Tradeoffs, tradeoffs. I expect there will be a variety of propulsion systems suited to the mission demands. Just as we prefer to fly to reduce travel time, but accept slower surface transport for goods, so will space transport likely have different types of ships and propulsion.

  • Alex Tolley September 25, 2020, 12:24

    Once again I find Nielsen’s POV of civilization and spaceflight occupying an unrecognizable dimension to what I have read about as being central. The industrial revolution facilitated by mythology rather than economics? A properly spacefaring culture requiring mythology rather than just an economic one (and yes, successful colonization is economic, whatever the rationale may be – profit, ideological separation, religion, etc. It requires resources that can be utilized to sustain life and trade.)

    What about some transformative technology, e.g. nuclear rockets or some other sort of propulsion that would make access to space easier (and cheaper)? Would this make a difference?
    Firstly, let us consider what happened on Earth when commercial air travel became safe and cheap in the 1960s. Did this hugely change commerce? No. It did facilitate tourism, however. And just as resource woes caused problems for countries relying on them, so has tourism caused a problem. The pandemic which has crushed the tourism and hospitality industry has had a devastating effect on countries that relied on this industry. (This loss, however, has a silver lining as it suddenly improved the conditions for wildlife.)

    So let us imagine that we have a near-instantaneous, near costless transmat. It allows a person to travel, with luggage, to any destination in the solar system at the speed of light. Would this stimulate commerce? I don’t think so. Tourism definitely would benefit. [What I wouldn’t give just to stand on the lunar surface, let alone Mars, or Titan, even Pluto. With a comfortable lodging to relax in creature comforts afterward.] But unless there are useful resources that make economic sense, then commerce will be marginal. It may be cost-effective to mine minerals if the cost of mining on Earth becomes prohibitive. Perhaps some micro-g and high vacuum processes will prove viable if the costs are very low. But otherwise, I see very little commercial potential unless a new, useful mineral is discovered.

    However cheap this transmat travel is, the difficulties of colonization remain, although the transport of materiel to create habitats in space or on planetary surfaces makes this easier. However, it will always be harder than colonizing almost anywhere on Earth, including the deserts, the poles, and even the oceans. The Mars colony advocates love to design cities and fantasize about living on Mars. However, they have never found anything valuable to trade other than speculative IP. Even a Martian abiogenesis would have limited value unless patented to death to capture as much value of any technologies as possible, a sure way to kill its potential. Mars is not like the Americas, but the European colonization of North America and the suggestion of manifest destiny seems to be central to the ideology of wannabe Martians.

    I conclude, at least for now, that any spacefaring would be of the indifferent category as defined by Nielsen. A transmat would facilitate exploration and scientific expeditions. But mostly it would facilitate tourism and technologies that make this easier to manage, e.g. life support systems, and spaceworthy local transport. Other technologies might be stillborn, e.g. fully recyclable life support systems – why bother when food, water, and air can be cheaply shipped from Earth. 5-star restaurant food delivery from Earth to Mars in minutes? But even such an exotic technology would not ensure a “properly spacefaring” civilization. [At least based on current information].

    As for the 4 hypotheses, I cannot agree with the mythology idea. It seems quite dispensible when considering other hypotheses. Animals colonize new habitats without mythology. Humans have done so for hundreds of thousands of years. The industrial revolution doesn’t need a mythology to facilitate it, just economics, and the ability of individuals to make tools and improve upon them. Technology does tend to shape cultures, as it creates a path dependency. Fossil fuels, especially oil and gas, have huge political influence built up over the 20th century. This has stymied change, especially in countries that have become co-dependent on fossil fuels. Automobiles resulted in suburbs and exurbs, which makes rebuilding public transport options very difficult. However, we think we know that civilizations generally don’t adapt to change, they decline and are replaced by others better adapted to new conditions, just as animal and plant populations don’t evolve suddenly to adapt, but are replaced by other species’ populations that are better adapted to the changing environment. Just as the British empire was replaced by the USA, so will the USA eventually be replaced by another.

  • Michael A Hutson September 25, 2020, 13:07

    IMO, the technology we still lack to fully open up space is a routine way to return people, payloads and intact vehicles from space. Much has been made of automated space exploration substituting for manned flight and this has been due to the requirement of returning people from space.
    In the mid-to late 1950s people such as Von Braun presumed that an extension of then advancing speed and altitude performance would produce aerospaceplanes of orbital capability. Von Braun believed that rocket powered aircraft with very high glide ratios could reenter from orbit slowly enough to shed sufficient heat. But aircraft designers ran into the “thermal barrier”: reentry heating proved more severe than anticipated. For level flight in the atmosphere a speed of Mach 3.5 was the practical limit. The X-15 rocket plane actually damaged itself on high-Mach flights, and the proposed X-20 Dyna-Soar never came to fruition in part because engineers were uncertain of its ability to withstand reentry.
    The working solution for ICBM warheads and later manned flight was ballistic reentry: protect a small reentry capsule with an expendable heat shield. This works but has limitations: the return payload is limited and it’s difficult to refurbish used capsules to any practical degree.
    A new thermal protection technology debuted with the Space Shuttle’s ceramic tiles. This made a space plane workable but the labor-intensiveness of retiling the craft and their inherent fragility doomed any hopes of making the Shuttle a cost-effective space transportation system.
    Now Space X’s proposed Starship intends to try yet another system: A combined payload and upper-stage structure of stainless steel for improved heat tolerance, a high surface area to weight ratio to reduce the heat load, and a new durable ceramic tile protection on the reentry side of the vehicle, possibly with active cooling of the tiles. IF this works Starship will be a quantum leap in the technology of both launching and recovering space craft. But as of this writing it remains untested.

  • jim September 25, 2020, 13:51

    Our fossil fuel powered civilization already has a powerful mythology built up that has replaced Christianity , it is called the myth of progress. You know the idea the Man is the Conqueror of Nature and is destined to use science in a process of self deification to achieve immortality, alter lifeforms, live in the heavens and go to the stars. This myth of progress has been the guiding principle for our economy and political system.

    Unfortunately we are now in a situation in which the lives of more than 7 billion people depend on the continued extraction of fossil fuels in order to live. But now that most of the low cost fossil fuels have already been extracted the remaining fossil fuels needs ever more energy to extract from the ground making them both more expensive and more environmentally damaging. That means the economic system will not have the energy it needs to grow – and if our economy doesn’t continue to grow all banks and governments as well as most businesses go into a crisis.

    And this is where we are now: having run face first into the limits to growth and facing the awful reality of massive ecological overshoot as the food for our fossil fuel civilization becomes ever more scarce.

    • Nick Nielsen September 25, 2020, 15:33

      The limits to growth are not fixed a priori, and our running face first into a wall is not inevitable. Social inertia may appear to point to this, but human beings are not automatons: they are self-interested agents who will change their behavior in order to improve their chances in the immediate term and to improve the chances of their children in the longer term. So even when things look discouraging—and sometimes things look discouraging precisely because of human self-interest—we can count on human self-interest to explore all possible options rather than to passively acquiesce to catastrophe.
      Best wishes,

      • tesh September 26, 2020, 7:51

        I agree with the first s:entence.

        “The limits to growth are not fixed a priori, and our running face first into a wall is not inevitable. Social inertia may appear to point to this, but human beings are not automatons: they are self-interested agents who will change their behavior in order to improve their chances in the immediate term and to improve the chances of their children in the longer term.”

        The sentence that follows is going to be a frightening and unpredictable prospect. Primarily because it requires the structures that maintain the current status quo to be overturned/reshaped, which isn’t going to be pretty in the slightest. I cannot see the US or China going quietly into the night in the way that UK, France, etc are did and allow new powers to take the reigns. The world is a different place now, it is much more rigid and connected and less flexible than 80-100 yrs ago.

        If there is a reshaping then it is one that will likely put us back into the dark ages and reset (set back) the clock some 1000-1500 years – best case scenario.

      • Alex Tolley September 26, 2020, 15:53

        So even when things look discouraging—and sometimes things look discouraging precisely because of human self-interest—we can count on human self-interest to explore all possible options rather than to passively acquiesce to catastrophe.

        Jared Diamond would certainly beg to differ. At the risk of Henry Cordova pointing out that Diamond’s scholarship is hardly uncontroversial, his

        • Alex Tolley September 27, 2020, 10:44

          [Correcting my appalling cut ‘n paste]

          Jared Diamond would certainly beg to differ. At the risk of Henry Cordova pointing out that Diamond’s scholarship is hardly uncontroversial, his book: Collapse: How Societies Choose to Fail or Succeed contains a sampling of 50% failures to adapt and 50% successes. At the moment, despite the known solutions to avoid the climate-induced collapse of global civilization, the forces of self-interest are winning. We have already gone past any hope of constraining average global temperatures being halted below 1.5C, probably also 2C, and quite possibly heading towards higher temperatures. James Lovelock may well have been correct when he said some years ago that we would fail. A recent article in the Guardian indicated that even youngsters are now believing it is “game over” and expecting the inevitable. One can hope that the increasing public opinion will eventually force leadership to enact the needed policies to create the needed change, but time has largely run out. To think that if the Rio meeting had stimulated global action 30 years ago, we could have averted the problem. But it didn’t.

    • Alex Tolley September 25, 2020, 16:33

      We know how to produce more food, and we can reduce our agricultural land use many fold simply by reducing our meat consumption. We can almost completely eliminate fossil fuel use with renewables, although it will require much more energy storage. If we had cheap access to space, we could power the planet with solar powersats that would provide all the energy we could possible want both on Earth and in space.

      The problem with both these solutions is an unwillingness to change and vested interests that are both intrinsically conservative despite the clear and present consequences of denying the needed changes.

      • Gary Wilson September 28, 2020, 17:45

        Everyone needs to do what they can and definitely not give up though. We (my family) have invested in solar panels (28, producing up to 10.3 kW), and an electric car to reduce our consumption of fossil fuels (a 75% reduction if my numbers are correct). Don’t assume others will carry the load. Make changes in your lifestyles (we have done that as well), travel by air less, buy fewer things encased in plastic, walk or run instead of using a vehicle, shop locally and vote wisely!!! We can make a huge difference as a population. Promote fair and decent educations for everyone, not just those that can afford to live in an expensive neighbourhood with high local taxes to pay for good schools. Educated people can think critically and vote wisely. It’s not too late but get on it people!!! :)

        • AlexTru September 29, 2020, 2:30

          Promote fair and decent educations for everyone

          There is one huge problem in your logic, you suppose that every human want to be educated, and sadly it is not true, I suppose that most people do not want to apply even minimal efforts to be educated.
          Knowledge collection – it is hard work, homo sapience is lazy by his nature and very diverse in personal ability to learn.
          For example many people try hard to learn math , but cannot success , despite efforts.

          • Gary Wilson September 30, 2020, 15:10

            A far greater number of people could be better educated though Alex. I agree not everyone is suited to it, but basing the quality of schools on the income level of people in the district is completely wrong and has led to a tremendous disparity in education and ability to earn a reasonable income in at least one country I can think of. They are seeing the results of that disparity now in their election process which has devolved into theatre of the absurd and farce, based on the behaviour of one individual and his lackeys. Effort is required to save the biosphere, yes, I agree. But allowing fools to lead who continuously lie about everything is disastrous. It is happening in many other parts of the world now as well. The quality of life in the future is up to all of us. Those who cannot lead can at least support leadership that will help safeguard our ecosystems if they are educated properly and not lied to. If we want to become a spacefaring race again as Nick suggests, we will need to take steps to protect the only world we have which is capable of supporting us and our efforts to move forward and possibly outward.

            • AlexTru October 4, 2020, 2:23

              Homo sapiences are born radically not equal, so even equal education, will not make people equal in their possibility, it is nature law, evolution consequence in real life, none can change it. Even theoretically, we cannot make everyone equally educated, but we can easily make more capable people to be poor educated – usually it is the real result of the violent equalization.

              But allowing fools to lead who continuously lie about everything is disastrous

              If we take separately every small community , we will find that most of local leader are far from the top if we will compare intelligence level, it is rule. This “foolification” of leaders seams to be natural homo sapience’s property, subconsciously human choose “fool” to be leader, we can see such behavior beginning from young age, as sequence the same situation naturally continue with government members. Brutal physical force + average intellectual level + amoral character , gives advantage in political battles.
              Bold exclusions only confirm the sad rule.

  • Dave Abbe September 25, 2020, 14:12

    I suspect that the sufficient condition for a human spacefaring civilization is the capability of bootstrapping a minimum self-sustaining city on Mars.

    Elon Musk’s plans incorporating reusable chemical rockets that can be refueled at Mars seem to be the best approach for transportation at this time.

    Robert Zubrin’s discussion of non-nuclear power sources, aero-thermal (think geothermal) and solar panels, may be the most feasible (politically acceptable) way to start.

    If solar power satellites are ever practical, they could be constructed in Earth orbit and provide their own power for ion propulsion to Mars orbit, where aero-synchronous orbit is much lower than at Earth and there is less atmosphere to punch through.

    And, of course, environmental impact statements and public hearings should go more easily, if ever folks did want to use nuclear fission.

    The lava tube caves found on the Tharsis bulge may be the best site for significant economical radiation sheltered real estate. (For the longer term Pavonis Mons, which is a fairly tall volcano and right on the equator, would make an excellent site for a major space port.)

    Perhaps mirrors or fiber optic cables can route sunlight to greenhouses in the lava tubes as well as LED lighting. In addition, a suitable algae could be grown in enclosed troughs during daylight hours, with the supporting water drawn down into a more protected environment at night.

    Perhaps the enabling technology is the ongoing development of computer technology, more than anything else. When the space shuttle was being developed, nobody had the capability to develop the software systems that would allow the design of fly back stages for chemical rockets, because the computerized control systems capabilities did not exist.

    In any event, if a significant community of people live on Mars, they will tinker with all sorts of technologies for closed cycle environments, local resource development, computer controlled mining and civil engineering construction equipment, and automated manufacturing. Labor will be dear, and costs of importing anything from Earth will be much higher than any usual tariff wall.

    I doubt very much if Earth bound folks will ever fully develop a spacefaring civilization, other than be going and living there.

    • Nick Nielsen September 25, 2020, 17:09

      This would be an interesting idea to explore, although I would generalize from your condition of, “the capability of bootstrapping a minimum self-sustaining city on Mars” to the capability of bootstrapping a minimum self-sustaining human presence beyond Earth. I may examine this idea in a future essay as it is of significant interest, and I would add self-sustaining off-world settlement to my list of key technologies and mythology as possible sufficient conditions for spacefaring civilization.

      A self-sustaining city on Mars would be an important milestone in human space settlement, but how would we get to the point of being able to construct a self-sustaining settlement on Mars? This question goes back to a Centauri Dreams post I wrote several years, ago, The Infrastructure Problem, in which I considered an infrastructure-rich approach to space settlement, by which a city on Mars would imply a spacefaring civilization that makes it possible, in contradistinction to the infrastructure-impoverished Zubrin/Musk architecture, which takes supplies “direct to Mars” and doesn’t bother with the spacefaring infrastructure.

      In the latter case (which seems to be the focus of most realistic hope at this point), human beings would go from being terrestrially geocentric to being Mars-centric, which is just an alternative form of geocentrism. We’re still stuck at the bottom of a gravity well, building a civilization much like that on Earth. In other words, Mars alone does not get us to a spacefaring civilization. Again, this would be a crucially important development, but it does not necessarily translate into human exploration of the cosmos.

      A self-sustaining presence off the surface of Earth in an artifical habitat, on the other hand, would be spacefaring infrastructure, and would be as crucially important as a self-sustaining city on Mars and also a significant addition of spacefaring infrastructure.

      I fully agree with you that Martians tinkering with their closed-cycle environment would be an important development—this will be one of the key experiences of settlement beyond Earth, and these developments would also characterize self-sustaining artificial habitats. The lessons of either would be applicable to the other.

      Best wishes,


      • Patient Observer September 25, 2020, 22:25

        A comment often made about Martian colonies is that a colony on Antarctica appears absurdly difficult as well as pointless. Yet, such an earthly colony would be orders of magnitude more plausible from a technical and economic basis.

        Short of dirt-cheap interplanetary transportation (regardless of the hype, Starship flying silos won’t do the job), there is little prospect to have the means to establish a self-sustaining colony on Mars. Perhaps, the Moon…

        • Brett P Bellmore September 27, 2020, 17:12

          Antarctica would probably already have been colonized by now, the obstacles are less economic and technological, than they are political: The great powers couldn’t agree how to divvy up the last continent, so they agreed that nobody would get it.

          Try colonizing Antarctica, and soldiers will show up to evict you. That’s the real obstacle to Antarctic colonization.

          • William Johnson October 3, 2020, 6:34

            Greetings to all of you ‘highly underpaid geniuses’: It’s great to shoot for ‘the stars’, but it’s also very wise to ‘keep one foot on the ground’ while you contemplate ‘conquering’ the cosmos.

            ANTARCTICA…..SAHARA DESERT…..hmm….?

            What if some consortium could be
            ‘organized’ to build an ‘ultra-sized’ aquaduct to ‘transport’ all of that fresh water ice covering the Antarctic continent to the Sahara Desert on the African continent?

            The ‘concept’ doesn’t seem to me anymore absurd than all of these grandiose notions regarding ‘human colonies’ on the Moon, Mars, Pluto, or Lord knows anywhere else!

            Just think of all that ‘mineral wealth’ exposed…..just ripe for ‘exploitation’ once the ice has been redeployed from Antarctica to the ‘new’ Garden of Eden once known as the Sahara Desert…..

            Money…money…money makes the ‘World’ go round!!!

            If absolute ‘globilization’ is the goal of ‘human destiny’, let’s get ‘our behinds’ off ‘the pot’ and do what needs to be done.

            Yours truly,
            William Johnson!

            • Alex Tolley October 3, 2020, 13:35

              I’m hoping this was a satirical comment.

              If you are old enough, you would recall that moving icebergs from Antarctica was once suggested for delivering water to parched regions. Making the Sahara bloom (as it one did) is possible.

              However, there are several major problems with denuding Antarctica of ice that immediately come to mind. Treaties forbid the extraction of minerals. So that avenue is currently closed off. Secondly melting glacial ice will eventually raise sea levels (a lot) so any benefit delivering water will be undermined by salt water penetrating aquifers and flooding coastal cities. And thirdly, reducing the albedo of the continent will increase the rate of global heating and its negative effects. I’m sure there are many more negative effects, which will more than negate any positive ones.

            • Dave Abbe October 4, 2020, 23:39

              Sailing Antarctic ice to Australia would be a much shorter trip, and wouldn’t even have to cross the equator!

              For Africa, water could be more easily diverted from the norther-most brand of the Congo river system, dam the river, use solar power to lift the water over the mountains, then through a dam to generate more electricity, then irrigate the land north to Lake Chad. (A similar plan was sketched up when the area was all European colonies.)

              Seems there is enough difficulty agreeing on the dam nearing completion on the upper Nile…

      • Dave Abbe September 26, 2020, 15:47

        Thanks for the comments Nick!

        My main concerns with a self contained settlement beyond Earth, other than on Mars, is the lack of significant natural resources and the very high cost of transporting significant mass to orbit, or Luna, for constructing or expanding infrastructure.

        Any space settlement in orbit will have to have all mass imported from Earth, Luna or perhaps near Earth asteroids.

        Luna has some potential. There appears to be frozen ice at the poles, and there is significant mass that could perhaps be refined into usable materials. However, it is unlikely that Luna has any concentrations of necessary materials in enriched ores, so it would be expensive to develop sources for many necessary components of a space settlement.

        Luna does have lava tubes which could provide protection from thermal extremes and ionizing radiation, whether coronal mass ejections or cosmic rays. I suppose that there may even be trace condensations of ice it the tubes…

        In addition to the ice at the south pole there does seem to be potential for continuous solar power. However, I haven’t found any information suggesting there are lava tubes in that vicinity.

        Mars, with its evident history of free water in abundance, albeit very early in its existence, may have ore bodies of minerals that dissolve at one ph and precipitate at another. Certainly there is relic water much closer to the lava tubes than at the poles.

        Mars also has carbon available world wide, unlike Luna, and probably nitrogen as well.

        Of course, we do not yet know what minimum gravity is required for healthy living. But if either Mars or Luna has it, it is more likely Mars. On Luna, folks could live in centrifuges spinning in caverns constructed underground. Or perhaps there will be some way around the concern altogether. (I do wish that someone would build a rotating space station so that we could discover what minimum gravity is needed!)

        I do love the illustrations of the O’Neil colonies, but I suspect that the concept of using a long tube with a big enough circumference to provide the idilic views will be impractical. A tube with a roughly two thousand foot diameter would have a diameter of over six thousand feet. To provide Earth normal gravity there would have to be numerous suspension cables to hold it all together…. Think of it as a suspension bridge 6 thousand foot long…

        A nice flourish on the O’Neil colonies is the long slender mirrors that spread out to simulate sunrise. Now think of the torque they would need be designed to withstand.

        If the atmosphere inside the tube is only 5 psi, counterbalanced with a higher oxygen content, you would still have 60 pounds per square foot on that 6 thousand foot suspension bridge.

        Certainly there are feasible designs for space cities, just not the ones that fascinated me in the day.

        I do expect that there will be cities on Luna and in free space. Probably in orbit around the outer planets and maybe Venus, perhaps complemented with cloud cities in the sky. However, my current best guess is Mars will be the first main success.

        Looking forward to all of your future columns.

        Regards, Dave


        • Brett P Bellmore September 27, 2020, 17:09

          Mechanical engineer here. I admit some bias on O’Neill, having founded a chapter of the L-5 society when in college. But I’ve also run perfectly legit engineering calculations on O’Neill colony designs, and they’re quite feasible from a strength of materials standpoint, and without having to get into exotic materials like carbon nanotubes. Steel is plenty good enough for the job, basalt fiber composites would be even better from a strength to weight and material availability standpoint.

          There are some alterations to O’Neill’s original design I’d make to economize on materials, but it’s basically sound. Hardly surprising, designing it was used as a class project in college, the students doing it WERE being graded.

          My chief concern would be the sheer mass of O’Neil infrastructure per inhabitant.

          • Dave Abbe October 1, 2020, 14:40

            Thanks Brett. I was also an early member of L5 and have continued with NSS.

            Best Regards, Dave

          • Alex Tolley October 1, 2020, 16:55

            As I expected, there are now designs that look more like Babylon 5. No O’Neill or Rama like open spaces, just levels of interior like a building. With a fixed structure, that means the artificial gravity gets lower towards teh axis,. With a dynamic structure where each block of levels is rotated to achieve a particular g force, it would be possible to maintain any g force required at any level.

            By building internally, the amount of lebensraum per capita increases at the cost of those vistas. However, I think that with use of screens to simulate views, this needn’t be a problem. It also allows for more agriculture space , and even better failure protection.

          • Nick Nielsen October 2, 2020, 1:50

            Do you have a link to your work? I’m very interested in how large an O’Neill colony could be given contemporary materials technology and engineering capabilities. Just as a thought experiment, I’m curious about maximizing living space in an artificial habitat given known science and technology, so, essentially, what a spacefaring civilization could do today if the resources and funding were available.

            Best wishes,


    • Henry Cordova September 26, 2020, 11:07

      The concept of a self-sustaining city off-planet could be tested. But we haven’t, and I doubt we ever will. We could build one right here on earth, in a comparably hostile environment, say on the deep sea floor or the Antarctic ice cap. Unless we can find some extremely valuable commodity near the site of this community AND some cheap and easy way to transport that commodity to its market, I find this highly unlikely.

      Self-sustaining settlements do exist (in more hospitable locations) all over our planet, but they all have the means (or the hope) of exporting their products easily to the rest of the world, such as central locations at the hub or choke points of transport networks, or seaports. Even so, an easily exploitable resource nearby helps.

      By “self-supporting” I concede our city need not produce everything it needs locally. It can certainly trade its produce with other cities, and receive what it needs from them, but again, availability of cheap transport is essential.

      Sure, we can put a colony anywhere we like, the abyssal plain, the polar waste, Mariner Valley or the Asteroid Belt. We have the technology, But it will cost us a great deal. It will not be self-sustaining, and this is critical. A non-sustaining outpost will be an unsustainable drain on the mother society as a whole. Sooner or later, especially if there are too many of them, some will have to be abandoned.

      • Alex Tolley September 26, 2020, 16:21

        Gerard K O’Neill’s book: 2081: A Hopeful View of the Human Future contains his idea of arcologies, essentially enclosed cities like Earthbound space colonies. We could experiment with them today if we wanted, but there seems little interest. Perhaps the failure of the extreme version, Biosphere II is a deterrent or more likely cost is a factor.

        When the idea of space colonies being economically supported by solar power sats was new, it quickly became apparent that construction costs, even with the “heavy lift shuttle” development would be infeasible. Today, with the hope of reusable launchers, thin film solar PV, and better designs, the hope of just building a reasonable niche solar power satellite is still controversial. All this suggests that a self-sustaining space city anywhere in the solar system would be possible remains unproven. Even if transport costs were reduced several orders of magnitude, what would they have to trade that would be worth shipping to earth for key essentials? Helium 3 for theoretical fusion reactors? Anti-matter trapped around Saturn? Information products developed out of necessity that have use on Earth? Perhaps the conditions in space will allow safe experimentation on the genetics of terrestrial (and non-terrestrial?) organisms, experiments that would be illegal on Earth. I suspect that any of these scenarios would most likely end up as company towns, like that depicted in the movie Outland.

        Given the cost and difficulties of maintaining human habitation off-planet, I tend to think that most space industrialization will be with autonomous robots, with perhaps local human supervisors. IOW, less like space cities, and more like mining camps or oil rigs, but with a higher ratio of robotic to human labor.

  • Jer September 25, 2020, 17:21

    To skip ahead to The Spacefaring Enabling Technology Concept: it will need to be a ‘system’ with the optimum symbiosis that brings together AGIs ability to adapt, plan, learn, and optimize –WITH– industry’s Ultimate Prize of self-sustaining creation; that is a mechanism that can find raw materials and then convert them to more of itself and beyond to that of the required infrastructure, effectively autonomously. I imagine a communal-aware fleet of various retrievers and builders within the LEO to GEO zone, constantly reviewing and correcting location, and harvesting very small NEO objects; enabling drop-off, storage, catalog, transform, build, and integrate. Metaphors of biologies and ecologies resonate with smart organisms, intra-dependent communities, and evolving needs/strategies. This unprecedented software/hardware integration with just-emerging technologies (AI control, space sensor, space retrieve, space build) — perhaps AI ExtraOrbital-Industrial Mechanistics. The point is that the infrastructure will need to build itself before we get there, and therefore be effectively autonomous from a fundamental precursor embryo ‘System’. I point people to current projects with: NASA APIS and Optical Mining – emerging developments.

  • Geoffrey Hillend September 25, 2020, 18:11

    A historical viewpoint is a limited viewpoint which will never be enough to be able to predict the future of technology and humanity because it is limited to time, place, the inventor or inventors of a technology. Understanding technology requires a knowledge of how the technology works which requires of the first principles in physics.

    As far as energy is concerned new discoveries lead to more efficient technology. Fossil fuels will become obsolete no matter what because they are non renewable, and there is not an unlimited supply of them.

    The incandescent light bulb is a good example obsolescence. Innovation and invention plays a role in progressiveness. We keep using and making the same technology until a better, more efficient one is invented. The florescent light only uses one third the power of the incandescent light bulb which has recently been made more efficient, but there is a limit to how efficient an incandescent light can be made because it really is a controlled short like a thin wire put across the positive and negative poles of a car battery. It gets hot and melts, it emits heat and light which is essentially and incandescent light, two wires connected by a piece of tungsten with a high melting temperature. The piece of tungsten gets white hot, but it is a terrific waste of energy since most of the electromagnetic radiation is in the infra red since it is so hot. Along comes the invention of LED light, the emitting diodes which only use on tenth the electricity of the incandescent light. All our computer LCD screens, cells phones and lap tops use LED backlighting through LCD, liquid crystal screen. Laptops first used florescent backlighting through LCD.

    The same is true about the combustion automobile engine which uses a heat sink, a radiator to cool of the engine. Since the combustion engine needs a heat sink, it can only be at best thirty percent energy efficient. Hydrogen fuel cells are sixty percent efficient. We knew that over forty years since these were used as a power source in space stations, I think Skylab, I recall reading, Space Frontier by Von Braun. There are also electric cars. We still need oil for axel grease though.

    It is a misconception that fusion reactors are dangerous. They use magnetic fields and if you shut the field off, the plasma would simply quickly cool off and the Deuterium and the Tritium would simply not fuse together any more to make helium one the temperature dropped below that is needed for their fusion. This happens in our Sun where only twenty five percent or the star or inner core gets hot enough to fuse hydrogen into helium through the proton proton chain. The outer part of the star is a hot plasma, but a lower temperature than the 14 million kelvin needed to fusion. In other words, a fusion reactor can’t explode like a hydrogen bomb because there is not fast atomic fission bomb to make an extreme compression of the secondary, the Plutonium spark plug as the radiation implosion in the Teller-Ulam design. There is also no primary atomic bomb with a large amount of Plutonium in the core.

    Fission nuclear reactors also can’t explode like an atomic bomb. The solid core nuclear rocket engine design is fifty years old. It is obsolete because it has a low specific impulse at best only twice that of conventional propellant rocket engines. They are also expensive and dangerous to operate because the exhaust is radioactive since the propellant has to be heated by flowing through the graphite reactor core. The core gets hot as the result of a graphite moderated uranium reaction which slows down the uranium fission so this can’t ever explode like a bomb but only at worst only get hot. An accident or crash would spread radiation. The exhaust does spread radiation. I don’t think these will be coming back since new, safer technology makes them obsolete. It is good that we never used NTR’s. Fission reactors will still be considered for powerplants in interplanetary space craft though. VASIMR could use a couple.


  • Bert Molloy September 25, 2020, 19:57

    Fascinating article but, unfortunately, there is no mention there or in any of the replies so far of what truly MAY become the Transformative Technology of Century # 21 !

    As an enthusiastic Member of ISEC.org I have been assisting, (somewhat), in one of our attempts to elucidate one small portion of the Space Elevator’s future utility, (Disposal of High-Level-Nuclear-Waste).

    ISEC’s latest Publication is:
    “Space Elevators are the Transportation Story of the 21st Century”,
    by ISEC President D. Peter Swan, et al., (July, 2020).
    The electronic version is available FOR FREE to all at:

    Many thanks for your fascinating Web-site which I have been following for about 3 or 4 years, and thanks to Mr. Nielsen for the wondefrful excertps quoted above.

    Bert Molloy

    • Paul Gilster September 25, 2020, 20:45

      Thank you, Bert. Really glad to have you as a reader!

    • Nick Nielsen September 25, 2020, 22:26

      I agree that space elevators could be a transformative technology that would lower the cost of delivery of materials into orbit, probably to a threshold that would make the industrial exploitation of space profitable as soon as such an elevator would be available. However, an elevator, while getting us into orbit, would not get us around the solar system or beyond. For that, we need a propulsion technology. Earth orbit is great, but it’s not exactly a spacefaring technology, though it would definitely facilitate spacefaring development.

      The materials technology for a space elevator will be a big hurdle, and at this present moment in time it looks like reusable rockets will be available to get material into Earth orbit at a reasonable price long before a space elevator becomes available. Here we have a consideration much like what I wrote above about and Age of Fission vs. an Age of Fusion: the period of time during which reusable rockets will be available will constitute a period of history that can be exploited to human advantage. When the space elevator becomes available, as when fusion becomes available, will be a welcome development, but we need to use the technology that we have now.

      Best wishes,


    • James Jason Wentworth September 28, 2020, 8:00

      Thank you, Bert! By using rockets only where they’re essential (or where their speed is advantageous, as for reduced trip times for human crews), and by using the much cheaper, non-rocket space transportation systems (space elevators, momentum transfer tethers, rotating “bolo” tethers, “orbit/surface-walking, rotating space station/elevator/tether systems” [no simple name for these seems to exist], solar sails, microwave-pushed sails, laser-pushed sails [laser lightsails; solar sails can also be pushed by microwave and laser beams, but “specialty” laser lightsails, “tuned” for one frequency of laser light, often can’t double as effective solar sails], electric sails [E-sails, pushed by the solar wind, using one or–usually–more, spin-rigidized, positively-charged wires; positively-charged solar sails can also function as decent E-sails], magnetic sails [magsails], etc.) wherever they can be used, cislunar (Earth-Moon space) and interplanetary space travel can be conducted far more efficiently and cheaply (especially for cargo transport), not to mention safely (because tethers and sails can’t explode! :-) ). ALSO:

      Space elevators are *already* feasible, with existing (and even common, everyday) materials, on worlds other than Earth. Fibers such as Spectra and Zytel are entirely adequate for lunar, Martian, Hermian (with suitable protection against the high solar flux), and large asteroid (Ceres, Pallas, Vesta, etc.) space elevators, and for space elevators on Jupiter’s Galilean moons and on other outer-planet moons. For smaller moons, small asteroids, moonlets (like Phobos and Deimos), and comets, even Nylon ^rope^ (or flat, woven Nylon tape [which pinch rollers on the elevator “cars” could engage], like a lanyard) would suffice in many if not most cases. In addition:

      For our Moon, which rotates quite slowly, studies have indicated that a Spectra or Zytel space elevator (which would not rise vertically, but could–through a swivel anchor on the ground–slant [curve] “equator-wards” from either polar region, at or near the pole) could extend through either the L2 or L1 “in-line” Lagrangian point, to keep the lunar space elevator (or elevators; one could serve each hemisphere) taut. The swivel mounting would take care of the Moon’s librations. (Given the Moon’s 27.3 Earth-day rotation period, a regular-type space elevator on the Moon–rising vertically from the equator [or close to it, in latitude], with a counterweight at its far end, to keep it taut–would be far too long to be feasible.) Plus:

      One study showed that a polar-region anchored, swiveling lunar space elevator, passing through either the L2 or L1 Lagrangian point on the Earth-Moon (and beyond, in both directions) line, would fit–reeled-up, of course–within the payload fairing of a SpaceX Falcon 9 launch vehicle, which could boost it to the Moon. A Falcon Heavy could certainly do it with more payload mass allowance to spare–perhaps it could also carry the swivel anchor, and/or an inspector robot that could travel up and down the deployed elevator cable (or woven, flat tape; pinch rollers on the robot, and on passenger and cargo vehicles, could engage the tape), and:

      At all of these space elevator-equipped destinations, spaceships–even low-acceleration ones, such as ion drive and solar sail vessels–could dock with a facility at the elevator’s top end. (In the case of solar sail or ion drive ships–or lightly-built rocket-powered spaceships–meeting the space elevators of fast-spinning bodies [such as small asteroids], they could match–or nearly match–velocities with the elevator top, then drop off self-propelled [by cold-gas, bi-propellant, or ion, Hall effect, or electrothermal thrusters] cargo/passenger modules that would dock with the elevator-top facility, while the ships kept coasting slowly away. After the passengers and/or freight were unloaded, the modules would simply “let go” of the elevator top at the right moment, to be flung outward toward the ships that released them earlier. By judicious, small thruster impulses, the modules–probably then carrying outbound passengers and/or cargo–would reach and then re-join the spaceships that had transported them. This no-spaceship-docking, “indirect payload transfer” method would avoid subjecting the interplanetary spaceships to high acceleration and deceleration loads, allowing them [especially solar sail ships, the most efficient types of which are spin-rigidized, having no structural booms] to be built as lightly–for maximum performance–as engineering safety factors allow.)

  • Spaceman September 25, 2020, 20:46

    In many ways, technological progress has slowed dramatically outside of the realm of information technology and computers. Think for a minute: yes, our beloved smart phones are more powerful than the best computers during the Apollo program, but the rockets we use to access space in 2020 have not seen any comparable level of improvement, as we are stilling using chemical rockets now just we did in the summer of 1969 even though, yes, now we can take “selfies” and “face-time”. Attempts to improve the capabilities of chemical rockets have thus far proved fruitless (though if metastable metallic hydrogen is created and remains stable under ambient conditions this could change). The lack of better chemical propellants and still no room temperature superconductors are two examples of the technological stall.

    If you plot our improvements in the speed of travel between 1900 and 2000, you would see a steep rise in the beginning followed by a flattening and leveling off in terms of the velocity with which we can project ourselves and our machines during the last 60 years. Obviously, speed matters given the distances between destinations in our solar system let alone interstellar distances. Even in the bio-sciences which are often touted as area wherein advances are occurring at break-neck pace, advancements in medicine as a result of the human genome project have come MUCH slower than the experts thought during the period of initial exuberance.

    The premise of “Star Trek” is that there will be another revolution in basic physics on par with the discovery of electricity or nuclear power. In Star Trek, we communicate FTL through “subspace” and travel FTL using warp drive. But what if all future technological development involves refining and coming up with new ways to harness the laws of physics that have already been discovered? This prospect seems somewhat limiting. How many of you think it likely, I ask? Our ability to access the Cosmos will suffer, I fear, without a fundamental breakthrough on the most basic level of physical science.

    Mr. Nielsen: I am curious about the following statement you made in your excellently crafted essay:

    “But because of the severe engineering challenges of fusion, the mastery of fusion technology will greatly enhance human agency, and as such it will eventually suggest the possibility of human extinction by means of the weaponization of fusion technologies, and so bring itself under a regime of tight control that would ensure that fusion technologies never achieve a transformative role in civilization because it never becomes practical, accessible, and ubiquitous.”

    What do you mean by the “possibility of human extinction by means of the weaponization of fusion technologies”? We already have “fusion weapons” so I was curious what you else you had in mind…I am wondering if you had something else in mind besides existing nuclear weapons (e.g. using fusion propulsion to reposition asteroids and use them as weapons or antimatter catalyzed fusion bombs)?

    • Alex Tolley September 26, 2020, 16:28

      Even in the bio-sciences which are often touted as area wherein advances are occurring at break-neck pace, advancements in medicine as a result of the human genome project have come MUCH slower than the experts thought during the period of initial exuberance.

      I don’t agree with this statement. We have now had the typical 20 year period between discovery (mapping the human genome) and technology dispersion. It seems to me that any perceived slowdown is due to the needed regulatory process of bringing medical products to market. Biological discoveries are coming thick and fast, many with direct medical applications. I have no idea whether Aubrey deGrey’s ideas for life extension will pan out, but I see many advances that appear to offer substantial health and life extension improvements. Significant life extension will have huge social consequences, both good and bad, with most people I think wanting to live longer, healthier lives.

      • Spaceman September 26, 2020, 22:00

        Please refer to the following source in which the authors contend that though there is still reason to be optimistic about medical advances from genomics, the advances are occurring slower than expected:

        “Overall, we argue that the optimism surrounding the transformational potential of genomics on medicine remains justified, albeit with a considerably different form and timescale than originally projected. ”


    • charlie September 28, 2020, 17:58

      “(though if metastable metallic hydrogen is created and remains stable under ambient conditions this could change). The lack of better chemical propellants and still no room temperature superconductors are two examples of the technological stall.”

      Lithium alloying reduces requisite pressure
      In 2009, Zurek et al. predicted that the alloy LiH
      6 would be a stable metal at only one quarter of the pressure required to metallize hydrogen, and that similar effects should hold for alloys of type LiHn and possibly “other alkali high-hydride systems”, i.e. alloys of type XHn where X is an alkali metal.[18] This was later verified in AcH8 and LaH10 with Tc approaching 270K [19] leading to speculation that other compounds may even be stable at mere MPa pressures with room temperature superconductivity.

    • Nick Nielsen October 2, 2020, 20:30

      “…I was curious what you else you had in mind…I am wondering if you had something else in mind besides existing nuclear weapons…”

      I didn’t have anything specific in mind when I wrote this, just the general principle that high energy technologies can be used as weapons. Most designs for fusion drives, for example, could be directed energy weapons, as in the Larry Niven story “The Warriors” in which the human characters only with hesitation realize that they have a weapon in the form of their drive.

      Best wishes,


  • Dmitry Novoseltsev September 26, 2020, 3:22

    An interesting question is that I have not yet had time to reflect deeply (although I myself and my newly created company D-Start are already working in a new paradigm, but we still think in terms of old concepts). In addition to the upward development of technologies, as they become more complex and more expensive, it is also possible to develop technologies “in breadth” – in the direction of their distribution and cheapening. There is reason to believe that the real breakthrough in space technology is being made not by SpaceX, but by the creators of the ChipSat format. In the previous paradigm, when space missions were carried out by powerful States (and in recent years by large private companies), the subject of activity on a cosmic scale was considered “civilization” as a whole. But now technology is giving more and more opportunities to individuals. Low-orbit satellites (such as AmbaSat) are now available to them. Thanks to the engines being created (in particular, by our D-Start company), they will soon have access to transition trajectories and missions in the Solar system. If further development goes well, even before the Russian nuclear spacecraft goes on its first test flight, individuals will be able to launch probes beyond the Solar system – including, for example, missions to disseminate information and analogs of directed panspermia. And these subjects of space activity – individuals will not be demigods with technologies of the distant future from Vernor Vinge’s books, for example, but our contemporaries. Even the largest dysonian structures, or structures such as the distributed solar gravity telescope (which we discussed with Claudio Maccone) or the simpler “terrascope” can be assembled from a variety of simple, cheap elements owned by private individuals. Perhaps it is such massive private projects that replace “space powers” – as once in biological evolution, social insects replaced large dinosaurs. How will this affect the above and similar reasoning? I would like to consider this issue in more detail.

    • James Jason Wentworth September 30, 2020, 6:54

      Also, ChipSats (and ChipCraft–extra-Earth orbit space probes) need not be limited to flat forms. To obtain more solar cell surface area (more power), as well as a reasonably constant power output regardless of the craft’s orientation with respect to the Sun, appropriately-shaped flat sections of it could fold (using pre-stressed springs) and latch together after deployment, to form tetrahedral, cubical (or square- & rectangle-sided prisms [like a shoe box shape, say], octahedral, dodecahedral, or other such shapes. The larger surface area would also provide more space for exterior-surface sensors, and/or for windows for outside-looking, internal-mounted instruments, and:

      Mason Peck, a ChipSat developer who has been published here on “Centauri Dreams,” liked the idea, and he told me that a student’s dissertation includes it. (TRW’s small ERS–Environmental Research Satellite–“hitch-hiker” payloads were made in different-sized tetrahedral [TRS], octahedral [ORS], and dodecahedral [DRS] shapes, although the DRS ones don’t seem to have been flown in space [the only reference I found on them was a picture of TRW’s ERS “family,” which included examples of them].) Like the ERS satellites, the self-folding ChipSats and ChipCraft could use either no stabilization (“drift mode”), spin stabilization, or magnetic stabilization (using permanent magnets or–as is now available today–active and controllable magnetic torque coil systems).

  • Michael Garrett September 26, 2020, 3:33

    “Victorian England” – James Watt must be birling in his grave.

  • Douglas Muir September 26, 2020, 5:56

    “these plans were largely derailed by construction costs that spiraled due to regulation”

    [citation needed]

    This is accepted as an article of faith by many, but the evidence for it is not strong.

    The main problem with nuclear power is cost overruns. Without exception, every single nuclear power plant built in North America has gone into massive cost overruns, frequently running to double or triple original projections. The end result is that nuclear electricity is just too damn expensive to be attractive.

    The weird thing is, *nobody is sure why*. Regulation is obviously one issue, but the same problems keep popping up under a wide range of regulatory regimes. It’s not just an American thing. Nuke plants in Germany, Australia, Canada, India and Japan have all run into the same issue. It’s really hard to believe that “regulation” has been the single overriding problem in a dozen different countries, with different laws and regulatory regimes, over a period of forty years.

    There are two kinda-partial-maybe exceptions to this broad rule: China and France. China, nobody’s quite sure, because Chinese government accounting is extremely opaque. France does seem to have lower cost overruns than anyone else. But nobody’s been able to show that France’s regulatory regime is much lighter than anyone else’s!

    It’s a deep hard problem that has been causing a lot of head-scratching over the last 20 years. But just saying “regulation” — really, no.

    Doug M.

    • Henry Cordova September 26, 2020, 14:15

      Very perceptive, Doug. Whenever something doesn’t work, blame it on the big bad government and its regulations and taxes. “If we just let the entrepreneurs do anything they want everything will be just wonderful.”

      In the early 1970s I worked for a while in the public relations branch of the nuclear power industry, a shadowy “institute” ensconced in the vague borderlands between private enterprise and big government. There were massive hand-outs by the taxpayer to help nuclear power get off the ground, even the insurance costs were subsidized by Uncle Sam. But the potential big expense, nuclear fuel waste processing, was never adopted by the industry, and the government soon learned that what was possible in the laboratory could not be scaled up to the industrial world without massive investment. Congress wouldn’t foot the bill and the industry never had any intention to. I quit my position and went back to graduate school just as the big push for nukes got underway.

      When the film “China Syndrome” was first released, my former colleagues attacked it in the press as sensationalistic and incorrect, pure scare tactics. I knew better. When the Three Mile Island incident occurred just a few weeks later, it worked out pretty much like it did in the movie. Except in the film, the accident occurred as the result of illegal acts and corner-cutting by crooked contractors and mismanagement by utility executives. In the real world, it was a perfectly designed and functioning facility, manned by a competent and heroic crew. It was all the result of unanticipated events and perfectly natural, but incorrect (in retrospect) human responses. That is, after all, the very definition of “accident”: an unforeseen and probably unavoidable event.

      I am not opposed in principle to fission-generated electricity, in fact, it is a tragedy for humanity it could never get properly off the ground. Its problems are technical in nature and they have technical solutions. But the failure of that commercial technology is not solely due to government meddling, it is primarily the result of the private sector not seeing a way to make a profit from it.

    • James Jason Wentworth September 28, 2020, 2:09

      France did two things (which the U.S. did ^not^ do), which appear to have resulted in lower costs and greater safety:

      [1] The French selected *one* reactor design (a General Electric one, if memory serves) for *all* of their nuclear power plants, whose associated turbine generator system could be de-rated as necessary (or as desired), for serving smaller communities;

      [2] They re-process their nuclear waste to produce new fuel rods, so that relatively little unusable radioactive waste remains. (A lot of the un-fissionable “leftovers” are still useful–and economically valuable–as inject-able medical tracers, food nutrients utilization tracers, medical treatment [such as for cancer] implantable radioactive “seeds,” radioactive markers, radioluminescent lighting device exciters, radiation sources for element abundance detectors [some of the Surveyor Moon landers carried these; an alpha particle source enabled the “little gold boxes,” as they were called due to their appearance, to identify and determine the abundances of all elements except hydrogen in lunar soil and rocks], fuel for RTGs [Radioisotope Thermo-electric Generators] and for longer-life, lower-power isotope batteries [not RTGs–which are also body-implantable to power pacemakers, insulin pumps, etc.–plutonium-238, strontium-90, promethium-147, and other “waste” isotopes can and do power these], and so on. In fact, today’s plutonium-238 pacemaker batteries often utilize Russian P-238 that came from their nuclear waste.) Now:

      In the United States, most nuclear power plants are “one-off” designs (including the use of different reactor coolant/heat exchanger types; pressurized water, molten salt, etc.)–there are some cases of multiple examples of one given design, but not many. This lack of commonality (which the French wisely designed in to their nuclear power infrastructure from the start) could hardly ^not^ result in problems, and in worrisome unknowns (for example, if a pressure vessel weld in Plant A cracks, is it just an isolated problem [maybe just a poorly-done weld, or maybe *that* reactor’s exposure to leaking salt coolant years ago was a factor, which is a non-issue for pressurized water reactors], or are Plants B, C, D, and so on also at risk for the same weld failure for some fundamental reason, such as unexpected low-intensity neutron exposure causing steel embrittlement that occurred over decades of operation?). Also:

      Many years ago the U.S. government decided, partly out of fear of terrorists acquiring nuclear materials (the mid-1970s “hidden atomic bomb scare” [fortunately, a hoax], which led to the birth of NEST [the Nuclear Emergency Search Team], may also have been a factor in the government’s decision), that nuclear waste from power plants would not be re-processed (the risk of terrorists hijacking the shipments, especially of re-processed fuel rods, was specifically mentioned), but would be buried in a secure facility. That facility, the Yucca Mountain nuclear waste repository in Nevada, was and remains a multi-billion-dollar boondoggle (funding has ceased; it is now perhaps the world’s most expensive tourist attraction), which has yet to “host” any nuclear waste. Somehow, the French seem to be able to re-process their nuclear waste (and they generate a lot of it, as about 90% of France’s electricity comes from their nuclear power plants) without it falling into the hands of terrorists; if they can do this, surely the U.S. can as well? As well:

      This nuclear issue, in a broader context, is an excellent reason for establishing settlements on the Moon, which is well-endowed with uranium, radium, and other actinic elements. While Nuclear Thermal Rockets (NTRs) do work, as NERVA and its predecessors demonstrated, such solid-core reactor NTRs are rather marginal in terms of their advantages over chemical rockets (fortunately, there are better nuclear alternatives).

      While their exhaust velocities are about double those of LOX/LH2 rockets (and solid-core NTRs do produce about twice the thrust, with long running times), the heavy radiation shielding they require, their relatively short operating lives (ten missions, for NERVA), and their radioactive exhaust make them less attractive than they appear to be at first glance. (NERVA’s “shadow shield” was required not only to protect its crew, but the crews of other ships approaching within miles [they would have had to stay within the conical “radiation shadow” to safely dock nose-to-nose, even with the NTR engine *off!*]. While NERVA was firing in space, NASA considered 100 miles to be the minimum safe distance for other spaceships.) However:

      Gaseous-core fission rockets, such as the “nuclear light bulb” design (which contains the vaporized fissionable material in a quartz envelope, heating the propellant via infrared radiation), can operate at far higher temperatures (with all that that implies for higher specific impulse, and with healthy thrust levels, for any propellant “working fluid” [liquid hydrogen, ammonia, methane, and even water]). Because the fissionable material and the working fluid do not physically contact each other, the exhaust is not radioactive. While a shadow shield would probably still be advisable (to ensure that the vessel’s crew, close ahead of the engine or engines, would be protected), the gaseous-core fission rocket is so much more energetic that the shield’s mass would exact a smaller performance penalty than is the case for the lower-performance, solid-core NTR. (In his 1965 book “Thrust Into Space” [which Arthur C. Clarke briefly discussed in his 1968 non-fiction book “The Promise of Space”], the McDonnell Douglas engineer Maxwell Hunter outlined a gaseous-core fission ship using water as its working fluid, which could [operating on a weekly schedule] transport 5,000 tons of cargo to the Moon each year, and could even compete against jet transports, traveling ballistically [like the McDonnell Douglas engineer Philip Bono’s LOX/LH2-propulsion Single-Stage-To-Orbit ships, which he also proposed as ballistic suborbital passenger and freight transports] between any two points on Earth in less than an hour. Either of these vehicles–and even more so, both of them together–would revolutionize space travel as well as intercontinental travel, package delivery, and mail transport on Earth.) Plus:

      Nuclear-electric (ion drive, HET [Hall effect thruster], PPT [Pulsed Plasma Thruster], etc.) spaceships would also benefit from Moon-sourced nuclear fuels. (Mining them there [Transient Lunar Phenomena, which consist of escaping sub-surface radon gas lifting dust particles which the Sun illuminates, indicate “where to dig” for uranium, thorium, etc.] would neatly side-step the problems associated with launching such materials from Earth. Besides, these ores would also be of great use to the lunarian settlers for providing electricity and heat during the two-week “night seasons,” as the industrial engineer Neil P. Ruzic–in his 1970 book “Where the Winds Sleep”–suggested lunarians might refer to the long lunar nights.) And:

      On the Moon (and later, on Mercury, too, as well as on some asteroids [Vesta appears to be a likely place]), the nuclear industry–mining uranium and other actinic elements and producing trans-uranic elements such as plutonium for local sale & use, and for off-world sale, and producing, selling, and servicing reactors, RTGs, boilers, isotope batteries, etc.–would easily be as vigorous, and as lucrative, including as investments (if not more so) as the Earth’s petroleum, natural gas, and coal industries (the “hydrocarbons energy and chemical products industry,” taken together) are today, and:

      The Moon has no wildlife or water tables to be possibly contaminated (not that we would, or should, treat Luna like a garbage landfill, strip-mining willy-nilly and dumping chemical wastes with abandon–we must not, especially since there are no forests to grow back and heal & hide such scars in the landscape–ditto for Mercury, Vesta, and other such worlds). The lack of a biosphere, a hydrosphere (the water ice in the permanently-dark lunar and Hermian polar craters–to which shipped-in asteroidal and cometary water ice and other ices could be added as desired [the water, methane, and ammonia could be condensed and separated as needed]–should be kept clean from dangerous contaminants), and any atmosphere worth mentioning on the Moon, Mercury, and asteroids does, however, facilitate easier–yet safe–construction and operation of fission reactors:

      A reactor to power a settlement could simply be set up in the open, in a convenient nearby crater (or a purposely-dug depression, if no such crater was close by) for radiation shadow shielding. A metal roof (perhaps a two-layer one, built like a “Whipple meteor bumper” [which the astronomer Dr. Fred Whipple invented in the 1950s to protect spaceships and space stations from puncture by meteoroids; the Soviet and ESA Halley’s Comet probes were equipped with Whipple meteor bumpers, as later comet fly-through probes such as Stardust have been]) would be set up over the reactor to protect it from gradual erosion by the nuisance–not menace–of the constant patter of tiny meteoroids. The roof would also prevent a stream of radiation from shooting up into the sky, where it might be a problem (not necessarily due to the radiation dose per se, but by causing “bit-flips” in computers [as space probes near the Sun and Jupiter have experienced]) for spacecraft and space stations orbiting overhead. The inner (reactor-facing) “ceiling” of the meteoroid & radiation roof-shield could be made of radiation-absorbing, carbon-rich quilted fabric material (like what Bigelow Aerospace’s expandable space station & surface habitation modules are made of), as this would prevent–or at least greatly reduce–the buildup of “induced radioactivity” in the metal roof over time. Lastly:

      In one of his essays, Arthur C. Clarke pointed out–to illustrate how the same thing can be done with regard to space travel–that the revolution in air travel, which occurred even before the advent of the jet airliner, occurred *without* any fundamental breakthroughs in aerodynamics knowledge, materials science, engine technology, fuel chemistry, aviation medicine, or electronics. Only incremental improvements (all-metal airframes [which Junkers successfully pioneered as early as 1915 with their J1 monoplane], semi-monocoque structures [frame-backed, stressed-skin structures, very strong yet lightweight], retractable landing gear, flaps, radial engines, engine-driven cabin pressurization air pumps, etc.) were needed to go from the Wright Flyer to the Spirit of St. Louis to the Douglas DC-3, -4, -6, and -7, the Lockheed Constellation, and the Boeing Stratoliner and Stratocruiser, which made air travel safe, fast, efficient, comfortable, and affordable for the average person (even if some people had to save up for a trip). The advent of the jet airliner, and in particular, the wide-body “jumbo jet” powered by high-fuel efficiency, high-bypass turbofans, capable of carrying hundreds of people at a time (the 747, L-1011, DC-10, A300 Airbus, and their descendants today), greatly lowered the cost per passenger-mile, largely through economies of scale. Yet this second, even greater revolution in air travel also took place without any fundamental breakthroughs in knowledge or technology, just incremental improvements, and:

      Such innovations, Clarke emphasized, do not merely add together; they multiply, as the history of aviation amply demonstrates. Likewise, the incremental improvements in launch vehicles and spacecraft, which the new private astronautics firms are pioneering, are–almost without anyone noticing it–creating a similar revolution in that field. SpaceX, whose Falcon 9 and Falcon Heavy rockets were already–thanks to vertically-integrated, nearly totally “in-house” production–the cheapest in terms of payload cost per pound, is further cutting launch costs (while increasing reliability) by recovering and reusing all of the hardware (even the payload fairings) except for the relatively small final stage. (Even they could be recovered, by building them like Philip Bono’s SSTO vehicles, so that base-first re-entry and landing of the stage–using just a few of the multiple small thrust chambers–could be done [incidentally, LOX/kerosene–not only LOX/LH2–also works fine for true SSTO vehicles, as studies by General Dynamics and others have shown].) Recovery and reuse of at least the first stage is even practical for small launch vehicles (being the largest component, it is economically well worth reusing), as Rocket Lab has been discovering through controlled first stage re-entry tests during operational missions of their Electron launch vehicle (and helicopter mid-air retrieval tests with a parafoil-lowered dummy Electron first stage); they will soon begin recovering and reusing Electron first stages, cutting their already-reasonable launch costs even more. And SpaceX’s Dragon spacecraft (both the recently-retired Cargo Dragon and the new Crew Dragon [which, like a jetliner, can be outfitted to carry passengers, cargo, or both]) were/are designed for reuse, and for lunar and interplanetary operation–their PICA-X heat shields are rated for Mars-return re-entry velocities, and can withstand hundreds of Earth orbit re-entries.

  • Douglas Muir September 26, 2020, 6:16

    “When funding for the SSC was cancelled (after an initial two billion had been spent), an entire generation of American scientists have had to go to CERN in Geneva because that is where the instrument is that allows for research at the frontiers of fundamental physics.”

    Good riddance. CERN has been an enormous waste of resources.

    It’s had exactly one major discovery: confirming the existence of the Higgs Boson. That cost an eye-watering $13 billion — in round numbers, about $5 billion to build the thing and over a billion a year to run it.

    Everything else CERN has done has been marginal, nibbling around the edges of the Standard Model. It’s produced absolutely nothing of any use or practical application. Okay, you can argue that pure science has value — but CERN has been a huge disappointment there too. It has produced no breakthroughs, no new physics, and honestly very little of interest. Even the specialist physicists will privately admit that CERN has failed to deliver.

    And the thing is, this was almost entirely predictable! Cosmic rays regularly arrive in Earth’s upper atmosphere packing far more energy than anything CERN can produce. Thirty years ago, we could look at those interactions and see that they weren’t producing any unexpected particles or new physics. So it wasn’t a case of “negative results are still results, we had to build CERN to know”. We already knew!

    The money spent on CERN — now well north of $20 billion, and counting — could have paid for about eight flagship-equivalent NASA missions (Cassini, Hubble, MSL/Curiosity) or about thirty Discovery class missions (Messenger, Dawn, Kepler).

    CERN was and is an immense waste of resources, and canceling the SSC was one of the best decisions America’s science establishment ever made. And it’s kind of maddening that people are still getting sad about it.

    Doug M.

    • Alex Tolley September 26, 2020, 16:42

      The wasteful cost of high energy physics installations was very much the sentiment of Per Bak, who experimented with sand piles to explore what he caused “self-organized criticality” in the mid-1990s. Even as CERN increases its energy to look for new particles, possibly to support super-symmetry, so far no discoveries have been made. It may well be that this line of research has reached a dead end. Pharmaceutical companies testing vast chemical libraries for new drugs seems to have similarly pretty much exhausted this approach, with the result of ever-diminishing new small-molecule drugs coming to market, increasing concentration in the industry, and financial games rather than product innovation as the source of profits. This seems to be a pattern in a number of once large industries.

      • Spaceman September 27, 2020, 23:12

        Might this trend of diminishing returns in both high energy physics and the pharmaceutical industry point to the idea that we may be facing a situation in which all future technological advances are applications of the laws of physics discovered in the 19th and 20th centuries?

  • Mike Serfas September 26, 2020, 16:50

    I tend to disagree with the thesis of this article. My impression is that “keystone technologies”, far from ensuring technological progress, are dependent on underlying social technologies for their success. For example, I’ve read that Heron’s use of steam power did not lead to an industrial revolution in Rome because they had abundant slave labor. On the other hand, Zheng He’s expedition, equipped with a better fleet than the Europeans, might have failed to cause lasting change because China didn’t have as rapacious a system of slavery as that which inspired Columbus. (Though doubtless there were more general economic and political differences) In our own time, we see that computer technology that *should* be absolutely world-changing, putting all of human knowledge into the hands of every individual, is held back by the medieval doctrine of copyright and the extreme fears of lost privacy that result when employees feel they have no sense of security against bullying (virtuous or otherwise) in a society that abhors forgiveness with nearly religious fervor. It may also be that greater advances in nuclear power, chemistry, and genetic engineering would have been possible had people felt a more secure social structure were in place to impartially evaluate and contain their risks. The perfect society in which all the right science is pursued avidly for all the right reasons … remains elusive.

    • Alex Tolley September 26, 2020, 21:56

      Wired’s editor at large, Kevin Kelly’s book: What Technology Wants has an interesting (and surprising) chapter about the Amish approach to adopting technology. Kelly seems quite sympathetic to their careful evaluations of new technology. If this were a societal model, we might have a much more technocratic society where technology development is limited and focussed based on the technocracy’s influence. It would be the antithesis of our entrepreneurial, market-based approach. However just as entrepreneurs unleash bad products that do well, technocracies can make bad bets on technologies too. As for publically funded science, a continuing critique is that the NSF tends to fund research where the outcomes are expected to be achieved, and far too little funding for “blue sky” experiments. This is particularly problematic today as corporate R&D has increasingly replaced government funding, and tends to be very focussed on short term results that can be monetized quickly.

    • Nick Nielsen September 26, 2020, 22:24

      …or perhaps what we need is a less secure social structure in which failure is commonplace and people feel free to take real risks.
      Best wishes,

  • Geoffrey Hillend September 26, 2020, 18:53

    I disagree about CERN being a waste of resources. The LCH has not been running for very long. Scientists still can make new discoveries with it. If they can discover the graviton, for that would be of benefit to space propulsion because understanding how the four forces couple could lead to the understanding of how to convert one force directly into another and help scientists eventually make gravity control which is a space warp. Negative energy or anti gravity is also a space warp so understanding a quantum theory of gravity and more about quantum field theory will lead to breakthroughs in FTL. If we can make gravity control, it will be a piece of cake to make anti gravity control, and it’s simply just reversing the warp field. A gravity wave already expands and contracts space time a little bit.

    I will agree that LHC type particle colliders and accelerators are not energy efficient because they use a lot of energy to run the superconducting electromagnets. There is the idea of using lasers to accelerate particles, so that table top lasers could have as much as ten times of the energy of the LHC. This is a new idea which is more energy efficient, but these are not really being developed at this time for those energies from what I know.

    Quantum field theory is very important because every piece of modern technology we enjoy today uses it, and we can thank particle accelerators and colliders and many quantum physicists of the past and present for today’s technological level. There will be even greater freedom as a result of technology in the future because of new discoveries and ways to manipulate the subatomic forces. I think the LCH is money well spent. We have discovered and confirmed the Higgs boson and field with the LCH which will be coming back online at full power next year in May 2021.

    • Nick Nielsen September 26, 2020, 22:16

      I do not consider CERN or LHC to be a waste of resources. On the contrary, I think that this is a wonderful use of resources, and would prefer a world in which there was competition between teams at the LHC and teams at the unbuilt SSC. I would favor dumping truckloads of money into ever-larger particle accelerators, because I know that basic science is going to accelerate the development of civilization in unexpected ways. I did not that the LHC is large and expensive, but I do not for that reason see it as a waste.

      Best wishes,


    • Douglas Muir September 27, 2020, 4:26

      “The LCH has not been running for very long.”

      — It’s been running since September 2008! That’s twelve years, minus a couple of years it’s been down.

      “If they can discover the graviton”

      — what? The LHC isn’t even looking for the graviton.

      “I will agree that LHC type particle colliders and accelerators are not energy efficient”

      — That’s not the argument. The argument is, it cost ~$5 billion to build and costs a billion a year to run and has produced little of interest and nothing of use. Cutting its running costs in half won’t affect that judgment. (And, as you note, nobody actually is planning to cut the LHC’s running costs.)

      “we can thank particle accelerators and colliders and many quantum physicists of the past”

      — Emphasis on “of the past”. Yes, we did learn a lot from accelerators and colliders! But we haven’t learned much from *this* extremely large and expensive collider. This one is a waste, and has been since day one.

      Doug M.

      • Mike Serfas September 28, 2020, 12:06

        To my non-expert eye, the Higgs boson seems a fairly substantial exception to a project’s uselessness. Its test of supersymmetry by Bs meson decay also seems rather substantial. Theoretical physicists appear to work within a vast menu of hypothetical options, narrowing the details of hypotheses that are most often invalid. Any one new fundamental particle of physics, observed and weighed, trims the menu options and puts more of the experts onto the right trail – which improves the payback from future research spending. There is something so fundamental about simply looking at a higher energy collision to see deeper principles of physics, it is hard to picture what alternative you imagine. This project consumed a few thousands of the resources spent on the Iraq War, and but a single casualty … and I can point to permanent benefits it has given to the world.

    • Robert October 10, 2020, 15:30

      “Quantum field theory is very important because every piece of modern technology we enjoy today uses it, and we can thank particle accelerators and colliders and many quantum physicists of the past and present for today’s technological level. ”

      To say that modern technology uses the quantum nature of particles is not to say you need to understand Quantum Field Theory (QFT) in order to understand, conceive and develop electronic technology any more than saying you need to understand Quantum Mechanics (QM) and the wave nature of electrons to understand and develop electrical technology. Our basic electrical infrastructure was invented and deployed in the late 19th century many years before the electron was even discovered. Active electronics, basically diodes, tubes (transistors) were discovered independent of QM let alone QFT. In fact, a version of solid state transistors were actually invented in the 1920’s before even QM was completely developed or understood. You can improve technology with detailed knowledge of solid state physics which depends on QM but you don’t need QFT.

  • Geoffrey Hillend September 26, 2020, 19:44

    What I forgot to write was with a fusion reactor, there is no concentration of a large amount of Plutonium in a single spot like in the primary atomic fission bomb core and the Plutonium spark plug. All of these are the components of a hydrogen bomb. Consequently, there can’t be any kind of chain reaction which leads to a super critical mass as in an atomic bomb which, needs a concentrated volume or large amount of Plutonium. High explosives cause the implosion of Uranium or Plutonium so there is no way to make a weapon out of a either fission or fusion reactor.

    The Plutonium spark plug fusses after it compressed by the explosion and radiation of the primary atomic bomb, the hot candle which fuses the spark plug which fuses the hydrogen into helium. In a fission reactor the Uranium spread out over a wide area or mixed with graphite and not concentrated so a compression won’t fission it and consequently, it can’t have a quick supercritical mass through implosion. There has to be so many pounds of Plutonium in a single spot or core to explode like an atomic bomb where a very large amount of Plutonium atoms are each split into two smaller fragments and lead to a fast chain reaction and release a lot of energy at once..

    • Alex Tolley September 27, 2020, 11:56

      I don’t think most people argue that fusion reactors are not the “great white hope” for centralized, low emission, electric energy production. The current hydrogen isotopes being tested do produce copious neutrons that do slowly damage the reactor materials and these must be disposed of safely. (Aneutronic He3 fusion largely eliminates the issue of irradiated containment.) The problem is that both major approaches have not created net energy, and seem unlikely to do so economically for decades. Research was begun in the mid-C20th with no ROI to date. One has to wonder whether collecting the energy of our sun might just be the better way to harness fusion. We know it is going to operate for billions of years, and that its output dwarfs anything we could produce on Earth. We solve the planetary surface intermittency issue first with storage, then ultimately with orbiting powersats. We can build out these powersats to support a huge industrial capability if that becomes desirable. If fusion rockets are easier to build, then I am all for that.

    • AlexTru September 27, 2020, 12:41

      so there is no way to make a weapon out of a either fission or fusion reactor

      I suppose you forgot one important thing, fission reactor if destroyed by chemical or thermal explosion creat , so called “junk bomb” , damage equal to be cause by Chernobyl or Fukushima incidents…
      As result of Chernobyl incident wide area became inhabitable.
      Fission reactor usually had inside much more radioactive material than atomic bomb…
      so possibility to cause long time damage to habitable territory is even better than with atomic bomb explosion.

  • Robin Datta September 27, 2020, 5:18

    Myths may help to muster the needed wherewithal, but may perform inadequately as a substitute for wherewithal.

    All species go extinct. A few of these are replaced by their direct descendants through a continuous lineage: our ancestors include Homo erectus; they live through us, although we now call them extinct. Further back they include arboreal apes, small quadruped mammals, amphibians, lungfish that came ashore, etc.

    Astronomy tells us that the sun will go red giant and incinerate the earth. To allow any then-extant descendants a chance at survival, it would not be inappropriate to start thinking about it now.

    The question of “Why survive?” probably has its answer in origins of the molecular machinery of the cells that were geared towards survival, and hence it is called a “biological imperative” now, and is wrapped up in its cocoon of myths. Yet in the grand scheme of things it pales into insignificance.

    There are of course myths that do not look endless survival, but rather to endless cycles of manifesting – manifest – de-manifesting – un-manifest, as in the Indic traditions.

  • James Jason Wentworth September 27, 2020, 7:49

    I encourage anyone pondering this issue to read Arthur C. Clarke’s non-fiction book “The Exploration of Space.” In it, he described–and provided eye-opening figures–showing how amazingly easy interplanetary travel is, even using ordinary chemical propellants (or ion drives, which can be either solar or nuclear powered; freight-only robotic ships would particularly benefit from them), if the spaceships depart from and arrive at space stations, which serve as filling stations, among other things. The room temperature-store-able, hypergolic fuel/oxidizer combinations would be convenient for interplanetary spaceships; so would non-cryogenic (even though non-hypergolic) but store-able combinations such as nitric acid (or dinitrogen tetroxide) and kerosene. Also:

    The space stations’ tanks (which need not be physically attached to the stations proper) could be filled and kept replenished by dedicated tanker rockets, and/or by residual propellants transferred from ships as they rise up from Earth to dock; ^their^ tanks would be replenished as needed. (The old-fashioned, synthetic-gravity “wheel”-type space stations would show their promise here.) I can also provide an illustration of how much such space stations (Mars already has two nice ones, courtesy of nature) could reduce the size and fuel requirements of interplanetary spaceships:

    Picture the Atlas-Agena B which sent the 447 pound Mariner 2–the first probe to examine another planet at close range–to its Venus flyby in 1962 (see: https://en.wikipedia.org/wiki/Mariner_2 ). All of the LOX and RP-1 kerosene in the huge Atlas ICBM first stage, and about half of the hydrazine and nitric acid in the much smaller Agena B second stage, had to be burned–while throwing away the entire Atlas (booster engines section and sustainer engine and tankage) vehicle in the process–in order to get the restart-able Agena B and the still-attached Mariner 2 spacecraft into the parking orbit. The remaining half (or so) of the Agena B’s propellant was sufficient not only to boost Mariner 2 out of the parking orbit and to distant Venus, but there was enough left over to vent overboard, to ensure that the spent Agena would not collide with the separated spacecraft (or block its radio signals), and that it would miss Venus (as neither it nor Mariner 2 was sterilized). Now:

    If a small spaceship of equivalent performance (the Agena was, in fact, also built and was often flown as a self-contained spacecraft rather than as just a rocket stage, having originally been developed as a self-propelled reconnaissance satellite with precision attitude control, and even optional solar panels for long usage in space) started its journey–fully fueled–from a space station in Earth orbit, it would have ample propellant for a round-trip journey to Venus or Mars. It could, however, do even better than that:

    The Agena was still, by necessity, designed to fly up through the Earth’s atmosphere, being exposed to aerodynamic drag and heating in most of its launch vehicle configurations (mounted atop Thor or Atlas first stages). Only in some of its Titan-boosted configurations, and in one (or at most, a handful of) special Atlas-Agena (like the Atlas H-Agena D, which orbited OAO-1 in 1966), was the Agena protected inside a payload fairing, which also extended down over it. But:

    Such a vehicle, if designed to operate *only* in space (a “true spaceship,” as Clarke called such orbit-to-orbit interplanetary vehicles), meeting ground-to-orbit–and vice-versa–spacecraft upon planetary arrivals and departures (and at moons and asteroids, too) to transfer personnel and cargo, could be very lightly built, since it would never experience heavy acceleration or deceleration. Such a ship (or a tug, perhaps, docked to a cargo or habitation module to create a “de facto spaceship” [the latter could spin the two components at the ends of a tether once underway, to generate synthetic gravity]), if designed to have the same propellant type and capacity as the Agena B or D (the Agena A had considerably shorter tankage and lacked the restart capability; the Agena D was very similar to the B model, but was designed with standardization in mind), would have considerably higher performance, because its dry mass would be significantly lower than that of the Agena B and D. In addition:

    With today’s nearly-fully-reusable Falcon 9 and Falcon Heavy launch vehicles (the fully-reusable Starship and its huge booster are currently under development), and existing expandable (Bigelow Aerospace) space station modules, we could have a “spacefaring civilizational breakout” fairly soon. (Goodyear and NASA Langley actually built nearly-space-worthy, inflatable “wheel” test space stations in the early 1960s [Goodyear’s 30′ one needed very few ‘extras’ to be ready for launch]; NASA was looking at a 150′ diameter version, see: https://tinyurl.com/y6nodpfu and https://history.nasa.gov/SP-4308/ch9.htm ). As well:

    If anyone thinks that the Agena (actually, a more lightly-built ship–or tug–based on its propellant capacity and total delta-v capability) is too small for interplanetary voyages, Arthur C. Clarke pointed out an astonishing fact in his later (1968) non-fiction book “The Promise of Space.” The Apollo CSM (Command & Service Modules), by themselves, were sufficient–except for food/water and air requirements–for a round-trip flyby mission to Mars or Venus. (Such Apollo planetary flyby missions–including to Eros, as well as Venus and Mars [*both* planets could be visited in the same flight, given carefully-selected launch dates: https://tinyurl.com/y4lttkbm ; Clarke listed several 1970s Mars, Venus, and one Venus-Mars—for December, 1978—round-trip flyby mission launch dates in Chapter 21 of “The Promise of Space” ] were proposed–and not much more than the CSM was needed.)

    In the most basic mission (“deluxe” versions, involving robotic planetary landers dispatched by the astronauts, were also studied), a frustum-shaped habitation module would have replaced the Lunar Module (LM) inside the four jettison-able SLA–Spacecraft/Lunar Module Adapter–panels, and it would have been affixed to the top of the Saturn 5’s S-IVB third stage. The CSM would have docked to the habitation module ^before^ the S-IVB fired again in the parking orbit to boost the vehicle into its interplanetary trajectory.

    (A very similar mission, using “stock”–or nearly so–Falcon 9 [or Falcon Heavy] launch vehicle and Dragon spacecraft hardware, could be flown today.) Such a Venus flyby mission proposal, which I can’t lay my hooves on at the moment, was actually made as a private venture three or so years ago; a Bigelow Aerospace expandable module, docked to a SpaceX Dragon capsule’s nose, would have served as the habitation module. Such a mission needs to be flown, even if only for psychological reasons (to prove that a crew ^can^ fly tens of millions of miles from Earth and return, and live to tell about it, *without* going crazy because home is just a bluish-white star in the sky). Besides, many scientifically useful observations (VLBI is just one) could be conducted by the crew–before and after the planetary flyby itself–during such a “space station mission that actually goes somewhere,” as such missions’ advocates have referred to them.

  • charlie September 27, 2020, 16:24

    The discussion is quite interesting (although exhaustively in extreme fine detail), but I would like to start out by saying that the entire issue, at least from my standpoint, seems to be falling into two basic categories (and it has always been so).
    First, space will be practically visited for the reason exclusively dealing with money-that is finding resources that are either virtually unavailable here on earth (helium-3) and/or mineral wealth that could be profitably extracted from non-earth bodies at reasonable cost and would have little if any environmental aspects for people of earth. Tourism as a monetary driver is possible but I think you would have to have a fair amount of money to begin with to take advantage of it, undo that; so I would put that aside.

    Second, is the idea that you would have a group of individuals who would be driven to lead their lives exclusively offer earth for the simple pleasure and reason of exploration and/or setting up new cultures (or however you wish to phrase it). I would expect that the numbers of people who actually wish to do this would be not as great as you might think but they would be considered among the ‘true believers’-those who are driven by an impulse to be the first and see what’s out there.

    I was especially struck by the earlier entry into Centauri dreams blog concerning trans-humanism and how people would fit into that. The more I thought about it the more I think that if people do begin to colonize other places that are off world in a few generations they won’t be able to come back to earth simply because they will have achieved such a biological diversity from us that they will not be able to withstand our gravity. Be it Mars or the moon for example or a few other bodies of our solar system they are so different from Earth as to qualify them as habitable but not earth returnable from. I believe we would see such profound biological changes in people and organisms transported to foreign worlds that that would preclude those individuals (barring some sort of genetic tinkering) from being able to come back to earth even if they wanted to. In addition we have the issue that people’s mindset, if they were Martian colonists for example, that would suggest that they might not wish to even have anything to do with us as they have their own perspective now shaped by being planetary colonist. And personally from my perspective if they wish to go their own way we should not do anything to stand in their way of following that course of action. We may have difficulty letting go of our planetary children but it’s almost inevitable they can’t come home even if they wish they could.

    Now onto two other topics which I believe have a great deal of relevance with regards to being game changers for space travel and off world colonization.

    The first deals with the idea behind nuclear fusion. Now I read the link that regarded the criticism behind fusion and how it wasn’t the Nirvana as has been popular told to the public. And I do have to disagree with this individual’s criticisms. It sounded more like an exercise in sour grapes than a thoughtful analysis of the pros and cons behind this technology. He speaks for example about the radiation-induced by neutron activation of the walls of the fusion reactor-how terrible such activation radiation will be such as to preclude replacement of parts and so on. Obviously anybody with the grain of sense knows that you will choose materials that will first off suffer an absorption of a neutron and produce a atom which produces basically a short lived radioisotope. Additionally we have been dealing with processing nuclear fuels for better than 75 years and that involves dealing with mechanisms that have to operate in extremely high radiation fields-and we don’t really have any problem in that area.
    Admittedly there has been a problem regarding disposal of the nuclear waste produced by fission power plants but that is something that is more associated with that technology than fusion. There is an enormous number of various chemical isotopes that is produced in the fission process and that complicates issues necessitating liquid processing of the spent fuel and then having to deal with various number of different half-life isotopes. This is not such an issue as much with fusion. Additionally, in reviewing the literature surrounding neutron activation of the lithium coolant that would be used to remove heat from the fusion reactor system I was pleased to find that several of the byproducts of that neutron activation produced in and of themselves useful nuclear fuels that would be then available for recycling back into the fusion reactor.
    Specifically certain lithium isotopes will absorbed neutrons and subsequently decay into both tritium and the tritium in turn can in and of itself decay into helium-3. Both tritium and helium-3 are themselves excellent fusion fuels, with helium-3 having the added bonus that it itself is a stable isotope of helium and therefore possesses no radioactive hazard in and of itself. Tritium does have a decay of beta particle but because it is a isotope of hydrogen it will probably react with the lithium to produce a lithium hydride (tritydride?) which will be a salt like material which can probably be separated from the molten lithium metal without too much problem.

    He criticizes the Q value which is the energy value that comes out of the plasma versus the energy required to heat the plasma and belittles it from the standpoint that virtually no energy will be left over to send to the electrical grid. I sincerely doubt that will not be a problem and to criticize it from a thermodynamic standpoint when we don’t even know what form the reactor will take (as well as what type of developments will occur in fusion technology) as well as almost a unlimited number of possible energy extraction schemes that can be developed in future years makes his criticism almost laughable. He may be a particle physicist, but I doubt he knows much about heat transfer and all the associated issues that go along with power plant construction. He also makes the totally asinine assertion that if the plasma should suddenly suffer a disruption that this will require an enormous amount of energy from other grid sources at a relatively high price to start the fusion reactor backup. Did he ever stopped to consider that you build two fusion reactors side-by-side and have one start at a different time than another? That way if one fusion reactor crashes then you have the other fusion reactor as a standby which is already in operation to restart the first one. These are the type of arguments that this guy makes as his criticism in the link provided in the article and I think most of them have been thought out and given much more consideration than he could ever possibly apply to the problem. The projected date of the first startup of a working fusion reactor is 2025 and while there may be issues that arise which push the date back right now the ITER (International thermonuclear experimental reactor) being built in France appears to have a pretty solid backing and is expected to produce more energy than it then it uses to heat the fuel.

    Finally lastly the issues concerning transformative technologies really isn’t in my mind an issue concerning technology; it concerns the nature of humanity – how to make the best of what we have in this world such that everyone can have a reasonably comfortable life without undue hardship.
    And for me that comes down to population control which is directly proportional to the resource usage and how we use (or misuse) what we have on this earth.

    Simply put it amounts to this: the more people you have the more resources you use and the more you damage the environment. So what do I suggest we do about this issue? If we look dispassionately at the numbers and ask where do we have the greatest population grows and resource usage we have to look at Africa and Asia. These populations are growing in their out-of-control. I’m not certain of this number but I believe that on average women in Africa have seven children per young female childbearing age appropriate woman. This is excessive in the extreme and in modern times this puts a extreme strain on family, income, resources, and the society at large in those African countries. It is not so much true in all Asian countries but they do have on average a high child to woman ratio even in those societies.

    I would personally suggest that these African and Asian societies enact a policy of a one child per couple standard for all women of childbearing ages. Such an action would result in a almost substantial reduction in the population; my guess would be that it would reduce the population in the generation by 50% (my reasoning is that you create one person for every two people that ultimately pass on). Within a few generations these billions of people will be reduced down to a manageable hundreds of millions. Imagine the amount of resources which will not have to be consumed and ultimately disposed of as waste products if we have fewer people using fewer amounts of resources. While I’m sure there would be political opposition (almost certainly) to such a suggested course of action I believe that these would be merely reactionary reactions which would be grounded in fears of not wanting yellow and black people in the world which is not the modus operandi behind the suggestion but rather stark realization that if you don’t control these burgeoning populations than these burgeoning populations will ultimately suffer their excessive ways. Fewer people = mean fewer resource consumption; it’s as simple as that and we don’t have to look to planetary exporting of our population as a means to control these issues.

    • James Jason Wentworth September 28, 2020, 10:42

      Charlie, I’m not ignoring your other points (nor do I think they’re unimportant), but your comments about gravity–and how its different strengths on other worlds could effectively divide humanity–really grabbed me. This is one of the factors that got Gerard K. O’Neill, Thomas A. Heppenheimer, and others thinking about space colonies, which reproduce Earth-surface conditions–including 1-g gravity–so closely that the differences are negligible, for all practical purposes, and:

      In a space colony, one can have free-fall (effectively, zero-g) and 1-g (generated centrifugally, of course; in large colonies, the associated Coriolis force isn’t noticeable, or even detectable without pretty sensitive instruments) right next to each other, which provides many economic and logistical advantages. Traveling from the Earth’s surface to the surface of another planet requires work–the expenditure of energy–to both climb out of the Earth’s gravitational crater, and later descend (at a reasonable rate of deceleration; an airless world requires rocket braking for the entire descent and landing) into the destination planet’s gravitational crater, (hopefully) coming to a gentle stop at its bottom. A space colony, in contrast, has a negligible gravitational field, making “landing” there merely a rendezvous & docking maneuver, which requires only a trivial expenditure of energy (ditto for leaving it)–yet its rotation gives it Earth-surface gravity, inside.

      People who were born and raised in space colonies could visit the Earth without experiencing any discomfort due to our planet’s conditions (our farther, downward-curving horizons would look different to them, but that’s just a different view; from inside Mercury’s orbit to about three light-days out from the Sun, space colonies could even maintain Earth surface-intensity sunlight, simply by using–or not using–appropriate amounts [areas] of lightweight solar mirror material). Earth dwellers would also find no physically stressful differences in the conditions in space colonies (although the views–especially outside–would be awe-inspiring!) But:

      On worlds with weaker gravity than the Earth, it is possible to have much of this “space colony advantage” (with the added advantage of having local ores, minerals, and–in some cases–useful atmospheric gases). On the Moon, Mars, and Mercury (to give just three examples), it would be feasible to provide 1-g gravity by means of a centrifuge room (or even a whole centrifuge house, although it is by no means certain that 1-g, experienced all 24-hour day long, is essential for maintaining health and bone density–possibly only 8 or 10 hours of 1-g “exposure” per day would be needed, in which case only the bedrooms need be centrifuges). In such a centrifuge room, the floor would be at an angle to the local horizon (with the floor’s outer edge higher than the inner edge), because the planet’s ‘native’ gravity, in combination with an appropriate amount of centrifugal force, would total 1-g, normal to (perpendicular to) the floor. The weaker the world’s gravity, the more centrifugal force would be needed to total 1-g, and the more steeply the floor would tilt upward. One of Fraser Cain’s–of “Universe Today”–YouTube videos (see: https://www.youtube.com/watch?v=ALBMdY9-SZs [also, watch for the deer behind Fraser! :-) ]) shows a settlement on Mercury, which has a centrifuge section to provide, in combination with Mercury’s ‘native’ 0.38 g gravity, 1-g gravity for the residents.

      On very small asteroids and moonlets (such as Deimos), the floor would be almost vertical (almost normal to the horizon), because the centrifugal force would have to provide virtually 100% of the 1-g force. A settlement on such a body would, in fact, look like a classic “wheel” space station, rotating on magnetic bearings within a frame, perhaps built across a crater. Entry and exit would be at the hub, where the building rotated most slowly, with access being via a walkway leading across the stationary frame, from the edge of the crater (although in the ~1/1000-g gravity on Deimos and other, similar-size bodies, one could float down the walkway, being virtually weightless). By providing Earth-surface gravity wherever they settle (and even 0.5 Earth-surface atmospheric pressure air with a 60% nitrogen/40% oxygen mixture [studied for “domed-over” towns on Mars and the Moon; it would make the pressure-supported dome easier to design] doesn’t cause any problems), people born and raised out there could come to Earth–and vice-versa, for Earth dwellers–without any problems.

      • charlie September 28, 2020, 20:17

        Mr. Wentworth !!

        Well I’ll be !! I believe I damn near heard everything now !! Being a high tech future astronaut in the interest of keeping his bones from softening and his muscles from turning to jelly would go and spend his sleeping hours in what amounts to a giant hamster wheel spinning at just such an amount and with a tilted floor to provide a total gravity field of 1G !!

        Ha ha ha ha ha ha ha !! I got to admit that is certainly a unique and interesting solution ! And I don’t have too much doubt that it would certainly work to provide the necessary ‘false gravity field’ necessary to duplicate that of Earth! It just took me by surprise I have to admit. Given the circumstances of each particular case you would certainly need to have such a centrifugal wheel carefully balanced at all times because any type of imbalance such as getting up in the middle of the night to go to the bathroom might be enough to kind of ‘rock the boat if you will’! And you know the old saying that the squeaky wheel gets the grease-I’m sure you would need a lot of grease on such a centrifugal apparatus to keep it from squeaking at night.

        While I am mostly just engaged in gentle kidding on the entire idea and I do think that it has merit I do have to ask and I am wondering about a certain aspect of this entire idea: namely to the point of has anybody considered what is the psychological and physiological impact of the daily shifting between different gravity fields and intensities?
        Essentially you would be engaged in cycling between two extremes in gravity fields and I wonder if that might start the play hell with one’s physiological health. Right now we live in one gravity field and our body is used to that I don’t know what the outcome would be if we transfer between two different gravity fields of highly varying intensity over a period of a 24-hour cycle. That may be something that we need to consider also.

        • Alex Tolley September 29, 2020, 13:14

          …what is the psychological and physiological impact of the daily shifting between different gravity fields and intensities?

          You are aware that Nasa conducted bed rest experiments to simulate some aspects of zero-g. Laying on a bed tilted down towards the head for weeks or months showed some of the problems of living in zero-g and the effects of returning to 1-g. We also advise bed rest for patients who have undergone any stress on the body, such as surgery. When we sleep at night, we experience similar effects, albeit for much shorter periods, yet we seem able to get up every morning none the worse for the experience. In summary, I think your concerns are overblown regarding this. What I would say is staying in a 1-g field whether working or sleeping is better for the crew overall.

          Regarding living in carousels. If the carousel is spun up from a central pivot point, mass imbalances, just as with car wheels are an issue. Designs for early rotating space stations usually depict a mass balancing mechanism – pumping fluids around to counteract any imbalance. However, this can all be eliminated by having the carousel run around tracks like a maglev train. The carousel would still have a central hub and connections to the working areas, but it would not be the point of rotation. For a planet or moon with an atmosphere, a carousel torqued around the hub could offset any mass imbalance using vanes to generate lift to counteract the extra force.

        • James Jason Wentworth September 30, 2020, 12:33

          Well–all residents of space colonies (which would rotate to generate synthetic gravity) would live a life mostly spent spinning, except for when they pushed off down the central corridor to go to work each day (in the colony’s weightless industries). :-) At other times, they would frequently experience variable gravity:

          On the outer walls inside the colony, the residents would live in a 1-g environment, but they would often ride bicycles or electric scooters–or simply walk–up toward, or to, the hub. Unlike on Earth, though, they would weigh less and less as they traveled uphill (which would be a delight, especially to visitors!) Elderly people and disabled people would find upper-elevation homes more comfortable, and:

          The hospital’s burn center and wound care center (I’ve had experience with the latter…) could be located very close to the hub, where the effective gravity was, say, 1/10-g or 1/20-g, so that the problems resulting from lying on one’s dressings (in 1-g Earth-surface gravity) would not exist. (For the very worst cases, say, of cardiac patients, their initial treatment clinic could be ^at^ the spin axis, in 0-g.) I’ve said it jokingly, but it may well come true–some space colonies (or parts of them) may be “Club Med in Space” ACLFs (Adult Congregate Living Facilities). The Moon may also, for less severely-afflicted people, become a new home, where they could live full lives and even have new, productive careers.

    • Mike Serfas September 28, 2020, 20:18

      Proposing population control on some other continent is an easier environmental fix than most, but please note there is nothing extraordinary about Africa’s population ( https://sedac.ciesin.columbia.edu/downloads/maps/gpw-v4/gpw-v4-population-density/gpw-v4-population-density-global-2015.jpg ). Also note Africa produces low CO2 emissions per capita, though even in Africa there is much room for improvement. ( https://www.economist.com/middle-east-and-africa/2018/04/21/africas-big-carbon-emitters-admit-they-have-a-problem )

    • Alex Tolley September 29, 2020, 13:25

      Demanding population control of “other people” is a rather racist idea. It is particularly a problem when the USA in particular has the highest per capita use of energy and as a nation has contributed the most to the current increased CO2 levels in the atmosphere. Doubly problematic is the current antipathy to reducing fossil fuel use. The US should be leading the way to decarbonize the economy rather than dragging its feet and denying there is even an issue.

      • James Jason Wentworth September 30, 2020, 6:08

        But being made largely of carbon myself, I don’t want to commit suicide for Mother Earth, or live in poverty (I enjoyed “Logan’s Run,” but I’d rather that it remained fiction; besides, being significantly older than Michael York and Jenny Agutter were in 1976, I could never evade the Sandmen…). I make such a 1970s reference because this climate change business–and it *is*, among other things, a business–is also a movie I’ve seen before (“In Search Of…” The Coming Ice Age [1978] https://www.youtube.com/watch?v=zSDLRm3jhc8 ):

        I remember how in the 1970s, an ice age was coming, and scientists were urging that we immediately begin spreading carbon black on the polar ice caps. I also remember an oft-repeated statement, which has come back into fashion today (“We don’t have time to debate this”). Fortunately, cooler ^heads^ prevailed, and we avoided the “fun” situation that melting the polar ice caps would have set in motion. Now:

        I strongly support and advocate the founding of space colonies and Solar Power Satellites (SPSs), but not out of “carboniphobia.” It’s a shame to *burn* so much of the Earth’s hydrocarbons, instead of utilizing them as the chemical feedstocks for countless value-added products, and the process of building the space colonies–Kalpana One could be built using terrestrial rather than lunar materials–and SPSs couldn’t help but have a positive effect on space travel and space transportation technology, and:

        Eventually (and “eventually” need not be a great way off), almost entirely rocket-less travel around the Solar System–for people as well as for supplies and goods for sale–could become commonplace and cheap. In addition to the BIS-advocated, three-ship-type transportation infrastructure (Type A, possibly winged, would be strongly-built and have powerful engines, to climb up from Earth to orbit; Type B, lower-powered and designed to land on airless worlds with footpad-equipped legs, would be just strong enough to stand, unfueled, on the Earth’s surface; and Type C, a true spaceship, low-powered and very lightly-built, never landing but meeting Type A and Type B ships [as well as space stations] in orbit around the various major worlds), electric launching tracks set up on airless worlds (Luna, Mercury, other planets’ airless moons, the larger asteroids [Ceres, Pallas, Vesta, etc.]) would facilitate rocket-less travel (except for mid-course corrections and orbit insertion burns [although rotating tethers in orbit could make braking burns unnecessary]) between them. For worlds with atmospheres (Earth, Mars, Venus, etc.), braking at arrival could be done via aerocapture; the push-pull electromagnetic coil launchers could be of modular construction and could be nuclear fission (and perhaps later, fusion) or solar powered, depending on which energy source is cheapest and most abundant on any given world. Solar power seems best for Mercury, the Moon-based launcher could use either, and a Ceres, Pallas, or Vesta launcher might best use nuclear power.

        • Gary Wilson October 1, 2020, 14:23

          Mr. Wentworth, I am not clear on your position with respect t0 climate change. Are you saying it’s all a hoax? So the thousands of climate scientists who are cataloguing the effects and using increasingly sophisticated computer models to predict future damage are all wrong? So the increasing intensity and frequency of hurricanes, tornadoes, droughts, fire (check out the west coast of the US, the increasing fire damage in Western Canada, the increasingly common and severe flood damage all over the world for examples) are all just imaginary? I think you should give this subject more serious thought before you comment on it. Your country and several others (China and Russia for example) are causing most of the damage so please take this seriously.

  • Brett P Bellmore September 27, 2020, 17:23

    I would say the “keystone” technology for space colonization, and especially interstellar travel, is self reproducing technology, the Von Neumann machine.

    The basic problem here is that life in space requires a much higher ratio of infrastructure to population. Especially if you’re going to try to create large, comfortable environments, like O’Neill colonies. Or deploy genuinely astronomical levels of resources to make a single journey, as in interstellar travel.

    So long as the amount of available infrastructure is directly tied to population, through the necessity of human labor, reaching such ratios seems doubtful.

    However, if you can break that link, so that the industrial ecology can expand exponentially at a substantially higher rate than human population for a while, you’d easily reach ratios where O’Neil colonies with low population densities, and even manned interstellar voyages, would become feasible. Indeed, we could feasibly become a Kardashev level 2 society within a century, the amount of material necessary to surround the Sun in a statite array taping its entire energy output is surprisingly low compared to the available material in the asteroid belt.

    So I see self-reproducing technology as the real challenge we need to surmount. It enables everything else on a sufficient scale to get the job done.

    • Alex Tolley September 28, 2020, 0:21

      I agree with your general point about population vs infrastructure. However, I don’t think we need von Neumann replicators for this. The model that I prefer is P K Dick’s autofac. We already have something very close with highly automated factories embedded in an extraction and processing industrial ecosystem. Reduce the sizes of these factories to something like small fabricators” that just need a few extra components to fully replicate themselves as well as a huge range of other artifacts. 3D printers might be another approach. Keeping a vital component under human control, like the microelectronics would be a safety feature just in case the “paperclip apocalypse” did get started. And ecosystem of fabs and robot workers could establish the needed infrastructure you are suggesting, and I think we are not that far off in being capable of getting that started. The lunar surface might be a good place to get started.

    • AlexTru September 28, 2020, 2:26

      Civilization based on Self reproducing Von Neumann machine – it will be not Homo Sapience civilization anymore, something different, machine civilization that does not need Homo Saience at all.

  • Geoffrey Hillend September 28, 2020, 17:11

    Jason James Wentworth, I am familiar with the nuclear light bulb design or gas core design. I read this on Wikipedia about twelve years ago. https://en.wikipedia.org/wiki/Nuclear_thermal_rocket The problem with it is that it is not a very efficient use of fuel. VASIMR can have the same specific impulse, and also a much great specific impulse and a much greater top speed through space, but it does not have the same thrust with a slower acceleration.

    I say NTR’s are obsolete because they use a liquid propellant which are heavy and have a lot of launch weight. The ideal is to have a propellant less space drive, but that might not be achieved until the distant future. Now we have VASIMR which has a much higher specific impulse than any NTR. My prediction is that the NTR’s won’t be used in the future because they are still dangerous and they have a limited lifetime and use because of the radiation and radioactive core and fancy plumbing, difficult assembly and launch which is very expensive. It’s easier to build a reactor for power and use a VASIMR. A nuclear power plant could be launched separately and attached to the interplanetary spacecraft. I don’t see any of the major powers China, Russia and the United States have any plans to build an NTR. Some kind of electromagnetic propulsion is now cutting edge and safer since it only needs solar power to operate and the nuclear powerplant is optional though it would be nice to go to Mars in only 39 days with a nuclear powered VASIMR. https://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magnetoplasma_Rocket

    The LCH and graviton:

    • James Jason Wentworth September 30, 2020, 11:45

      I have followed VASIMR since its inception, and it sounds great, but when will a flyable unit be here? It isn’t even a new idea, as Robert G. Jahn’s 1968 book “Physics of Electric Propulsion” mentions the concept, yet we haven’t yet even had a suborbital SERT 1-type test of a VASIMR engine. Arthur C. Clarke and Maxwell Hunter both strongly advocated the gaseous-core nuclear rocket engine, and:

      (Clarke said that it would do no less than “throw open the whole Solar System to mankind,” although he did characterize the engineering problems of developing it as being “slightly fantastic” [I don’t think the nuclear light bulb concept had yet been thought of; the “old style” gaseous-core fission rocket had a plume of vaporized uranium in the center of the ‘combustion’ chamber, with liquid hydrogen injected around it–retaining the fissionable material required magnetic containment, which would be, well…fantastically challenging :-) at such temperatures].) My personal favorite is NEP (Nuclear Electric Propulsion–using a SNAP-10A type space reactor to power an array of ion engines); the technology is mature (it was proposed for powering a Neptune Orbiter in the 1980s).

  • Robert September 29, 2020, 12:12

    “I will only observe that an abundant and non-polluting source of energy is necessary to the continued existence of technological civilization. ”

    I hesitated to bring this up but feel complelled to. I have been aware of and followed the discovery and development of a new kind of energy source since the year 2000 which would fit your requirements. It is a reaction discovered by chemist Randell Mills where a new state of hydrogen is formed with the electron more tightly bound than usual called the hydrino. It is clean, green and only requires reacting atomic hydrogen atoms with a catalyst. The ash of the reaction is the hydrino atom. The process is documented in over 100 peer reviewed papers in several scientific journals as well as thousands of experiments and has been replicated by other scientists. As an energy source, it holds unlimited potential to replace virtually all forms of energy generation both fixed and mobile.

    The favorable thermodynamics of this reaction permit the splitting water and reacting the hydrogen atoms with a catalyst to release net energy. Reacting all the hydrogen from a gallon of water would be the equivalent energy release of burning about 200 gallons of gasoline. As this process releases more than two orders of magnitude more energy that typical combustion reactions, it would also allow extremely powerful rockets for practical solar system expansion and energy sources anywhere in the outer solar system where there is hydrogen to react.

    This new energy state also has cosmological implications whereby most of the matter in the universe is likely to be in this newly discovered form of hydrogen which is highly stable, inert and non radiative once formed. The unique spectra of hydrino formation is seen in the cosmos and matches that seen in the lab. This is a very strong candidate for Dark Matter.

    I realize that for many complex reasons there is still widespread skepticism in the scientific community and that is sometimes a natural part of coming to grips with a highly disruptive and new concept, but I hope as this technology is beginning to breakout of the lab and into practical applications (test reactors now operate at 250kW thermal) that people would re-evaluate their skepticism, understand the importance of this discovery and begin to incorporate it into long range planning.

    • Ron S. September 29, 2020, 14:30
      • Robert September 30, 2020, 12:49


        The Wikipedia page is biased and highly unbalanced. Confirming evidence or support by corroborating scientists is generally not allowed to be referenced. It is usually immediately taken down. Readers remain uninformed of the true state of the art and the history of the science and technology. The focus is on criticisms which usually either misunderstand Mills’ theory or reject it because it ‘is not quantum mechanics’ or ‘quantum mechanics doesn’t predict this’ or some version of that. Nobel Laureate Phillip Anderson rejected it precisely because he got that the implications are huge and seemed to feel that lower energy state of hydrogen would be too dangerous so they simply couldn’t exist thus he was ‘sure’ it was a fraud. Others are simply wrong like the Rathke paper which has fundamental math errors. Others simply claim Mills’ data *must be* artifactual.

        I’m sorry to have to say that the Wikipedia page is the worst place to go to get up to date and unbiased information on both the science and technology of this discovery. They don’t even reference the company website for completeness. That has a lot of interesting data and the history and progress of the discovery.

        If anyone wants to understand what this is and how it was discovered as well as the history and progress of the technology please check out this book by Brett Holverstott;


        • Ron S. September 30, 2020, 16:34

          Thanks for your reply. In response I’ve renewed my annual donation to the Wikimedia Foundation.

    • Alex Tolley September 29, 2020, 15:15

      Whatever the mechanism, the company seems to consistently fail to produce any products. If the “we will deliver an [X] device in 12-18 months” which never materializes suggests a con, we have a very similar situation with the current US administration to compare with. Promises of cheap, unlimited energy have been made for centuries, and yet here we are with none produced. This seems like another case of “deliver the product you have been promising for so long now or stop making these claims”.

      • Robert September 30, 2020, 14:08


        It’s not a ‘con’. It’s an extremely challenging proposition.

        It is true that Mills has always been an optimist and that has been interpreted as promises to deliver. He expressed optimistic plans to manufacture a product at various stages when he believed a path to commercialization was feasible but always contingent on not running into technical difficulties. The fusion community does this at every funding cycle. The history of development of the hydrino reaction and means to produce it is fascinating. In the early years the process involved electrolytic cells and his experiments and data were assumed to be ‘cold fusion’ and summarily dismissed. Power was in milliwatts. In 2014 he discovered a breakthrough in reaction kinetics allowing a millionfold increase in power levels. Currently, the power levels are at megawatt levels. Mills is doing something entirely new and had to solve a litany of difficult problems in reaction kinetics, catalytic chemistry, material science, reactor design, energy conversion ect. and all with a small team of scientists, engineers and technicians and all with private investments.

        On top of that he is heavily invested in the science side with incredible analytic lab capabilities for hydrino state conformation. Again, with no government funding for any of it.

        Yet so many folks casually throw out the word ‘con’. I think that is grossly unfair and unappreciative as to the nature of the research and development and the massive difficulties overcome.

        Mills rightly gets excited when discussing the potential of this discovery. I’m a physics guy and I’ve been looking at this for twenty years now and I’ve come to these conclusions;

        1) It’s real.
        2) It’s difficult.
        3) It will be transformative if successfully implemented.
        4) It deserves serious attention.

        • Alex Tolley September 30, 2020, 21:46

          Like Ron, I also donated to Wikimedia again this year (although last week, before your comment) ;)

          Abundant free energy, reactionless space drives, they all have the same MO. A claim is made, it fails to any obvious proof in demonstrations, the inventor may claim “new physics”, investors are tapped for the needed breakthrough funds, year in your out. Nothing substantive ever emerges as the years go by.

          Whether delusion or con, the result is the same. Physicists can be wrong, but betting against them is a very long odds proposition.

          • Robert October 1, 2020, 15:09

            Skepticism is fine but I can see that no amount of my explaining that there is real solid scientific evidence will generate enough curiosity to bother to look for yourselves since you both ‘know’ better. I suppose you will both wait until the ‘right’ scientific authority tells you it’s real.

            I’ve seen Wikipedia poison so many minds against this over the years. I mention it, they go there first and it’s done. No curiosity at all to investigate any further. What a shame.

            Wikipedia is the vanguard of an ever growing intellectual laziness where people think instant knowledge and complete understanding is just one click away.

  • Mike Serfas September 29, 2020, 14:48

    One of the great frontiers in technology is *efficiency*. Two stories I’ve seen just in the past month: a six seat private plane that claims after 30 test flights to use only 18 to 25 miles per gallon ( https://www.businessinsider.com/new-private-plane-otto-aviation-celera-500l-2020-9 – use NoScript for best results) and a new battery technology that is asserted to make electric cars affordable ( https://abcnews.go.com/US/teslas-battery-technology-drive-cost-electric-cars-company/story?id=73222745 ). I haven’t confirmed these, but efficiency is something we can rarely call impossible. We have seen what efficiency in solar and wind technologies has done for power generation. There is still a great deal that could be discovered – there is no reason, for example, why a car equipped with ultrafast sensors and computers and complex appendages that do regenerative braking for each motion could not move across farmland and wilderness as efficiently as a road, or a disintegration beam of cleverly tuned phonons couldn’t excavate through solid rock with little hindrance. Altering the efficiency of technologies greatly affects society – whether pollution is emitted, whether roads need to be cleared and maintained through the wilderness.

    A sorry consequence of resource consumption, ecological devastation and overpopulation is that the human race is preadapting itself to survival in other environments. When people expand maritime operations into formerly avoided arctic habitats, even for the villainous purpose of oil exploration, they are starting to prepare for the Great Lakes (! https://www.upi.com/Science_News/2020/09/29/Study-Mars-has-four-bodies-of-water-underneath-surface/7421601399953/ !) of Mars. When people make do with power from local renewable sources produced without exotic elements, they are developing technologies for the Moon and Venus. When people dig bunkers to take shelter from radioactive fallout and nerve gas artillery, they will be learning to live in a way that emulates, if not envies, other planets and moons. Such preadaptations imply countless improvements in efficiency that change the overall viability of extraplanetary adventure. This may not be a sensible way to other planets, yet it may reach them nonetheless.

    • James Jason Wentworth September 30, 2020, 7:25

      As an Alaskan (and by choice, not by birth), I take great exception to oil exploration (and production, I infer) being called “villainous”–ditto for all of the oil producers, from the large corporations down to the family frackers, all around the country. While I enjoyed watching “Little House on the Prairie,” I wouldn’t care to live in such an energy-poor world. (Also, where would SpaceX, Rocket Lab, Astra, and ULA get their RP-1 kerosene rocket fuel from otherwise today, if not from U.S. producers? Most likely from folks we’ve had to kowtow to in the past. While RP-1 can in theory be refined from any grade of petroleum, in practice it can only be made from light sweet crude oil, which we produce here in Alaska–and have plenty more of, in the explored but as-yet-untapped rest of the state [when the petroleum geologists surveyed Alaska, they found it easier to list the relatively few places where oil ^wasn’t^ found here].) Also:

      Living here (where petroleum production is the primary industry), we care about about our land, sea, and wildlife a *lot* more than the outsiders who want to shut down our oil industry and make this place a largely human-free nature preserve (being unaware of technologies such as slant drilling, which enables us to access oil in offshore deposits *without* building offshore oil platforms).

      • Mike Serfas September 30, 2020, 20:34

        I had been thinking of offshore production by Russian and Chinese rigs in the Kara Sea, which had been in the news recently. As you say, Alaskan production has been onshore, so I would think less directly applicable to future deep exploration/exploitation of frozen Martian lakes. Still, I see Shell just filed for offshore drilling in Alaska. The progressive exploitation of hard to reach resources on earth preadapts us to explore other worlds.

        “Villainous” was intended in the mild sense that carbon dioxide release from any source is problematic; but note when you speak of great abundance of untapped oil in Alaska I’m hearing an abundance of carbon dioxide.

  • Geoffrey Hillend September 29, 2020, 15:45

    To be more precise, the type of propulsion which does not have a reaction mass which uses a space warp is the space travel technology of the distant future. A low weight and amount of propellant is technology we have today ready to go right now.

    I don’t think we need a centrifuge for Mars as long as we don’t try to colonize it or raise humans there from birth to adult. The centrifuge is really needed for spacecraft which use conventional liquid propellants because those take a long time to get to Mars like a year. The spacecraft would have to be spun like a centrifuge to create the artificial gravity in order to remove the deteriorating effects of muscle and bone loss from a long term space flight through the zero G environment of empty interplanetary space. The centrifuge would work on Mars, but these make people dizzy. .38 of Earth gravity is good enough to live there for a while with an exercise regimen like on the international space station would be helpful to reduce the long term effects in a lower gravity. environment. There is also not a lot of room in a centrifuge, but maybe a giant one could be make, the whole station could spin and with that one could also make it space in orbit around Mars like Werner Von Braun’s orbiting Earth wheel spinning space station with artificial gravity. We will have to wait for cheaper heavy duty launch vehicles to reduce the cost and time to build such a large space station in orbit. These would make us more space faring.

    • Alex Tolley September 29, 2020, 20:54

      It seems to me that the only reason to have a surface-bound carousel is to place it below ground on low gravity bodies to provide some g forces and protect the crew from radiation. The cost and complexity for other uses seems to make this a non-starter. A carousel in Phobos or Deimos could provide convenient living quarters for a crew to control surface robots for the needed tasks. No need for exposure of the crew on the Martian surface and maintaining a base in a specific location. The Martian moons are easily accessible and large crew rotations are possible from large spacecraft without the need for landers and ascenders. This approach would make sense for controlling robotic explorers on Titan, with a nearby moon as the base for the human crew.

      The most interesting fantasy use I have read is in Schroeder’s “Virga” series. Here the protagonists live in a huge bubble of air in space, and rotating habitats in a rather steam punkish style provide the g forces.

      • James Jason Wentworth September 30, 2020, 9:08

        I mentioned carousels (although not by that name) because they would enable people to live permanently, and make their homes–including bearing and raising children–just about anywhere they want (within reason), in this Solar System and, later, in others (even around gas giant, ice giant, and “inferno” terrestrial-type planets [like Venus] with economically useful resources, space colonies could be built in orbit), and:

        It is also by no means certain that on worlds with significant fractional-g surface gravity, such as Mars and Mercury (both 0.38 of Earth’s), people would need 1-g all 24 hours of each Earth-length day in order to remain healthy; 8 or 10 hours per Earth day might be entirely adequate. We just don’t know, thanks to NASA’s stubborn refusal to try even simple (30′ to 150′ diameter, inflatable [expandable], “orbit-all-in-one-shot”) rotating space stations (which they *were* interested in in the early 1960s [see: https://tinyurl.com/y6nodpfu and https://history.nasa.gov/SP-4308/ch9.htm ], but Apollo’s growing budget soon vacuumed-up the money for such non-Moon-landing projects). In the 1950s, space medicine researchers guessed that centrifugally generating synthetic gravity 1/4 – 1/3 of the Earth’s surface gravity would be sufficient for space station crew shifts of up to six weeks or so, but:

        While that may be correct, 60+ years later their surmise is still the only “data” we have on that, and we have no better information on how long people on Mars and Mercury could safely go without “doses” of 1-g synthetic gravity (including how such intervals might vary according to sex, age, body mass, etc.). As with recoverable and reusable ballistic launch vehicle first stages and payload fairings (which SpaceX pioneered, and which NASA *could* have, but didn’t), it looks like private industry will have to make these findings, too. To this purpose:

        Bigelow Aerospace https://bigelowaerospace.com/ , which has already had ^three^ completely successful expandable space station modules orbited (Genesis I and Genesis II [both orbiting freely], and BEAM [attached to the ISS as an extra “room”]), could produce a small, expandable “doughnut-like” rotating space station, even made up of their existing expandable habitat modules, linked by short access sections between their end hatches. In addition to refining the water tanks/pumps/sensors rotation balance-maintaining system (which was invented back in the 1950s), the various fractional-g vs. time vs. other (as-yet-unknown) factors data would be generated over multiple missions, while the everyday aspects of living and working in a centrifugal synthetic gravitational field (moving ^across^ the plane of rotation, how best to pour liquids, including drinks, etc.) would also be investigated (the 1950s–and even much earlier–space station literature covers these matters, but there’s no substitute for experience). Plus:

        An electrically de-spun section at the hub would facilitate docking by visiting spacecraft, and it could mount astronomical and Earth resources instruments, as well as TV cameras providing deep space and Earth views. (An old belief is that a space station crew, seeing the stars “spinning” outside the rotating station’s windows, would get disoriented and develop nausea. Many have doubted this [I’m one of them, from flying sailplanes, including circling rapidly in thermals], but the only way to find out is to test it; should the pessimists be right, the de-spun TV cameras would provide a dizziness-avoidance solution for seeing outside the station.) Ships sent out to assay–and perhaps also recover resources from–NEAs could also be rotated to generate various levels of onboard synthetic gravity. (In the cases of the very small NEAs, they might be brought back to LEO in once chunk, if they were made mostly of valuable metals; they could be wrapped in quartz cloth and de-orbited by attached solar & aerodynamic drag sails, or by small retro-rockets, to impact in isolated areas [like Alaska or Australia], where ordinary Earth-moving equipment could recover their shattered fragments for processing [except for the option of deorbit sails–he was writing before Echo 1 and its aluminized Mylar material–Willy Ley suggested this type of asteroid mining in the 1950s].)

    • charlie September 30, 2020, 17:37

      “I don’t think we need a centrifuge for Mars as long as we don’t try to colonize it or raise humans there from birth to adult.”
      That’s exactly what everybody’s been talking about, I think, colonization and permanent settlements on distant bodies. In fact that’s what I thought the entire thrust of this blog has been from the very very beginning. Space exploration. The whole point of this entire exercise has been finding a way to sever the ties to earth and start a new on some other celestial bodies weathered in this planetary system or in a far-reaching planetary system around another star.

      We just had a complete segment of the blog devoted to altering the human body such as a way to colonize other worlds which would not be initially friendly to the human body form. And I assume that gravitation would be especially pertinent given the fact that gravity changes the human body as we now see in these early explorations of space. The idea of the carousel to provide earthlike gravity fields seems to be the only way to maintain a connection to our own home planet. I would imagine that somebody who spends many years on Mars for example will undergo a significant deterioration in body strength, bone strength and other cellular changes that we are just beginning to understand.

  • James Jason Wentworth September 30, 2020, 11:12

    But the current administration has never said we will have “cheap and unlimited” energy–rather, it promised “cheap and plentiful energy” by removing barriers to entrepreneurs, and that goal–thanks to big oil companies down to family-run fracking outfits–*has* been realized. We are now a net energy exporter, which we haven’t been for quite a long time (this has enabled us to do things–such as ^finally^ moving the U.S. Embassy in Israel to Jerusalem–and take bold actions [like the new Middle East peace accord] without fear of having our energy supplies cut), and this affects space matters, too:

    As SpaceX CEO Gwynne Shotwell has said (Rocket Lab’s Peter Beck has also mentioned this): since rocket reusability and simpler & cheaper (increasingly computer-controlled) rocket manufacturing methods–these also increase reliability, which also cuts launch costs due to lower launch insurance premiums–are continually lowering launch costs closer to the point at which the main cost is that of the propellant, the per-kilogram (or per-pound, gallon, or liter) costs of the fuel and oxidizer are becoming increasingly important. Now:

    LOX (liquid oxygen), which the vast majority of launch vehicles–U.S. and foreign–use as the oxidizer, is already quite cheap. In “rocket quantities” (as opposed to dewars or small, portable tanks), in 2001 (see: https://www.quora.com/How-much-does-NASA-pay-per-kg-for-hydrogen-and-oxygen-in-rocket-fuel ) NASA paid $0.16 per kg (slightly less than $0.08–8 cents per pound) for the Space Shuttle’s LOX. RP-1, a highly-refined, rocket-grade kerosene (made to the tight Military Specification [Milspec] 25576), cost, as of late 2018, $93.87 per gallon (see: https://www.quora.com/What-is-the-cost-of-RP-1-rocket-grade-kerosene ). Liquid methane (and LNG [Liquid Natural Gas, which is rich in methane])–which several under-development rockets (such as Relativity Space’s Terran 1, ULA’s Vulcan [first stage], and SpaceX’s Super Heavy/Starship) are designed to burn with LOX–cost about $1.35 per kg (the December 29, 2015 spot price), as *this* https://www.thespacereview.com/article/2893/1 article mentioned. Having domestic as well as foreign petroleum sources–and the competition in the field that reduces prices of the light sweet crude oil from which RP-1 kerosene (which will remain in use for a long time to come, as liquid methane has its own list of significant [but by no means “show-stopping”] problems of use and storage) is refined–is all to the good for the launch providers who use kerolox (RP-1/LOX powered) launch vehicles.

    • Alex Tolley September 30, 2020, 22:36

      How pollyannish of you. maybe it is still cool in Alaska, but you may have heard that California is burning, a direct result of reduced rainfall and higher temperatures. (Not raking leaves is not the cause). There were record temperatures in the Russian arctic this summer, and Arctic sea ice has been declining for decades. Oil production in the Gulf of Mexico caused one of the greatest marine and coastal environmental disasters in decades, perhaps only bested by the Exxon Valdez oil spill in Alaska. Oh, and let’s not forget all that contaminated groundwater that gas fracking has caused. Are fossil fuel companies “evil”? They pursue their interests to the point where they mimic the AI apocalypse with the paperclip maximizer analogy. Unlike AIs, they can understand what the impact of their actions is. At some point ignoring these populations and global impacts can be called evil. Are they less detrimental than Satan is to Christians?

      As for RP-1. At the moment, rockets are a tiny consumer of fossil fuel, especially in comparison to the airline industry that is the cause of 12% of global carbon emissions and also has no current substitute for jet fuel. Note how the possible greener future is being abandoned in favor of keeping these companies afloat in the current pandemic. All talk of frequent flyer surcharges dropped to get back to business as usual.
      If SpaceX’ methalox rockets are the future, maybe RP-1 is not a requirement, and methane can be produced both biologically as a renewable fuel, or synthetically. If only there was a currently viable way to redesign aircraft with liquid methane as fuel, perhaps adding wing fuel pods. That would offer a transition path to renewables.

      Actors, whether individual, corporate, or governmental, cannot continue to operate as if the planet is an infinite sink for industrial waste. Cholera outbreaks in cities were common until it was understood why the outbreaks happened. The planet is visibly deteriorating in front of our eyes and yet as long as human needs, however destructive, come first, this will not stop. Choosing technological developments can help ameliorate the damage but it requires a changed mindset to take this path. Sadly this is not happening fast enough.

      Without a viable, home planet, there will be no hope for a starfaring human expansion.

  • Geoffrey Hillend September 30, 2020, 16:38

    The strength of gravity is limited by the mass of the object. Phobos and Deimos have such low gravity that one could jump and run and leap and go into a low orbit which is why the centrifuge is important. Phobos and ‘Deimos are in free fall around Mars.

    I agree with the expensive cost on the ground for rotating space station which is why I said that it could be put in orbit around Mars, but the cost of that would still be expensive. I am thinking in the far future because I want the Werner Von Braun style rotating wheel space station like on the movie Odyssey 2001 which inspired George Lucas to make the Star Destoyers on the movie Star Wars. It is the grand scale of the space station which I like that could be build near the Earth and moved through rockets to the orbit of Mars. How long that trip would take I don’t know but it might be fuel costly for a fast trip. It’s the large size. A spacecraft could be docked there, and there can be a lot of room for crew and science laboratory on board, etc.

  • ljk October 12, 2020, 17:42

    Beyond “Fermi’s Paradox” XI: What is the Transcension Hypothesis

    OCTOBER 1, 2020


    Welcome back to our Fermi Paradox series, where we take a look at possible resolutions to Enrico Fermi’s famous question, “Where Is Everybody?” Today, we examine the possibility that the reason for the Great Silence is that all the aliens have evolved beyond the need to explore!


  • ljk October 22, 2020, 12:41

    Could fusion propulsion get us to Titan in just two years?


    Fission propulsion in the form of Orion could have gotten us there and farther even sooner. And we have fission power.