The Interstellar Imperative

by Paul Gilster on December 5, 2014

What trajectory will our civilization follow as we move beyond our first tentative steps into space? Nick Nielsen returns to Centauri Dreams with thoughts on multi-generational projects and their roots in the fundamental worldview of their time. As the inspiring monuments of the European Middle Ages attest, a civilizational imperative can express itself through the grandest of symbols. Perhaps our culture is building toward travel to the stars as the greatest expression of its own values and capabilities. Is the starship the ultimate monument of a technological civilization? In addition to continuing work in his blogs Grand Strategy: The View from Oregon and Grand Strategy Annex, Nielsen heads Project Astrolabe for Icarus Interstellar, described within the essay.

by J. N. Nielsen


If interstellar flight proves to be possible, it will be possible only in the context of what Heath Rezabek has called an Interstellar Earth: civilization developed on Earth to the degree that it is capable of launching an interstellar initiative. This is Earth, our familiar home, transformed into Earth, sub specie universalis, beginning to integrate its indigenous, terrestrial civilization into its cosmological context.

Already life on Earth is thoroughly integral with its cosmological context, in so far as astrobiology has demonstrated to us that the origins and processes of life on Earth cannot be fully understood in isolation from the Earth’s cosmic situation. The orbit, tilt, and wobble of the Earth as it circles the sun (Milankovitch cycles), the other bodies of the solar system that gravitationally interact with (and sometimes collide with) Earth, the life cycle of the sun and its changing energy output (faint young sun problem), the position of our solar system with the galactic habitable zone (GHZ), and even the solar system bobbing up and down through the galactic plane, subjecting Earth to a greater likelihood of collisions every 62 million years or so (galactic drift) – all have contributed to shaping the unique, contingent history of terrestrial life.

What other distant unknowns shape the conditions of life here on Earth? We cannot yet say, but there may be strong bounds on the earliest development of complex life in the universe, other than the age of the universe itself. For example, recent research on gamma ray bursts suggests that the universe may be periodically sterilized of complex life, as argued in the paper On the role of GRBs on life extinction in the Universe by Tsvi Piran and Raul Jimenez (and cf. my comments on this), which was also the occasion of an article in The Economist, Bolts from the blue. Intelligent life throughout the universe may not be much older than intelligent life on Earth. This argument has been made many times prior to the recent work on gamma ray bursts, and as many times confuted. A full answer must await our exploration of the universe, but we can begin by narrowing the temporal boundaries of possible intelligence and civilization.


Image: Lodovico Cardi, also known as Cigoli, drawing of Brunelleschi’s Santa Maria del Fiore, 1613.

From the perspective of natural history, there is no reason that cognitively modern human-level intelligence might not have arisen on Earth a million years earlier than it did, or even ten million years earlier than it did. On the other hand, from the same perspective there is no reason that such intelligence might not have emerged for another million years, or even another ten million years, from now. Once biology becomes sufficiently complex, and brains supervening upon a limbic system become sufficiently complex, the particular time in history at which peer intelligence emerges is indifferent on scientific time scales, though from a human perspective a million years or ten million years makes an enormous difference. [1]

Once intelligence arose, again, it is arguably indifferent in terms of natural history when civilization emerges from intelligence; but for purely contingent factors, civilization might have arisen fifty thousand years earlier or fifty thousand years later. Hominids in one form or another have been walking the Earth for about five million years (even if cognitive modernity only dates to about 60 or 70 thousand years ago), so we know that hominids are compatible with stagnation measured on geological time scales. Nevertheless, the unique, contingent history of terrestrial life eventually did, in turn, give rise to the unique, contingent history of terrestrial civilization, the product of Earth-originating intelligence.

The sheer contingency of the world makes no concessions to the human mind or the needs of the human heart. Blaise Pascal was haunted by this contingency, which seems to annihilate the human sense of time: “When I consider the short duration of my life, swallowed up in the eternity before and after, the little space which I fill and even can see, engulfed in the infinite immensity of spaces of which I am ignorant and which know me not, I am frightened and am astonished at being here rather than there; for there is no reason why here rather than there, why now rather than then.” [2]

Given the inexorable role of contingency in the origins of Earth-originating intelligence and civilization, we might observe once again that, from the perspective of the natural history of civilization, it makes little difference whether the extraterrestrialization of humanity as a spacefaring species occurs at our present stage of development, or ten thousand years from now, or a hundred thousand years from now. [3] When civilization eventually does, however, follow the example of the life that preceded it, and integrates itself into the cosmological context from which it descended, it will be subject to a whole new order of contingencies and selection pressures that will shape spacefaring civilization on an order of magnitude beyond terrestrial civilization.

The transition to spacefaring civilization is no more inevitable than the emergence of intelligence capable of producing civilization, or indeed the emergence of life itself. If it should come to pass that terrestrial civilization transcends its terrestrial origins, it will be because that civilization seizes upon an imperative informing the entire trajectory of civilization that is integral with a vision of life in the cosmos – an astrobiological vision, as it were. We cannot know the precise form such a civilizational imperative might take. In an earlier Centauri Dreams post, I discussed cosmic loneliness as a motivation to reach out to the stars. This suggests a Weltanschauung of human longing and an awareness of ourselves as being isolated in the cosmos. But if we were to receive a SETI signal next week revealing to us a galactic civilization, our motivation to reach out to the stars may well take on a different form having nothing to do with our cosmic isolation.

At the first 100YSS symposium in 2011, I spoke on “The Moral Imperative of Human Spaceflight.” I realize now I might have made a distinction between moral imperatives and civilizational imperatives: a moral imperative might or might not be recognized by a civilization, and a civilizational imperative might be moral, amoral, or immoral. What are the imperatives of a civilization? By what great projects does a civilization stand or fall, and leave its legacy? With what trajectory of history does a civilization identify itself and, through its agency, become an integral part of this history? And, specifically in regard to the extraterrestrialization of humanity and a spacefaring civilization, what kind of a civilization would not only recognize this imperative, but would center itself on and integrate itself with an interstellar imperative?

Also at the first 100YSS symposium in 2011 there was repeated discussion of multi-generational projects and the comparison of interstellar flight to the building of cathedrals. [4] In this analogy, it should be noted that cathedrals were among the chief multi-generational projects and are counted as one of the central symbols of the European middle ages, a central period of agrarian-ecclesiastical civilization. For the analogy to be accurate, the building of starships would need to be among the central symbols of an age of interstellar flight, taking place in a central period of mature industrial-technological civilization capable of producing starships.

To take a particular example, the Duomo of Florence was begun in 1296 and completed structurally in 1436—after 140 years of building. When the structure was started, there was no known way to build the planned dome. (To construct the dome in the conventional manner would have required more timber than was available at that time.) The project went forward nevertheless. This would be roughly equivalent to building the shell of a starship and holding a competition for building the propulsion system 122 years after the project started. The dome itself required 16 years to construct according to Brunelleschi’s innovative double-shelled design of interlocking brickwork, which did not require scaffolding, the design being able to hold up its own weight as it progressed. [5]

It is astonishing that our ancestors, whose lives were so much shorter than ours, were able to undertake such a grand project with confidence, but this was possible given the civilizational context of the undertaking. The central imperative for agrarian-ecclesiastical civilization was to preserve unchanged a social order believed to reflect on Earth the eternal order of the cosmos, and, to this end, to erect monuments symbolic of this eternal order and to suppress any revolutionary change that would threaten this order. (A presumptively eternal order vulnerable to temporal mutability betrays its mundane origin.) And yet, in its maturity, agrarian-ecclesiastical civilization was shaken by a series of transformative revolutions—scientific, political, and industrial—that utterly swept aside the order agrarian-ecclesiastical civilization sought to preserve at any cost. [6]

The central imperative of industrial-technological civilization is the propagation of the STEM cycle, the feedback loop of science producing technologies engineered into industries that produce better instruments for science, which then in turn further scientific discovery (which, almost as an afterthought, produces economic growth and rising standards of living). [7] One cannot help but wonder if this central imperative of industrial-technological civilization will ultimately go the way agrarian-ecclesiastical civilization, fostering the very conditions it seeks to hold in abeyance. In any case, it is likely that this imperative of industrial-technological civilization is even less understood than the elites of agrarian-ecclesiastical civilization understood the imperative to suppress change in order to retain unchanged its relation to the eternal.

It may yet come about that the building of an interstellar civilization becomes a central multi-generational project of industrial-technological civilization, as it comes into its full maturity, as a project of this magnitude and ambition would be required in order to sustain the STEM cycle over long-term historical time (what Fernand Braudel called la longue durée). We must recall that industrial-technological civilization is very young—only about two hundred years old—so that it is still far short of maturity, and the greater part of its development is still to come. Agrarian-ecclesiastical civilization was in no position to raise majestic gothic cathedrals for its first several hundred years of existence. Indeed, the early middle ages, a time of great instability, are notable for their lack of surviving architectural monuments. The Florence Duomo was not started until this civilization was several hundred years old, having attained a kind of maturity.

The STEM cycle draws its inspiration from the great scientific, technical, and engineering challenges of industrial-technological civilization. A short list of the great engineering problems of our time might include hypersonic flight, nuclear fusion, and machine consciousness. [8] The recent crash of Virgin Galactic’s SpaceShipTwo demonstrates the ongoing difficulty of mastering hypersonic atmospheric flight. We can say that we have mastered supersonic atmospheric flights, as military jets fly every day and only rarely crash, and we can dependably reach escape velocity with chemical rockets, but building a true spacecraft (both HOTOL and SSTO) requires mastering hypersonic atmospheric flight, as well as making the transition to exoatmospheric flight) and this continues to be a demanding engineering challenge.

Similarly, nuclear fusion power generation has proved to be a more difficult challenge than initially anticipated. I recently wrote in One Hundred Years of Fusion that by the time we have mastered nuclear fusion as a power source, we will have been working on fusion for a hundred years at least, making fusion power perhaps the first truly multi-generational engineering challenge of industrial-technological civilization—our very own Florentine Duomo, as it were.

With machine consciousness, if we are honest we will admit that we do not even know where to begin. AI is the more tractable problem, and the challenge that attracts research interest and investment dollars, and increasingly sophisticated AI is likely to be an integral feature of industrial-technological civilization, regardless of our ability to produce artificial consciousness.

Once these demanding engineering problems are resolved, industrial-technological civilization will need to look further afield in its maturity for multi-generational projects that can continue to stimulate the STEM cycle and thus maintain that civilization in a vital, vigorous, and robust form. A starship would be the ultimate scientific instrument produced by technological civilization, constituting both a demanding engineering challenge to build and offering the possibility of greatly expanding the scope of scientific knowledge by studying up close the stars and worlds of our universe, as well as any life and civilization these worlds may comprise. This next great challenge of our civilization, being a challenge so demanding and ambitious that it could come to be the central motif of industrial-technological civilization in its maturity, could be called the interstellar imperative, and we ourselves may be the Axial Age of industrial-technological civilization that first brings this vision into focus.

Even if the closest stars prove to be within human reach in the foreseeable future, the universe is very large, and there will be always further goals for our ambition, as we seek to explore the Milky Way, to reach other galaxies, and to explore our own Laniakea supercluster. This would constitute a civilizational imperative that could not be soon exhausted, and the civilization that sets itself this imperative as its central organizing principle would not lack for inspiration. It is the task of Project Astrolabe at Icarus Interstellar to study just these large-scale concerns of civilization, and we invite interested researchers to join us in this undertaking.


Image: Frau im Mond, Fritz Lang, 1929.

Jacob Shively, Heath Rezabek, and Michel Lamontagne read an earlier version of this essay and their comments helped me to improve it.


[1] I have specified intelligence emergent from a brain that supervenes upon a limbic system because in this context I am concerned with peer intelligence. This is not to deny that other forms of intelligence and consciousness are possible; not only are they possible, they are almost certainly exemplified by other species with whom we share our planet, but whatever intelligence or consciousness they possess is recognizable as such to us only with difficulty. Our immediate rapport with other mammals is sign of our shared brain architecture.

[2] No. 205 in the Brunschvicg ed., and Pascal again: “I see those frightful spaces of the universe which surround me, and I find myself tied to one corner of this vast expanse, without knowing why I am put in this place rather than in another, nor why the short time which is given me to live is assigned to me at this point rather than at another of the whole eternity which was before me or which shall come after me. I see nothing but infinites on all sides, which surround me as an atom and as a shadow which endures only for an instant and returns no more.” (No. 194)

[3] Or our extraterrestrialization might have happened much earlier in human civilization, as Carl Sagan imagined in his Cosmos: “What if the scientific tradition of the ancient Ionian Greeks had survived and flourished? …what if that light that dawned in the eastern Mediterranean 2,500 years ago had not flickered out? … What if science and the experimental method and the dignity of crafts and mechanical arts had been vigorously pursued 2,000 years before the Industrial Revolution? If the Ionian spirit had won, I think we—a different ‘we,’ of course—might by now be venturing to the stars. Our first survey ships to Alpha Centauri and Barnard’s Star, Sirius and Tau Ceti would have returned long ago. Great fleets of interstellar transports would be under construction in Earth orbit—unmanned survey ships, liners for immigrants, immense trading ships to plow the seas of space.” (Cosmos, Chapter VIII, “Travels in Space and Time”)

[4] While there are few examples of truly difficult engineering problems as we understand them today (i.e., in scientific terms) prior to the advent of industrial-technological civilization, because, prior to this, technical problems were only rarely studied with a pragmatic eye to their engineering solution, agrarian-ecclesiastical civilization had its multi-generational intellectual challenges parallel to the multi-generational scientific challenges of industrial-technological civilization — these are all the familiar problems of theological minutiae, such as the nature of grace, the proper way to salvation, and subtle distinctions within eschatology. And all of these problems are essentially insoluble for different reasons than a particularly difficult scientific problem may appear intractable. Scientific problems, unlike the intractable theological conflicts intrinsic to agrarian-ecclesiastical civilization, can be resolved by empirical research. This is one qualitative difference between these two forms of civilization. Moreover, it is usually the case that the resolution of a difficult scientific problem opens up new horizons of research and sets new (soluble) problems before us. The point here is that the monumental architecture of agrarian-ecclesiastical civilization that remains as its legacy (like the Duomo of Florence, used as an illustration here) was essentially epiphenomenal to the central project of that civilization.

[5] An entertaining account of the building of the dome of the Florence Duomo is to be found in the book The Feud That Sparked the Renaissance: How Brunelleschi and Ghiberti Changed the Art World by Paul Robert Walker.

[6] On the agrarian-ecclesiastical imperative: It is at least possible that the order and stability cultivated by agrarian-ecclesiastical civilization was a necessary condition for the gradual accumulation of knowledge and technology that would ultimately tip the balance of civilization in a new direction.

[7] While the use of the phrase “STEM cycle” is my own coinage (you can follow the links I have provided to read my expositions of it), the idea of our civilization involving an escalating feedback loop is sufficiently familiar to be the source of divergent opinion. For a very different point of view, Nassim Nicholas Taleb argues strongly (though, I would say, misguidedly) against the STEM cycle in his Antifragile: Things That Gain from Disorder (cf. especially Chap. 13, “Lecturing Birds on How to Fly,” in the section, “THE SOVIET-HARVARD DEPARTMENT OF ORNITHOLOGY”); needless to say, he does not use the phrase “STEM cycle.”

[8] This list of challenging technologies should not be taken to be exhaustive. I might also have cited high temperature superconductors, low energy nuclear reactions, regenerative medicine, quantum computing, or any number of other difficult technologies. Moreover, many of these technologies are mutually implicated. The development of high temperature superconductors would transform every aspect of the STEM cycle, as producing strong magnetic fields would become much less expensive and therefore much more widely available. Inexpensive superconducting electromagnets would immediately affect all technologies employing magnetic fields, so that particle accelerators and magnetic confinement fusion would directly benefit, among many other enterprises.


Alex Tolley December 5, 2014 at 13:04

The building of cathedrals was more about empowering the church’s political hold on the population than achieving some aspiration of communing with God. By analogy, building a starship would be about the industrial complex maintaining its business rather than reaching the stars or communication with ETI, very much as missile building was/is less about defense than business.

A starship in this context could be anything from small interstellar probes for scientific exploration to full fledged gigantic worldships carrying human crews/colonists. I would hope the former can be build with advanced technologies well within a lifetime, even if the results are multi-generational. The latter might be worth building sometime, but I suspect will be irrelevant in our civilizational trajectory. I suspect that more likely star travelers will be machines with conscious/unconscious AI or uploaded human minds – allowing much simpler/cheaper travel options and far more flexible destination options. That vision is perhaps more in the Olaf Stapledon tradition (e.g. “Star Maker”) than that of golden age SF.

spaceman December 5, 2014 at 20:32

In the above article it was mentioned that the human race might one day travel beyond the Milky Way. I remember reading somewhere that because the expansion of the universe is accelerating under the influence of dark energy, there will be a limit as to how many other galaxies we can reach before they are accelerated beyond our cosmic horizon. Does any know what this distance is based on our current knowledge of dark energy? Are we limited to the Local Group even if we can eventually travel close to c?

Eniac December 5, 2014 at 22:36

Note that the work on the “lethality” of GRBs is based on the definition of a temporary depletion of the ozone layer as the “lethal event”. I think there is a huge gulf between temporary ozone layer depletion and “sterilization”, a distinction that is unfortunately lost to those reading the popular accounts. We have here another instance of escalating a speculative, potential danger into certain doom by layering exaggeration upon exaggeration.

ljk December 6, 2014 at 0:47

If we want to inspire this generation and the next to expand into space, let us inspire and educate them via their favorite media:

Brett Bellmore December 6, 2014 at 8:47

“civilization developed on Earth to the degree that it is capable of launching an interstellar initiative. ”

I think it’s fairly clear that we are not going to be launching interstellar missions of any significant extent while civilization is still limited to Earth. Solar system civilization will do it, and Earth might very well have little involvement.

Tom Mazanec December 6, 2014 at 9:04

For a contrarian view of our Industrial Civilization’s future, see

Al Jackson December 6, 2014 at 10:08

The timescale for the accelerating universe is hugely longer than relativistic flight to Andromeda , a 1 g ship has only to accelerate for 60 years to make to about 2, 500,000 light years. While 5 million years elapse for those who stayed on earth.
Five million years is a piffle of a time under one scenario that takes about 30 billion years before the Big Rip. That’s a totally uncertain number because it is parameter dependent. In fact the Big Rip makes the news because it’s tabloid worthy, it is not at all clear just how to definitively model the future of the accelerating universe , no one know what the heck dark energy really is.
No worry about attaining Tau Zero!

Tom December 6, 2014 at 11:36

I recently was helping my granddaughter with her social studies homework.
How governments rise, how source documents become national laws, even international political tension; however, the course was quite sterile with matters of technical capabilities established for their times.
Metal working, forges and the cultural infrastructure does impact an age.
Many critiques on our contemporary ‘space age’ seem leveled at manned flight or budgets for exploration.
Yet space travel seeded fields as diverse as fabric manufacture to gps systems.
Spaceflight was realized as an application of guided missiles marrying telecommunications. And I’ve written on previous occasions, it revolutionized how humans see the Universe.

What will make the human race push towards the stars?
Nothing. We are naturally inclined to seek out whatever holds our interest.
Will we venture any significant distance before the end of the 21st Century?
I suspect we’ll have already landed on Mars with human presence well before NASA’s centennial.

Humankind can be a space faring species; but we got a lot of work ahead of us. I don’t think archetypes or gestalts are causes, rather they are attempts to stretch an existential dialogue on human events.

Nick Nielsen December 6, 2014 at 20:36

@ Tom Mazanec

I am aware of the enormous amount of apocalypticism present in contemporary society and given exposition on the internet, and I have even read the archdruid report on occasion. It might even be said that apocalypticism is one of the dominant ideologies of our time. I think that there is an explanation for this in the fact that industrial-technological civilization simultaneously escalates the hopes and expectations of the individual while transforming that same individual into an anonymous cog in a gigantic machine. In this context, apocalypticism represents an escape from a disciplined society even while retaining the sense of individualism we have gained. (I wrote about this some time ago in Fear of the Future and Humanity’s Responsibility for Itself.)

I sometimes develop my views in conscious contradistinction to this prevailing apocalypticism, not least because a countervailing point of view needs to be available. But that is never my primary motivation. I believe that there is a rational basis for a hopeful and optimistic future for humanity and our civilization, and that this alternative view is in danger of being swamped by contemporary apocalypticism. (I might also mention that this was also a motivation for Gerard K. O’Neill.) The interstellar imperative is central to my vision of a future worth having, a future that stimulates individuals to greater exertion rather than leaving them disengaged and apathetic.

Nick Nielsen December 6, 2014 at 21:10

@ Eniac

There certainly is “a huge gulf between temporary ozone layer depletion and ‘sterilization’,” but I am assuming in the long history of our universe that GRBs of various degrees of intensity and proximity have occurred. Some researchers have suggested (although the evidence is far from definitive) that GRBs have already shaped life on Earth, occurring when life was still at a level of simplicity that was not so vulnerable to the effects of GRBs on the rudimentary biosphere.

Depending on the relatively complexity of life, the robustness of the biosphere, the proximity of the GRB, and the strength of the GRB, the consequences might range from nil to catastrophic. No one, single GRB is going to sterilize the known universe, and it may not even sterilize a single galaxy or a single planet, but the possibility of a very powerful GRB sterilizing a planet under certain conditions is something we must consider.

When we attempt to place our biosphere, our species, and our civilization in a cosmological context we are faced with many unknowns, and our task at the present time is to try to at least define some parameters of our condition even while we do not have an exhaustive knowledge of the cosmological conditions that are the basis of our existence.

Nick Nielsen December 6, 2014 at 22:05

@ Tom

In the dialectic of archetypes and implementations, it really doesn’t matter which is the chicken and which is the egg. If we trace the development backward in the scientific spirit, we will find that the two cannot be clearly distinguished the further we go back in time. Each is a function of the other.

RE: “What will make the human race push towards the stars? Nothing. We are naturally inclined to seek out whatever holds our interest.” And our interests are manifold; this is a function of our diversity. Temperamental diversity is an intellectual expression of that individual variation that is among the drivers of natural selection. Some among us will have an intrinsic interest in exploration and adventure beyond Earth. But not all.

From historical examples, we all know that societal majorities often act to prevent social minorities from acting upon their intrinsic interests that deviate from the social majority (which latter defines a civilizational imperative). This is one of the discontents of civilization of which Freud wrote. This is why I have written in many places that we must take steps in order to ensure the widest possible range of experimentation in the structure of society. Today this is a problem, as vested interests (and not merely financial vested interests) almost always prefer uniformity, stability, predictability, and conformity to the status quo.

Daniel Högberg December 7, 2014 at 5:42

Start with the moon instead of Mars. By the time the basic infrastructure/society/industries is up to speed on the moon, building and sending satellites (mining helium3 and r&d in countless other scientific and industrial areas) to earth orbit for almost no cost at all, earth will have finished at least one space elevator (or a single stage to orbit vehicle) which will further speed up the rate at which humans will start moving away from earth and truly discover our solarsystem. The economy will grow at an unprecedented rate..

Michael Spencer December 7, 2014 at 7:57

Brett writes ” Solar system civilization will do it, and Earth might very well have little involvement”.

Indeed. Interstellar travel as viewed from the 21st century appears appallingly expensive, as Paul and others have pointed out here over and over.

And we are very far from inhabiting our solar system. Current accolades over another damn capsule demonstrate that we haven’t even figured out how to think about pioneering the wide open spaces.

Al Jackson December 8, 2014 at 7:12

@Footnote [3]
“Or our extraterrestrialization might have happened much earlier in human civilization…”
I beg to differ that enlightenment of Greece ‘flickered out’ , on entering the ‘dark ages’ civilization did not slip back into the stone age. Science, art and the craft of artisans still advanced , at a snails pace until the Renaissance.
It’s still not clear to me that attainment of early enlightment would have radically changed the social-economic-political landscape that much.
The rational use of technology still eludes humankind, and we might still not survive the misuse of technology.
Seems right now the only response of climate change will be adaptation. When sea level rise impacts the world’s economy there is either a convergence of world cooperation or total chaos. I am going to suppose that there will be , eventually, a unified world response but not before civilization is rolling around the floor with a bloody nose.
A social-eonomic-political world unification has no historical match, thus humankind’s future is unpredictable.
I think Earth’s civilization will project an instrumentality to the stars but on a time scale that has a totally unknown horizon of predictability.

ljk December 8, 2014 at 10:29

Speaking of interstellar imperatives, while I have (or had) no real desire to see the upcoming miniseries called Ascension as it looks like a standard melodrama that just happens to be set in space, I was pleased to see the following:

The spaceship is actually a multigenerational starship, or Worldship, and it is powered with Orion-style propulsion, not a warp drive or any cosmic wormhole jumping. That alone is refreshing for a television science fiction series (or SF film for that matter).

Someone at least gave some thought to the layout of the Worldship, as seen here:

You can all debate whether it is feasible or not. What I hope is that it gets Joe and Jane Sixpack thinking about such concepts and supporting any real plans by our fledgling interstellar groups.

ljk December 8, 2014 at 10:34

Published on Aug 19, 2014

Animated short film about the interstellar colony with Bussard ramjet.

Story, design and animation – Maksim Lushchyk

Habitat design – Steve Summerford

Sound – Daniil Koronkevich

(c) Condenser Studio for Polytechnical Museum

Alex Tolley December 8, 2014 at 12:56

Lovely mix of retro (O’Neill era interiors), contemporary (spacesuits) and future tech (Skylon). I like the approach for the rotating habs, although I’m not sure about the module designs. All in all, a nice animation.

Brett Bellmore December 8, 2014 at 15:16

Cute animation, but, still: Every effort to design a Bussard ramjet has ended up designing a brake, hasn’t it? Tau Zero is a story nobody will forget after reading, but the thing just doesn’t seem to work.

Mind, there are places in the galaxy where you could probably make one work. Nebula close to young, hot stars, where the interstellar media is both dense and ionized. But we don’t live there. (That’s why we’re living, actually…)

ljk December 15, 2014 at 18:17

How Data From The Kepler Space Telescope Is Changing The Drake Equation
Many of the parameters in the Drake equation could only be guessed at…until now

Back in 1961, a small group of scientists met at the National Radio Astronomy Observatory in Greenbank, West Virginia, to discuss the search for extraterrestrial intelligence for the first time. The group was an eclectic mix including the astronomer Carl Sagan, the neuroscientist John Lilly who worked on Dolphin communication and the radio astronomer Frank Drake who organised the meeting.

Before the meeting, Drake wrote down all the factors that determine the likelihood of extraterrestrial intelligence elsewhere in the universe. These include the fraction of stars with planets, the average number of these planets that can potentially support life, the fraction of these that actually develop life and so on. He realised that multiplying these numbers together produced an important figure: the number of detectable civilisations in the galaxy.

Since then, Drake’s equation has become a famous rallying point in the search for extraterrestrial intelligence. But it has never been an accurate one. Drake was well aware at the time that many of the parameters in his equation were extremely hard to quantify and that has led some critics to say that the equation is little better than a guess or even of no use at all.

But in recent years, astronomers have begun to gather data that has a significant impact on some of the parameters in the Drake equation. In particular, NASA launched a space telescope called Kepler in 2009 that was designed to look for exoplanets orbiting other stars and produce an estimate of the proportion that have planets.

During its mission, Kepler has identified some 2000 exoplanet candidates, a huge increase on the 400 or so that were known before it was launched. What’s more, before Kepler, the known exoplanets were mainly Jupiter-sized, making it hard to estimate the number of Earth-like planets.

By contrast, most of the planets discovered by Kepler are Neptune-sized or smaller. Indeed, the Kepler data has led to a dramatic change in astronomers’ understanding of the likely number of Earth-like planets around other stars.

So an interesting question is how the new data changes the Drake equation. Today, we get an answer thanks to the work of Amri Wandel at The Hebrew University of Jerusalem in Israel, who has made a number of inferences based on the new data. “The recent results of the Kepler mission significantly reduce the uncertainty in the astronomical parameters of the Drake equation,” he says.

First, some background about the equation itself, which comes in a number of forms. The biotic Drake equation, which describes the number of planets with life, takes the following form:

Nb = R*.Fs. Fp. Fe. Nhz. Fb. Lb

Where Nb is the number of biotic planets in the Milky Way, R*is the rate of star birth, Fs is the fraction of stars suitable for the evolution of life, Fp is the fraction of stars that have planets, Fe the fraction of Earth-sized planets, Nhz is the number of such planets within the habitable zone , Fb is the probability of evolution of life and Lb is how long biotic life survives on average.

Some of these numbers are straightforward to estimate. For example, the rate of star formation, R*, is well known. In the Milky Way, it is about 10 stars per year. However, the fraction of stars suitable for the evolution of life, Fs, is less clear. Many astronomers assume that life is limited to stars similar to the Sun, in which case, Fs is about 0.1.

This is clearly a conservative estimate given that many stars seem to have habitable zones. Wandel points out that if red giants are included in this number then Fs is probably closer to 1.

The Kepler mission has significantly improved astronomers understanding of the next term Fp. The data indicates that most stars have planetary systems so Fp is probably about 1 as well.

The Kepler data also suggests that between 7 and 15 per cent of Sun-like stars have an Earth -sized planet in the habitable zone so Fe.Nhz is about 0.1. However, Wandel points out that if biotic life is not restricted to Earth-like planets but includes places like Jupiter’s moon Europa, then Fe.Nhz could be much closer to 1.

All that allows Wandel to extrapolate about the density of planets with life in the Milky Way. His conclusion, assuming that life often evolves on habitable planets, is that life-bearing planets could be remarkably close. “The extended analyses, updated by the Kepler results, suggests that our nearest biotic neighbor exoplanets may be as close as 10 light years,” he says.

And even if life is less likely, the chances are good that biotic planets like close by. “Even with a less optimistic estimate of the biotic probability, for example that biotic life evolves on one in a thousand suitable planets, our biotic neighbor planets may be expected within 100 light years,” he says.

But the existence of life is very different from the existence of an intelligent civilisation. And on this point, Wandel is less optimistic. Little if anything can be reliably said about the likelihood of life evolving to a civilised stage.

Nevertheless, Wandel says the new data suggests that we are unlikely to have any close neighbours of this type. “The distance to the nearest putative civilizations, even for optimistic values of the Drake parameters, is estimated to be thousands of light years,” he says.

That’s an interesting update on an equation that has fascinated people for decades and is likely to continue to do so. If life-bearing planets really do exist within 10 light years of here, the chances of seeing biomarkers, such as methane or oxygen, in their atmospheres are relatively good (provided, of course, that life there is anything like life here).

All that contributes to the growing sense among astrobiologists and others that humanity is close to detecting other lifeforms for the first time, perhaps even within the lifetimes of people who are alive today.

That’s a goal that is surely worth pursuing aggressively given that such a discovery would be one of the greatest in the history and future of science.

Ref: : On The Abundance Of Extraterrestrial Life After The Kepler Mission

ljk December 15, 2014 at 18:19

What Alien Civilizations We’ve Never Met Can Teach Us About Saving the Earth


December 9, 2014 // 07:00 AM EST

The closest intelligent life may be thousands of light-years away, but aliens may still be able to help us solve some of humanity’s greatest challenges. For instance, how to transition to sustainable, low-carbon economies before our biosphere falls to pieces.

Astronomers Adam Frank and Woodruff Sullivan believe that, when it comes to 21st century crises—global warming,ocean acidification,the sixth mass extinction—there’s solace to be found in the cosmos. See, all of this has (probably) happened before. That is, we’re probably not the first intelligent species to find ourselves at a crossroads between sustainability and self-annihilation.

Now, this may sound like science-fictional speculation. But it’s actually a conclusion arrived at by math, and it may herald a new way of thinking about conservation. In Frank and Sullivan’s new paper, published in the journal Anthropocene, the researchers call for the creation of a new research program that merges the space-oriented field of astrobiology and the Earth-oriented field of sustainability. While sustainability science focuses on the effects of a single species (us) during a particular epoch, astrobiology broadens its purview to all possible species, everywhere. But the two fields share common goals:

“Sustainability science and astrobiology both seek to understand the intimate, symbiotic, and continually evolving connections between life and host planets,” Frank and Sullivan write. Furthermore, emerging theories in astrobiology may help us develop a better understanding of the different pathways a “species with energy intensive technology,” or SWEIT, can follow.

Full article here:

ljk December 15, 2014 at 18:21

Galactic-scale macro-engineering: Looking for signs of other intelligent species, as an exercise in hope for our own

Joseph Voros

(Submitted on 28 Nov 2013)

If we consider Big History as simply ‘our’ example of the process of cosmic evolution playing out, then we can seek to broaden our view of our possible fate as a species by asking questions about what paths or trajectories other species’ own versions of Big History might take or have taken.

This paper explores the broad outlines of possible scenarios for the evolution of long-lived intelligent engineering species—scenarios which might have been part of another species’ own Big History story, or which may yet lie ahead in our own distant future. A sufficiently long-lived engineering-oriented species may decide to undertake a program of macro-engineering projects that might eventually lead to a re-engineered galaxy so altered that its artificiality may be detectable from Earth.

We consider activities that lead ultimately to a galactic structure consisting of a central inner core surrounded by a more distant ring of stars separated by a relatively sparser ‘gap’, where star systems and stellar materials may have been removed, ‘lifted’ or turned into Dyson Spheres.

When one looks to the sky, one finds that such galaxies do indeed exist—including the beautiful ringed galaxy known as ‘Hoag’s Object’ (PGC 54559) in the constellation Serpens. This leads us to pose the question: Is Hoag’s Object an example of galaxy-scale macro-engineering? And this suggests a program of possible observational activities and theoretical explorations, several of which are presented here, that could be carried out in order to begin to investigate this beguiling question.

Comments: 17 pages. To be published in: Teaching and Researching Big

History: Exploring a New Scholarly Field; Selected Papers from the inaugural International Big History Association conference, held at Grand Valley State University, Grand Rapids, MI, USA, 2-5 Aug 2012; L. Grinin, D. Baker, E. Quaedackers and A. Korotayev (eds). Uchitel Publ House, Volgograd, Russia, 2014

Subjects: Popular Physics (physics.pop-ph)

Cite as: arXiv:1412.4011 [physics.pop-ph]
(or arXiv:1412.4011v1 [physics.pop-ph] for this version)

Submission history

From: Joseph Voros [view email]

[v1] Thu, 28 Nov 2013 11:24:07 GMT (172kb)

ljk January 13, 2015 at 16:04

This Is Why Manatees Need Space Suits

by Annalee Newitz


Yesterday 2:04 pm

This manatee lives in a hollowed-out asteroid in space. Did you really expect that humans would be the only animals from Earth who would colonize the solar system? It’s all part of a research project about how different space colonization might look than what you expect.

The project was created by the Working Group on Adaptive Systems. They call it the “Nonhuman Autonomous Space Agency,” and it’s a whimsical futurist speculation built on top of a serious thought experiment. Its roots are in environmental science fiction like the movie Silent Running, about a spaceship that holds Earth’s last remaining ecosystems; and Kim Stanley Robinson’s recent novel 2312, where activists recreate Earth’s destroyed ecosystems inside hollowed-out asteroids. But it also shares territory with David Brin’s Uplift saga and Cordwainer Smith’s Underpeople stories, about what happens when our tech allows us to give animals human-like intelligence.

Writes the group on their website:

In recent decades, space exploration has been the heroic imperative of humankind, but this was not always the case. The first Earthlings in space were dogs, monkeys, and rabbits. Offering the opportunity to explore space back to nonhumans reveals new opportunities, risks, and rewards. Would an animal already adapted for life in a weightless medium not be better suited for free fall? What would an intelligent, curious, nonhuman mammal with a twitter account want to see and do in high Earth orbit and beyond?

Full article here:

To quote:

“In intelligence tests, manatees have performed at least as well as dolphins, in both pattern recognition, and task performance, if more slowly. Unlike most other intelligent aquatic mammals, the manatee’s flippers are visible in their field of vision, allowing for fine grained flipper-eye coordination. There is no reason why a manatee would not be able to operate a touchscreen device, in theory.”

Why do I get the feeling that if manatees were Earth’s organic representatives in the Milky Way galaxy that interstellar relations would be much better than, say, if a certain third order chimpanzee species were assigned the same task. Yes, yes, I am being cynical. Maybe.

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