Existential Risk and Far Future Civilization

How do we ensure the survival of our civilization over future millennia? Yesterday Heath Rezabek discussed installations called Vessels that would contain both archives and habitats to offset existential risk. Today Rezabek’s collaborator, author Nick Nielsen, broadens the view with an examination of risk itself and three possible responses for protecting our culture. Nick is the author of two books, The Political Economy of Globalization (Palgrave Macmillan, 2000) and Variations on the Theme of Life (Trafford, 2007). In addition to his recent talk at Starship Congress in Dallas, he presented “The Moral Imperative of Human Spaceflight” in 2011 at the 100 Year Starship Symposium in Orlando, and “The Large Scale Structure of Spacefaring Civilization” at the 2012 100YSS conference. In addition, he authors two blogs: Grand Strategy: The View from Oregon and Grand Strategy Annex, focusing on the future of civilization and the philosophical implications of contemporary events. Mr. Nielsen is a contributing analyst with Wikistrat, an online strategic consulting firm.

by J. N. Nielsen

Nick Nielsen

To see our world as a pale blue dot barely visible in the vastness of space graphically shows Earth’s place in the universe, and if we could continue to expand our scope for several more orders of magnitude while remaining focused on our pale blue dot, we would perceive our Earth in the full magnitude of its cosmological context. Just as Earth is placed in cosmological context in its appearance as a pale blue dot, we must similarly place earth-originating life, intelligence, and civilization in its cosmological context, and we can do so by way of astrobiology. Astrobiology can be considered an extrapolation and extension of terrestrial biology, or as biology in a cosmological context.


There are many definitions of astrobiology, some quite detailed and others quite concise. The NASA strategic plan of 1996 (quoted in Steven J. Dick and James E. Strick, The Living Universe: NASA and the Development of Astrobiology, 2005) gives this definition of astrobiology:

“The study of the living universe. This field provides a scientific foundation for a multidisciplinary study of (1) the origin and distribution of life in the universe, (2) an understanding of the role of gravity in living systems, and (3) the study of the Earth’s atmospheres and ecosystems.”

The NASA astrobiology website characterizes astrobiology as follows:

“Astrobiology is the study of the origin, evolution, distribution, and future of life in the universe. This multidisciplinary field encompasses the search for habitable environments in our Solar System and habitable planets outside our Solar System, the search for evidence of prebiotic chemistry and life on Mars and other bodies in our Solar System, laboratory and field research into the origins and early evolution of life on Earth, and studies of the potential for life to adapt to challenges on Earth and in space.”

More briefly, astrobiology has been called, “The study of life in space” (Mix, Life in Space: Astrobiology for Everyone, 2009) and that, “Astrobiology… removes the distinction between life on our planet and life elsewhere.” (Plaxco and Gross, Astrobiology: A Brief Introduction, 2006). Taking these sententious formulations of astrobiology as the study of life in space, which removes the distinction between life on our planet and life elsewhere, gives us a new perspective with which to view life on Earth.

With earth-originating life, intelligence, and civilization placed in cosmological context, we ourselves and our civilization can be understood in terms of the Fermi paradox. Fermi asked, if the universe is filled with life, “Where is everybody?” The universe is billions of years old, demonstrably compatible with the existence of intelligent life, and yet we find no evidence of highly advanced civilizations. The paradox has only been sharpened by recent scientific discoveries of exoplanets, including small, rocky planets in the habitable zones of stars, some of them relatively nearby in cosmological terms.


Once we remove the distinction between life on earth and life elsewhere we see that the idea of an “alien” is an anthropocentric concept, and a Copernican conception such as astrobiology must do away with the idea of “aliens” as constituting all life other than earth-originating life. So when we ask, “Where are all the aliens?” We must answer, “Right here, on earth; we are the aliens.”

A conception of intelligence and civilization as comprehensive as astrobiology would place these phenomena in cosmological context, and drawing on the insights of astrobiology we can see that an anthropocentric conception of alien intelligence as all intelligence other than earth-originating intelligence limits our conception of intelligence, as an anthropocentric conception of alien civilization as all civilization other than earth-originating civilization limits our conception of civilization. A Copernican conception will be concerned with the fate of life, intelligence, and civilization as such, but we must also acknowledge that we are all that is known so far of life as such, uncopernican though that sounds.

We are the only known “aliens” to pass through the Great Filter – which is what we call whatever it is that has filtered out other possible civilizations in the universe and left us only with our own civilization on Earth – and the development of astrobiology has directed our attention to the many near disasters we have experienced in the past – disasters that have shaped the surface of our planet and the history of life on Earth. The emergence of a single hominid species from several branches of hominid evolution makes homo sapiens a kind of existential choke point or bottleneck in the history of intelligent life, so that there is a sense in which we are the great filter. And this life, which is itself a marvelous and meaningless accident of the cosmos, is vulnerable at any moment to being annihilated by another meaningless accident of the cosmos.


Through the ages of cosmological and geological time our homeworld has been subject to massive volcanism, asteroid impacts, solar flares, gamma ray bursts, and the extensive glaciation that characterizes the present Quaternary glaciation, with its warmer inter-glacial periods such as the Holocene, during which the whole of human civilization has emerged. These natural forces of the Earth, the solar system, and the cosmos at large have shaped terrestrial life, humanity, and human civilization; we have been hammered on the anvil of a violent and dynamic universe. And we have survived thus far, but our survival is not guaranteed.

Earth-originating life has now given rise to industrial-technological civilization, which continues in its development to this day. What follows planet-bound industrial-technological civilization is the process of extraterrestrialization – the movement of the infrastructure of terrestrial civilization off the surface of the Earth and into space – which places earth-originating civilization in cosmological context, just as the pale blue dot places Earth in cosmological context and astrobiology places life in cosmological context. The process of extraterrestrialization, should it come to pass, furnishes us with a more comprehensive conception of civilization that begins to transcend our anthropic bias.


The resources of industrial-technological civilization hold the promise that life, intelligence, and civilization can spread beyond our terrestrial homeworld. Each stage in the development of a civilization capable of harnessing the energy resources required to expand beyond exclusively planet-bound conditions represents passing through further layers of the Great Filter. The gravitational thresholds of our home world, our local solar system, our local galaxy, and our local universe are each of them existential risks and existential opportunities for the future development of earth-originating life, intelligence, and civilization. With the passage beyond one gravitational threshold to another, existential risk is mitigated but not eliminated; the mitigation of one level of existential risk means ascending to a more comprehensive level of existential risk.

The technology that our civilization develops will influence the structure of extraterrestrialized civilization. If the settlement of the universe is parallel to the settlement of our planet, each gravitational threshold will first be passed by an initial slow wave, only to much later be filled in by faster waves of expansion resulting from later, higher technology. But in the event of a disruptive technological breakthrough, as, for example, any of the technologies based on the Alcubierre drive concept, there could be an initial fast wave of expansion only later filled in by slower and more thorough later waves filling in the gaps.

Given extraterrestrialized civilization in its cosmological context, we can approach existential risk mitigation through three principles: knowledge, which transforms unknown uncertainties into quantifiable risks that admit of calculation and mitigation, redundancy, which means multiple self-sufficient centers for Earth-originating intelligent life, and autonomy, which assures the independence of each self-sufficient center to seek its own strategies for survival.

What does knowledge have to do with risk? Following economist Frank Knight, what we call Knightian risk distinguishes between predictability, risk, and uncertainty, with predictability implying total knowledge, risk implying partial knowledge, and uncertainty implying the absence of knowledge. These are simplified and idealized categories; no risk is entirely free of uncertainty, and even uncertainty must lie within what is possible within our universe, and in that sense is predictable. But Knightian risk offers a framework to think about the dynamic nature of risk, which changes over time. The growth of knowledge moves the boundary of risk outward, meaning less uncertainty and more predictability.


For example, even if we have done very little in the past forty years in terms of human space exploration and extraterrestrial settlement, and we are still accessing earth orbit with disposable chemical rockets, space science has made enormous progress during this period of time, and this knowledge has transformed our understanding of our universe and our place within it. This growth of our knowledge of the universe has made the universe a little less uncertain and a little more predictable for us, suggesting clear paths for the management and mitigation of existential risk.

Knowledge alone is not enough. Without redundancy of earth-originating life, intelligence, and civilization we still face the possibility of a terrestrial single-point failure. Existential risk mitigation ultimately means multiple self-sufficient centers for Earth-originating intelligent life. These distinct centers of earth-originating life, intelligence, and civilization will be subject to distinct risks and distinct opportunities, and these distinct populations of Earth-originating life, intelligence, and civilization will be subject to distinct selection pressures, so that they will evolve into unique forms.

Knowledge of risks and redundant centers of earth-originating life together are not yet enough to secure on the long-term viability of Earth-originating life, intelligence, and civilization. Redundancy without diversity incurs the risk of homogeneity and monoculture. Existential risk mitigation also points to the necessity of the independence of each self-sufficient center to seek its own strategies of survival. The mutual independence of self-sufficient centers means the possibility of continued social and technological experimentation, which will in turn lead to the realization of distinct forms of civilization.

Autonomy seems like a simple enough condition, but it may be more difficult to achieve than we suppose. If we look around the planet today, with all its ethnic and cultural diversity, we see that there is, for all practical purposes, only one viable form of political organization – the nation-state – and again, for all practical purposes, only one viable form of civilization – industrial-technological civilization. We need to proactively seek to transcend social and technological monoculture to arrive at a civilizational pluralism from which social and technological experimentation flows naturally.

Taking existential risk seriously means that certain moral imperatives follow from this perspective, but who would possibly object to preventing human extinction? Of course, it is not as simple as that. It might be more difficult than we suppose to define human extinction, because to do so we would need to agree upon what constitutes human viability in the long term. Additionally, there are vastly different conceptions of what constitutes a viable civilization and of what constitutes the good for civilization. What is stagnation? What is flawed realization? What exactly is subsequent ruination, when achievement is followed by failure? What constitutes a civilizational failure? What exactly would constitute the “drastic failure of… life to realise its potential for desirable development”? What is human potential? Does it include transhumanism? For some, transhumanism is a moral horror, and a future of transhumanism would be a paradigm case of flawed realization, while for others a human future without transhumanism would constitute permanent stagnation. These are difficult questions that cannot be wished away; to pretend that they are not contentious is to fail to do justice to the complexity of the human condition.

These different conceptions of human potential and desirable outcomes for civilization will issue in different ideals, different aspirations, and different actions, but if we can continue to increase knowledge, establish redundancy and assure autonomy there is reason to hope that existential catastrophe can be avoided and an OK outcome realized, which is the point of what Nick Bostrom calls the maxipok rule – maximizing the probability of an OK outcome, where an OK outcome is defined as an outcome that avoids existential catastrophe.

If we do nothing, we will have on our conscience the extinction of all earth-originating life, intelligence and civilization. In the long term, our survival is only to be had through the extraterrestrialization of our civilization. But survival is not salvation. Survival often simply means that we will have the opportunity to go on to make later mistakes on a larger scale, which constitutes an OK outcome that is better than the alternative.


Deep Time: The Nature of Existential Risk

At the recent Starship Congress in Dallas, writer, librarian and futurist Heath Rezabek discussed the Vessel Archives proposal — a strategy for sustaining and conveying Earth’s cultural and biological heritage — which was directly inspired by Gregory Benford’s idea of a Library of Life. Working with author Nick Nielsen, Rezabek is concerned with existential risk — Xrisk — and the need to ensure the survival of our species and its creations in the event of catastrophe. Rezabek and Nielsen’s presentation was the runner up for the Alpha Centauri Prize awarded at the Congress, and it was so compelling that I asked the two authors to offer a version of it on Centauri Dreams. Heath’s work follows below, while we’ll look at Nick’s in tomorrow’s post. Both writers will be returning on a regular basis for updates and further thoughts on their work.

by Heath Rezabek


Some challenges are too daunting to approach alone.

Existential risk is certainly one; bringing a comprehensive strategy to a room full of seasoned interstellar advocates is another. Collaboration can sometimes be a greater challenge than solo work, but often it yields rewards far greater than the sum of their parts. I met Nick Nielsen through his asking an audience question of me, after my first presentation of the Vessel proposal at the 100 Year Starship Symposium in September 2012. My work with Nick has been a continuing process of encountering unexpected ideas in unexpected combinations, and this collaboration led us to propose and present a combined session on our work since 2012: ‘Xrisk 101: Existential Risk for Interstellar Advocates’, at the first Starship Congress, organized by Icarus Interstellar, in August 2013.

I have felt the importance of answering the challenge of existential risk (put simply, risks to our existence) since the moment my own sense of this subject achieved critical mass and began drawing all other related ideas into its orbit — which I can, amazingly, pin to the reading of a key article in io9 on June 18 of 2012. This reading began a process of nearly frenzied integration and streamlining, which culminated in a draft proposal for very long term archives and habitats as a means of mitigating long term risk, presented at 100YSS 2012. My preprint of that first, sprawling, 52 page paper emerged from a month of intense creation. It is still available on figshare.

I call these proposed installations Vessels. While this is a discussion for later, I deliberately invoke that term as the best and most descriptive one available, for something which includes all senses of the word that I can find: not only the sense of a craft, but of a receptacle, a conduit, a medium. If an eventual interstellar vessel does not contain a Vessel, then it may be incomplete.

I had no idea, going into 100YSS 2012, whether this proposal had any merit or use whatsoever. Being a librarian by career and calling, it certainly felt right, as the first and last and best I could do. Yet meeting Nick Nielsen was pivotal: his patient unpacking of the implications of mitigating Xrisk for the future of civilization has been crucial to my own optimism over humanity’s prospects, should we fulfill our full potential.

Offered here is a post which casts our Starship Congress 2013 session into blog format. The content can be found in much the same form in our video and slides, but I still encourage you to view them both if you connect with any of these ideas whatsoever. For links to video and slides, go to http://labs.vessel.cc/.

Though the concept stands for risks to our very existence, existential risk or Xrisk is far from intractable or imponderable. Because of the subtypes described in our session below (Permanent Stagnation and Flawed Realization), we can do much to improve the prospects for Earth-originating intelligent life tomorrow by working to improve its prospects today.

This begins with directly mitigating the extinction risks that we can, and with safeguarding — to the best of our abilities — our scientific, cultural, and biological record so that future recoveries are possible if needed; and the Vessel proposal attempts a unified approach to this work.

“Build as if your ancestors crossed over your bridges.
— Proverbial


Xrisk 101: Existential Risk for Interstellar Advocates (Part 1)

(Xrisk 101) is divided into two parts. In the first, I will cover the fundamentals of Xrisk, and update on the Vessel project, a framework for preserving the cultural, scientific, and biological record. In the second, Nick Nielsen will explore the longer term implications of overcoming Xrisk for the future of civilization.

Though discussed in other terms, Xrisk was a key concern and priority for the DARPA 2011 starship workshop. In its January 2011 report, that workshop prioritized “creating a legacy for the human species, backing up the Earth’s biosphere, and enabling long-term survival in the face of catastrophic disasters on Earth.” [1]

At the 100YSS 2012 Symposium, I presented a synthesis of strategies to address all three of these goals at once, called Vessel. Before updating on the Vessel project, I want to talk first about Existential Risk, what it includes, and why we should prioritize finding ways to meet its challenge.

Existential Risk denotes, simply enough, risks to our existence. Existential Risk encompasses both Extinction Risk and Global Catastrophic Risk.

Nick Bostrom, Director for the Future of Humanity Institute, defines Existential Risk this way in a key paper we’ll cover throughout, Existential Risk Prevention as Global Priority : “An existential risk is one that threatens the premature extinction of Earth-originating intelligent life, or the permanent and drastic destruction of its potential for desirable future development.” [2] In an array of possible risks presented in the paper, small personal risks are down in the lower left, while situations of widespread suffering such as global tyranny are in the middle as Global Catastrophic Risks. Finally, the destruction of life’s long term potential defines Existential Risk, in the upper right.


Xrisk has become a popular shorthand for this whole spectrum of risks. We can see signs of it emerging as a priority for various space-related efforts. One of the most popular images of Xrisk today is that of a sterilizing asteroid strike. And asteroids play a big role in some of the most visible efforts in space industry today, such as the ARKYD telescope or NASA’s asteroid initiative. Specialists sometimes see unpredicted cultural or technological Xrisks as even more urgent.

Starship Congress had its eye on some pretty long-term goals, and Earth provides our only space and time to work towards them. On that basis alone, the challenge of Xrisk must be answered.

But setting aside our own goals, what are the stakes? How many lives have there been, or could yet be if extinction is avoided? Nick Bostrom has run some interesting numbers.

“To calculate the loss associated with an existential catastrophe, we must consider how much value would come to exist in its absence. It turns out that the ultimate potential for Earth-originating intelligent life is literally astronomical.” [2]

How so? First we need a standard for measurement. Let’s start with the total number of humans ever to have lived on Earth. Wolfram Alpha lists the total world population as 107.6 billion people over time. The current global population is 7.13 billion. If we leave out the current population, we get 100 billion — About the number of neurons in a single human brain.


100 billion lives.

One Pale Blue Dot.

Here’s an excerpt of Carl Sagan’s thoughts on that famous image of Earth from afar:

Consider again that dot.

That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.

In … all this vastness … there is no hint that help will come from elsewhere to save us from ourselves. The Earth is the only world known, so far, to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment, the Earth is where we make our stand.


100 billion lives is our basic unit of measure.

Now; How much value would come to exist if our future potential is never cut short?

1016 — 10 million billion — is one estimate of the potential number of future lives on Earth alone, if only 1 billion lived on it sustainably for the 1 billion years it’s projected to remain habitable.


But if we consider the possibility of the spread of life beyond Earth, or synthetic minds and lives yet to come, Bostrom’s estimate [2] grows vast:

1052 potential lives to come. 100 million x 100 billion x 100 billion x 100 billion x 100 billion


This means that reducing the chances of Xrisk by a mere 1 billionth of 1 billionth of 1 percent…

is worth 100 billion billion lives.



With just a slight shift in priorities, we can hugely boost the chances of life achieving its full future potential by working to enhance its prospects today.

Let’s look at Bostrom’s definition again: “An existential risk is one that threatens the premature extinction of Earth-originating intelligent life, or the permanent and drastic destruction of its potential for desirable future development.”

Notice that fragment – “… destruction of its potential for desirable future development.” Survival alone is not enough. In some cases, a surviving society may be brutalized, stagnant, or diminished irreparably, unable to aspire or to build itself anew. This brings us to two subtypes of Xrisk as crucial as extinction itself, and both fall into the realm of Global Catastrophic Risks.

  • Permanent Stagnation – Humanity survives but never reaches technological maturity or interstellar civilization.
  • Flawed Realization – Humanity reaches technological maturity but in a way that is irredeemably flawed.

Pop culture has a working knowledge of them both, in different terms. Nick and I joke that it’s a bit like: Zombies vs Vampires.


Permanent Stagnation and Flawed Realization. Losing our capability as a civilization, or enduring only in a deeply flawed form. These two risks fill our dystopian movies. But because popular culture understands them, we can learn valuable lessons about our messaging and priorities by understanding them too.

These two types of Xrisk cut to the heart of what it means to achieve our full potential. There is a vast opportunity between these risks, because of the many advances needed to achieve an interstellar future – and because of the benefits such advances could have for life on Earth — in areas such as habitat design, energy infrastructure, biotechnology, as well as advanced computing, networking, and archival.

If we work to prototype here and now, solving real-world problems along the way, all will benefit. If we make advances open and adaptable to humanity’s best minds, we will gain allies in our effort to uplift Earth and thrive beyond it. Perhaps advanced, resilient technologies could carry a seal standing for the dual design goals of uplifting life on Earth while advancing our reach towards the stars. Like LEED certification for an infinite future. What would such projects be like?

Last year, I proposed the Vessel project as a means to safeguard cultural potential on Earth and beyond. I’ll close with a brief update on this approach to advanced computing, compact habitat design, and long-term archival. With deep appreciation to Paul, I’ll continue in future guest entries by updating on the progress of the Vessel project, as I’ve continued to connect with interested specialists in several areas crucial to its implementation as a concrete strategy for Xrisk mitigation.


Image: Vessel Installation Symbol.

Vessel, as a design solution, begins with a simple premise: Capability lost before advanced goals are reached will be very difficult to recover, without a means of setting a baseline for civilization’s capabilities.

A Vessel is an installation, facility, or habitat that serves as a reservoir for Earth’s biological, scientific, and cultural record. Into a Vessel is poured what must be remembered for humanity’s potential to be maintained. On Earth or beyond, a Vessel habitat is designed to carry forth the sum of all we’ve been. In 2012, Vessel was pictured as the Lilypad seasteading habitat.


But different Vessels would have different designs based on their needs and settings. These traits remain key in each case:

At a Vessel’s core would lie biological archives, meant to preserve key traces of Earth’s biodiversity. Here the primary model is Gregory Benford’s groundbreaking 1992 Library of Life proposal. Benford details a program for freezing and preservation of endangered biomass for possible future recovery. [4]

Also crucial would be core archives for cultural and scientific knowledge, both physical and digital. I’m working with Icarus Interstellar to make sure the Vessel framework is compatible with Icarus projects. Several examples exist of information storage technologies engineered to endure the passage of time, such as the digital DNA encoding strategies of George Church’s team as well as Ewan Birney and Nick Goldman’s approach, the fused quartz technologies of Hitachi or Jingyu Zhang, and the Rosetta Disk project of the Long Now Foundation, which is the first deliverable for their Library of the Long Now. As yet I have not seen it proposed that such initiatives could or should be brought together in the service of a unified goal or project. Throughout 2014, I will be surveying these proposed strategies, as well as interviewing (when possible) their inventors and project leads on potential implementations.


Surrounding these archives would be Research Labs, where specialists could collaborate on advanced technologies, seeking critical paths which avoid and mitigate Xrisk. Or, in a time of recovery, sealed labs could be the birthplace of new beginnings. Research Labs would open inwards to draw upon the Core Cache. Experts in their relevant fields could be both stewards and users of the core archives.

But in the near term, through an outer ring of Learning Labs, Vessel facilities could welcome the curious, and give visitors an inspiring glimpse at advanced studies. Immersive labs could be catalysts for change, helping people understand the arc of history in nature, culture and science, the common risks ahead, and the limitless possibilities if Earth achieves its full potential. This function, familiar in one form to any who have visited a nature & science museum and seen paleontologists at work, hints at a pathway towards actual present-day implementations of the Vessel project as popular, well-attended, comprehensive exhibitions for a public trying to make sense of the patterns of our present day.

Built around these three roles — of Learning, Research, and Archival — the Vessel framework is designed to adapt to any setting or situation. What all Vessels would have in common is a dedication to preserving cultural capability, and a layered, approachable presence adapted to its setting. Many should be built, using many approaches. Some could be public, while mission critical Vessels may be as remote as the Svalbard Seed Vault, or even secret.

Some may be massive as habitats, with others more like sculptures, compact and dense as a room. At the recent Starship Century conference in May, Freeman Dyson envisioned terrarium-like habitats which could seed the vast reaches of space with life. This egg-like approach is hugely inspiring to ponder from the perspective of the Vessel project. Whether urban or remote, extreme habitats or modules on a starship, Vessel is offered as a flexible framework for the long term survival of life’s capabilities.


The Vessel project has several routes forwards. Plans for 2014 include the previously mentioned global survey of existing long-term archival projects, an open design document to help others adapt and evolve the Vessel framework (on which I am already working with a small team of interested artists and specialists), and a Kickstarter for a Vessel- related art project. And, at the invitation of Paul Gilster, we can add to these plans our regular updates on the Vessel project’s progress to the readers of Centauri Dreams. While I explore the nuts and bolts of Vessel’s critical path to an implementation, Nick will help deepen our grasp of the long term potential for a civilization that has chosen to mitigate Xrisk.

Right before Starship Congress, I began an Internship with the Long Now Foundation, working on a project called the Manual for Civilization (See here and here). As the first core collection for their planned Library of the Long Now, a 10,000 year archive, this work will overlap deeply with the Vessel project. So, my own timeline for Vessel is in flux. But if you’d like to collaborate, discuss ways of applying Xrisk mitigation to your own work, or want to help accelerate these efforts, please get in touch. You can register for updates on the Vessel project at vessel.cc.launchrock.com.

And, you can ask questions in the comments; both I and Nick will do our best to answer.

Our discussion of Xrisk continues tomorrow with Nick Nielsen.


[1] 100 Year Starship. 2011. “The 100-Year Starship Study: Strategy Planning Workshop Synthesis & Discussions” (http://100yearstarshipstudy.com/100YSS_January_Synopsis.pdf). Accessed August 2012.

[2] Bostrom, N. “Existential Risk Reduction as Global Priority” (http://www.existential-risk.org/concept.pdf). Accessed August 2013.

[3] Sagan, C. Pale Blue Dot: A Vision of the Human Future in Space (Random House, 1997).

[4] Benford, G. “Saving the library of life,” Proceedings of the National Academy of Sciences 89, 11098-11101 (1992).


Sun-Skimming Planets (and a Riff on Brown Dwarfs)

It’s time to catch up with recent exoplanet finds out of MIT as I start weaving in recent news with conference notes and ideas from other reading. Kepler 78b is much in the news because of its orbit, which takes it around its star in a breathtaking 8.5 hours, so that you can cram almost three Kepler 78b years into a single Earth day. That means, of course, that this is a planet that all but skims its star, with an orbital radius about three times the radius of the star. In Solar System terms, we’re talking about a world forty times closer to its star than Mercury is to the Sun.


Image: A scorched Kepler 78b may have yet more to tell us, as the article below explains. Credit: NASA/JPL-Caltech.

With temperatures somewhere between 2300 K and 3100 K on the bright side (and I would assume this is a tidally locked world), we would be looking at a veritable ocean of lava on the surface. This MIT news release points out that because the researchers were able to detect the light emitted from the planet, we should be able to parse out further information about the composition of that surface and its reflective properties. From the paper on this work:

The robust detections of the occultations of the planet by the star, and of the time-variable illuminated fraction of the planet as it orbits around the star, make the system important for future observational and theoretical work. Observations with ?ner time sampling could better pin down the transit parameters. This in turn would clarify the equilibrium temperature of the planet’s dayside… It is unclear at this point if the occultations would be large enough in any band to be detected with any telescope besides Kepler, but the prospect of studying the surface or atmosphere of an Earth-sized exoplanet may be attractive enough to justify a large investment of telescope time.

Kepler 78b orbits a late G-class star and has, according to the paper, the shortest orbital period among all planets yet found transiting a main sequence star. The researchers, led by Roberto Sanchis-Ojeda (M.I.T. Kavli Institute for Astrophysics and Space Research) note that the rarity of giant planets in orbits this tight may be the result of smaller rocky worlds being less vulnerable to tidally-induced decay of their orbits. Among the other Kepler Objects of Interest (KOI) are 17 exoplanet candidates with orbital periods of less than 16 hours and inferred planetary sizes smaller than that of Neptune.

All this intrigues me especially because of my interest in brown dwarfs, dim and cool enough that a planet needing warmth for habitability would have to orbit exceedingly close to the object. Then we come to work on KOI 1843.03, a still unconfirmed candidate whose transit period is a mere 4.5 hours. The MIT team involved with this one, led by Saul Rappaport, finds that for a planet to orbit its star this closely, it must be extremely dense to prevent tidal forces from disrupting it.

The paper on this candidate argues that while planets with masses from 0.1 to 8 Earth masses can exist with orbital periods as low as 3.5 hours, they must be composed largely of iron with silicate mantles. “A number of planets with very short orbital periods are starting to be found,” the paper adds, “and a continuing search for them is likely to prove fruitful.” And later:

We ?nd it interesting that constraints on the composition of close-in terrestrial planets can be obtained from such elementary considerations. There remain, of course, profound questions about why planets actually exist in such close-in orbits, which we will leave for another day.

The Rappaport work is interesting because of its methodology. The Roche limit is the distance from the star where its tidal forces would disrupt the planet and cause it to disintegrate. Even a small planet has to orbit outside that limit. Rappaport’s team argues that these ultra-short period candidates can be studied by using the Roche calculations to set limits on the planet’s mean density. If the planet’s radius can be measured by studying its transits (this contrasts transit depth with measured stellar radius) then the composition of the planet can be inferred.

Musing on Close Planets and Brown Dwarfs

Neither Kepler 78b (a G-class primary) nor KOI 1843.03 orbits a star anywhere as faint as a brown dwarf, but let’s extend our speculations to these dim objects. Nature seems to be telling us to expect planets just about everywhere we look. It will be fascinating to learn whether or not brown dwarfs can sustain planets pushing up against the Roche limit and thus remaining warm enough to sustain some kind of life. Gregory Benford’s story “The Man Who Sold the Stars” explores at its conclusion what a planet orbiting a dim Y-class brown dwarf might look like. Imagine, then, being on the surface of a planet circling the brown dwarf called Redstar:

Even though their helmets amped the visible spectrum, the effect was eerie. Stars shone in pale gray here against the inky black. The huge hull of Redstar hung as a burgundy disk cut off by the sea. Here and there across the long panorama of perpetual twilight, slanting rays of a deep Indian red showed floating plants, lapping on the waves in a somber sprawl. Everything glowed with infernal incandescence…. Down from the desolate slope to his left came an echoing cry, long and slow. In the thick air a thing like a huge orange gossamer butterfly fluttered on a thin wind. It swooped across a sky peppered with amber clouds and vanished with deliberate, long flaps of its enormous wings, vanishing behind a low eroded hill.

This artist's conception illustrates the brown dwarf named 2MASSJ22282889-431026.

Image: Can a brown dwarf produce planets close enough to the object to be habitable? Credit: NASA, ESA, and JPL-Caltech.

A place like this is worth looking for, which is why brown dwarfs have such a large place in my imagination. Whether or not a Y-class dwarf could produce planets in such a configuration is something that only future observation will tell us. We are, though, beginning to learn the tricks of observing planets moving incredibly close to their parent star.

The paper on Kepler 78b is Sanchis-Ojeda et al., “Transits and Occultations of an Earth-Sized Planet in an 8.5 hr Orbit,” Astrophysical Journal Vol. 774, No. 1, p. 54 (abstract). The paper on KOI 1843.03 is Rappaport et al., “The Roche limit for close-orbiting planets: Minimum density, composition constraints, and application to the 4.2-hour planet KOI 1843.03,” Astrophysical Journal Vol. 773, No. 1, L15 (abstract). Greg Benford’s story is available in the Starship Century anthology.


Neil Armstrong: One Small Friendship Remembered

Neil McAleer is probably best known in these pages for his fine biography Visionary: The Odyssey of Arthur C. Clarke (Clarke Project, 2012), but this is just one of his titles. In fact, his book The Omni Space Almanac won the 1988 Robert S. Ball Award from the Aviation and Space Writers Association, and his work has appeared in magazines from Discover to the Smithsonian’s Air & Space and in many newspapers. A recent note from Neil reminded me that August 25th marked one year since the death of Neil Armstrong. This reminiscence of the astronaut brings Armstrong wonderfully to mind and gives us a bit more of Clarke, leaving me to wonder only how time has gone by so quickly in the days since the death of both men. McAleer’s article also gives me a chance to pause in Starship Congress coverage as I begin to collect papers from many of the presenters, the first of which we’ll be looking at a bit later this week.

by Neil McAleer

From the great deep to the great deep he goes.
— Alfred Lord Tennyson


The first letter I ever received from Neil A. Armstrong was dated May 21, 1987. Earlier that month, I had sent his office a copy of my recently published The OMNI Space Almanac with the hope he would agree to read and verify its text covering the final descent and landing on the moon of the Apollo 11 mission.

I had no clue if he would respond to my request or not, but it was worth a try. When I saw Lebanon, Ohio, on his return address a few weeks later, I was thrilled to have his reply — whatever it said. He thanked me for the book and wrote:

“I have been overwhelmed with business obligations this past several months, and have not yet had the chance to read it carefully.

“I will give my comments when the pressure subsides.”

Of course, I was all but certain that his pressure would never subside, but I was very grateful for his words.

That letter was my bonding with Armstrong for life, and it began a small friendship that lasted over 21 years and was sustained through occasional letters, emails, and phone conversations, several of which were interviews for my various works in progress.

Five months after receiving that special letter, in October 1987, I published a piece in Space World, “The Space Age Turns 30,” for which I interviewed 26 astronauts, science fiction and science writers, and various other space experts, asking them where they were when Sputnik 1 was launched — the event that would forever mark the beginning of planet Earth’s space age. Among the astronauts I interviewed for this piece were all three Apollo 11 crew members: Neil Armstrong, Buzz Aldrin, and Michael Collins.

Here is the published text that was distilled from the Armstrong interview that took place in the summer months of 1987.

“You know, going back 25 years or more and trying to remember something accurately is dangerous. I think many people remember what they remember rather than what happened.

“My recollection is that I was at the Society of Experimental Test Pilots symposium at Los Angeles at the time. The SETP symposium is always in the fall, about the time of the World Series. And I believe that to be true because I remember that it caused the Society some consternation at its inability to get press coverage, when every journalist was concentrating on Sputnik.

“I was flying various projects at Edwards Air Force Base at the time, including the X-15. [Its first flight took place post-Sputnik, in June 1959.] Those of us at Edwards High Speed Flight Station were working on projects we thought might lead eventually to spaceflight, so I’m certain that Sputnik was of extreme interest and concern to all of us in that business. What it came down to was: The Russians had one and we didn’t. We got one and then went on to the Moon.”

Those last two short sentences let us into the mind and heart Armstrong — the core of the man — as few short phrases can: Cut to the essence; cut to the action; take over the manual controls to land successfully on the moon! It demonstrates the truth of the succinct phrase describing him in his high school yearbook: “He thinks, he acts,’tis done.”


Image: Neil Armstrong as I (PG) like to remember him, a laser-focused professional at the top of his game.

Neil and I had two more informal project interviews, with follow-up correspondence, for works in process. One interview took place on March 16, 1989, which was part of my research for my first Arthur C. Clarke biography, originally published in 1992. The second focused on Neil Armstrong himself, a 1994 piece in the Baltimore Sun (“Neil Armstrong, Reluctant Hero”) that celebrated the 25th anniversary of the Apollo 11 landing, and the exemplary character of its commander, Neil A. Armstrong.

This piece was primarily my research, but I sent a draft to Neil and followed up with a phone call. My intent here was to make sure there were no egregious or even minor errors, which I knew he would tell me about if they appeared. Armstrong’s reach for excellence was ever-present.

My memory tells me that the last phone conversation/interview we had was for this Baltimore Sun piece in the spring of 1994, but there were a few email exchanges during the rest of the 1990s and into the first decade of the 21st century.

I was completely unaware of the last letter from Neil Armstrong that I played a part in. It wasn’t until I visited Arthur Clarke at his home in Colombo Sri Lanka, for the first time in April-May 2004 that I learned about it and read the original there.

Before my trip I wrote Neil to tell him I was making the long voyage over. It would be the first and last time I saw Arthur Clarke in his native habitat, where he chose to live in the 1950s. I was seeking a few special “gifts” to bring Arthur. Neil had said this about Clarke in a speech at the National Press Club in February of 2000:

“For three decades I have enjoyed the work and friendship of Arthur Clarke, a prolific science and science fiction writer, who back in 1945 first suggested the possibility of the communications satellite. In addition to writing some wonderful books, he has also proposed a few memorable laws. Clarke’s third law seems particularly apt today: Any sufficiently developed technology is indistinguishable from magic. Truly, it has been a magical century.”

My letter to Neil, dated April 10, 2004, read in part: “I’m taking a brand spanking ‘new’ copy of ‘The Engineered Century’ piece from The Bridge* in Spring 2000 to Sri Lanka with me to give to Arthur as a gift… Would it be possible for you to sign and date a copy to him on the first page of your piece?” (This was after Neil Armstrong had put a moratorium on requests for his signatures. “Unless I sign the wet concrete of a building cornerstone, and it can’t be carried away,” he told me once.)

* A quarterly magazine, issued by the National Academy of Engineers. This article was an edited version of a speech Armstrong delivered at the National Press Club, 22 February 2000.

Neil’s answer came back the next day: “I will be happy to help out as you have suggested. I will mail the book directly to Arthur to save you the trouble of carting it to Sri Lanka.”

After arriving at Clarke’s home and office in Colombo in late April, I asked Arthur if a package had arrived from Neil Armstrong. “Yes,” he said. “The inscribed Bridge and a letter.”

The letter was a complete surprise to me—and much more significant than an accompanying note.

It was the best letter written by Neil Armstrong that I had ever seen because it was a personal one to Clarke, who at 87 years was having multiple medical issues, including memory loss. And Armstrong’s humor and personality came through clearly in his words.

So two gifts had been sent to Arthur by Neil Armstrong: the inscribed magazine that was a cooperative initiative between the two of us; and his wonderful letter to Arthur—now in the Clarke archives. A photograph of that letter is below.


And here is Neil’s article with inscription to Clarke:

Neil Armstrong's article 01

There was a brief email exchange between us in mid-October 2005. I happened to see an obituary in the New York Times of a fellow test pilot that he may have missed, so I forwarded it on. I first sent this with a brief personal note attached to his office via the NY Times email forward, but apparently it never arrived. So I sent it again, “in a more straightforward manner,” and he replied a few days later:

“Thank you for the obit on George Watkins. Although I get the Times, I did not see the article. I didn’t know George well, but he came to Edwards on a number of occasions when I was working there.”

The fact that he replied at all to such an off-the-cuff brief forward was indicative of Neil’s warmth and generosity. But I was especially happy about the consistent use of abbreviated greetings and signature closings that framed this round of emails: I had headed mine: Neil A. from Neil M., and he replied with: Neil M. from Neil A. He accepted the usage. And he kept his message short: “‘Tis done.”

Our last emails were sent during 2008, the year that Arthur C. Clarke died at the age of 90 (March 19). Several months later, not long after Neil celebrated his 78th birthday on August 5, I brought him up to date and sent him a link to the last professional photographs of Clarke taken shortly before he died. That was our final communication—some 21 years after I received Neil’s first letter.

I never met Neil Armstrong face to face, but I knew him through his own words and voice, and our small friendship was life-changing for me. In the 1980s, our occasional interactions renewed and invigorated my natural propensity for optimism that had slowly gone into hibernation during my forties.

I’ve always thought of Neil when looking at the moon—ever since he and Buzz and Mike flew there and back, not quite a half century ago. Like countless admirers around the planet, I too grieved last August, reluctant to give up the hope that he had many more good years left. I genuinely thought Neil would be with us for the 50th Anniversary of Apollo 11 in 2019—and I take great comfort in the fact that his life story and giant spirit will always be with us.


Interstellar Studies in Context

With the beginning of a new week it’s time to ponder how best to move forward with coverage not only of the recent Starship Congress in Dallas, but the upcoming 100 Year Starship Symposium in Houston. For that matter, I still have material from the Starship Century event in San Diego, a gathering I was unable to attend but which continues to be available online. The Starship Congress videos are also up for those who missed Dallas, and I’m going to assume the Houston conclave will likewise be recorded. Watching online can’t match the interaction and conversation of being there, but getting to hear the presentations is a major plus.

What I’ll be doing as Houston approaches is continuing to reflect on the conferences I’ve attended so far this year while also trying to keep up with ongoing news. In the days since Dallas I have continued to speak with a number of presenters who will be joining us, as Charles Quarra did on Friday, with reports on their own work. Several have also agreed to drop in as regular columnists, so we’ll be tracking ongoing progress in a number of interesting areas as reported by people directly involved. I’m seeing the level of engagement between researchers and the public growing, a fact that speaks well for using the Internet to move the ball forward.

Interstellar Flight Before DARPA 2011


Kelvin Long is head of the Institute for Interstellar Studies and one of the founders of Project Icarus, the attempt to redesign the Project Daedalus fusion starship of the 1970s. As befits the latter, he is also editor of the Journal of the British Interplanetary Society, whose role in interstellar studies has always been immense. It was Geoffrey Landis who told me many years back that JBIS (‘J-biz,’ as it is affectionately known) had been the home of advanced concept thinking for decades, and as a BIS member myself, I can tell you that seeing that familiar cover appear in my mailbox renews my energy levels for tackling these issues.

Project Daedalus, of course, was designed largely in London’s pubs, particularly the Mason’s Arms, while Project Icarus takes a different tack, the effort being distributed over the Internet in addition to gatherings at conferences (and yes, the occasional pub still crops up). When Long spoke to Starship Congress, he offered up a history of the field as it grew from the Renaissance musings of Leonardo da Vinci all the way through the first astronauts on the Moon and into the present day. It was a useful session (and I thank Kelvin for the kind words about Centauri Dreams) because it helped to frame where we are today in relation to the DARPA grant of 2011 that drew so much press attention.

The DARPA grant of $500,000 resulted in the 100 Year Starship organization that is putting on the upcoming Houston conference, and in many ways awakened public interest in the idea that a trip to the stars was feasible. Popular science fiction on television and in the movies has for the most part made star travel out to be a simple matter, and it’s my guess that the average home viewer looks at the Enterprise flitting about the galaxy and regards the idea of star travel as something akin to fantasy. Thus to have newspapers and other venues begin to report in on serious work that researchers were performing came as a bit of a surprise to many.

Who knew that so much was going on, even if most of it was not being funded by government agencies? Kelvin and I have had this discussion before, and I’m always glad that he hearkens back to Les Shepherd, the British nuclear physicist who played such a large role not only in the British Interplanetary Society but in organizations like the International Astronautical Federation, which he served twice as president. Also a founder of the International Academy of Astronautics, Shepherd wrote a key paper in 1952 called “Interstellar Flight,” another JBIS contribution that moved the field forward by looking critically at how to move a starship.

Here I think of Giovanni Vulpetti’s words about Shepherd, which he kindly supplied for my obituary of the man that ran early last year:

Dr. Shepherd realized that the matter-antimatter annihilation might have the capability to give a spaceship a high enough speed to reach nearby stars. In other words, the concept of interstellar flight (by/for human beings) may go out from pure fantasy and (slowly) come into Science, simply because the Laws of Physics would, in principle, allow it! This fundamental concept of Astronautics was accepted by investigators in the subsequent three decades, and extended/generalized just before the end of the 2nd millennium.

Long’s talk went through Shepherd’s work and touched on many of the figures that have helped the field grow. On the first night of Starship Congress, Heath Rezabek gathered a number of those who had submitted proposals to DARPA for the 2011 grant, including Joe Ritter’s Starship Alliance and the Tau Zero Foundation. I was asked to supply some closing remarks to that event and gave the audience my view that the DARPA grant had put the earlier interstellar work into context and raised its visibility, firming up the idea that journeys to the stars moved beyond fantasy into the realm of extraordinarily difficult but not impossible mission challenges.

Like Long, I went through many of the names of the great players. After Shepherd, Eugen Sänger came to mind with his work on a so-called ‘photon drive’ in the 1950s. The great Robert Forward more than anyone worked out the physics of antimatter and sail possibilities and studied how powerful laser or microwave beams could drive a starship. George Marx wrote a seminal paper on beamed propulsion, while Clifford Singer studied particle beams to drive the craft. Gregory Matloff and Eugene Mallove examined worldships and sails (Matloff, of course, is still active), while the aforementioned work on Project Daedalus gave us the first true starship design.

The background is indeed rich, and bear in mind that many of these researchers were doing this work in their spare time while holding down demanding positions at labs or universities. The interstellar effort has been driven largely by will and determination. Alan Bond and Anthony Martin of Daedalus fame conceived new ideas for worldships, while in Italy the physicists Giovanni Vulpetti, Claudio Maccone and engineer Giancarlo Genta ignited an Italian solar sail effort that defined the issues and developed mission concepts that are still under investigation. One of these, Maccone’s FOCAL, is an ambitious mission to the Sun’s gravitational focus.

I won’t spend the entire post dwelling on the past, but it’s worth remembering that when Robert Forward was nearing the end of his life, he declared Geoffrey Landis (NASA GRC) to be his successor, and Landis indeed worked through many of the problems in sail materials that so interested Forward. The DARPA grant didn’t happen until 2011, but in the mid-90s we had the Vision-21 conference at NASA Glenn (then Lewis Research Center) followed by the creation of the Breakthrough Propulsion Physics project under Marc Millis. Ed Belbruno ran a conference called Robotic Interstellar Flight: Are We Ready in New York in 1994, this one sponsored by The Planetary Society and with involvement from NASA and JPL. The point is that tough-minded researchers have been tackling these issues since long before the public began to notice. We can hope the new interest will be quickened by future events, the most likely driver being the discovery of a truly Earth-like world around a star close enough for detailed study.


Image: Icarus Interstellar’s Andreas Tziolas, along with wife Zoi Maroudas-Tziolas, son Constantine, myself and, to my left, my son Miles.

Awakening the Mythos

Meanwhile, we continue with the interstellar effort while acknowledging that this is a multi-generational quest. The critical scientific and engineering studies are increasingly engaging the strands of science fiction and the popular media as the effort continues. We are discovering interest from sociologists, psychologists, historians, biologists, making the case that this is not a project that can remain purely a matter of physics and engineering. To engage the public we need the humanists as well, for we must ignite the vision in our culture, communicating sound reasons for deep space.

I sometimes turn to the Greek word mythos in describing what is happening. It’s the origin of the word myth, of course, and it has a range of meanings from ‘word’ through ‘fiction.’ The Greeks used ‘logos’ to mean ‘word’ as well, but logos was the word that can be argued and demonstrated, whereas mythos aimed at something ineffable, beyond argument, something that could provide guidance for the critical aspects of our lives. Mythos is all about how we face death, how we confront falsehood, how and where we find the meaning that keeps us going. Tennyson has Ulysses, that great figure of Homeric myth, speak for all those who go journeying:

“…my purpose holds
To sail beyond the sunset, and the baths
Of all the western stars, until I die.”

Whether consciously or not, we find in myths the inspiration we need to continue traveling. We tap mythos to get things done. In confronting the challenge of interstellar flight, we are re-learning what as a culture we knew in the days of ancient Athens and the earliest Chinese dynasties, that our works must not just reflect but surpass us. Because they are multi-generational, we must hand them along to our children so that they can build upon them to discover their meaning. Yes, we are dealing with the greatest problems of physics and engineering we have ever faced. But we know in our bones that to be successful, an interstellar effort must supercede all of this.

The problem of the starship, then, is problem of science but it is also a problem of philosophy as we choose how to live. The problem of the starship is a problem of engineering but it is also a problem of poetry, as we draw upon sources of inspiration to motivate our species. The starship mythos happens in that place where dreams confront reality and both grow and change from the experience. In leaving Earth we reinvigorate a mythos that may one day take us into the galaxy.