From Centauri Dreams:
Astronautics pioneer Robert H. Goddard is usually thought of in connection with liquid fuel rockets. It was his test flight of such a rocket in March of 1926 that demonstrated a principle he had been working on since patenting two concepts for future engines, one a liquid fuel design, the other a staged rocket using solid fuels. “A Method of Reaching Extreme Altitudes,” published in 1920, was a treatise published by the Smithsonian that developed the mathematics behind rocket flight, a report that discussed the possibility of a rocket reaching the Moon.
While Goddard’s work could be said to have anticipated many technologies subsequently developed by later engineers, the man was not without a visionary streak that went well beyond the near-term, expressing itself on at least one occasion on the subject of interstellar flight. Written in January of 1918, “The Ultimate Migration” was not a scientific paper but merely a set of notes, one that Goddard carefully tucked away from view, as seen in this excerpt from his later document “Material for an Autobiography” (1927):
“A manuscript I wrote on January 14, 1918 … and deposited in a friend’s safe … speculated as to the last migration of the human race, as consisting of a number of expeditions sent out into the regions of thickly distributed stars, taking in a condensed form all the knowledge of the race, using either atomic energy or hydrogen, oxygen and solar energy… [It] was contained in an inner envelope which suggested that the writing inside should be read only by an optimist.”
Optimism is, of course, standard currency in these pages, so it seems natural to reconsider Goddard’s ideas here. As to his caution, we might remember that the idea of a lunar mission discussed in “A Method of Reaching Extreme Altitudes” not long after would bring him ridicule from some elements in the press, who lectured him on the infeasibility of a rocket engine functioning in space without air to push against. It was Goddard, of course, who was right, but he was ever a cautious man, and his dislike of the press was, I suspect, not so much born out of this incident but simply confirmed by it.
In the event, Goddard’s manuscript remained sealed and was not published until 1972. What I hadn’t realized was that Goddard, on the same day he wrote the original manuscript, also wrote a condensed version that David Baker recently published for the British Interplanetary Society. It’s an interesting distillation of the rocket scientist’s thoughts that speculates on how we might use an asteroid or a small moon as the vehicle for a journey to another star. The ideal propulsion method would, in Goddard’s view, be through the control of what he called ‘intra-atomic energy.’
Image: Rocket pioneer Robert H. Goddard, whose notes on an interstellar future discuss human migration to the stars.
Atomic propulsion would allow journeys to the stars lasting thousands of years with the passengers living inside a generation ship, one in which, he noted, “the characteristics and natures of the passengers might change, with the succeeding generations.” We’ve made the same speculation here, wondering whether a crew living and dying inside an artificial world wouldn’t so adapt to the environment that it would eventually choose not to live on a planetary surface, no matter what it found in the destination solar system.
And if atomic energy could not be harnessed? In that case, Goddard speculated that humans could be placed in what we today would think of as suspended animation, the crew awakened at intervals of 10,000 years for a passage to the nearest stars, and intervals of a million years for greater distances. Goddard speculates on how an accurate clock could be built to ensure awakening, which he thought would be necessary for human intervention to steer the spacecraft if it came to be off its course. Suspended animation would involve huge changes to the body:
…will it be possible to reduce the protoplasm in the human body to the granular state, so that it can withstand the intense cold of interstellar space? It would probably be necessary to dessicate the body, more or less, before this state could be produced. Awakening may have to be done very slowly. It might be necessary to have people evolve, through a number of generations, for this purpose.
As to destinations, Goddard saw the ideal as a star like the Sun or, interestingly, a binary system with two suns like ours — perhaps he was thinking of the Alpha Centauri stars here. But that was only the beginning, for Goddard thought in terms of migration, not just exploration. His notes tell us that expeditions should be sent to all parts of the Milky Way, wherever new stars are thickly clustered. Each expedition should include “…all the knowledge, literature, art (in a condensed form), and description of tools, appliances, and processes, in as condensed, light, and indestructible a form as possible, so that a new civilisation could begin where the old ended.”
The notes end with the thought that if neither of these scenarios develops, it might still be possible to spread our species to the stars by sending human protoplasm, “…this protoplasm being of such a nature as to produce human beings eventually, by evolution.” Given that Goddard locked his manuscript away, it could have had no influence on Konstantin Tsiolkovsky’s essay “The Future of Earth and Mankind,” which in 1928 speculated that humans might travel on millennial voyages to the stars aboard the future equivalent of a Noah’s Ark.
Interstellar voyages lasting thousands of years would become a familiar trope of science fiction in the ensuing decades, but it is interesting to see how, at the dawn of liquid fuel rocketry, rocket pioneers were already thinking ahead to far-future implications of the technology. Goddard was writing at a time when estimates of the Sun’s lifetime gave our species just millions of years before its demise — a cooling Sun was a reason for future migration. We would later learn the Sun’s lifetime was much longer, but the migration of humans to the stars would retain its fascination for those who contemplate not only worldships but much faster journeys.
Goddard was obviously influenced by his contemporary J.D. Bernal with his The World, the Flesh and the Devil which predicted Man’s spread out into the Solar System and interstellar space with artificial worlds and hollowed out asteroids.
These worlds are needed because such journeys will take hundreds or perhaps thousands of years.
Of course that brings in natural evolution and what these people inside these places will become when they eventually reach their destinations and if they’ll actually have need of them.
From Technology Review:
Two high-profile entrepreneurs say they want to put a DNA sequencing machine on the surface of Mars in a bid to prove the existence of extraterrestrial life.
In what could become a race for the first extraterrestrial genome, researcher J. Craig Venter said Tuesday that his Maryland academic institute and his company, Synthetic Genomics, would develop a machine capable of sequencing and beaming back DNA data from the planet.
Separately, Jonathan Rothberg, founder of Ion Torrent, a DNA sequencing company, is collaborating on an effort to equip his company’s “Personal Genome Machine” for a similar task.
“We want to make sure an Ion Torrent goes to Mars,” Rothberg told Technology Review.
Although neither team yet has a berth on Mars rocket, their plans reflect the belief that the simplest way to prove there is life on Mars is to send a DNA sequencing machine.
“There will be DNA life forms there,” Venter predicted Tuesday in New York, where he was speaking at the Wired Health Conference.
Venter said researchers working with him have already begun tests at a Mars-like site in the Mojave Desert. Their goal, he said, is to demonstrate a machine capable of autonomously isolating microbes from soil, sequencing their DNA, and then transmitting the information to a remote computer, as would be required on an unmanned Mars mission. (Hear his comments in this video, starting at 00:11:01.) Heather Kowalski, a spokeswoman for Venter, confirmed the existence of the project but said the prototype system was “not yet 100 percent robotic.”
Meanwhile, Rothberg’s Personal Genome Machine is being adapted for Martian conditions as part of a NASA-funded project at Harvard and MIT called SET-G, or “the search for extraterrestrial genomes.”
Christopher Carr, an MIT research scientist involved in the effort, says his lab is working to shrink Ion Torrent’s machine from 30 kilograms down to just three kilograms so that it can fit on a NASA rover. Other tests, already conducted, have determined how well the device can withstand the heavy radiation it would encounter on the way to Mars.
NASA, whose Curiosity rover landed on Mars in August, won’t send another rover mission to the planet before at least 2018 (see “The Mars Rover Curiosity Marks a Technological Triumph“), and there’s no guarantee a DNA sequencing device would go aboard. “The hard thing about getting to Mars is hitting the NASA specifications,” says George Church, a Harvard University researcher and a senior member of the SET-G team. “[Venter] isn’t ahead of anyone else.”
Venter has a great idea here, but it reminds me of a certain movie in which sequencing alien DNA wasn’t such a great plan.
Like many geeks of the post-Sputnik generation, I grew up hoping that space travel would be common by the time I reached middle age. Weaned on a youthful diet of speculative fiction by the likes of Ray Bradbury and Arthur Clarke, raised on Star Trek and The Outer Limits, and thrilled by real-life hero Neil Armstrong’s “one small step” onto the gravelly surface of the Moon when I was in elementary school, it never occurred to me that humankind’s manifest destiny in the stars would be undone by changing political winds, disasters like the Challenger explosion, and a mountain of debt to pay for misguided military adventures like the War in Iraq.
It’s true that, in some ways, we’re living in a new golden age for space nerds. Bard Canning’s gorgeously enhanced footage of Curiosity’s descent to Mars — made instantly available by the global network we built instead of a Hilton on the Moon — certainly beats grainy snippets beamed down from Tranquility Base. A newly discovered exoplanet that “may be capable of supporting life” seems tomake headlines every few months. Cassini’s ravishing closeups of Saturnregularly put the fever dreams of ILM’s animators to shame. But wasn’t I supposed to be “strolling on the deck of a starship” by now, as Paul Kantner’s acid-fueled hippie space epic Blows Against the Empire promised me when it was nominated for a Hugo award in 1971?
The problem, it turns out, isn’t just a loss of political will to finance manned space flight. Rocket science turns out to be rocket science — not easy, and constrained by some very real limitations dictated by material science, the physics of acceleration, and the unwieldy economics of interstellar propulsion. Until a real-life Zefram Cochrane comes along to invent a practical warp drive, I may not be sightseeing on any Class M planets anytime soon.
One of the best briefings on the state of the art of interstellar exploration is Lee Billings’ essay “Incredible Journey,” recently reprinted in a wonderful new anthology called The Best Science Writing Online 2012, edited by Scientific American’s Bora Zivkovic and Jennifer Ouellette. I’m very honored to have a piece in the anthology myself: my NeuroTribes interview with John Elder Robison, author of the bestselling memoir of growing up with autism, Look Me in The Eye, and other books. When SciAm’s editors suggested that each author in the book interview one of the other authors, I jumped at the chance to interview Billings about his gracefully written and informative article about the practical challenges of space flight. Billings is a freelance journalist who has written forNature, New Scientist, Popular Mechanics, and Seed. He lives outside New York City with his wife, Melissa.
Steve Silberman: Before we even get into the meat of your piece, I want to mention how impressed I was by the power and lyricism of your writing. Phrases like “the cosmos suddenly becomes less lonely” and “the easiest way the Daedalus volunteers found to fuel their starship was, in effect, the industrialization of the outer solar system” make vast and highly abstract concepts immediately comprehensible and visceral to lay readers. What made you want to become a science writer, and who are your role models for writing, in any genre?
Lee Billings: My attraction to science preceded my attraction to the act of writing, perhaps because, like every child, I was intensely curious about the world around me. Science, more so than any other source of knowledge I could find, seemed to change the world into something at once eminently understandable and endlessly mysterious.
I became interested in science writing, science journalism, at approximately the same time I realized I would make a poor scientist. I was midway through my college prerequisites, thinking I was on a path to a career in neuroscience. I’d been having a lot of trouble with the more quantitative courses — calculus, organic chemistry, and so on. Many of my friends would ace their assignments and tests after sleeping through lectures and rarely cracking a book. I would study hard, only to receive poor grades. Meanwhile I was breezing through courses in English, literature, history, and art. After a particularly fervent all-night cram-session for a final exam that I still almost flunked, I decided if I wasn’t destined to excel within science itself, perhaps I could instead try to make my mark by helping communicate the world-changing discoveries scientists were making. So I switched my academic emphasis from neuroscience to journalism, and became something of a camp follower, scavenging and trailing behind the gifted few at the front lines of research. I’ve never looked back, and have no regrets. The job never gets old: Rather than being at best a mediocre, hyper-specialized bench worker, being a science writer lets me parachute in to varied fields on a whim, and invariably the brilliant individuals I find upon landing are welcoming and happy to talk to me.
As for influences… I still have a long way to go, but if my writing ever comes to possess a fraction of Carl Sagan’s charisma and elegance, John McPhee’s structure and eye for detail, Richard Preston’s depth of focus and cinematic flair, Stanislaw Lem’s imagination and analytic insight, or Ray Bradbury’s lyrical beauty, I will be a happy man.
Ray Bradbury’s “The Martian Chronicles”
Silberman: Several times a year now, we hear about the discovery of a new exoplanet in the “Goldilocks zone” that could “potentially support life.” For example, soon after he helped discover Gliese 581g, astronomer Steven Vogt sparked a storm of media hype by claiming that “the chances for life on this planet are 100 percent.” Even setting aside the fact that the excitement of discovering a planet in the habitable zone understandably seems to have gone to Vogt’s head at that press conference, why are such calculations of the probability of life harder to perform accurately than they seem?
Billings: The question of habitability is a second-order consideration when it comes to Gliese 581g, and that fact in itself reveals where so much of this uncertainty comes from. As of right now, the most interesting thing about the “discovery” of Gliese 581g is that not everyone is convinced the planet actually exists. That’s basically because this particular detection is very much indirect — the planet’s existence is being inferred from periodic meter-per-second shifts in the position of its host star. The period of that shift corresponds to the planet’s orbit as it whips from one side of the star to the other; the meter-per-second magnitude of the shift places a lower limit on the planet’s mass, but can’t pin down the mass exactly. So that’s all this detection gives you — an orbit and a minimum mass. That’s not a lot to go on in determining what a planet’s environment might actually be like, is it?
Now, get up and walk around the room. You’re moving at about a meter per second. Imagine discerning that same rate of change in the motion of a million-kilometer-wide ball of plasma, a star many light-years away. Keep in mind this star’s surface is always moving, in pounding waves and swirling eddies, in rising and falling convection cells, in vast plasmatic prominences arcing above the surface, often at many kilometers per second. At any particular moment, all that stellar noise can swamp the faint planetary signal. Only by building up hundreds or thousands of careful measurements over time can you get that crucial periodicity that tells you what you’re seeing might be a planet. So the measurement is quite statistical in nature, and its interpretation can change based on the statistical assumptions being used. This is further complicated by the fact that planets are rarely singletons, so that any given stellar motion may be the product of many planets rather than one, requiring careful long-term study to tease apart each world’s contribution to the bulk signal. It’s also complicated by the instability of astronomical instruments, which must be kept carefully, constantly calibrated and stabilized lest they introduce spurious noise into the measurements. In the case of Gliese 581g, not everyone agrees on the putative planetary signal actually being caused by a planet, or even being real at all — the signal doesn’t seem to manifest equally in the handful of instruments purportedly capable of detecting it.
So it’s very difficult to just detect these things, and actually determining whether they are much like Earth is a task orders of magnitude more difficult still. Notice how I’m being anthropocentric here: “much like Earth.” Astrobiology has been derisively called a science without a subject. But, of course, it does have at least one subject: our own living planet and its containing solar system. We are forced to start from what we know, planting our feet in the familiar before we push out into the alien. That’s why we, as a species, are looking for other Earth-like planets — they probably offer us the best hope of recognizing anything we might consider alive. It’s not the strongest position to be in, but it’s the best we’ve got. Calculating the probability of life on an utterly alien world outside the solar system for which we know only the most basic information — its mass, its orbit, maybe its radius — is at this stage a very crude guess. The fact is, we still don’t know that much about how abiogenesis occurred on Earth, how life emerged from inanimate matter. There are very good physical, chemical, thermodynamic reasons to believe that life arose here because our planet was warm, wet, and rocky, but we really don’t yet know all the cogent occurrences that added up to build the Earth’s earliest organisms, let alone our modern living world. A warm, wet, rocky planet may be a necessary but not a sufficient condition for life as we know it to form and flourish.
Lee Billings with planet hunter Geoff Marcy
This is really a chicken-and-egg problem: To know the limits of life in planetary systems, we need to find life beyond the Earth. To find life beyond Earth, it would be very helpful to know the limits of life in planetary systems. Several independent groups are trying to circumvent this problem by studying abiogenesis in the lab — trying to in effect create life, alien or otherwise, in a test tube. If they manage to replicate Earth life, the achievement could constrain just how life emerged on our own planet. If they somehow manage to make some single-celled organism that doesn’t use DNA, or that relies on silicon instead of carbon to build its body, or that prefers to swim in liquid ethane rather than liquid water, that gives us a hint that “Earth-style” biologies may only be one branch in a much larger and more diverse cosmic Tree of Life.
Silberman: Going deeper than the notion of the cosmos feeling “less lonely” – as well as the fact that we all grew up watching Star Trek and Star Wars and thinking that aliens are frickin’ cool (as long as they’re not the mama alien fromAlien) — why do you think people are so motivated to daydream about extraterrestrial life? What need in us do those dreams fulfill?
Billings: I don’t really think most people are necessarily motivated to daydream about just any sort of extraterrestrial life. It will probably take more than a microbe or a clam to excite most of our imaginations, even if that microbe happens to be on Venus or that clam happens to be on Mars.
I do think humans are motivated to daydream about extraterrestrial intelligence, and, to put a finer point on it, extraterrestrial “people.” They are motivated to dream about beings very much like them, things tantalizingly exotic but not so alien as to be totally incomprehensible and discomforting. Maybe those imagined beings have more appendages or sense organs, different body plans and surface coverings, but they typically possess qualities we recognize within ourselves: They are sentient, they have language, they use tools, they are curious explorers, they are biological, they are mortal — just like humans. Perhaps that’s a collective failure of imagination, because it’s certainly not very easy to envision intelligent aliens that are entirely divergent from our own anthropocentric preconceptions. Or perhaps it’s more diagnostic of the human need for context, affirmation, and familiarity. Why are people fascinated by their distorted reflections in funhouse mirrors? Maybe it’s because when they recognize their warped image, at a subconscious level that recognition reinforces their actual true appearance and identity.
More broadly, speculating about extraterrestrial intelligence is an extension of three timeless existential questions: What are we, where do we come from, and where are we going? The late physicist Philip Morrison considered SETI, the search for extraterrestrial intelligence, to be the “archaeology of the future,” because any galactic civilizations we could presently detect from our tiny planet would almost certainly be well more advanced than our own. It’s unlikely that we would ever receive a radio message from an alien civilization in the equivalent of our past Stone Age, and it’s unlikely Earth would ever be visited by a crewed starship that powered its voyage using engines fueled by coal or gasoline. Optimists consider this, and say that making contact with a superior alien civilization could augur a bright future for humanity, as it would suggest there are in fact solutions to be found for all the current seemingly intractable problems that threaten to destroy or diminish our species. It’s my opinion that most people think about aliens as a way of pondering our own spectrum of possible futures.
I’m inclined to believe some of the things Billings has to say in that it’s doubtful we’ll build anything like a starship in the near future and folks ( taxpayers ) just won’t fund those kinds of projects. Entrepreneurs such as Elon Musk, James Cameron and Peter Diamandis could in the future fund projects such as starprobes and starships – only if they prove profitable.
IMO it looks like stronger telescopes both on Earth and in space will be the only human built machines exploring the closer solar systems for any signs of life and extant civilizations because they can be economically constructed – and if they found anything interesting, the items are still a safe distance away.
From Kurzweil AI:
1. Your great-great-grandma was probably not from outer space.
“I get emails every week saying that Homo sapiens are the result of alien intervention. I’m not sure why aliens would be interested in producing us. I think people like to think we’re special. But isn’t that what got Galileo and Copernicus into trouble – questioning how special we were? But if we’re just another duck in the road, it’s not very exciting.”
2. If aliens come, we’re probably toast.
“Whoever takes the trouble to come visit us is probably a more aggressive personality. And if they have the technology to come here, the idea that we can take them on is like Napoleon taking on U.S. Air Force. We’re not going to be able to defend ourselves very well. But if I wanted that to be correct, it would be a very short movie.”
3. They won’t catch our colds.
“Alien life forms wouldn’t come here only to be done in by our bacteria, unless they were related biochemically to humans. Bacteria would have to be able to interact with their biochemistry to be dangerous, and their ability to do that is far from a sure thing.”
4. Aliens don’t look like Screen Actors Guild members.
“Thanks to computer animation, we now have more variety of aliens in films, but they’re still soft and squishy—and big on mucus. Chances are, the first invaders will be some sort of artificially intelligent machinery. But in films, even machinery needs to look like biology, otherwise actors would be talking to a box.”
5. Nobody’s getting lucky.
“The idea that they’ve come for breeding purposes is more akin to wishful thinking by members of the audience who don’t have good social lives. Think about how well we breed with other species on Earth, and they have DNA. It would be like trying to breed with an oak tree.”
I think Dr. Shostak listens to too much Dr. Hawking, but that’s just my opinion.
As to his last point, he doesn’t think too much about the theory of interplanetary ( interstellar ) panspermia.
He should read this article about the ” red rain ” espisode in Kerala, India in 2001.
Maybe life in the Universe is related at the basic level?