by Paul Gilster | Apr 20, 2009 | Culture and Society |
Postponements of major science projects are generally dismaying, but sometimes they become so grand they attain a kind of immortality. The latest multi-billion dollar delay boggles the mind:
“Delays of this magnitude were once the stuff of science fiction,” Scolese told reporters during a noon press conference Monday that actually started around 3:15 p.m. “But now, thanks to a number of long-overdue technological advances, this historic delay will stretch the very limits of what humankind can push back indefinitely.”
You won’t want to miss The Onion‘s take as NASA Embarks On Epic Delay.
by Paul Gilster | Apr 18, 2009 | Administrative |
And I thought I was going to more or less take the weekend off, maybe finishing up a second reading of Rare Earth and enjoying some of the delightful spring weather that has taken hold around here. So much for that. Server issues caused this site to be transferred to a new server, which subsequently brought the whole site down. When it came back up, most of my customizations were gone and I haven’t yet figured out how to get them back. It’s been a long day and I’m not sure how long this is going to take, so please bear with me. It seems more important to get the site up and running again even if it’s suddenly in a minimalist guise. I’ll tune it back up as time permits.
by Paul Gilster | Apr 17, 2009 | Exoplanetary Science |
‘First light’ from any new telescope is an exciting moment, but never more so than with the Kepler instrument. Dust cover off, the space-based telescope is now looking at its target, a starfield in the Cygnus-Lyra region of the Milky Way. Kepler’s full field of view covers a 100-degree swath of sky, containing scenery like NGC 6791, an eight-billion year old cluster some 13,000 light years from us, as seen in the image below.
Image: The area pictured is 0.2 percent of Kepler’s full field of view, and shows hundreds of stars in the constellation Lyra. The image has been color-coded so that brighter stars appear white, and fainter stars, red. It is a 60-second exposure, taken on April 8, 2009, one day after the spacecraft’s dust cover was jettisoned. Credit: NASA/JPL-Caltech.
Loosely bound, the stars in NGC 6791 have begun to spread out from each other, the signature of what is called an ‘open cluster.’ The view is impressive but also blurry, an intentional effect that is being used, as this NASA news release points out, to keep the brightest stars from overloading the individual pixels in the spacecraft’s detectors. You’ll see the same blurry effect in the second image, which centers on a star known to have at least one planet orbiting around it. TrES-2 is a ‘hot Jupiter’ that makes its way around its host every 2.5 days.
Image: Here we see an area one-thousandth of Kepler’s full field of view, showing hundreds of stars at the very edge of the constellation Cygnus. The image has been color-coded like the one above. Note the star orbited by TrES-2 in the center of the image. Credit: NASA/JPL-Caltech.
It’s interesting how our methods have come together in this second image. TrES-2 was detected by the Trans-Atlantic Exoplanet Survey, which uses 4-inch Schmidt telescopes equipped with CCD cameras (located at Palomar, Lowell Observatory and the Canary Islands) to run automated search routines. This humble instrumentation was able to snare the transit of a Jupiter-like planet across a star some 750 light years from Earth. The Keck Observatory confirmed the discovery, which will now be examined by a space telescope capable of seeing much smaller worlds.
TrES-2 thus offers an early tune-up for Kepler’s instrumentation as well as an early target for further science. We’re about to embark on a three and a half year project to sample light from 100,000 stars, a study that will vastly expand our existing catalog of exoplanets and give us our earliest sense of how common small worlds in the habitable zone of their stars are. With a 95-megapixel camera able to detect changes in brightness of 20 parts per million, Kepler will be ready to go as soon as the necessary calibration of its photometer and subsequent alignment is completed. Figure just a few more weeks before Kepler’s hunt begins in earnest.
by Paul Gilster | Apr 16, 2009 | Astrobiology and SETI, Autonomy and Robotics |
A symposium called Crossroads: The Future of Human Life in the Universe seems timely about now (the site has been down all morning but should be up soon). With the Kepler mission undergoing calibration and CoRoT actively searching for small extrasolar worlds, we’re probably within a few dozen months of the detection of an Earth-like world around another star (and maybe, by other methods, much closer). This is sometimes referred to as the ‘Holy Grail’ of planetary sciences, but as soon as we accomplish it, a new ‘Grail’ emerges: The discovery of life on these worlds. And then another: Finding intelligent life.
We can kick the Fermi Paradox around all day, and enjoyably so because it forces us to use our imaginations, but ultimately we hope to put together the hard data that will tell us which of our speculations is most accurate. I see that the Crossroads symposium, which will take place May 1-2 as part of the Cambridge Science Festival, will include Frank Drake’s re-examination of his famous Drake Equation, but will also question whether crisis points like exhaustion of our natural resources may be the kind of ‘filter’ that any intelligent species must overcome.
Chokepoints for Technological Cultures
That’s a good Fermi solution if you posit the emergence of a million technological civilizations in our galaxy, as Carl Sagan once did. Those of us who think intelligent life is rare see no real contradiction in our lack of observed neighbors, but where are all those highly adapted technological cultures otherwise? Thus the plausibility of the doomsday hypothesis: Getting through that phase when a society is capable of destroying itself may be too high a hurdle for most to overcome. There are other forms of cultural collapse, too, as our own experience with the fragmentation of Roman culture in the 5th Century and later makes clear.
Then again, maybe that ‘great silence’ is only a transient phenomenon. Yesterday I talked about Seth Shostak’s new book Confessions of an Alien Hunter, and because it’s germane to this discussion (and sitting right here on my desk), I’ll return to it. Shostak notes that ever more powerful computers are ramping up SETI’s powers to the point that by the year 2030, the Allen Telescope Array ought to be able to check for signals in the direction of a million or more star systems. He points to Sagan as well as Frank Drake’s estimate of 10,000 communicating civilizations in examining the implications:
That’s enough to offer success if Drake is correct. If Sagan’s right, a signal will be found sooner. In other words, either we will discover evidence for ET within the lifetime of the present generation or we’ve erred badly in our presumptions.
Moore’s inexorable law thus makes our generation possibly the first with a real chance to witness that detection. The pace of change in digital technology seems inexorable. By 2020, a desktop computer should have the computational capabilities of a human being. Will we have something — electromagnetic leakage, a beacon, a directed transmission — by then?
A Machine on the Line
Assuming we are indeed at that crossroads the symposium notes in its title, it’s also plausible to speculate that another key filter is the development of artificial intelligence. If we do go through a ‘singularity’ event and our intelligent equipment begins to evolve on the fly in directions we cannot imagine, it’s more than possible that any SETI signal we receive is going to come, as Shostak notes, from a machine. All of which has ramifications for where we look for a signal:
Serbian astronomer Milan ?irkovi? has suggested that the best location for cerebrating hardware would be the outer fringes of the galaxy. In those godforsaken neighborhoods, where temperatures are colder than dead penguins, energy-consuming machinery could run most efficiently. That’s basic thermodynamics. But while ?irkovi?’s argument has its appeal, the galactic boondocks might be too dull for big brains with semi-eternity on their hands. They might prefer to exchange thermal efficiency for the opportunity to be situated closer to the galaxy’s central regions, where there’s a lot more astronomical action.
But then, if we’re truly dealing with machines at this order of complexity, it’s clear that our ability to gauge their intentions is going to be minimal. A crossroads indeed looms ahead as we ponder all this, hoping to hear a signal from another star system, wondering whether Earth-like worlds are indeed as common as some have come to believe, and speculating on the survivability of a nuclear-tipped species like our own whose digital tools may one day be beyond our ability to control. All good reasons to check out this symposium, which will be available as a Webcast.
by Paul Gilster | Apr 15, 2009 | Culture and Society |
Seth Shostak’s recent op-ed in the New York Times offers an unsettling title: ‘Boldly Going Nowhere.’ And Seth, an astronomer at the SETI Institute, gets right to his point: “…we’re not about to breach the final frontier. Piling into a starship and barreling into deep space may long remain — like perfect children or effort-free bathroom cleaners — a pipe dream.”
The homely similes reinforce the theme, one that also surfaces in Shostak’s new book Confessions of an Alien Hunter (National Geographic, 2009), which makes a strong case for continuing SETI as our digital capabilities expand. Indeed, given the daunting challenge of interstellar distances, it could be argued that our sole contact with extraterrestrial civilizations, if they exist, will take place through communications from afar, mediated by radio or light.
Let’s face it, the numbers are tough. The fact is that we can already do interstellar travel, provided we’re content with transit times of many tens of thousands of years, which is what our fastest spacecraft ever, New Horizons, would take to reach Proxima Centauri. A quick look at alternatives leads Shostak to note that ion engines aren’t up to the challenge, while antimatter requires the creation and storage of vast amounts of exotic, hard to contain particles. Wormholes? Fine, but we don’t know yet whether they exist or how to use them.
A Remote Presence in the Stars
If all this sounds depressing, consider Shostak’s alternative, the use of telepresence to extend human vision, hearing and touch to our stellar neighbors. Thus we go, but we go robotically, sending what he calls ‘proxy explorers’ to nearby stars, aided by ever increasing miniaturization that allows us to make payloads tiny. Perhaps the idea is a driver for nuclear-powered rocket technologies whose development has stalled:
A plausible solution would be to re-energize NASA’s development of nuclear-powered rockets, with the intention of building a craft able to send clusters of micro-bots into deep space at velocities of, say, one-tenth light speed. Depending on financing and our ability to garner international cooperation, these probes could be sent off before the 21st century starts to wane. By the middle of the following century, on-the-scene data from Epsilon Eridani, the nearest known planetary system, could be in our hands.
Image: An artist’s conception of a planet around Epsilon Eridani. A robotic probe with telepresence capabilities could allow us to experience such scenes without ever leaving our planet. Credit: Nova Celestia.
Virtual wanderings through a data feed from another star are compelling indeed, fueled by our telepresence proxies and data collectors. Who wouldn’t want to plug into the Epsilon Eridani Channel, immersing the senses in a wrap-around virtual experience that not only allows us to explore another planetary system, but also suggests that the wave of such exploration is ever outward?
Physics on the Edge
Here I want to plug in another Shostak quote, this one from Confessions of an Alien Hunter, which is a lively and satisfying account of what it’s like to be SETI’s major spokesman in today’s world. Here Seth is talking about various schemes for interstellar travel and he touches upon new physics:
Numerous and highly intriguing schemes have been proposed to do this. Alas, most of them require marshaling massive amounts of energy or rounding up exotic material that might not even exist. Scientists will not say that such schemes are impossible. We also can’t say whether they are possible, because theories in this field are still incomplete. Yet even if one of these schemes eventually looks right on the blackboard, there is no guarantee that it is feasible in practice.
Exactly so. The key statement is ‘theories in this field are still incomplete.’ Completing them is not the work of a single lifetime, nor is the resultant coupling of theory with technology that may develop. As we examine realistic technologies like telepresence via robotic probes, what can be done to keep our investigations of other possibilities alive?
Parallel Streams of Research
For as lively as telepresence would be, many of us would like to go one better. Propulsion research is a parallel stream, one that continues to flow even as we tune up and deploy the latest technologies available to us. Pushing its limits may or may not result in breakthroughs of the sort Shostak mentions. But one thing we can say for sure is that if we stop searching for them because of our current limits, we won’t find them.
And if they’re not there to be found? Here’s the point: By focusing our efforts on the nature of the possible, we should learn more about how the universe works, which is an end in and of itself. I’ve been asked on more than one occasion what will happen if scientists fail to find a way to achieve the kind of travel we see in Star Trek. The answer is that we’ll take different, slower methods to get to the stars, but we will still have learned a great deal about physics along the way, identifying key issues and sketching in many unknowns.
That’s a quest worth taking. And while it’s reassuring to realize that the kind of telepresence probes Shostak is talking about are feasible in a not terribly distant future, we still find ourselves confronted with a universe whose vast mysteries — dark energy, dark matter, the very nature of gravity — point to possibilities we have yet to explore. Nature yields up her secrets but slowly and often confronts us with surprises, which is why we must keep basic research alive. And if we create an Epsilon Eridani or Tau Ceti Channel along the way, count me an avid subscriber.
