by Paul Gilster | Sep 19, 2006 | Astrobiology and SETI |
The Fermi Paradox (‘Where are they?’) is becoming something of a cottage industry; everyone has an answer. My own hunch is that while life is widespread, technological civilizations are not, with perhaps as few as 5 to 10 active at any given period in the galaxy. But many would disagree with this assessment, including Itzhak Shechtman. The Israeli theorist speculates that ancient super-civilizations may well be out there, and perhaps detectable through an upgraded SETI effort. But his first task, in a recent article in the Journal of the British Interplanetary Society, is to silence the critics.
For cosmic catastrophe theory has gained traction in recent years. In its scenarios, certain cosmic events — gamma-ray bursts, neutrino-induced extinctions, disastrous interactions with galactic spiral arms — could cause species extinction that would prevent long-lasting cultures from ever developing. A solution to the Fermi Paradox? Nobody lives long enough to visit us.
But Shechtman believes such theories disregard the pivotal role advanced civilizations could play in changing their own destinies. His terms will be familiar to anyone following the development of advanced computers:
The present paper introduces a new concept: ‘immunity-through-singularity.’ According to it, within a cosmically very short time span after a culture attains approximately the level of humanity it develops into a singularity. From that time on the rules of the game change: it becomes immune against most terrestrial and cosmic catstrophes, developing into a super or hyper civilization.
Such advanced cultures could, Shechtman argues, predict long in advance the threatening cosmic events that must be modified, thus avoiding their consequences. Even in our present era, we are beginning to develop tools (albeit a bit too slowly, in Centauri Dreams‘ view) to deflect incoming asteroids or other space debris. Other types of disaster such as gamma-ray bursts or stellar collapse neutron fluxes still pose a threat to young civilizations like ours, but it remains the case that despite them life on Earth survives and now contemplates expansion into the cosmos. They are not, then, necessarily fatal.
The question remains: where are the advanced cultures that survive these events? Shouldn’t we see the handiwork of super-civilizations if they are out there? Shechtman argues that we are not looking for their markers. Here he describes the current state of such research and argues for a willingness to consider alternative solutions:
Many cosmic phenomena are presently poorly or not at all understood, perhaps because we try to interpret them using solely the known laws of inanimate nature, disregarding possible intervention by super intelligence, which can master and exploit these laws much better than we do, thereby adding a new aspect to these phenomena.
And later:
Thus we arrive at an important conclusion: that a new branch should be created in Astronomy/Astrophysics which would aim to include in its endeavours to interpret poorly-understood cosmic phenomena also the assumption that they may involve intervention by some super intelligence.
The paper thus makes a contribution to the growing field of what might be called ‘advanced SETI,’ the study of which involves methods like Shechtman’s and goes well beyond current efforts that are limited to eavesdropping for signals in radio and optical frequencies. If a change to SETI outlook is needed, as Milan ?irkovi? and others have argued for some time now, then developing the analytical tools to apply to future SETI efforts could teach us much about life’s potential for altering natural processes that might otherwise seem ineluctable.
The paper is Shechtman, “Is the Universe Teeming with Super Civilizations?,” Journal of the British Interplanetary Society Vol. 59 No. 7 (July, 2006). My photocopy of this article obscures the page numbers; if anyone can supply them, please do, as to the best of my knowledge JBIS continues to be unavailable online. The fact that the journal Geoffrey Landis calls ‘the home of advanced concept thinking’ should have so meager an online presence continues to baffle me.
Addendum: The page reference for the above is pp. 257-61. Many thanks to Brett Holman for this information. Thanks also to Tibor Pacher, who points out that abstracts are available here, though you have to be a BIS member to download entire papers. So the JBIS online situation is less limiting than I had believed.
by Paul Gilster | Sep 18, 2006 | Outer Solar System
The upcoming solar occultation should be quite an event for Saturn-orbiting Cassini. The Sun will pass directly behind the planet from the spacecraft’s vantage point, and will remain there for twelve hours. New ring structures may turn up in the resulting images, along with views of the D, F, G and E rings that will be like none ever observed. In addition, the event should allow scientists to map microscopic particles moving within the ring system.
“We are all sort of on pins and needles waiting for the results,” says Brad Wallis, Cassini Rings Discipline Scientist. “When you get these kinds of high phase angles, very small particles almost focus the light right at the observer. So these faint rings that are so hard to see are going to be considerably brighter and show us details that are just not possible to see in other viewing conditions. All the space between Enceladus and the G ring is probably going to be pretty well lit up. It’s really a unique event.”
By phase angle, Wallis is talking about the angle between the light falling on the rings and the light reflected from them. Ranging from 0° to 180°, phase angles are all about the relationship between light, observer and illuminated object (a 180° phase angle occurs when the object is between the illumination source and the observer). A higher phase angle teases out fine detail that would be lost at a lower angle; in this case, Cassini will be looking almost straight into the Sun, but the Sun will be behind the planet. A similar view of Uranus observed by Voyager 2 in 1986 (see below) was quite useful at showing details of the ring structure there.
That makes this 12-hour occultation a unique event, but it’s not just about the rings — there’s an Enceladus connection as well. For the unusual Saturnian moon seems to be the source of the E ring, based on the ice jets that Cassini has already discovered on it. Observing how uniform the E ring’s composition is should tell us something about the rate of outflow from Enceladus, and thus illuminate a small part of its history.
Image: NASA’s Voyager 2 looks at Uranus’ rings. The view above, which was taken at much higher phase angle, shows details not visible from any other angle. Credit: Jet Propulsion Laboratory.
Centauri Dreams‘ note: It’s remarkable how fine the cloud of dust that makes up the E ring is. The ring is between 5000 and 10,000 kilometers thick, but made up of such small particles that it poses no danger to the spacecraft. Says Wallis: “We pass through the E ring all the time.” Now we get a chance to see its structure in its entirety. More information is available on this JPL page.
by Paul Gilster | Sep 16, 2006 | Culture and Society |
by Marc Millis
Apropos of our recent discussion of species differentiation and what may happen when humans spread into the Solar System and beyond, Marc Millis forwarded a whimsical piece he wrote for Aerospace Frontiers, the internal news publication of NASA Glenn Research Center. The item ran in August of 2000 and makes for an enjoyable weekend diversion.
From the Author: The visions presented here do not necessarily reflect the opinions of NASA Glenn, “Aerospace Frontiers,” or even the author himself. What this story does represent, however, is a light-hearted glimpse of an unintended turn of events. History itself is a collection of unplanned twists and turns, so our visions of the future should prepare us for more of the same. Prepare yourself.
——-
It finally happened. Access to space became cheap enough so that the average “Joe” and “Joanne” could venture beyond the bounds of Earth, and long-duration space habitats became robust enough to provide reliable places to live once they got up there. We truly became a “spacefaring” civilization. The face of humanity changed.
It didn’t quite evolve as expected. Sure, we finally made that grand observatory and hotel on the Moon, had a multinational colonization of Mars that made the International Space Station pale in comparison, and even sent out interstellar probes. But after the novelty of Moon vacations and zero-g sex wore off (space sickness really put a damper on those romantic weekend getaways), the humanism of space took on a more human course of events.
As it turned out, it wasn’t the average Joes and Joannes who went out in search of adventure. Instead, it started with hordes of self-proclaimed misfits that finally escaped the bounds of Earth — specifically escaping the oppression of the authority figures that had the audacity to expect them to obey laws and social norms. Individuals and clusters of subcultures set up residency in space to create their own little worlds on whatever piece on non-Earth territory they could find. Asteroids became the favorite homesteading choice for these escapists. Mars and the Moon had too much of that old Earth-culture to be attractive. Religious cults, hate-mongers, and ultra-geeks each claimed their piece of a rock. In isolation, their cultural diversity blossomed.
Enter stage two. Medical needs and simple cravings drove these escapists to invite the mainstream humans out to service them. Roving med-service and fast food space ships made weekly runs across the asteroid belt. And this created another shift. Although space habitats were built to be self-sufficient (which meant they didn’t need further investment once purchased) junk food and medical help cost money. Now the escapists needed jobs. Some, like the ultra-geeks, had no trouble pulling in finances over the Internet with their intellectual services, but other groups turned to some of the oldest professions including, among other things, piracy.
Space pirates evoked the need for space patrols. This meant that those old authority figures were back again, but now they were the outsiders. Skirmishes broke out like dogs barking at night. And it wasn’t just the escapists versus the conventionalists. The inherent diversity of the various escapists combined with their human instincts for territorialism, led to battles amongst the groups. With zeal akin to religious righteousness, the cries went out: “My way is the right way – convert or die!”
Meanwhile, as these “cultural exchanges” ran their course, another technology infusion made a dramatic impact. Drawing on genetic engineering and biomechanical technology, it became chic to “reinvent yourself.” The ultra-geeks now had the resources and will to modify their own bodies to be better suited to their new space environment:
rad hard, micro-g adapted, power boosted, and so forth. Some even went as far as to mutate themselves into having insect-like exoskeletons to endure the space vacuum, complete with eyes in the back of their heads and appendages armed with automatic targeting weapons. Even though life on Earth remained pretty much the same, this engineered biodiversity flourished in space beyond terrestrial imagination.
Survival of the fittest eventually ran its course. What remained to dominate the space frontier no longer looked quite human, but still retained all the instincts for territorial and conquest of their human origins. The face of humanity had literally changed.
by Paul Gilster | Sep 15, 2006 | Exoplanetary Science |
As planet hunters catalog stellar wobbles and light-curves, some of them are working their way down through the various planetary types aiming at the ultimate discovery, an Earth-like world around another star. And if Lisa Kaltenegger has her way, they’ll be able to tell us something about the existence of life on that planet. Kaltenegger faced a Washington DC audience yesterday to announce a new methodology for examining terrestrial worlds. Unable to be there myself, I attended via a much appreciated Webcast.
Kaltenegger (Harvard-Smithsonian Center for Astrophysics) and Wesley Traub (JPL and CfA) are looking closely at the history of Earth’s atmosphere to understand what happens in the various stages of planetary evolution. The development of life is one of many factors that changed the atmosphere in the past 4.5 billion years. When the day comes that we have spectroscopic data from exoplanets as small as Earth, we’ll be able to study the signatures of the gases there to learn something about conditions on the surface.
Traub puts all this succinctly:
“By studying Earth’s past, we can learn about the present state of other worlds. If an extrasolar planet is found with a spectrum similar to one of our models, we potentially could characterize that planet’s geological state, its habitability, and the degree to which life has evolved on it.”
The researchers have broken Earth’s history down into six epochs, starting in the era 3.9 billion years ago when the atmosphere was primarily nitrogen, carbon dioxide and hydrogen sulfide and a muddy brown ocean covered the planet, warmed by a red sun shining through an orange brick-colored sky. They chart that history through high methane concentrations to the shift in atmospheric balance caused by the production of oxygen, beginning about 2.4 billion years ago. Some 300 million years ago, the atmosphere had reached its current nitrogen/oxygen balance at the beginning of the Mesozoic.
Image: Earth’s early atmosphere of nitrogen, methane and carbon dioxide was hostile to life as we know it, but friendly to the first methane-loving bacteria. Astronomers modeled the history of Earth’s atmosphere to learn what fingerprints to seek on alien worlds. Credit: David A. Aguilar (CfA).
The most intriguing question is this one: Is our present era distinctive enough that astronomers here could detect not just life but signs of a technological civilization on a distant planet? Here we may be moving beyond the capabilities of the Terrestrial Planet Finder and Darwin missions, but much larger space-based arrays of infrared telescopes may one day make it happen.
So we’ll be able to tell a lot about habitability and the existence of life with near-future missions, even if unequivocally spotting an exo-civilization may take a little longer. “As daunting as this challenge sounds,” said Kaltenegger, “I do believe in the next few decades we will know whether or not our little blue world is all alone in the Universe or if there are neighbors out there waiting to meet us.” Which is enough to keep many an exoplanet hunter mining those wobbles and light-curves with renewed enthusiasm.
by Paul Gilster | Sep 14, 2006 | Exoplanetary Science |
A Jupiter-sized planet with the density of cork? The idea seems farcical, but it’s under discussion as I write at a news conference held by the Harvard-Smithsonian Center for Astrophysics (CfA). The planet, called HAT P-1, revolves around ADS 16402, a star much like our Sun that is part of a binary system some 450 light years away in the constellation Lacerta. The first planet found by the Hungarian Automated Telescope observing network, HAT P-1 may represent a new class of planet entirely.
For despite a radius of 1.38 times Jupiter’s, HAT P-1 has only half its mass. “This planet is about one-quarter the density of water,” said Gaspar Bakos (CfA). “In other words, it’s lighter than a giant ball of cork! Just like Saturn, it would float in a bathtub if you could find a tub big enough to hold it, but it would float almost three times higher.” Intriguingly, the new world isn’t the first planet with oddly low density. Another planet found by the transit method, HD 209458b, is also about 20 percent larger than predicted by theory.
So how do you puff up a planet? Additional heat in its interior would do the job, and that could be accomplished through tidal heating if the planet were titled in a Uranian-style orbit on its side. But that scenario doesn’t seem likely. As Smithsonian astronomer Matthew Holman puts it, “The circumstances required to tip over a planet are so unusual that this would seem unlikely to explain both known examples of inflated worlds.” Another possibility: tidal heating due to an eccentric orbit, but the current observations do not favor this possibility.
Image: The newly discovered world HAT-P-1 has baffled astronomers, since it is puffed up much larger than theory predicts. HAT-P-1 has a radius about 1.38 times Jupiter’s but contains only half Jupiter’s mass. Credit: David A. Aguilar (CfA).
HAT P-1 revolves around its primary once every 4.5 days at a distance twenty times closer to the Sun than the Earth. What we’ll hope to gain from detailed follow-up studies of this bizarre world is new information about how giant planets are formed and evolve. Right now there seem to be more questions than answers, and it will be fascinating to read this work in its entirety when it appears in The Astrophysical Journal. A preprint has just been posted at the arXiv site.
We’ll discuss the second announcement from this morning’s news conference — on biomarkers and the analysis of exoplanet atmospheres — tomorrow.
