Recently in The Universe Category
"'This is a landmark discovery because it implies that solar system analogs may be very common, at least scaled-down versions,' said Sara Seager, an extra-solar planet expert from the Massachusetts Institute of Technology. '...We are on an inexorable path to finding other Earths.'" Astronomers find a solar system not unlike our own 5,000 light years away. "We are seeing the emergence of a new planet-finding technique -- one that opens up an entirely new capability for planet finding. It is more powerful than we ever thought possible."
"It could be the weirdest and most embarrassing prediction in the history of cosmology, if not science. If true, it would mean that you yourself reading this article are more likely to be some momentary fluctuation in a field of matter and energy out in space than a person with a real past born through billions of years of evolution in an orderly star-spangled cosmos. Your memories and the world you think you see around you are illusions."
In today's NYT, Dennis Overbye attempts to explain the Boltzmann Brain problem, a theoretical puzzle causing consternation among cosmologists. “'It is part of a much bigger set of questions about how to think about probabilities in an infinite universe in which everything that can occur, does occur, infinitely many times,' said Leonard Susskind of Stanford, a co-author of a paper in 2002 that helped set off the debate. Or as Andrei Linde, another Stanford theorist given to colorful language, loosely characterized the possibility of a replica of your own brain forming out in space sometime, 'How do you compute the probability to be reincarnated to the probability of being born?'”
Um, yeah. The graphic sorta helps explain what may be going on: Minute fluctuations in the universe's general move towards entropy create random pockets of order, some of which could hypothetically organize as floating brains, or pocket universes or whales and flowerpots too, I suppose. Or something like that...Now my brain hurts.
"...as if millions of voices suddenly cried out in terror and were suddenly silenced." Scientists at NASA catch a glimpse of cosmic devastation on a galactic scale, as a "death star galaxy," fueled by a black hole, destroys its neighbor with a beam of radiation. "The telescope images show the bully galaxy shooting a stream of deadly radiation particles into the lower section of the other galaxy, which is about one-tenth its size...Tens of millions of stars, including those with orbiting planets, are likely in the path of the deadly jet...If Earth were in the way -- and it's not -- the high-energy particles and radiation of the jet would in a matter of months strip away the planet's protective ozone layer and compress the protective magnetosphere." And what does that mean? "'You would basically render extinct all surface forms of life,' Tyson said. 'But it may be that subterranean life is...immune to this kind of violence in the universe.'" You heard the man...start digging.
Have we inadvertently killed Schrödinger's cat? No, it's much, much worse. Cosmologists at Case Western Reserve and Vanderbilt speculate that mankind may have hastened the end of the universe by observing dark energy in 1998. "[Q]uantum theory says that whenever we observe or measure something, we could stop it decaying due what is what is called the 'quantum Zeno effect,' which suggests that if an 'observer' makes repeated, quick observations of a microscopic object undergoing change, the object can stop changing - just as a watched kettle never boils...Prof Krauss says that the measurement of the light from supernovae in 1998, which provided evidence of dark energy, may have reset the decay of the void to zero -- back to a point when the likelihood of its surviving was falling rapidly. 'In short, we may have snatched away the possibility of long-term survival for our universe and made it more likely it will decay,' says Prof Krauss." D'oh! But wouldn't this presume that at no other place or time in our unfathomably gigantic universe did any other civilization make the same observations? Given the odds of intelligent life out there, that seems unlikely. (And, if you think this all sounds goofy and ridiculous, just wait until we get to the multiverse...)
"Fact:...The density of Saturn is so low that if you were to put it in a giant glass of water it would float." And another pilfered link, which I meant to post last week: Megg of Quiddity points the way to 10 Cool Facts about Space (although, to paraphrase The Smiths, some facts are cooler than others.)
"'We're thrilled to have identified clear signs of water on a planet that is trillions of miles away,' said study leader Giovanna Tinetti of the Institut d'Astrophysique de Paris in France." Scientists discover clear signs of existing water well outside the solar system at HD 189733b, a Jupiter-ish gas giant in the Vulpecula constellation, 64 light years away. "The researchers found that the planet absorbed starlight in such a way that could only be explained by the presence of water vapor in its atmosphere."
"Because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extraterrestrial life. On the treasure map of the Universe, one would be tempted to mark this planet with an X." The big news today, of course: Astronomers announce the discovery of an earth-like planet, Gliese 581c, at the galactically tiny distance of 120 trillion miles (20.5 light years) away. (For the stargazers, Gliese 581 is a red dwarf "located in the northeastern part of constellation Libra.") Of course, we still don't know if we even have to go that far to find extraterrestrial life -- Europa, Mars, Ganymede, and Callisto all still pose unresolved questions. Nevertheless, it's an exciting moment in our history to discover the first planet far afield that might possibly be inhabited (and inhabitable)...and even more exciting to know that there'll assuredly be many more to come. The stars, our destination!
A faraway Jupiter-like gas planet, HD 209458b, is found (by some) to have water in its atmosphere. I saw this on Blivet on Friday and spent the weekend dreaming about it: If my sleeping brain can be trusted, HD 209458b has winged, eel-like space reptiles cavorting amidst the gaseous clouds there. Alas, my subconscious makes for a lousy exobiologist: "[A] Jupiter-like gaseous planet such as this one, as opposed to a rocky one like Earth, is highly unlikely to harbour any kind of life." Well, damn.
Using the thankfully soon-to-be-refurbished Hubble, astronomers find more evidence of "dark energy" in the early universe working along the lines of Einstein's famous fudge factor, the cosmological constant, to combat a gravitational crunch. "'Dark energy makes us nervous,' said Sean Carroll, a theoretical physicist at the California Institute of Technology who was not involved in the supernova study. 'It fits the data, but it's not what we really expected.'"
The WP takes a gander at the Southern African Large Telescope (SALT), which "can see 13 billion years back in time, nearly to the big bang. With its 10-by-11-foot hexagonal mirror -- the largest of its type in the world -- SALT concentrates the faintest, most distant light in the universe. If a candle were to flicker on the moon, SALT could detect it."
After discovering a disk of gas, dust, and rubble orbiting a pulsar, astronomers believe they've figured out how planets are made. "It shows that planet formation is really ubiquitous in the universe. It's a very robust process and can happen in all sorts of unexpected environments."
Using the relatively new technique of gravitational microlensing, astronomers discover their "most Earth-like planet yet", orbiting a star in Sagittarius 20,000 light-years away. While this planet -- currently named OGLE-2005-BLG-390Lb -- is likely too cold for habitation, "'we may predict with reasonable probability that microlensing will discover planets with masses like that of Earth at a similar distance from their stars and with comparable surface temperature,' said study co-author Bohdan Paczynski from Princeton University."
"'As you go back in time, the universe is pushing [outward] less and less,' he said. 'At some point, the pressure of dark energy is zero and is exerting no force on the universe. There is no explanation for it.'" New cosmological research announced yesterday further muddles our understanding of the expansion of the early universe and (once again) casts doubt on Einstein's recently resurrected cosmological constant. "Schaefer based his findings on analysis of ultra-bright cosmic explosions called gamma-ray bursts, detected as far as 12.8 billion light-years away. He found that the most distant explosions appeared brighter than they should have been if the universe were accelerating at a constant rate."
