#71: Sciences/Computers: 0) Universes/Life. 1) Math. 2) Quantum Physics: Scientists find new 'quasiparticles' 08.6.3=2 - 6.18=3 11am.

#71: Sciences/Computers: 0) Universes/Life. 1) Math. 2) Physics: Top Supercomputers Jun18,08 http://tinyurl.com/4mn3j5 next-generation stream processor, the AMD FireStream 9250, specifically designed to accelerate critical algorithms in high-performance computing (HPC), mainstream and consumer applications. Jun16,08 http://tinyurl.com/6m5njy 0-1) Universes:---------- 'Before the beginning' Ron Cowen, ScenceNews WebEd Jun12,08 http://tinyurl.com/5w3wcw "" Theory suggests a pre-Big Bang universe "" " Caltech scientists have developed new models of the universe that account for the recent finding that temperature variations in the cosmic microwave background radiation over half the sky appear to be about 10 percent greater than the variations in the other half. " http://tinyurl.com/4y3nyk "" Some people are loath to take a lopsided view of the universe, but cosmologist Sean Carroll and his colleagues are positively reveling in it. Embracing a study that suggests the pattern of radiation left over from the Big Bang looks surprisingly different from one side of the sky to the other, Carroll and colleagues have come up with some mind-bending possibilities to explain the puzzle, described in a paper posted online June 3. In one scenario, the universe existed before inflation — the short-lived but enormous growth spurt associated with the Big Bang. In the other scenario, the universe is but a tiny part of a primordial structure now grown so big it exceeds the horizon of the observable universe. Either way, the explanations suggest “that something outside our observable universe or before the period of inflation left a relic, left some imprint on what we can observe today,” says Carroll, of Caltech. Inflation theory posits that during the first minuscule fractions of a second, the subatomic-sized universe swelled to something like the size of a grapefruit. The rapid stretching explains why widely separated parts of the universe appear so much alike. It also explains why the radiation generated during the Big Bang, known as the cosmic microwave background, is uniformly distributed across the sky. Tiny temperature differences in that radiation signify the primordial seeds that ultimately gave rise to galaxies and galaxy clusters, but according to the simplest model of inflation the magnitude of those tiny hot and cold spots ought to be about the same over different parts of the sky. However, that belief seems to be contradicted by a recent finding. An analysis of the cosmic radiation recorded by NASA’s Wilkinson Microwave Anisotropy Probe, or WMAP, shows that the temperature variations over half the sky appear to be about 10 percent greater than the variations in the other half, Hans Eriksen of the University of Oslo in Norway first reported in 2004. He says the asymmetry “looks quite significant, but one shouldn't throw everything else overboard quite yet.” WMAP theorist David Spergel of Princeton University says the finding is “certainly not at the level to make a convincing claim of an asymmetric sky.” But taken at face value, an asymmetric sky poses a problem for the simplest model of inflation, notes Carroll. That’s where he and his Caltech colleagues Marc Kamionkowski and lead author Adrienne Erickcek come into the story. Simply tweaking the theory doesn’t work, Carroll notes. But when his team added major modifications, the model reproduced the asymmetry seen by Eriksen. One of those revisions posits the existence of a “supermode” — a primordial fluctuation in density so much larger than the universe that the fluctuation appears to look uniform. As Carroll notes in a recent blog, it’s as if the cosmos were sampling such a tiny piece of a sine wave that the wave looks likes a straight line instead of oscillating. The neat thing about having a supermode, says Carroll, is that it must have originated before the period of inflation during which the tiny lumps were created that grew into galaxies. Either the supermode came from an even earlier period of inflation, or it preceded inflation entirely. Inflation’s stretch “usually provides a veil between us and the pre-inflationary and/or superhorizon universe,” says coauthor Kamionkowski. But if the asymmetry in the microwave background is confirmed “and if our interpretation is correct, then it provides a window toward regimes of the early universe that we hitherto thought observationally inaccessible.” The new work may also shed light on what sparked inflation in the first place. “What I'm happiest about with this new work are the prospects it opens up for learning more about the physics of inflation, how it got started and/or what happened before inflation,” Kamionkowski adds. The European Space Agency’s Planck mission, set for launch this fall, will look at variations in the cosmic microwave background on finer scales than WMAP and should determine whether or not the asymmetry is real, Eriksen says. Alan Guth of MIT, who first proposed the inflation theory nearly three decades ago, says he suspects “the reported lopsidedness will more likely turn out to be a fluke.” However, he adds, “the concept of inflation is really only the framework of a theory, and so far experiment has given us very little guidance in trying to fill in the details. The authors of this paper are doing just what is needed: they are taking a hint from the data and elaborating it into a theory.… It is only by pursuing such hints that … we will have a chance to find the right way to put meat on the inflationary skeleton.” - - - - - - - - - - - - ======================= 0-2) Life:------------- 'The Ordovician: Life's second big bang' James O'Donoghue, NewScietist 2660: Jun11,08 http://tinyurl.com/5l34pq "" JUST over half a billion years ago, evolution hit a purple patch. In the space of a few million years, once-empty seas were suddenly overrun by all manner of newfangled life forms. Animals had arrived on the scene and life on Earth never looked back. At least, that's what we originally thought the fossil record was telling us. It now turns out that this spectacular event - known as the Cambrian explosion - stuttered to a halt not long after it began. Around 515 million years ago, evolution ran out of steam and the increase in biodiversity went into reverse. For the march of progress to continue, life needed rebooting. It came in the form of a second explosion of life called the Great Ordovician Biodiversification Event, a little-heard-of episode which has been the focus of intense scientific interest in recent years. Since discovering hints of it around 20 years ... "" ======================= ======================= 1) Math:--------------- 'Grand designs: Symmetry's hidden depths' Jun11,08 http://tinyurl.com/3glz2o * Marcus du Sautoy * Magazine issue 2660 OSLO, May 2008. King Harald of Norway presents mathematicians John Thompson and Jacques Tits with the Abel prize, one of the highest accolades in mathematics. There is a pleasing symmetry at the heart of this year's award. The winners are being honoured for ground-breaking work that led to the completion of a project started by Niels Abel, the 19th-century Norwegian mathematician after whom the prize is named. Appropriately enough, that project concerns mathematicians' attempts to answer the question: what is symmetry? 2) Physics:------------- ' Scientists find new 'quasiparticles' ' Jun2,08 http://tinyurl.com/59qjds : " Weizmann Institute physicists have demonstrated, for the first time, the existence of 'quasiparticles' with one quarter the charge of an electron. This finding could be a first step toward creating exotic types of quantum computers that might be powerful, yet highly stable. " ---------------------------- 'World's Largest Quantum Bell Test Spans Three Swiss Towns ' Lisa Zyga; PhysOrg.com. Jun16,08 http://tinyurl.com/5tsq7l

: "" In the Bell test, two photons from an entangled pair were sent from Geneva to Satigny and Jussy, two small towns located 18 km apart. This distance enabled the space-like separation necessary for finishing a quantum measurement in each town, which required a macroscopic mass to move. Detection of the mass’ movement was completed before information could have traveled between the two towns. Credit: D. Salart, et al. In an attempt to rule out any kind of communication between entangled particles, physicists from the University of Geneva have sent two entangled photons traveling to different towns located 18 km apart – the longest distance for this type of quantum measurement. The distance enabled the physicists to completely finish performing their quantum measurements at each detector before any information could have time to travel between the two towns. Many other experiments have observed quantum nonlocality – the “spooky interaction at a distance” that occurs between two entangled particles – and also known as a violation of Bell inequalities. " " Different interpretations of quantum mechanics lead to different answers. The most common view is that a quantum measurement is finished as soon as the photons are absorbed by detectors. Previous experiments have been set up to allow enough distance between particle detectors to prohibit communication under this view. But there are also other views of when the measurement is finished, including “when the result is secured in a classical system,” “when the information is in the environment,” or even that it is never over – a view that leads to the many worlds interpretation. The Swiss team followed a view proposed independently by Penrose and Diosi, which assumes a connection between quantum measurements and gravity, and requires a macroscopic mass to be moved. In this view, the measurement takes more time than it does for a photon to be absorbed by a detector. The significance of the Swiss test is that it is the first “space-like separated” Bell test under the Penrose-Diosi assumption. “There is quite a large community of physicists that speculates on possible connections between quantum gravity and the measurement problem,” coauthor Hugo Zbinden told PhysOrg.com. “The advantage of the Penrose-Diosi model is that it is testable using today's technology.” In the physicists’ experiment, the detection of each photon by a single-photon detector triggers a voltage to a piezoelectric actuator. The actuator expands, which in turn causes a tiny gold-surfaced mirror to move. By measuring the mirror displacement, the researchers could confirm by the gravity-quantum connection that the quantum measurement had been successfully finished. All of the steps – from photon detection to mirror movement – take about 7.1 microseconds, which is significantly less than the 60 microseconds it would take a photon to cover the 18 km between interferometers. So measurements made simultaneously at each of the interferometers could not be been influenced by anything traveling at – or even a few times more than – the speed of light. “The significance of our experiment lies entirely in achieving space-like separation, even under the assumption that a quantum measurement is only finished after a macroscopic mass has moved, as in the Penrose-Diosi model,” Zbinden explained. Altogether, the experiment serves to fill a loophole by ruling out any kind of communication between two entangled particles separated by a distance, provided the collapse happens only after a mass has moved. By spatially separating the entangled photons, the test once again confirms the nonlocal nature of quantum correlations. More information: Salart, D.; Baas, A.; van Houwelingen, J. A. W.; Gisin, N.; and Zbinden, H. “Spacelike Separation in a Bell Test Assuming Gravitationally Induced Collapses.” Physical Review Letters 100, 220404 (2008). ""