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Enlarge ImageKilljoy. NASA's orbiting Fermi Gamma-ray Space Telescope has not reproduced a previously claimed signature of dark matter. Credit: NASA and General Dynamics Last November, data from a balloon-borne particle detector circling the South Pole revealed a dramatic excess of high-energy particles from space--a possible sign of dark matter, the mysterious substance whose gravity seems to hold our galaxy together. But satellite data reported today stick a pin in that claim. Researchers working with NASA's orbiting Fermi Gamma-ray Space Telescope say they do not see the purported excess. The observations don't disprove the existence of dark matter, but they...

New data from two experiments -- one in space, one on a balloon floating above Antarctica -- hint at a tantalizing detection of dark matter, the mysterious stuff comprising 85% of the universe's matter. The evidence is a reported excess of high-energy electrons and their antimatter counterparts, positrons, which could be created as dark matter particles annihilate or decay. The signal from Fermi, the orbiting gamma-ray telescope, is subtle, whereas that claimed by the balloon-borne Advanced Thin Ionization Calorimeter (ATIC) is much more pronounced. The differences are puzzling, but the findings -- according to some -- could herald the birth...

As modern cosmologists rely more and more on the ominous "dark matter" to explain otherwise inexplicable observations, much effort has gone into the detection of this mysterious substance in the last two decades, yet no direct proof could be found that it actually exists. Even if it does exist, dark matter would be unable to reconcile all the current discrepancies between actual measurements and predictions based on theoretical models. Hence the number of physicists questioning the existence of dark matter has been increasing for some time now. Competing theories of gravitation have already been developed which are independent of this...

BRIAN GREENE spent a good part of the last decade extolling the virtues of string theory. He dreamed that one day it would provide physicists with a theory of everything that would describe our universe - ours and ours alone. His bestselling book The Elegant Universe eloquently captured the quest for this ultimate theory. "But the fly in the ointment was that string theory allowed for, in principle, many universes," says Greene, who is a theoretical physicist at Columbia University in New York. In other words, string theory seems equally capable of describing universes very different from ours. Greene hoped...

ScienceDaily (May 2, 2009) — The great science fiction writer Arthur C. Clarke famously noted the similarities between advanced technology and magic. This summer on the big screen, the young wizard Harry Potter will once again don his magic invisibility cloak and disappear. Meanwhile, researchers with Berkeley Lab and the University of California (UC) Berkeley will be studying an invisibility cloak of their own that also hides objects from view. A team led by Xiang Zhang, a principal investigator with Berkeley Lab’s Materials Sciences Division and director of UC Berkeley’s Nano-scale Science and Engineering Center, has created a “carpet cloak”...

This artist's conception shows a rogue black hole floating near a globular star cluster on the outskirts of the Milky Way. New calculations by Ryan O'Leary and Avi Loeb suggest that hundreds of massive black holes, left over from the galaxy-building days of the early universe, may wander the Milky Way. Fortunately, the closest rogue black hole should reside thousands of light-years from Earth. Credit: David A. Aguilar (CfA) (PhysOrg.com) -- It sounds like the plot of a sci-fi movie: rogue black holes roaming our galaxy, threatening to swallow anything that gets too close. In fact, new calculations by...

2008 Nebula Awards

A stellar explosion has smashed the record for most distant object in the known universe. The gamma-ray burst came from about 13 billion light-years away, and represents a relic from when the universe was just 630 million years old. "It easily surpassed the most distant galaxies and quasars," said Edo Berger, an astrophysicist at Harvard University and a leading member of the team that first demonstrated the burst's origin. "In fact, it showed that we can use these spectacular events to pinpoint the first generation of stars and galaxies." "The burst most likely arose from the explosion of a massive...

The first mirror segment that will fly on the James Webb Space Telescope, built by Northrop Grumman Corporation, has completed its first series of cryogenic temperature tests in the X-ray and Cryogenic Facility at the Marshall Space Flight Center in Huntsville, Ala. ... Engineers will measure how the mirror changes shape going from room temperature to cryogenic (frigid) temperatures, as the metal expands and contracts. They can model these changes to some extent, but not perfectly. The mirrors will be polished to about 100 nanometers (a human hair is approximately 60,000 to 120,000 nanometers) accuracy at room temperature, based on...

This image of the Himiko object is a composite and in false color. The bar at the lower right represents 10,000 light years. Credit: M. Ouchi et al. This mysterious, giant object existed at a time when the universe was only about 800 million years old. It stretches for 55 thousand light years, a record for that early point in time. Its length is comparable to the radius of the Milky Way’s disk. Besides being a great candidate for a future “Where in the Universe Challenge,” what is it? In general, objects such as this one are dubbed extended...

LONDON – Famed mathematician Stephen Hawking was rushed to a hospital Monday and was seriously ill, Cambridge University said. ... Hawking, 67, gained renown for his work on black holes, and has remained active despite being diagnosed at 21 with ALS, (amyotrophic lateral sclerosis), an incurable degenerative disorder also known as Lou Gehrig's disease.

Researchers have come up with a theory for how stars can end in a spectacular so-called Type Ia supernova in less than 100 million years.While such early-stage supernovae are well-known, theory has been unable to explain them. The secret, the researchers say, is that white dwarf stars steal mass from nearby "helium stars" until they have enough mass to initiate a supernova.

A jet of gas spewing from a huge black hole has mysteriously brightened, flaring to 90 times its normal glow. For seven years the Hubble Space Telescope has been watching the jet, which pours out of the supermassive black hole in the center of the M87 galaxy. It has photographed the strange phenomenon fading and then brightening, with a peak that even outshines M87's brilliant core. Scientists have dubbed the enigmatic bright blob HST-1, and are so far at a loss to explain its weird behavior. "I did not expect the jet in M87 or any other jet powered by...

Perfect liquids suggest theory’s math mirrors something real Shadows live in a simple world. They glide effortlessly across any sort of surface, oblivious to the higher dimension of space in which 3-D bodies move, collide and sometimes block the paths of rays of light. Shadows have no idea how important that third dimension is, and how objects in it endow those very shadows with their quasi-physical existence. Indeed, the laws of shadow physics all depend on the third dimension’s presence. And just as the clueless inhabitants of the shadow world require an extra dimension to explain how they exist and...

Is theoretical physics becoming the next battleground in the culture wars? Not according to some theologians and scientists.People have long sought after a theory of everything, even when they had nothing but their five senses as tools of measurement. In the 6th century BCE Thales asserted that all matter is made of water; Anaximenes responded that itÂ’s all air. Parmenides a century later concluded with exacting proofs that everything we see is an illusion and that reality really consists of a single, unchanging sphere. Today, scientists are once again looking beyond the pale of measurable time and space to answer...

A new kind of laser could mean cheaper gadgets for allLasers might be pushing 50, but they are still the youthful pin-ups of fundamental physics. Since the first one was unveiled in 1960, the more apocalyptic predictions of how they might be used - as death rays, for example - have proved to be overblown. Their peaceful application, on the other hand, can be seen everywhere from cutting and welding to combating cancer and cataracts, to powering telecoms and consumer electronics, and has mushroomed into an industry worth $6 billion in 2007. Advances in the laser lab translate into gadgets...

Europe's innovative Goce satellite has switched on the super-sensitive instrument that will make ultra-fine measurements of Earth's gravity. The sophisticated gradiometer will feel the subtle variations in Earth's tug as it sweeps around the globe. The spacecraft has also fired up the British-built engine that will help maintain its orbit. Goce needs tiny but continuous levels of thrust to keep it stable and prevent it from falling out of the sky. European Space Agency (Esa) mission manager Rune Floberghagen said all systems on the spacecraft had now been activated following the launch from Russia last month.

A 10-year study of 100,000 galaxies close to our own offers compelling proof that long-hypothesized "dark matter" does exist and is in fact a guiding force behind the structure of the universe, a team of Australian, British, and American astronomers revealed this week. Saying that "the universe we see is really quite structured," one of the lead researchers explained that the 10-year "census" of galaxies near our own Milky Way offers powerful evidence that this invisible dark matter "seems to hold the galaxies together." The dark matter's influence on galaxies "stops their constituent stars from flying off and it seems...

In this centennial year of Albert Einstein's revolutionary theories of space, time, and gravity, humanities scholars say that his influence extended far beyond science. Time is a nebulous thing, except maybe for lunchtime. That's a lesson from The Hitchhiker's Guide to the Galaxy, the science-fiction romp by Douglas Adams that was thrown into Hollywood's Infinite Improba bility Drive and emerged as an early-summer movie hit. Consider the elaborately imagined history of the Guide itself, and of its various editors. We learn that one Lig Lury Jr., hired by a publishing consortium operating from a chunk of celestial real estate called...

Lutherans sure love screwing with bulbs. Especially ones at St. Olaf College. The dynamic minds won the national Rube Goldberg competition. This is seriously the coolest science competition in the nation. All those years playing Mouse Trap don't compare to the video you are about to see. Watch the video on their website.