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Invisible dark matter particles may regularly pass through our bodies, and dozens to thousands of these particles may be colliding with atoms inside us every year, according to a new calculation. However, radiation from these impacts is unlikely to cause cancer, investigators added. Dark matter is one of the greatest scientific mysteries of our time — an invisible substance thought to make up five-sixths of all matter in the universe. Scientists think it might be composed of things called weakly interacting massive particles, or WIMPs, that interact normally with gravity but very weakly with all the other known forces of...

A new study has found no trace of the mysterious substance known as dark matter around the sun, adding a twist to current theories, researchers say. Dark matter is one of the greatest cosmic mysteries of our time — an invisible, intangible material thought to make up five-sixths of all matter in the universe. Scientists currently think it is composed of a new type of particle, one that interacts normally with gravity but only very weakly with all the other known forces of the universe. As such, dark matter is detectable only via the gravitational pull it generates. Astronomers first...

Enlarge Image Home sweet home. In the vicinity of the sun, our Milky Way galaxy seems to contain no dark matter, one team of astronomers claims. Credit: Serge Brunier/NASA If a new study is true, then the search for dark matter just got a lot weirder. Our little corner of the Milky Way contains no observable concentration of the mysterious stuff whose gravity binds the galaxy, claims one team of astronomers. That finding would present a major problem for models of how galaxies form and may undermine the whole notion of dark matter, the researchers claim. But some scientists...

Analysis of data from the National Science Foundation-(NSF) funded 10-m South Pole Telescope (SPT) in Antarctica provides new support for the most widely accepted explanation of dark energy, the source of the mysterious force that is responsible for the accelerating expansion of the universe. The results begin to hone in on the tiny mass of the neutrinos, the most abundant particles in the universe, which until recently were thought to be without mass. The SPT data strongly support Albert Einstein's cosmological constant—the leading model for dark energy—even though researchers base the analysis on only a fraction of the SPT data...

Einstein is still the boss, say researchers with the BOSS project for measuring key properties of the universe. BOSS, for Baryon Oscillation Spectroscopic Survey, has measured the distance to faraway galaxies more precisely than ever before, mapping the universe as it existed roughly 6 billion years ago, when it was only 63 percent of its current size. The findings suggest that the mysterious “dark energy” causing the universe to expand at an accelerating rate was foreseen by Einstein, the researchers reported April 1 at the American Physical Society meeting. To keep the universe in a static state, Einstein added a...

Astronomers have measured the precise distance to over a quarter of a million galaxies to gain new insights into a key period in cosmic history. The 3D map of the sky allows scientists to probe the time six billion years ago when dark energy became the dominant influence on the Universe's expansion. No-one knows the true nature of this repulsive force, but the exquisite data in the international BOSS survey will help test various theories. The analysis appears in six papers. These have all been posted on the arXiv preprint server. "This is an incredibly exciting time to be working...

Frenetic star-forming activity in the early Universe is linked to the most massive galaxies in today's cosmos, new research suggests. This "starbursting" activity when the Universe was just a few billion years old appears to have been clamped off by the growth of supermassive black holes. An international team gathered hints of the mysterious "dark matter" in early galaxies to confirm the link. The findings appear in Monthly Notices of the Royal Astronomical Society. ... Using the 12-metre Atacama Pathfinder Experiment telescope in Chile, an international team led by Ryan Hickox of Dartmouth College studied the way distant galaxies from...

Explanation: What's large and blue and can wrap itself around an entire galaxy? A gravitational lens mirage. Pictured above, the gravity of a luminous red galaxy (LRG) has gravitationally distorted the light from a much more distant blue galaxy. More typically, such light bending results in two discernible images of the distant galaxy, but here the lens alignment is so precise that the background galaxy is distorted into a horseshoe -- a nearly complete ring. Since such a lensing effect was generally predicted in some detail by Albert Einstein over 70 years ago, rings like this are now known as...

Scientists' predictions about the mysterious dark matter purported to make up most of the mass of the Universe may have to be revised.Research on dwarf galaxies suggests they cannot form in the way they do if dark matter exists in the form that the most common model requires it to. That may mean that the Large Hadron Collider will not be able to spot it. Leading cosmologist Carlos Frenk spoke of the "disturbing" developments at the British Science Festival in Bradford. The current theory holds that around 4% of the Universe is made up of normal matter - the stuff...

First results from a major astronomical survey have confirmed the existence of mysterious dark energy using a cutting-edge technique. Dark energy makes up some 74% of the Universe and its existence explains why the Universe appears to be expanding at an accelerating rate. The finding was based on studies of more than 200,000 galaxies. Scientists used two separate kinds of observation to provide an independent check on previous dark energy results. Two papers by an international team of researchers have been accepted for publication in the Monthly Notices of the Royal Astronomical Society journal. One type of observation used by...

Is an Adjacent Universe Causing the Dark Flow of Hundred of Millions of Stars at the Edge of the Observable Universe? Or, Might It Be Something ElseBack in the Middle Ages, maps showed terrifying images of sea dragons at the boundaries of the known world. Today, scientists have observed strange new motion at the very limits of the known universe -- kind of where you'd expect to find new things, but they still didn't expect this. A huge swathe of galactic clusters seem to be heading to a cosmic hotspot and nobody knows why. The unexplained motion has hundreds of...

Discovery of dark matter's behavior would solve many outstanding mysteries in physics Dark matter makes up five times more of the universe's mass that visible matter (~25% vs ~5%), yet scientists have yet to directly observe this ultra-abundant substance.  Scientists also have yet to observe dark energy, which may well beat out normal energy in universal abundance.  This lack of direct observations means that scientists no precious little about two of the most important physical components of our universe. That could soon change.  CERN's Large Hadron Collider, a 17-mile long circular underground track that is chilled to almost zero degrees Kelvin,...

WELLINGTON (AFP) – An extraordinary underground observatory for subatomic particles has been completed in a huge cube of ice one kilometre on each side deep under the South Pole, researchers said. Building the IceCube, the world's largest neutrino observatory, has taken a gruelling decade of work in the Antarctic tundra and will help scientists study space particles in the search for dark matter, invisible material that makes up most of the Universe's mass. The observatory, located 1,400 metres underground near the US Amundsen-Scott South Pole Station, cost more than 270 million dollars, according to the US National Science Foundation (NSF)....

Researchers have developed a simple technique that adds evidence to the theory that the Universe is flat. Moreover, the method - developed by revisiting a 30-year-old idea - confirms that "dark energy" makes up nearly three-quarters of the Universe. The research, published in Nature, uses existing data and relies on fewer assumptions than current approaches. Author Christian Marinoni says the idea turns estimating the Universe's shape into "primary school" geometry. While the idea of the Earth being flat preoccupied explorers centuries ago, the question of whether the Universe itself is flat remains a debatable topic. The degree to which the...

Today physicists announced that they may have found the key to explaining dark matter in the universe. It all has to do with the potential discovery of a "sterile neutrino." According to a release about the new study: Neutrinos are neutral elementary particles born in the radioactive decay of other particles. The known "flavors" of neutrinos are the neutral counterparts of electrons and their heavier cousins, muons and taus. Regardless of a neutrino's original flavor, the particles constantly flip from one type to another in a phenomenon called "neutrino flavor oscillation." An electron neutrino might become a muon neutrino, and...

PASADENA, Calif. -- Astronomers have devised a new method for measuring perhaps the greatest puzzle of our universe -- dark energy. This mysterious force, discovered in 1998, is pushing our universe apart at ever-increasing speeds. For the first time, astronomers using NASA's Hubble Space Telescope were able to take advantage of a giant magnifying lens in space -- a massive cluster of galaxies -- to narrow in on the nature of dark energy. Their calculations, when combined with data from other methods, significantly increase the accuracy of dark energy measurements. This may eventually lead to an explanation of what the...

British scientists have claimed that the method used to calculate the make-up of the universe may be wrong. The universe as we know it -- formed of recognisable components such as planets, stars, asteroids and gas -- accounts for just four per cent of the cosmos, according to the decades old Standard Model. The rest is thought to be made up of mysterious dark matter and dark energy. This permeates space and powers the expansion of the universe. But physicists at Durham University now claim the calculations on which the Standard Model is based could be fatally flawed. This raises...

Research scientists announced on Monday they had identified the missing piece of a major puzzle involving the make-up of the universe by observing a neutrino particle change from one type to another. Science The CERN physics research center near Geneva, relaying the announcement from the Gran Sasso laboratory in central Italy, said the breakthrough was a major boost for its own LHC particle collider programme to unveil key secrets of the cosmos. According to physicists at Gran Sasso, after three years of monitoring multiple billions of muon neutrinos beamed to them through the earth from CERN 730 kms (456 miles)...

Found: 90% of the distant Universe This is fascinating news: 90% of the distant Universe was thought to be missing, but it was recently found. And what’s weird is, it was found to be in the red. Quite literally. [Note: before you ask, this has nothing to do with dark matter. See below!] GOODS_deepfield First, a bit of background. Galaxies are filled with hydrogen gas, and that gas is a major component of the clouds that collapse to form stars. When that happens, the hot stars ionize the gas: the flood of ultraviolet light strips the electron away from the...

GENEVA (Reuters) – Dark matter, which scientists believe makes up 25 percent of the universe but whose existence has never been proven, could be detected by the giant particle collider at CERN, the research center's head said Monday. Rolf-Dieter Heuer told a news conference some evidence for the matter may emerge even in the shorter term from mega-power particle collisions aimed at recreating conditions at the "Big Bang" birth of the universe some 13.7 billion years ago. "We don't know what dark matter is," said Heuer, Director-General of the European Organization for Nuclear Research on the Swiss-French border near Geneva....

Scientists announced Thursday that they believe they have detected evidence of dark matter in data collected at an underground physics lab in Soudan... According to the Department of Energy's Fermilab, which is conducting the search for dark matter at the Soudan lab, "judging by the way galaxies rotate, scientists have known for 70 years that the matter we can see does not provide enough gravitational pull to hold the galaxies together. There must exist some form of matter that does not emit or reflect light." In the announcement, the lab said the Cryogenic Dark Matter Search experiment has "detected...

Physicists have detected a particle of dark matter for the first time in human history, according to rumours buzzing around the internet. Should it prove correct the finding would have an Earth-shattering effect on our understanding of how galaxies form. This week news leaked onto a physics blog that researchers from this Cryogenic Dark Matter Search will publish some important results in the next edition of the journal Nature. Physics papers rarely appear in that journal, except to announce a new discovery. The New Scientist has also reported that talks have hurriedly been scheduled for 18 December at SLAC National...

What if the discrepancy arises from a flaw in our theory of gravity rather than from some provider of mass that we cannot see? In the 1980s physicist Mordehai Milgrom of the Weizmann Institute of Science in Rehovot, Israel, proposed a modification to Newtonian dynamics that would explain many of the observational discrepancies without requiring significant mass to be hidden away in dark matter. But it fell short of describing all celestial objects, and to incorporate the full span of gravitational interactions, a modification to Albert Einstein's theory of general relativity is needed. A review article in the November 6...

I came across a news item in the USA Today website, dated August 18, that got my attention. It concerns "Dark Energy", the mysterious force that seems to be speeding up the expansion of the universe, that no one can find or explain. Two scientists say is doesn't exist now because of a "mathematical solution they have produced, that suggests it is a natural result of the Big Bang. Part of the article is reproduced here. "What's the answer? It doesn't exist, suggest mathematicians Blake Temple and Joel Smoller, in a study released Monday by the Proceedings of the National...

Gamma-ray spike in Fermi telescope data hikes anticipation.The jury is still out on whether Fermi has spied dark matter.NASA/DOE/International LAT Team The murky hunt for dark matter has just got a little bit brighter. New gamma-ray results from the FERMI telescope fit with previous tantalizing hints of a detection of the mysterious stuff.Last year, a series of independent experiments caused a stir because they seemed to have detected signals of dark matter, which is believed to make up 85% of the universe's matter."There's been tremendous excitement about cosmic ray signals that have dark matter as one possible explanation," says Neal...

Imagine a time when the entire universe froze. According to a new model for dark energy, that is essentially what happened about 11.5 billion years ago, when the universe was a quarter of the size it is today. The model, published online May 6 in the journal Physical Review D, was developed by Research Associate Sourish Dutta and Professor of Physics Robert Scherrer at Vanderbilt University, working with Professor of Physics Stephen Hsu and graduate student David Reeb at the University of Oregon. A cosmological phase transition -- similar to freezing -- is one of the distinctive aspects of this...

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...

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...

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...

PARIS (AFP) – European astronomers said on Wednesday that an anomalous energy signal detected by an orbiting satellite could be a telltale of the enigmatic substance known as dark matter. The researchers, in a study appearing in the British journal Nature, say the hunch is that they picked up a signature of this strange phenomenon, but more work is needed. Some years ago, astrophysicists calculating the amount of matter in the Universe arrived at the startling discovery that ordinary material -- atoms -- comprises perhaps as little as five percent of the stuff in the cosmos. The rest, they believe,...

Does Dark Energy Really Exist? Or does Earth occupy a very unusual place in the universe? Scientific American, March 2009 By Timothy Clifton and Pedro G. Ferreira ... Most of us are very familiar with the idea that our planet is nothing more than a tiny speck orbiting a typical star, somewhere near the edge of an otherwise unnoteworthy galaxy. In the midst of a universe populated by billions of galaxies that stretch out to our cosmic horizon, we are led to believe that there is nothing special or unique about our location. But what is the evidence for this...

Nov. 19, 2008: An international team of researchers has discovered a puzzling surplus of high-energy electrons bombarding Earth from space. The source of these cosmic rays is unknown, but it must be close to the solar system and it could be made of dark matter. Their results are being reported in the Nov. 20th issue of the journal Nature. "This is a big discovery," says co-author John Wefel of Louisiana State University. "It's the first time we've seen a discrete source of accelerated cosmic rays standing out from the general galactic background." Galactic cosmic rays are subatomic particles accelerated...

The first stars to light the early universe may have been powered by dark matter, according to a new study. Researchers from the University of Michagan, Ann Arbor call these very first stars "Dark Stars," and propose that dark matter heating provided the energy for these stars instead of fusion. The researchers propose that with a high concentration of dark matter in the early Universe, the theoretical particles called Weakly Interacting Massive Particles(WIMPs), collected inside the first stars and annihilated themselves to produce a heat source to power the stars. "We studied the behavior of WIMPs in the first stars,"...

For the past quarter century, dark matter has been a mystery we've just had to live with. But the time may be getting close when science can finally unveil what this befuddling stuff is that makes up most of the matter in the universe. Dark matter can't be seen. Nobody even knows what it is. But it must be there, because without it galaxies would fly apart. Upcoming experiments on Earth such as the Large Hadron Collider (LHC) particle accelerator in Switzerland, and a new spacecraft called Gaia set to launch in 2011, could be the key to closing the...

Proton discovery may cast doubt on dark-matter theories. The Milagro detector has seen cosmic-ray hot-spots.Milagro / U. Maryland / LANL Hot on the heels of speculation that cosmic rays may have revealed the signature of elusive dark matter in space, new observations could challenge that idea and reinforce an alternative explanation.A seven-year-long experiment at the Milagro cosmic-ray detector near Los Alamos, New Mexico, has revealed 'bright patches' of high-energy cosmic rays in the sky1 – something incompatible with a dark-matter source.Cosmic rays are charged particles, mostly protons and electrons, that are produced in space and generally have a characteristic energy...

The multi-million dollar 1000 Genomes project is set to be finished in a year. The same but different. The 1000 Genomes project aims to catalogue human genetic variation.Punchstock An almost complete catalogue of human genetic variation could be available by the end of 2009, thanks to a massive genome sequencing project that includes academic and industrial partners around the world.Announcing completion of the pilot phase of the 1000 Genomes project, the project's co-chair David Altshuler said last week that it has already successfully catalogued 3.8 trillion bases of sequence — approximately a thousand times the number found in a single...

Dark energy - the mysterious force that is speeding up the expansion of the Universe - has been a part of space for at least nine billion years. That is the conclusion of astronomers who presented results from a three-year study using the Hubble Space Telescope. The finding may rule out some competing theories that predict the strength of dark energy changes over time. Dark energy makes up about 70% of the Universe; the rest is dark matter (25%) and normal matter (5%). "It appears this dark energy was already boosting the expansion of the Universe as much as...

PARIS (AFP) – An orbiting observatory has spotted a massive cluster of galaxies in deep space that can only be explained by the exotic phenomenon known as dark energy, the European Space Agency (ESA) said on Monday. Spotted in a scan by ESA's orbiting X-ray telescope XMM-Newton, the cluster's mass is about 1,000 times that of our own galaxy, the Milky Way, it said. The huge cluster, known by its catalogue number of 2XMM J083026+524133, lies 7.7 billion light years from Earth and helps confirm the existence of dark energy, the agency said. Under this hypothesis, most of the Universe...

Tsunami invisibility cloak, dark energy v. the void, sorting nanotubes with light, and moreNews from the American Physical SocietyTsunami Invisibility Cloak M. Farhat, S. Enoch, S. Guenneau and A.B. Movchan Physical Review Letters (forthcoming) Rather than building stronger ocean-based structures to withstand tsunamis, it might be easier to simply make the structures disappear. A collaboration of physicists from the Centre National de la Recherche Scientifique (CNRS) and Aix-Marseille Universite in France and the University of Liverpool in England have conducted laboratory experiments showing that it's possible to make type of dike that acts as an invisibility cloak that hides off-shore...

If the notion of dark energy sounds improbable, get ready for an even more outlandish suggestion. Earth may be trapped in an abnormal bubble of space-time that is particularly void of matter. Scientists say this condition could account for the apparent acceleration of the universe's expansion, for which dark energy currently is the leading explanation.

Nobody knows what dark matter is, but scientists may now have a clue where to look for it. The strange stuff makes up about 85 percent of the heft of the universe. It's invisible, but researchers know it's there because there is not enough regular matter -- stars and planets and gas and dust -- to hold galaxies and galaxy clusters together. Some other unseen material, dubbed dark matter, must be gluing things together... A new computer simulation of the evolution of a galaxy like our Milky Way suggests it might be possible to observe high-energy gamma-rays given off by...

A study of small galaxies circling around the Milky Way found that while they range dramatically in brightness, they all surprisingly pack about the same mass. The work suggests there is a minimum size for galaxies, and it could shed light on mysterious dark matter. Spinning around the Milky Way are at least 23 pint-sized galaxies, each shining with the light of anywhere from a thousand to a billion suns. Though each of these galaxies is very dim compared to large galaxies like our own, they span a large range in brightness. Astronomers led by Louis Strigari of the University...

Everything in the known universe is said to be racing toward the massive clumps of matter at more than 2 million miles (3.2 million kilometers) an hour -- a movement the researchers have dubbed dark flow. The presence of the extra-universal matter suggests that our universe is part of something bigger -- a multiverse -- and that whatever is out there is very different from the universe we know, according to study leader Alexander Kashlinsky, an astrophysicist at NASA's Goddard Space Flight Center in Maryland... Dark flow was named in a nod to dark energy and dark matter -- two...

As if the mysteries of dark matter and dark energy weren't vexing enough, another baffling cosmic puzzle has been discovered. Patches of matter in the universe seem to be moving at very high speeds and in a uniform direction that can't be explained by any of the known gravitational forces in the observable universe. Astronomers are calling the phenomenon "dark flow." The stuff that's pulling this matter must be outside the observable universe, researchers conclude.

As if the mysteries of dark matter and dark energy weren't vexing enough, another baffling cosmic puzzle has been discovered. Patches of matter in the universe seem to be moving at very high speeds and in a uniform direction that can't be explained by any of the known gravitational forces in the observable universe. Astronomers are calling the phenomenon "dark flow." The stuff that's pulling this matter must be outside the observable universe, researchers conclude. When scientists talk about the observable universe, they don't just mean as far out as the eye, or even the most powerful telescope, can see....

GENEVA - It has been called an Alice in Wonderland investigation into the makeup of the universe — or dangerous tampering with nature that could spell doomsday. Whatever the case, the most powerful atom-smasher ever built comes online Wednesday, eagerly anticipated by scientists worldwide who have awaited this moment for two decades.

HERE IS THE STORY. A black activist commissioner in Dallas County was upset in a meeting by the use of the term "black hole." I called the Commissioners Court and asked for Commissioner Price. They connected me with his secretary, Melanie. We had a nice friendly conversation. It is not racist, and I am not afraid to say it, but her voice indicated that she was a black lady. MELANIE: Commissioner Wiley. DFU: Yes, ma'am, I'm Doug and I'm calling from California about the story of the black hole and Commissioner Wiley. M: Yes, sir. (sort of a little...

A team of Italian and Chinese physicists on Wednesday renewed a controversial claim that they had detected the mysterious dark matter particles that astronomers say swaddle the galaxies in halos and direct the evolution of the universe. The team, called Dama, from “DArk MAtter,” and led by Rita Bernabei of the University of Rome, has maintained since 2000 that a yearly modulation in the rate of flashes in a detector nearly a mile underneath the Gran Sasso mountain in Italy is the result of the Earth’s passage through a “wind” of dark matter particles as it goes around the Sun....

A detailed analysis of eight dwarf galaxies that orbit the Milky Way indicates that their orbital behaviour can be explained more accurately with Modified Newtonian Dynamics (MOND) than by the rival, but more widely accepted, theory of dark matter. The results were presented by Garry Angus, of the University of St Andrews, at the RAS National Astronomy Meeting in Belfast on Wednesday 2nd April. 'MOND was first suggested to account for things that we see in the distant universe. This is the first detailed study in which we've been able to test out the theory on something close to home....