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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...

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...

You can manipulate a black hole as much as you like but you’ll never get rid of its event horizon, a new study suggests. This may sound a little odd, the event horizon is what makes the black hole, well… black. However, in the centre of a black hole, hidden deep inside the event horizon, is a singularity. A singularity is a mathematical consequence, it is also a point in space where the laws of physics do not apply. Mathematics also predicts that singularities can exist without an associated event horizon, but this means that we’d be able to physically...

Enlarge ImageBreaking their way. Makoto Kobayashi (left), Toshihide Maskawa (center), and Yoichiro Nambu share the prize for work on two different aspects of "broken symmetry."Credit: KYODO/Reuters This year's Nobel Prize in physics honors three particle theorist of Japanese origin, one for pioneering the use of a key conceptual tool and the other two for making, in essence, an inspired educated guess that expanded the family of fundamental subatomic particles. Yoichiro Nambu, 87, of the University of Chicago in Illinois receives half the $1.4 million prize for, in the early 1960s, applying to particle physics the concept of spontaneous symmetry...

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.

HONOLULU — A federal judge in Hawaii has dismissed a lawsuit trying to stop the world's largest atom smasher. U.S. District Court Judge Helen Gilmor ruled Friday that federal courts don't have jurisdiction over the Large Hadron Collider in Europe, near Geneva. Two Hawaii residents sued because they feared that the machine could create small black holes or other phenomena that could destroy the planet.

The standard model of cosmology predicts that the universe is infinite and flat. However, cosmologists in France and the US are now suggesting that space could be finite and shaped like a dodecahedron instead. They claim that a universe with the same shape as the twelve-sided polygon can explain measurements of the cosmic microwave background – the radiation left over from the big bang – that spaces with more mundane shapes cannot.Power spectrum of the cosmic microwave background (CMB) radiation. Data from WMAP have extended the accuracy of the spectrum far beyond what was known from earlier measurements. This plot...

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...

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.

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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....

"Plans to begin smashing particles at the Large Hadron Collider (LHC) may be delayed after a magnet failure forced engineers to halt work." "The failure, known as a quench, caused around 100 of the LHC's super-cooled magnets to heat up by as much as 100C." "The fire brigade were called out after a tonne of liquid helium leaked into the tunnel at Cern, near Geneva." "The LHC beam will remain turned off over the weekend while engineers investigate the severity of the fault."

Don't get the idea that we've found every kind of astronomical object there is in the universe. In a paper to appear in the Astrophysical Journal, astronomers working on the Supernova Cosmology Project report finding a new kind of something that they cannot make any sense of. Now you don't see it, now you do. Something in Bootes truly in the middle of nowhere — apparently not even in a galaxy — brightened by at least 120 times during more than three months and then faded away. Its spectrum was like nothing ever seen, write the discoverers, with "five broad...

Six months ago, satellite telescopes spotted an exceptionally bright burst of energy that would have been the most distant object in the universe ever visible to the naked eye, if anyone had noticed it. Even though no humans have reported seeing it directly, the gamma-ray burst, an explosion that signals the violent death of a massive star, is changing theories of how these events look. Gamma-ray bursts are typically accompanied by intense releases of other forms of radiation, from X-rays to visible light. This burst, dubbed GRB 080319B, was first detected by the Swift satellite on March 19, while the...

THREE hundred feet below the outskirts of Geneva lies part of a 17-mile-long tubular track, circling its way across the French border and back again, whose interior is so pristine and whose nearly 10,000 surrounding magnets so frigid, that it’s one of the emptiest and coldest regions of space in the solar system. The track is part of the Large Hadron Collider, a technological marvel built by physicists and engineers, and described alternatively as heralding the next revolution in our understanding of the universe or, less felicitously, as a doomsday machine that may destroy the planet. After more than a...

5 Things You Need to Know About the Large Hadron Collider Now Study up with new mysteries from the celebrity particle collider before it doesn't destroy the world on Wednesday, then talk physics with the interactive chat widget below—and stay tuned for on-the-scene reporting in the morning! A a large dipole magnet is lowered into the tunnel to complete the basic installation of the more than 1700 magnets that make up the Large Hadron Collider (LHC), which measures 27 km in circumference. The largest particle accelerator in history will take another step on Wednesday toward living up to its own...

A massive gamma-ray burst detected last March, believed to be the brightest ever seen, turns out to have been aimed directly at the Earth. A narrow jet that drove material toward us at 99.99995 of the speed of light is revealed in the data, itself wrapped within a somewhat slower and wider jet. The best estimates are that an alignment like this occurs only once every ten years. Says Paul O’Brien (University of Leicester, and a member of the team working on the Swift satellite): “We normally detect only the wide jet of a GRB as the inner jet is...

Once considered rare and exotic objects, black holes are now known to exist throughout the Universe, with the largest and most massive found at the centres of the largest galaxies. These "ultra-massive" black holes have been shown to have masses upwards of one billion times that of our own Sun. Now, Priyamvada Natarajan, an associate professor of astronomy and physics at Yale University and a fellow at the Radcliffe Institute for Advanced Study, has shown that even the biggest of these gravitational monsters can't keep growing forever. Instead, they appear to curb their own growth - once they accumulate about...