Today at 10 a.m. Swiss time, researchers fired up the Large Hadron Collider (LHC), successfully sending a stream of protons all the way around a 17-mile track for the first time. The enormous collider has been eagerly anticipated by physicists, who hope the device will answer questions about the behavior of subatomic particles and reveal secrets of the universe, but some people have also worried (needlessly, physicists say) that its unprecedented experiments will cause the world to end. For all that hype, the action today was somewhat anticlimatic: Two white dots flashed on a computer screen indicating that the protons reached the final point of the world’s largest particle collider [AP].
As many scientists have pointed out, today’s test run didn’t involve any actual collisions; those will come later when particles shoot around the track in both directions and smash into each other. Therefore today’s event could never have produced any breathtaking results, it was simply intended to test the equipment.
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It may not be a big market, but it’s presumably a lucrative one: To meet the needs of consumers who are in the business of transmitting classified national secrets, physicists are working on an absolutely secure communication system that uses the strange laws of quantum mechanics to encode information. The latest experiments in this field, called quantum cryptography, produced a system that researchers say would theoretically work to transmit information around the globe.
The system relies on a concept known as quantum entanglement to establish hack-proof communication. Entanglement allows two particles to be quantum-mechanically connected even when they are physically separated. Although the specific condition of either particle cannot be precisely known, taking measurements of one will instantly tell you something about the other. The trick can’t be used to actually send information, because each particle’s condition is random until it is measured. But entanglement can be used for encrypting data if a sender and a receiver make measurements on a number of entangled particles and then compare their results [Nature News].
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The cosmic collision of two galaxy clusters has given astronomers a clearer look at the mysterious substance known as dark matter. Researchers say when the two clusters crashed into each other, the dark matter from each cluster [appeared] to pass through the cosmic mess unscathed, leaving ordinary matter behind in the galactic pileup [SPACE.com]. Using data from NASA‘s Hubble and Chandra space telescopes, astronomers were able to produce an image showing clouds of dark matter, colored blue, on either side of the impact site.
Dark matter, mysterious stuff that exerts a gravitational force on other matter, was originally proposed to explain what holds spinning galaxies, like the Milky Way, together. Observations suggest it outweighs ordinary matter by a factor of about 6 to 1. But no one knows what it is made of, and normally dark matter and ordinary matter are too well mixed to observe the dark matter independently [New Scientist].
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Yesterday, NASA released the first set of images from its newest space telescope, the Gamma-Ray Large Area Space Telescope, which has now been renamed Fermi in honor of the particle physicist Enrico Fermi. After less than three months of collecting data, the Fermi telescope produced a map of the sky showing the sources of powerful gamma rays as bright spots of light.
“I like to call it our extreme machine,” said Jon Morse, the director of astrophysics for NASA. “It will help us crack the mysteries of these enormously powerful emissions.” Gamma rays are powerful light rays invisible to the naked eye [Washington Post]. As the Earth’s atmosphere absorbs gamma rays, they can only be studied from an orbiting telescope.
The $700 million telescope will observe gamma rays emitted by black holes, neutron stars, and other cosmic eccentrics, and will also scan the skies for the mysterious gamma ray bursts that are of special interest to astronomers because they are among the brightest events ever observed. The intense flashes of gamma rays can release within seconds the same amount of energy that the sun will put out over its entire ten-billion-year lifetime—but no one is sure what causes them. The going theory is that the bursts are tied to the explosive deaths of massive stars, but exactly what types of stars and how the explosions are triggered remains a mystery [National Geographic News]. Already, the Fermi telescope has detected gamma ray bursts at a rate of about one a day.
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After 15 years of construction, the world’s largest particle accelerator is warmed up, fully tested, and ready to rumble. The Large Hadron Collider will go into operation on September 10th, and researchers are celebrating every step towards that momentous day. Last weekend, physicists popped champagne to toast the results of a test in which beams of protons were sent barreling into a massive block of concrete, causing the protons to fragment into smaller particles. Researchers have also successfully sent test batches of protons part-way around the collider’s 17-mile circular track.
The Large Hadron Collider represents the science world’s latest, greatest attempt to smash its way into the mysteries of the universe: Beams of protons will eventually collide with the energy of two bullet trains – spawning sprays of subatomic debris that are certain to lead to new discoveries…. One experiment at the LHC, known as ALICE, seeks to re-create the conditions that existed just an instant after the big bang that gave rise to the universe as we know it. [The collider's] researchers want to understand why matter won out over antimatter after the creation of the cosmos [MSNBC].
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Of all the weirdness in the universe, the quantum mechanics phenomenon called “entanglement” may be the most mind-boggling. Physicists have long shaken their heads at the theory that two particles that become entangled will always and instantly mirror each other’s properties, no matter how far they are separated, which seems to go against all other physical understanding. In the everyday world, objects can organize themselves in just a few ways. For example, two people can coordinate their actions by talking directly with each other, or they can both receive instructions from a third source…. But quantum mechanics allows for a third way to coordinate information [Nature News].
Einstein rebelled against the notion of quantum entanglement, derisively calling it “spooky action at a distance” [LiveScience]. Entanglement would look a lot less spooky if we could prove that an entangled object releases an unknown particle or some other signal at high speeds to influence its partner, giving the illusion of a simultaneous reaction [LiveScience]. But a new study shows that if some hidden signal is passing between the separated particles, it would have to travel at 10,000 times the speed of light. As this explanation seems impossible, the research team favors the alternate, weirder idea: that a measurement on one photon instantly influences the other [New Scientist].
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Scientists at CERN had said all along that they planned to activate the Larger Hadron Collider this summer. Now it looks like they’ll slide in just before the official end of the season. The world’s most powerful particle accelerator, aimed at unlocking secrets of the universe, will be launched on September 10 [Reuters].
“We’re finishing a marathon with a sprint,” said project leader Lyn Evans. “It’s been a long haul, and we’re all eager to get the LHC research program under way” [San Jose Mercury News].
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The exact mechanism that triggers the colorful auroras that dance across the night sky near the Earth’s two poles has been revealed by a quintet of NASA satellites. Scientists already knew that disturbances in the Earth’s magnetic field, called “substorms,” bring charged particles into the Earth’s upper atmosphere, where they collide with gas particles. Those gas particles then release energy as light, which flickers across the sky in waves of greens, reds, and blues.
Now, researchers with NASA’s THEMIS mission say they’ve discovered what sets off those magnetic disturbances. The substorms begin far out in space, roughly a third of the way to the Moon, where magnetic fields from the Earth are thrown together and reconnect to sling charged particles back toward the planet, they say [New Scientist].
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Well, that’s a relief. After a long safety review, physicists have declared that the enormous atom smasher that’s expected to go online this fall won’t create tiny black holes that will “eat” our planet. So that’s one less thing to worry about.
The Large Hadron Collider, which is being built near Geneva, Switzerland, will do things with subatomic particles that humans have never done before, causing some people to worry that scientists might be unwittingly building a doomsday devise. The $8 billion machine is designed to accelerate protons, the building blocks of ordinary matter, to energies of 7 trillion electron volts and then bang them together to produce tiny primordial fireballs, miniature versions of the Big Bang. Physicists will comb the detritus from those fireballs in search of forces and particles and even new laws of nature that might have prevailed during the first trillionth of a second of time [The New York Times].
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