If there was a race to see which Large Hadron Collider experiment would provide the first surprise, and the first giddy claims of possible “new physics,” it appears the Compact Muon Solenoid (CMS) has won. CERN scientists announced this week that the most high-energy proton smash-ups produced an weird effect: particles created in the collision were somehow linked together and flew off in an unexpected direction.
In the new experiment, the CMS team took data on the charged particles produced in hundreds of thousands of collisions. The team observed the angles the particles’ paths took with respect to each other, and calculated something called a “correlation function” to determine how intimately the particles are linked after they separate. The plot of the data ends up looking like a topographical map of a mountain surrounded by lowlands and a long ridge behind it (see below). [Wired.com]
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After analyzing light coming from distant quasars, some researchers have asked a physical constant a blunt question: Are you really constant at all? And since the “fine structure constant” that they’re interrogating is important for how physicists understand things like electrons’ behavior in atoms and fusion in stars, other physicists are asking their own question: Are your measurements correct?
The paper, which appeared last month in arXiv, argues that the constant might vary depending on location. This controversial claim is a new twist on a previous controversial claim–made over the past decade by some of the same physicists–which said that the constant varied with time.
Craig Hogan of the University of Chicago and the Fermi National Accelerator Laboratory in Batavia, Ill., acknowledges that “it’s a competent team and a thorough analysis.” But because the work has such profound implications for physics and requires such a high level of precision measurements, “it needs more proof before we’ll believe it.” [Science News]
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Science: It’s best with stuffed fish and a wind tunnel.
When flying fish leap from the water and glide through the air, they appear as streamlined as any bird or insect. But how does one put that assumption to the test? Easy: Catch flying fish from the Sea of Japan (or East Sea, as South Korea calls it), kill them, stuff them, place them in a wind tunnel, and turn on the breeze.
Hyungmin Park and Haecheon Choi did just that. Their study of airflow around the fish, which is out in The Journal of Experimental Biology, concludes that flying fish glide as efficiently as some birds, and perhaps even more so than some flying insects.
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Had compass-toting Boy Scouts existed around fifteen million years ago, they may have had a fun time making it through the forest. New geological research questions if the Earth’s magnetic field changed, at that time, at the remarkable pace of one degree per week, leading to a particularly fast magnetic pole flip.
In a paper to appear in Geophysical Research Letters, Scott Bogue and Jonathan Glen suggest that the Earth’s magnetic field changed 53 degrees in one year’s time, based on their study of preserved lava flows in Nevada. As the solid rock formed from cooling liquid lava, it preserved a pattern corresponding to the “super-fast” geomagnetic field reversal, the researchers believe. This is the second time that Bogue has controversially argued for the existence of such speedy flips, finding hints of a faster one in 1995.
In 1995 an ancient lava flow with an unusual magnetic pattern was discovered in Oregon. It suggested that the field at the time was moving by 6 degrees a day–at least 10,000 times faster than usual. “Not many people believed it,” says Scott Bogue of Occidental College in Los Angeles. [New Scientist]
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Physicist Sean Carroll, one of the people behind Cosmic Variance here at DISCOVER blogs, tweeted yesterday: “I think Stephen Hawking could say ‘ice cream is delicious’ and get massive media coverage.” He’s probably right.
Last month the renowned physicists made the news by warning of the great threat of human extinction over the next couple centuries, but kindly softened the blow by saying that we’ll be fine if we can get through our growing pains and get off this planet. Back in April, the wave of attention came from his warning that it might not be such a great idea to attempt to contact aliens, should they be more advanced than us and try to wipe us out.
Now, he’s taking on the almighty. Hawking’s new book, The Grand Design, co-authored by Leonard Mlodinow, snagged media attention this week because of an excerpt that appeared in the U.K.’s The Times (which we can’t link to, because it’s behind an online pay wall).
“Spontaneous creation is the reason why there is something rather than nothing, why the universe exists, why we exist,” he wrote. “It is not necessary to invoke God to light the blue touch paper [fuse] and set the universe going.” [CNN]
Or, to put it another way, here’s a bit from the book’s final chapter about the nature of the universe:
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Physicists have designed the world’s smallest refrigerator, small enough that it can’t hold any of your food. The fridge consists of three qubits–quantum particles that act as on-off switches. These quantum particles could be ions, atoms, or subatomic particles.
Other small systems have been created, but this is the first that doesn’t rely on external mechanisms, such as sophisticated lasers. “The whole guts of the fridge, it’s all accounted for and not hidden in some macroscopic object which is really doing the work,” [coauthor Noah] Linden says. [Science News]
Kitchen refrigerators work by shuttling heat away from one area (where you store your food) and dumping it somewhere else (the coils behind). This transfer isn’t news. Fans of thermodynamics have built devices to wick away heat from one source and dump it somewhere else since the nineteenth century. The device proposed in a paper to appear in Physical Review Letters uses the same basic technique but at a much smaller scale–on the size of three qubits, connected to two “baths,” one cold (or around room temperature) and one hot.
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If you want to make a supermassive black hole quickly, collide young, massive proto-galaxies. After running the numbers on a supercomputer, that’s what researchers have recently concluded. Their simulation shows that a collision between massive gas clouds could make a black hole “from scratch” in a relatively short time.
Supermassive black hole truly are super massive–possibly billions of times the mass of our sun. They also appear to be super old; some estimates say they formed less than a billion years after the Big Bang. Thus the puzzle, how do you get so big so quickly?
The paper which appeared online yesterday in Nature (with associated letter) modeled the collision of two gas clouds that formed into a unstable gas disk, which channeled gas into its center. Eventually this dense center collapsed in on itself to make the black hole king. (See simulations of the proto-galaxies colliding, above.)
“It has been perplexing how such black holes with masses billions of times the mass of the sun could exist so early in the history of the universe,” astronomer Julie Comerford of University of California Berkeley, who was not involved in the study, wrote in an e-mail to Wired.com. “These simulations are an important advance in understanding how those supermassive black holes were built up so quickly.” [Wired]
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The sun is breaking the known rules of physics—so said headlines that made the rounds of the Web this week.
That claim from a release out about a new study by researchers Jere Jenkins and Ephraim Fischbach of Purdue, and Peter Sturrock of Stanford. The work suggests that the rates of radioactive decay in isotopes—thought to be a constant, and used to date archaeological objects—could vary oh-so-slightly, and interaction with neutrinos from the sun could be the cause. Neutrinos are those neutral particles that pass through matter and rarely interact with it; trillions of neutrinos are thought to pass through your body every second.
In the release itself, the researchers say that it’s a wild idea: “‘It doesn’t make sense according to conventional ideas,’ Fischbach said. Jenkins whimsically added, ‘What we’re suggesting is that something that doesn’t really interact with anything is changing something that can’t be changed.’”
Could it possibly be true? I consulted with Gregory Sullivan, professor and associate chair of physics at the University of Maryland who formerly did some of his neutrino research at the Super-Kamiokande detector in Japan, and with physicist Eric Adelberger of the University of Washington.
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The United States currently holds around half of the world’s helium supply and we’re selling it, for cheap.
We’ve known this for a while. We started stockpiling the stuff near Amarillo, Texas in 1925, in part for dirigible use, and stepped up reserves in the 1960s as a Cold War asset. In 1996, Congress passed the Helium Privatization Act mandating that the United States sell the gas at artificially low prices to get rid of the stockpile by 2015. This February, the National Research Council published a report estimating that, given increasing consumption, the world may run out of helium in 40 years. That’s bad news given helium’s current applications in science, technology, and party decorations–and possible future applications in fusion energy.
Now physicist Robert Richardson, who won a 1996 Nobel Prize for work using helium-3 to make superfluids, has come forward to stress the folly of underselling our supply of the natural resource. He suggested in several interviews that the gas’s price should mirror its actual demand and scarcity. He estimates that typical party balloons should cost $100 a pop.
“They couldn’t sell it fast enough and the world price for helium gas is ridiculously cheap,” Professor Richardson told a summer meeting of Nobel laureates…. “Once helium is released into the atmosphere in the form of party balloons or boiling helium it is lost to the Earth forever, lost to the Earth forever,” he emphasised. [The Independent]
If we don’t heed Richardson’s warning, here are some sources the United States might have to tap when we run out:
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One of the top three priorities for the next decade of astrophysics and astronomy, we noted this week, is unraveling dark energy, the weird force that pushes the universe apart. Given that scientists know next-to-nothing about dark energy—besides the fact that it makes up most of the universe—any step could be an important one. Thanks to a study out this week in Science, astrophysicists at least can have more confidence in this phenomenon that can’t be directly seen or measured: Their estimates for dark matter’s extent appear to be on target.
The technique scientists used in this study is called gravitational lensing, and the lens in this case is a huge galactic cluster called Abell 1689.
Because of its huge mass, the cluster acts as a cosmic magnifying glass, causing light to bend around it. The way in which light is distorted by this cosmic lens depends on three factors: how far away the distant object is; the mass of Abell 1689; and the distribution of dark energy [BBC News].
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Astronomers have confirmed it: Neptune has a stalker. They have spotted, for the first time, an asteroid follower that keeps a fairly constant distance behind the planet in its orbit around the sun. And there may be many more.
Asteroid 2008 LC18 can’t help itself. It’s caught in a balancing game between the gravitational tug of the sun and Neptune, and effects from its whirling course. The conflicting tugs cause the asteroid not to orbit Neptune or crash into it, but instead to follow the planet from a little distance behind (about 60 degrees on its path).
Neptune has five of the these pits–called Lagrangian points (see diagram below the fold)–but the spots ahead and behind the planet, researchers say, are best for asteroid-trapping, since the hold is particularly stable in these places. Researchers have previously spotted several asteroids in front of the planet (again by about 60 degrees), but this is the first time they’ve found one following it. The findings appeared online yesterday in Science.
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Scientists have cranked through the numbers and determined that no matter how you mangle a Rubik’s Cube, if you’re doing it right you can theoretically solve the puzzle in 20 moves or fewer. By doing it right, we mean doing it like a supercomputer: Researchers tapped Google’s spare computing power to burn through the Cube’s 43,252,003,274,489,856,000 starting positions.
Even given Google’s processing power, the team–which included a mathematician, a Google engineer, a math teacher, and a programmer–could not solve the problem using brute force alone. They had to take all the starting positions and divide them into more manageable chunks, 2.2 billion smaller groups called “corsets,” which Google’s computers could solve simultaneously.
“The primary breakthrough was figuring out a way to solve so many positions, all at once, at such a fast rate,” says Tomas Rokicki, a programmer from Palo Alto, California, who has spent 15 years searching for the minimum number of moves guaranteed to solve any configuration of the Rubik’s cube. [New Scientist]
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Listen, people of Earth: Everything’s going to be fine. All we have to do is survive another century or two without self-destructing as a species. Then we’ll get off this rock, spread throughout space, and everything will be all right.
If this is not your idea of “optimism,” then you are not Stephen Hawking. The esteemed physicist garnered headlines, and some eye-rolls, after telling Big Think last week that humanity needs to leave the Earth in the future or face extinction.
He’s not knocking climate scientists’ attempts to figure things out on Earth–he’s just thinking long term. “There have been a number of times in the past when our survival has been touch-and-go,” explains Hawking at Big Think, mentioning the Cuban Missile Crisis, and “the frequency of such occasions is likely to increase in the future…. Our population and our use of the finite resources of the planet earth are growing exponentially along with our technical ability to change the environment for good or ill,” while “our genetic code still caries our selfish and aggressive instincts” [The Atlantic].
Combined with Hawking’s statement earlier this year that it might be dangerous to contact aliens because they could come and wipe us out, the physicist’s latest warning makes it feel like he’s increasingly a member of the gloom-and-doom crowd. But not so. He’s just the kind of person who thinks on the long, long term.
Let’s jump back to another publicly engaged scientist: Carl Sagan’s message in Cosmos that the stars await… if we don’t destroy ourselves.
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P is not equal to NP. Seems simple enough. But if it’s true, it could be the answer to a problem computer scientists have wrestled for decades.
Vinay Deolalikar, who is with Hewlett-Packard Labs, has sent to peers copies of a proof he did stating that P is not equal to NP. Mathematicians are reviewing his work now—a task that could go on for a long time. If he’s correct, Deolalikar will have figured out one of the Clay Mathematics Institute’s seven Millennium Prize Problems, for which they give $1 million prizes. (Grigory Perelman won one of the seven for solving the Poincaré conjecture, but turned down the money last month.)
What’s all the hubbub? First, an explainer:
The P versus NP question concerns the speed at which a computer can accomplish a task such as factorising a number. Some tasks can be completed reasonably quickly – in technical terms, the running time is proportional to a polynomial function of the input size – and these tasks are in class P. If the answer to a task can be checked quickly then it is in class NP [New Scientist].
That definition is pretty abstract, so here’s a more concrete example:
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Sure, a laser can shine finely-tuned light to do anything from scanning your barcodes to correcting your vision, but soon that precise hero may meet its match: Physicists have recently imagined a device that can absorb light of certain frequencies, an “anti-laser.”
Absorbing light may not seem all that impressive, since after all, anything that appears black works as an absorber. Your driveway, however, is not the anti-laser. A paper in the Physical Review Letters lays out the plans for this device which can absorb light wave clones (same frequency, phase, and polarization) that some lasers emit. The pickiness of this theoretical light absorber is part of what would make the device unique, just as an important part of what separates a laser from a flashlight is the precision of the light a laser emits.
Instead of amplifying light into coherent pulses, as a laser does, an antilaser absorbs light beams zapped into it. It can be “tuned” to work at specific wavelengths of light, allowing researchers to turn a dial and cause the device to start and then stop absorbing light. “By just tinkering with the phases of the beams, magically it turns ‘black’ in this narrow wavelength range,” says team member A. Douglas Stone, a physicist at Yale University. “It’s an amazing trick.” [Science News]
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