Two Is the Magic Quantum Number

Extending an experiment at the foundation of quantum physics confirms that two is company and three is a crowd. In a new twist on the famous double-slit experiment, researchers have verified a basic tenet of quantum mechanics by showing that adding a third slit doesn’t create additional interference between packets of light.

sciencenewsThe double-slit experiment embodies the mystery at the heart of quantum mechanics, the famous physicist Richard Feynman observed in his Lectures on Physics. The experiment illustrates some of the strangest predictions of quantum mechanics, including the dual particle-wave nature of tiny objects.

In the 1920s, German physicist Max Born proposed that particle pairs — and not triplets, quadruplets or more — can interfere, causing their wavelike forms to boost and diminish one another. Born’s math puts the interference contribution of the third slit (and any additional slits) at exactly zero. Although the reason why quantum interference stops at two isn’t clear, Born’s postulate has been widely accepted and used by physicists, yet until now it hadn’t been explicitly tested in experiments.

“It’s important that you test all the postulates of quantum mechanics,” says Urbasi Sinha of the Institute for Quantum Computing at the University of Waterloo in Canada, coauthor of the new study July 23 in Science. “What is the point of just advancing a theory in its theoretical form if you don’t have experiments backing things up?”

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You Are Sexually Attracted to Your Parents, and Yourself

It’s not an excuse, but there may be a biological reason that jail-bound Aimee Sword was sexually attracted to the teenage son she gave up for adoption.

In a series of experiments where subjects viewed photographs of their opposite-sex parent or a photo morphed with their own face, researchers found that people are turned on by photographs of people who resemble their close genetic counterparts.

“People appear to be drawn to others who resemble their kin or themselves,” said psychologist R. Chris Fraley of the University of Illinois, lead author of the study published July 20 in Personality and Social Psychology Bulletin. “It is possible, therefore, as Freud suggested, that incest taboos exist to counter this primitive tendency.”

The debate about whether aversions against incest stem from a cultural adaptation to suppress biological urge or a psychological adaptation that evolved by natural selection dates back to the early 1900s. Psychoanalyst Sigmund Freud proposed the former explanation, and sociologist Edward Westermarck proposed the latter, arguing that there is a critical period while people are growing up during which if they are raised with someone they won’t find them attractive.

In recent years, Fraley says, contemporary scholars have concluded that Westermarck was right, and Freud was wrong. But based on his study, Fraley argues that the debate may have been settled prematurely.

“There is evidence on both sides now,” said psychologist David Schmitt from Bradley University. “There is some reason to think that there is something to Westermarck, that there is a critical period, but it may also be that we find and trust and align ourselves with people who have more common alleles.”

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Space Food Turns Gross Within a Year

CHICAGO — Most people find the palatability of in-flight entrees an oxymoron. But even frequent fliers seldom encounter more than a few such meals per week. Astronauts, in contrast, may have to survive months in orbit dining on a really limited menu of processed foods and reconstituted beverages served from oh-so-glamorous plastic pouches. Luckily, even the International Space Station can restock its pantry several times a year because these foods are relatively perishable. Which explains the problem NASA faces in planning for really long missions — like a trip to Mars.

sciencenewsAstronaut foods may appear indestructible, but many crew favorites don’t retain their nutrition or palatability for even a year, notes Michele Perchonok.

She should know. Perchonok manages not only NASA’s advanced food technology program, but also the development and preparation of foods for Shuttle astronauts. At the Institute of Food Technology annual meeting, on July 20, she described NASA’s limited larder.

Foods destined for Space Shuttle missions must have a shelf life of a year, and 18 months if they’ll be deployed on the International Space Station. Of the roughly 65 foods currently available for stocking spacecraft and deemed really palatable by NASA taste panels, 10 will lose their appeal within a year — turning off-color, mushy or tasteless, she reported. By the end of five years, Perchonok says, “we’re down to seven items.” Continue Reading “Space Food Turns Gross Within a Year” »

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Jellyfish Eyes Solve Optical Origin Mystery

Eyes are one of evolution’s marvels, described by Darwin as “an organ of extreme perfection.” But whether the animal kingdom’s kaleidoscope of eyes evolved from a common structure, or separately in dozens of forms, is a nagging evolutionary question.

Now a study of optical genes in jellyfish, which are descended from creatures that swam Earth’s ancient seas, long before vertebrates and invertebrates took their separate paths, suggests a common optical origin.

“Eyes have evolved in parallel many times, but they all go back to one prototype,” said University of Basel cell biologist Walter Gehring.

In a study published July 27 in the Proceedings of the National Academy of Sciences, researchers led by Gehring describe genes isolated from Cladonema radiatum, a jellyfish with highly elaborate eyes. The genes belong to a family called Pax.

In earlier research, Gehring found that a gene called Pax-6 is a “master regulator” of optical development, controlling eye formation in creatures as simple as fruit flies and as complex as mice and men. That suggested a common origin — but Pax-6 couldn’t be found in jellyfish, leaving open the possibility that eyes evolved independently in higher animals.

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Good Connection Really Does Lead to Mind Meld

When two people experience a deep connection, they’re informally described as being on the same wavelength. There may be neurological truth to that.

Brain scans of a speaker and listener showed their neural activity synchronizing during storytelling. The stronger their reported connection, the closer the coupling.

The experiment was the first to use fMRI, which measures blood flow changes in the brain, on two people as they talked. Different brain regions have been linked to both speaking and listening, but “the ongoing interaction between the two systems during everyday communication remains largely unknown,” wrote Princeton University neuroscientists Greg Stephens and Uri Hasson in the July 27 Proceedings of the National Academy of Sciences.

They found that speaking and listening used common rather than separate neural subsystems inside each brain. Even more striking was an overlap between the brains of speaker and listener. When post-scan interviews found that stories had resonated, scans showed a complex interplay of neural call and response, as if language were a wire between test subjects’ brains.

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Math Is No Match for Locust Swarms

Mathematicians have now figured out the dynamics that drive locusts across the landscape, devastating everything underfoot — and the math says people will never be able to predict where the little buggers will go.

sciencenewsThe new analysis, reported in an upcoming issue of Physical Review E, suggests that random factors accumulate and influence how swarming locusts collectively decide to change course.

“These swarms are driven by intrinsic dynamics,” says team member Iain Couzin, a biologist at Princeton University. “In all practical terms, predicting when a swarm is going to change direction is going to be impossible.”

Still, others say the information may one day allow researchers to better inform locust-control efforts — for instance, by suggesting the best times and places to apply insecticide ahead of an approaching swarm.

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Gamma-Ray Bursts Could Halt Photosynthesis

Cosmic explosions thousands of light-years away could shut down photosynthesis in the ocean at depths of up to 260 feet, a new study suggests. The calculations add to a growing body of research linking these great blasts, called gamma-ray bursts, with biological damage and even mass extinctions on Earth.

Gamma-ray bursts are tremendous explosions detonated during a massive star’s death throes. When stars eight times the mass of the sun or larger reach the end of their lives, they die in spectacular supernova explosions that can temporarily outshine entire galaxies.

Under certain conditions — astronomers aren’t exactly sure what — all that energy can be concentrated into a tight beam extending like a spotlight away from the star. These bright beams, known as gamma-ray bursts, can last up to 10 seconds, and carry energies equivalent to billions of nuclear bombs going off at once.

And according to the new research, phytoplankton would not enjoy them. In a paper published on the astronomy preprint site arXiv.org, biologist Liuba Penate of the Universidad Central de Las Villas in Cuba and colleagues model the marine food web from plankton up if a gamma-ray burst were to strike.

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Video: Exploding Moss Spores Form Mushroom Clouds

The air resistance to something as small as dust is so great that even if you threw it at mach speeds it would only go a couple inches. That is, unless you create a vortex ring — like a smoke ring or mushroom cloud from a nuclear explosion.

Peat moss (Sphagnum moss), one of the most primitive living plants, does just that. By releasing its spores at up to 65 miles per hour in less than a thousandth of a second through a cylindrical opening, it can launch them up about half a foot high.

It might not sound like much, but getting spores to that height is critical for a plant that can grow less than half an inch tall. Half a foot is high enough to intersect normal air currents, which can carry the spores for miles and miles — theoretically indefinitely.

“Vortex rings allow the spores to be carried up very efficiently, because they have very little drag in the air and don’t mix with the air around it,” said physicist Dwight Whitaker of Pomona College, co-author of the study published July 23 in Science. ”The air coming out of the spore capsule is like the a core of a tornado, but if you took the top and the bottom of a tornado and glued them together. The tornado holds the spores in because of its very motion.”

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Help BP Learn How to Use Photoshop

Apparently BP can no longer afford to employ people with even remotely reasonable Photoshop skills. As I’m sure you’ve heard by now, the company has admitted to (poorly) altering photos of its clean up operations in the Gulf of Mexico that were released to the public.

BP claims these truly pathetic Photoshop jobs are the work of a contract photographer. It’s hard to know what to believe about this, but if there really is a photographer who took it upon himself to mess with these images, then this individual should be ashamed. We just can’t decide which is more shameful, the complete lack of ethics or the complete lack of Photoshop skill.

So let’s lend poor, embattled BP a hand and show them what people who actually know how to use Photoshop can do. Choose any of the three original photos from BP’s Flickr album of altered images, and have at it. Our favorite is the cockpit photo that was altered to look like the helicopter is in the air (above). But almost as charming is the first altered photo discovered of BP’s crisis command center (below). Gizmodo and Americablog do a great job of tearing down these photos and showing just how bad the Photoshopping is.

We’ll choose some of your best, most interesting, funniest and most skilled images you send us and post them early next week. Feel free to take as much creative liberty with the images as you like (as long as the end product isn’t obscene).

Submit your photos and vote for your favorites at the bottom of this post.

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Meteor Crater Discovered With Google Earth

Researchers poring over Google Earth images have discovered one of Earth’s freshest impact craters — a 45-meter-wide pock in southwestern Egypt that probably was excavated by a fast-moving iron meteorite no more than a few thousand years ago.

sciencenewsAlthough the crater was first noticed in autumn 2008, researchers have since spotted the blemish on satellite images taken as far back as 1972, says Luigi Folco, a cosmochemist at the University of Siena in Italy. He and his colleagues report their find online July 22 in Science.

The rim of the Egyptian crater stands about 3 meters above the surrounding plain, which is partially covered with distinct swaths of light-colored material blasted from the crater by the impact. These rays, which emanate from the impact site like spokes from the hub of a wheel, are what drew researchers’ attention to the crater, says Folco. While such “rayed craters” are common on the moon and other airless bodies of the solar system, they are exceedingly rare on Earth because erosion and other geological processes quickly erase such evidence.

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