sciencehabit writes: Scientists hunting unseen dark matter are looking deeper into the shadows. With searches for a favored dark matter candidate—weakly interacting massive particles (WIMPs)—coming up empty, physicists are now turning to the hypothetical “dark sector”: an entire shadow realm of hidden particles. This week, physicists will meet at the University of Maryland in College Park for a workshop, sponsored by the U.S. Department of Energy (DOE), to mull ideas for a possible $10 million short-term experiment that would complement the agency’s current WIMP search and other dark-matter efforts. And many researchers believe DOE should focus on the dark sector. Whereas WIMPs would be a single massive particle tacked onto the standard model of known particles, the dark sector would consist of a slew of lighter particles and forces—such as a dark version of electromagnetism—with tenuous connections to known particles. To spot dark-sector particles, physicists will have to rethink their detection techniques, but the new experiment could be small and cheap, physicists say. Still, DOE officials warn that the $10 million isn’t a sure thing.
sciencehabit writes: NASA’s Curiosity rover has shot more than 500 movies of the clouds above Mars, including the first ground-based view of martian clouds shaped by gravity waves, researchers report. The shots are the best record made so far of a mysterious recurring belt of equatorial clouds known to influence the martian climate. Understanding these clouds will help inform estimates of ground ice depth and perhaps recurring slope lineae, potential flows of salty water on the surface, says John Moores, a planetary scientist at York University in Toronto, Canada, who led the study. “If we wish to understand the water story of Mars’s past,” Moores says, “we first need to [separate out] contributions from the present-day water cycle.”
sciencehabit writes: Today’s autonomous cars can already harness the power of artificial intelligence (AI) software to drive from Los Angeles, California, to New York City without any human input, as long as it’s a sunny day. They still struggle to spot a stop sign in the rain after all. Now, researchers say they are on the cusp of giving self-driving cars the ability to read road signs in all sorts of weather and light conditions, an AI advance that brings the vehicles one step closer to being safe enough for everyday people to operate.
sciencehabit writes: As the mycobacterium that causes tuberculosis has frighteningly become resistant to one drug after another, scientists for years have searched for new compounds that will stop the pathogen before it kills. Now, in a novel twist, researchers have found a way to recruit help from none other than Mycobacterium tuberculosis itself to make the deadly pathogen susceptible to an existing tuberculosis (TB) drug that it has learned to dodge. It's like a biological version of “malware,” says co–senior author Benoit Déprez of the University of Lille in France. In effect, he says, the approach activates a previously silent system that, when coupled with a TB drug, instructs the bacteria to self-destruct.
sciencehabit writes: In the recent movie Rogue One: A Star Wars Story, the face of the character Grand Moff Tarkin was constructed digitally, as the actor who had originally played him had died. Some who knew about the computer trickery saw his appearance as slightly unnatural, leading to a sense of unease. Their discomfort demonstrates what the Japanese roboticist Masahiro Mori referred to in 1970 as the “uncanny valley”: Our affinity toward robots and animations increases as they physically appear more humanlike, except for a large dip where they are almost but not quite there.
But what happens when a character’s appearance remains the same, but observers think its mind has become more humanlike? New research reveals that this, too, unnerves people, a finding that could have possible implications for a range of human-computer interactions. The researchers are calling the phenomenon the “uncanny valley of the mind.”
sciencehabit writes: Metallurgists have followed nature’s lead, creating steel with a structure similar to human bone. In addition to harboring a layered structure that tends to keep cracks from spreading beyond the layers where they start, the material has different alloy components with different degrees of hardness. That way if a crack does begin to form, it has to follow a different path to propagate, which reduces the chance a small crack will grow. Also, some areas within the steel are more flexible than others, which can help absorb the energy of repeated stresses applied to the steel and even close up cracks after they occur. That could allow engineers to use the material to build everything from bridges to spacecraft that are less susceptible to catastrophic failure, which can happen when a tiny crack becomes a full-blown fracture.
sciencehabit writes: Astronomers have long known that Pan, one of Saturn’s innermost moons, has an odd look. Based on images taken from a distance, researchers have said it looks like a walnut or a flying saucer. But now, NASA’s Cassini probe has delivered stunning close-ups of the 35-kilometer-wide icy moon, and it might be better called a pan-fried dumpling or an empanada.
sciencehabit writes: Scientists have trained a quantum computer to recognize trees. That may not seem like a big deal, but the result means that researchers are a step closer to using such computers for complicated machine learning problems like pattern recognition and computer vision. The team fed hundreds of NASA satellite images of California into the D-Wave 2X processor, and asked the computer to consider dozens of features–hue, saturation, even light reflectance–to determine whether clumps of pixels were trees as opposed to roads, buildings, or rivers. They then told the computer whether its classifications were right or wrong so that the computer could learn from its mistakes, tweaking the formula it uses to determine whether something is a tree. After it was trained, the D-Wave was 90% accurate in recognizing trees in aerial photographs of Mill Valley, California. The results demonstrate how scientists can program quantum computers to “look” at and analyze images, and opens up the possibility of using them to solve other complex problems that require heavy data crunching.
sciencehabit writes: Last month, Facebook announced software that could simply look at a photo and tell, for example, whether it was a picture of a cat or a dog. A related program identifies cancerous skin lesions as well as trained dermatologists can. Both technologies are based on neural networks, sophisticated computer algorithms at the cutting edge of artificial intelligence (AI)—but even their developers aren’t sure exactly how they work. Now, researchers have found a way to "look" at neural networks in action and see how they draw conclusions.
sciencehabit writes: A lawsuit over alleged cruelty to a special breed of horse appears to have prompted the U.S. Department of Agriculture’s (USDA’s) move last week to remove thousands of reports and documents relating to animal welfare from its website. The scrubbing has outraged animal welfare advocates — and made strange bedfellows of groups that oppose and support scientific research involving animals, with both sides condemning USDA’s actions. It appears, however, that the agency’s decision had little—if anything—to do with animal research.
sciencehabit writes: Could dark matter consist of primordial black holes, as numerous as the stars? It’s an old, improbable idea, but it made a Lazarus-like comeback a year ago, when the discovery of gravitational waves suggested that the cosmos abounds with unexpectedly heavy black holes. With decades-long searches failing to find the hypothetical dark matter particles that theorists have favored, physicists are turning to more radical ways of explaining the universe’s missing mass.
sciencehabit writes: The Laser Interferometer Gravitational-Wave Observatory (LIGO) is not only the most sensitive detector of ripples in spacetime. It also happens to be the world's best producer of gravitational waves, a team of physicists now calculates. Although these waves are far too feeble to detect directly, the researchers say, the radiation in principle could be used to try to detect weird quantum mechanical effects among large objects.
sciencehabit writes: After decades of effort, physicists have probed the inner working of atoms of antihydrogen—the antimatter version of hydrogen—by measuring for the first time a particular wavelength of light that they absorb. The advance opens the way to precisely comparing hydrogen and antihydrogen and, oddly, testing the special theory of relativity—Albert Einstein’s 111-year-old theory of how space and time appear to observers moving relative to one another, which, among other things, says that nothing can move faster than light.
sciencehabit writes: In an unusual paper, a leading theoretical physicist says that the citation for the 2015 Nobel Prize in Physics is wrong. The two winners, who led enormous experiments that studied particles called neutrinos, deserved the prize, says Alexei Smirnov of the International Centre for Theoretical Physics in Trieste, Italy. But the Nobel committee's pithy 12-word description of their findings misstates what one of the experiments did.
sciencehabit writes: It’s often said that the heavens run like clockwork. Astronomers can easily predict eclipses, and they can foretell to a fraction of a second when the moon passes in front of a distant star. They can also rewind the clock, and find out when and where these events happened in the past. But a new historical survey of hundreds of eclipses, some dating back to the 8th century B.C.E., finds that they aren’t as predictable as scientists thought. That’s because Earth’s spin is slowing down slightly. Not only that, the study also identifies short-term hiccups in the spin rate that have been missed by cruder models.