Science

The notion of an artificial leaf makes so much sense. Leaves, of course, harness energy from the sun to turn carbon dioxide into the carbohydrates that power a plant’s cellular activities. For decades, scientists have been working to devise a process similar to photosynthesis to generate a fuel that could be stored for later. This could solve a major challenge of solar and wind power—providing a way to stow the energy when the sun is not shining and the air is still. Many, many investigators have contributed over the years to the development of a form of artificial photosynthesis in which sunlight-activated catalysts split water molecules to yield oxygen and hydrogen—the latter being a valuable chemical for a wide range of sustainable technologies. A step closer to actual photosynthesis would be to employ this hydrogen in a reduction reaction that converts CO2 into hydrocarbons. Like a real leaf, this system would use only CO2, water …

Well connected: an optical clock at PTB was used in the comparison Atomic clocks in France, Germany and the UK have been used to perform the best-ever confirmation of time dilation as set out in Einstein’s special theory of relativity. The clocks have been connected recently by optical-fibre links, which let the devices be compared to each other to an extremely high degree of statistical resolution. The work was done by an international team of physicists that says the test could still be improved further by several orders of magnitude. The study uses the “Robertson–Mansouri–Sexl” (RMS) framework for violating special relativity. RMS assumes that there is a preferred reference frame in which the average speed of light measured on a return journey (there and back again) between two points is constant in all directions. RMS contradicts special relativity in all other reference frames by assuming that the average speed of light of a return journey …

The world’s most massive animal, the blue whale, is like a 100-passenger jet gliding below the ocean’s surface. Whales are among the largest organisms ever to exist, and now scientists say they may know when and why these majestic mammals evolved to be so enormous. In a study published in May in the Proceedings of the Royal Society B, researchers modeled the sizes of baleen whales that lived between roughly 35 million years ago and the present. The team measured the skulls of 63 extinct whale species from the fossil collection at the Smithsonian Institution’s National Museum of Natural History (skull size is a known indicator of body size). The scientists then compared these measurements against the sizes of living whales. Their analysis concluded that whale body length had varied randomly for about 30 million years before making a leap to more than 10 meters between 4.5 million and hundreds of thousands of years ago—a …

Tough to pop: the gas marbles can be handled without bursting “Gas marbles” have been created by encapsulating a bubble of gas within a shell of tiny plastic particles. Developed by Yousra Timounay and colleagues at the Université Paris-Est (UPE) in France, the beads of gas could be used for isolating toxic gases or stabilizing foams. The work by Timounay and team takes inspiration from “liquid marbles”, which were developed in 2001 by Pascale Aussillous and Davide Quéré from the Collège de France. Aussillous and Quéré had added hydrophobic powder to water droplets, thereby spontaneously creating balls of liquid securely held within water-repellent shells. The surface tension and incompressibility of the liquid allows the marbles to maintain their shape, and they can bounce and roll across surfaces without leaking. Like soap bubbles Now, the UPE researchers have created the gas version with a method similar to making bubbles with a soap solution and wire hoop. …

After a decade of searching and verification, a research team revealed a new exoplanet, and you could say it’s coming in hot. The orb is the hottest giant exoplanet ever found, according to a study published today in Nature. “KELT-9b” intrigues astronomers not just because of the unusual chemistry the heat is bound to create in its atmosphere, but also because of the opportunities it offers for more in-depth studies.  “We’re fascinated with the weirdness that nature hands us,” says B. Scott Gaudi, an astronomer at the Ohio State University who helmed the study, as he explains why his academic circle is ablaze with KELT-9b curiosity. First and foremost, there is the planet’s impressive heat. Gaudi and his team calculated KELT-9b to be roughly 3,777 degrees Celsius (6,830 degrees Fahrenheit) on the dark side and 4327 degrees C (7,820 degrees F) on the star-exposed side. This makes KELT-9b almost 20 percent hotter than the next-most-scorching …

Climate change is warming the Arctic more than twice as fast as anywhere else on the planet. One of the most serious consequences is sea level rise, which threatens nations from Bangladesh to the U.S. But exactly how does melting Arctic ice contribute to sea level rise? Scientific American asked Eric Rignot, professor of earth system science at the University of California, Irvine, and Andrea Dutton, assistant professor of geology at the University of Florida, how changes in this particular northern region are driving the oceans to dangerous heights. Seas are now rising an average of 3.2 millimeters per year globally, and are predicted to climb a total of 0.2 to 2.0 meters by 2100. Rignot and Dutton say that in the Arctic, the Greenland Ice Sheet poses the greatest risk for ocean levels because melting land ice is the main cause of rising seas—and “most of the Arctic’s land ice is locked up in …

Twenty years ago IBM’s Deep Blue computer stunned the world by becoming the first machine to beat a reigning world chess champion in a six-game match. The supercomputer’s success against an incredulous Garry Kasparov sparked controversy over how a machine had managed to outmaneuver a grand master, and incited accusations—by Kasparov and others—that the company had cheated its way to victory. The reality of what transpired in the months and years leading up to that fateful match in May 1997, however, was actually more evolutionary than revolutionary—a Rocky Balboa–like rise filled with intellectual sparring matches, painstaking progress and a defeat in Philadelphia that ultimately set the stage for a triumphant rematch. Computer scientists had for decades viewed chess as a meter stick for artificial intelligence. Chess-playing calculators emerged in the late 1970s but it would be another decade before a team of Carnegie Mellon University graduate students built the first computer—called Deep Thought—to beat a …

Editor’s Note (6/1/17): This story has been updated to reflect the Trump administration’s announcement today of its decision to withdraw from the Paris climate agreement. Pres. Donald Trump announced today that he would pull the U.S. out of the Paris climate accord. But whether Trump had kept the U.S. in the agreement or not, his policies—if they all become reality—already had the power to profoundly undermine the nation’s ability to reach the U.S.’s Paris climate goals. According to a new report (pdf) released by analysts at the recent Bonn climate talks, the president’s rollback of current climate regulations, if successful, could cause the U.S. to release 0.4 gigatonne more carbon dioxide in annual emissions in the year 2030 than if those policies remained. That gap gets much larger when the report authors accounted for Trump’s decision to dump the Climate Action Plan, which was created by the Obama administration but has not yet been fully implemented. That …

When zapped with the world’s strongest x-ray laser beam, big atoms within some molecules do something very strange: They behave a bit like minuscule “black holes,” sucking in electrons from the molecules around them, a new study has found. But rather than just teaching us more about the cosmos, these findings may help with something a lot closer to home. Researchers think this tactic could let scientists better analyze viruses, bacteria and other tiny complex structures here on Earth. X-rays have long been used not only to help doctors peer into people but also to help scientists probe the structures of molecules and other microscopic objects. The more powerful the x-ray beams, the higher the resolution of the images researchers can get. In the new study scientists at Kansas State University (K.S.U.) and their colleagues experimented with the world’s most powerful x-ray laser, the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory—a …

Some three billion years ago, when Earth was a sprightly ocean world dotted with protocontinents and inhabited solely by single-celled organisms, a pair of black holes spiraled together and collided in a far-off region of the universe, leaving behind a single black hole some 50 times heavier than our sun. Emitting no light, the entire affair should have remained forever lost to the void. Instead, the invisible violence of the pair’s final moments and ultimate merging was so great that it shook the fabric of reality itself, sending gravitational waves—ripples in spacetime—propagating outward at the speed of light. In the early morning hours of January 4, 2017, those waves washed over our modern Earth and into the most precise scientific instrument ever built, the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO). There the waves shifted the positions of vacuum-insulated, laser-bathed mirrors by less than the radius of a single subatomic particle. Traveling at light-speed, the waves …

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