Science

The Pentagon’s research and development division, DARPA—the creative force behind the internet and GPS—retooled itself three years ago to create a new office dedicated to unraveling biology’s engineering secrets. The new Biological Technologies Office (BTO) has a mission to “harness the power of biological systems” and design new defense technology. Over the past year, with a budget of about $296 million, it has been exploring challenges including memory improvement, human–machine symbiosis and speeding up disease detection and response. DARPA, or the Defense Advanced Research Projects Agency, is hoping for some big returns. The director of its BTO, neuroprosthetic researcher Justin Sanchez, recently spoke with Scientific American about what to expect from his office in 2017, including work on neural implants to aid healthy people in their everyday lives and other advances that he says will “change the game” in medicine. [An edited transcript of the interview follows.] Before your office was created in April 2014, …

Until 10 years ago, radio astronomers thought they had assembled an essentially complete picture of the sky. In this view, with telescopes attuned to radio waves rather than visible light, the solar system’s brightest radio sources—the sun and Jupiter—would pale against the Milky Way’s splendor. Aglow with radio emissions from sizzling supernovae debris, gas-shrouded stellar nurseries and the metronomic flashes of pulsars, our galaxy would dominate the vista overhead. Beyond that the entire sky would be speckled with steady, starlike points of luminosity from radio-belching supermassive black holes at the centers of distant galaxies. It turns out, however, those astronomers had missed something big. The heavens also sparkle with something entirely unexpected: fast radio bursts, or FRBs—flashes of radio waves as “bright” as a half-billion suns, which flare from seemingly random locations and fade in just milliseconds. Because most radio telescopes can only survey small patches of sky for short periods, the phenomenon had gone …

Many of us are familiar with the feeling of passing someone in a supermarket or making eye contact on a crowded subway and wondering, Do I know that person? As we move through life we are tasked with remembering and recognizing thousands of faces, and a study released today in Science reveals our brains improve at this as we reach adulthood. Researchers had children and young adults complete a combination of behavioral tests and anatomical and functional brain scans. They found that not only were the young adults better than the children at recognizing faces, they also had a stronger response in brain regions associated with facial recognition when they looked at faces, along with denser tissue in these areas. The findings suggest these changes in brain anatomy underlie our improving facial recognition skills. Until age 10, children undergo a dramatic brain transformation known as synaptic pruning, in which unused brain connections are trimmed away …

Frequency double: Maria del Rocio Camacho-Morales studies the new optical material A new method of fabricating nanoscale optical crystals capable of converting infrared to visible light has been developed by researchers in Australia, China and Italy. The new technique allows the crystals to be placed onto glass and could lead to improvements in holographic imaging – and even the development of improved night-vision goggles. Second-harmonic generation, or frequency doubling, is an optical process whereby two photons with the same frequency are combined within a nonlinear material to form a single photon with twice the frequency (and half the wavelength) of the original photons. The process is commonly used by the laser industry, in which green 532 nm laser light is produced from a 1064 nm infrared source. Recent developments in nanotechnology have opened up the potential for efficient frequency doubling using nanoscale crystals – potentially enabling a variety of novel applications. Materials with second-order nonlinear susceptibilities – …

Various studies have debunked the idea of a pause, or hiatus, in global warming—the contention that global surface temperatures stopped rising during the first decade of this century. The arguments for and against “the pause” were somewhat muted until June 2015, when scientists at the National Oceanic and Atmospheric Administration published a paper in Science saying that it had slightly revised the sea surface temperatures it had been citing for the 1900s. The measurement methods, based on sensors in the engine intake ports of ships, had been flawed, NOAA said. The revised methodology also meant that sea surface temperatures during the 2000s had been slightly higher than reported. NOAA adjusted both records, which led to a conclusion that global surface temperatures during the 2000s were indeed higher than they had been in previous decades. No hiatus. Critics attacked NOAA, claiming it had cooked the books to dismiss claims of a pause. Republican Rep. Lamar Smith …

On the move: strontium atoms in an atomic clock An optical atomic clock has been used by physicists in the US to study the effects of spin–orbit coupling. Spin–orbit coupling is fundamental to understanding how electrons behave within condensed-matter systems and could be exploited in the design of new materials, such as topological insulators and superconductors. The researchers also plan to adapt their atomic-clock design to study other fundamental phenomena in condensed-matter systems. The work is another example of how physicists have mimicked the behaviour of electrons in solids by fine-tuning interactions between ultracold atoms. Spin–orbit coupling links the motion of a particle to its quantum spin. For example, an electron has two possible spin states: up and down. Spin–orbit coupling means that otherwise identical electrons with different spins will follow different trajectories in the same electromagnetic field. The consequences of spin–orbit coupling are particularly important in solid materials, where electrons move under the influence …

Perhaps all money should be laundered. Studies have piled up in recent years describing exactly how filthy—specifically how bacteria-laden—our dollars and cents can be. Fecal bacteria and other pathogens may have hitched a ride from someone’s hands, nose or apron onto our cash. And yeast or mold might have taken hold, too. The result could be a durable risk to our health whenever our money changes hands. The fibrous surfaces of U.S. currency provide ample crevices for bacteria to make themselves at home. And the longer any of that money stays in circulation, the more opportunity it has to become contaminated. Lower-denomination bills are used more often, so studies suggest our ones, fives and tens are more likely to be teeming with disease-causing bacteria. Some of these pathogens are known to survive for months, according to a recent review of “dirty money” studies. Unfortunately, dirty dollars—whether denominations of $1 or $100—are not whisked away to …

Droughts, wildfires, heat waves, intense rainstorms—these are all extreme weather phenomena that occur naturally. But climate change is now increasing the frequency and magnitude of many of these events. Flooding in Paris and the Arctic heat wave are just two instances where climate change contributed to extreme weather in 2016—and there are many more examples. Yet how do scientists know that global warming influenced a specific event? Until recently, they couldn’t answer this question, but the field of “attribution science” has made immense progress in the last five years. Researchers can now tell people how climate change impacts them, and not 50 or 100 years from now—today. Scientific American spoke with Friederike Otto, deputy director of the Environmental Change Institute at the University of Oxford, about how attribution science works and why it’s a critical part of helping communities prepare for and adapt to climate change. [An edited transcript of the interview follows.] What exactly …

Actress and writer Carrie Fisher, who died earlier this week after suffering a cardiac event on a flight, was not only an entertainment icon, but also a prominent mental health advocate. Fisher was well known for being outspoken about her experiences with drug and alcohol addiction and bipolar disorder, which she was diagnosed with in her early twenties, and she frequently wrote about them in articles and her best-selling 2008 memoir Wishful Drinking (Simon Schuster). Her voice countered the stigma surrounding psychiatric disorders and helped support others with similar struggles—sometimes directly. In an advice column she wrote for The Guardian just last month Fisher offered guidance to a young adult with bipolar disorder. In it, she explains that she initially rejected the bipolar disorder diagnosis she received at the age of 24, only accepting it at age 28, “when I overdosed and finally got sober. Only then was I able to see nothing else could …

If artificial intelligence takes over our lives, it probably won’t involve humans battling an army of robots that relentlessly apply Spock-like logic as they physically enslave us. Instead, the machine-learning algorithms that already let AI programs recommend a movie you’d like or recognize your friend’s face in a photo will likely be the same ones that one day deny you a loan, lead the police to your neighborhood or tell your doctor you need to go on a diet. And since humans create these algorithms, they’re just as prone to biases that could lead to bad decisions—and worse outcomes. These biases create some immediate concerns about our increasing reliance on artificially intelligent technology, as any AI system designed by humans to be absolutely “neutral” could still reinforce humans’ prejudicial thinking instead of seeing through it. Law enforcement officials have already been criticized, for example, for using computer algorithms that allegedly tag black defendants as more likely …

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