Archivo: Science

Swimming in sync is one of the most important lessons a school of fish can learn: The coordination helps them find food—and evade predators. But when scientists try to train robots to match this stunning natural feat, most fall short. Now, researchers have developed a fleet of seven underwater “fishbots” that can swim in circles—without crashing into one another.

One of North America’s most famous ancient predators—and a favorite of Game of Thrones fans—emerged as mysteriously as it disappeared. Dire wolves, which died out with mammoths and saber-toothed cats at the end of the last ice age, were long thought to be close cousins of gray wolves. Now, the first analysis of dire wolf DNA finds they instead traveled a lonely evolutionary path: They are so different from other wolves, coyotes, and dogs that they don’t belong in the genus that includes these animals. Instead, researchers argue, they need an entirely new scientific classification.

Hard disks and optical drives store gigabits of digital data at the press of a button. But those technologies—like the magnetic tapes and floppy drives before them—are apt to become antiquated and unreadable when they are overtaken by new technology. Now, researchers have come up with a way to electronically write data into the DNA of living bacteria, a storage option unlikely to go obsolete any time soon.

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The observations are already challenging astrophysicists’ assumptions about how black holes form and influence their surroundings. The smaller black holes detected by LIGO and, now, the European gravitational wave detector Virgo in Italy have proved heavier and more varied than expected, straining astrophysicists’ understanding of the massive stars from which they presumably form. And the environment around the supermassive black hole in our Galaxy appears surprisingly fertile, teeming with young stars not expected to form in such a maelstrom. But some scientists feel the pull of a more fundamental question: Are they really seeing the black holes predicted by Einstein’s theory?

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Some robots swim and dive through the water; others scurry across the land. Now, researchers want to build a machine that can do both. Their inspiration? The California sea lion.

You’d never know it by looking at the dragonflylike adult antlion, but its wingless larvae—fingernail-size eating machines with huge, poison-filled jaws—build deadly sand traps to capture tiny insects, including ants. Now, scientists know precisely how they do it: As the hapless prey falls into its pit, an antlion at the bottom uses its head to fling a blizzard of sand grains up the funnel-shaped slope, creating a minilandslide that pulls the unfortunate insect to its doom. The pits, scientists say, are feats of engineering—and physics.

In seafloor trenches around the world, slabs of old ocean crust fall in slow motion into the mantle, while fresh slabs are built at midocean ridges, where magma emerges at the seams between separating tectonic plates. The engine is relentless—but maybe not so steady: Beginning about 15 million years ago, in the late Miocene epoch, ocean crust production declined by one-third over 10 million years to a slow pace that pretty much continues to today.

Watch the two simulated robots above, and you’ll notice a big difference. Even though both of their “brains” have evolved over 300 generations to allow them to walk, only one succeeds; the other falls flat on its back.

Fifteen hundred years ago, Mexico’s Teotihuacan was a multicultural metropolis, enlivened by the diverse dress, foods, and dialects of its immigrant groups. Artifacts show the city of more than 100,000 depended on a steady stream of foreigners, who brought skilled labor and exotic goods from across Mesoamerica. But after Teotihuacan faded, during a period of upheaval and uncertainty, locals may have turned against outsiders—and archaeologists now think they’ve found the decapitated heads to prove it.

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For years, the controversial idea of solar geoengineering—lofting long-lived reflective particles into the upper atmosphere to block sunlight and diminish global warming—has been theoretical. It’s starting to get real: Today, after much technical and regulatory wrangling, Harvard University scientists are proposing a June 2021 test flight of a research balloon designed to drop small amounts of chalky dust and observe its effects.

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