The Quest to Make a Bot That Can Smell as Well as a Dog

Unfortunately, the other reason we don’t have robots that can smell is that olfaction remains a stubborn biological enigma. Scientists are still piecing together the basics of how we sense all those volatile compounds and how our brains classify that information. “There are more unknowns than knowns,” says Hiroaki Matsunami, a researcher at Duke University. Mershin, however, believes that we don’t really have to understand how mammals smell to build an artificial nose. He’s betting that things will work the other way around: To understand the nose, we have to build one first. In his efforts with a brilliant mentor named Shuguang Zhang, Mershin has built a device that can just begin to give dogs—his panting adversaries—a run for their …

A Bizarre Form of Water May Exist All Over the Universe

Recently at the Laboratory for Laser Energetics in Brighton, New York, one of the world’s most powerful lasers blasted a droplet of water, creating a shock wave that raised the water’s pressure to millions of atmospheres and its temperature to thousands of degrees. X-rays that beamed through the droplet in the same fraction of a second offered humanity’s first glimpse of water under those extreme conditions. The X-rays revealed that the water inside the shock wave didn’t become a superheated liquid or gas. Paradoxically—but just as physicists squinting at screens in an adjacent room had expected—the atoms froze solid, forming crystalline ice. “You hear the shot,” said Marius Millot of Lawrence Livermore National Laboratory in California, and “right away you …

How to Build, and Keep Building, a Cathedral Like Notre-Dame

The roof of Notre-Dame Cathedral wasn’t just a roof. Sure, it kept the rain out. But what burned away in Paris in April was a technical marvel, the height—literally—of 12th- and 13th-century engineering. “If one imagines the stresses on a large sail of timber and lead rising over 100 feet from the ground, one can only marvel at the ingenuity and skill of these early builders,” as the historian Lynn Courtenay writes in an essay for the Society of Antiquaries of London. The wooden trusses—made of trees cut down in 1160 or so—were specially braced with an extra plate linking them to the walls, and clasps to keep them from sagging across the span. The wood was in tension, helping …