The Download: quantum squeezing, and a game-building AI model

When two black holes spiral inward and collide, they shake the very fabric of space, producing ripples in space-time that can travel for hundreds of millions of light-years. Since 2015, scientists have been observing these so-called gravitational waves to help them study fundamental questions about the cosmos, including the origin of heavy elements such as gold and the rate at which the universe is expanding. By the time they reach Earth, the ripples have dissipated into near silence. Our detectors must sense motions on the scale of one ten-thousandth the width of a proton to stand a chance. And making them more sensitive is a huge challenge.