The device is a cylinder a bit smaller than a pinky finger, filled with helium and cooled to just above absolute zero. Inside, a young universe—or something very much like one—evolves. As the helium sloshes about, it mimics a process that may have powered our own universe a few moments after the big bang. And once the fluid settles down, the little whirlpools that remain may be akin to the defects in early spacetime that ultimately gave rise to galaxies, stars and planets.