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.
This universe in a teacup was built by a team at Lancaster University in England. Their study, reported in the January issue of the journal Nature Physics, probed the theory of cosmological inflation. This theory posits that just after the big bang, the universe suddenly grew very rapidly for a split second and then, just as suddenly, slowed down. This faster-than-light expansion is supposed to explain all sorts of things about the universe today, such as why it seems to be more or less the same in every direction, and how large objects, such as clusters of galaxies, coalesced out of the cosmos.
Most physicists believe that inflation occurred. The trouble is in the details—no one knows why it happened, nor quite how. It takes an awful lot of energy to make a universe accelerate, and pretty powerful brakes to get it to slow down again. Plenty of physicists have hazarded guesses at where all that energy came from, but with only one universe around to look at, and with the period of inflation 13 billion years or so in the past, it’s tough to say which of the proposals are right.single page