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.

Is all this work on string theory and multiple dimensions and extra universes still science? That’s the question physicist Sean Carroll and writer John Horgan recently debated. Carroll, of the California Institute of Technology, also blogs regularly for Cosmic Variance, and he wrote out a detailed post explaining his position. Obviously, as a cosmologist who works full-time on these seemingly preposterous ideas, he is a bit biased. He’s not the guy you’d expect to stop and say it isn’t real science. But his piece on the subject does effectively explain why he and, one assumes, other theoretical physicists working on these problems think this way.

For those of you who sometimes wonder why string theory can be one of the most talked about scientific ideas of our day without a whisper of evidence backing it up—admit, there are a few of you out there—there's a very interesting and not too complex article in the new issue of Physics World. The piece reviews some of the history and progress of past scientific theories, and why considering only the big ideas that can be backed by some experimental proof isn't a good thing for advancing our understanding of the universe. The simplified conclusion: At this point, string theory is the only real candidate capable of pulling together gravity and quantum physics, so we might as well stick with it.—Gregory Mone

This past Sunday the New York Times featured an excellent piece by Dennis Overbye about the film What the Bleep: Down the Rabbit Hole, a sequel to the cult hit of two years ago What the #$%* Do We Know!? Both movies feature a coterie of scientists, philosphers and “visionaries” who speak with mixed credibility about quantum physics and the possibility that reality could be a mental construct. Overbye clearly thinks this is a bunch of hooey (as does PopSci's own Greg Mone—see for yourself how he ripped the makers of the original film a new one in 2004 here) and his essay makes for really entertaining reading. —Megan Miller