“Is our universe extremely unnatural, a weird permutation among countless other possibilities, observed for no other reason than that its special conditions allowed life to arise, or, are the properties of the universe are inevitable, predictable, that is, ‘natural,’ locking together into a sensible pattern?” This is the question, the great unknown, that preoccupies theoretical physicist Nima Arkani-Hamed, a professor at the Institute for Advanced Study (IAS) in Princeton, N.J.
“I knew, of course, that, at least in our corner of the universe, there are lots more electrons than positrons, but I still found it an exciting idea to think of trajectories in spacetime that could go unrestricted in any direction — forward in time, backward in time, up, down, left, or right.”
