National Geographic : 2014 Mar
that went beyond Einstein’s general relativity, which determines the motion of stars and galax- ies. And you’d have to surpass quantum mechan- ics, which predicts what happens to microscopic particles. Both theories are fine approximations of reality, but in a place of extremes, like the interior of a black hole, neither applies. Singularities are imagined to be extremely tiny. Beyond tiny: Enlarge a singularity a tril- lion trillion times, and the world’s most power- ful microscope wouldn’t come close to seeing it. But something is there, at least in a mathe- matical sense. Something not just small but also unimaginably heavy. Don’t bother wondering what. The vast majority of physicists say, yes, black holes exist, but they are the ultimate Fort Knox. They’re impenetrable. We will never know what’s inside a singularity. But a couple of unorthodox thinkers beg to differ. In recent years it’s become increasingly ac- cepted among theoretical physicists that our uni- verse is not all there is. We live, rather, in what’s known as the multiverse—a vast collection of universes, each a separate bubble in the Swiss cheese of reality. This is all highly speculative, but it’s possible that to give birth to a new universe you first need to take a bunch of matter from an existing universe, crunch it down, and seal it off. Sound familiar? We do know, after all, what became of at least one singularity. Our universe began, 13.8 billion years ago, in a tremendous big bang. The moment before, everything was packed into an infinitesimally small, massively dense speck—a singularity. Perhaps the multi- verse works something like an oak tree. Once in a while an acorn is dropped, falls into the ideal soil, and abruptly sprouts. So too with a singularity, the seed of a new universe. And like a sapling oak, we’ll never send a thank-you note to our mother. For the message to escape our universe, it would have to move faster than the speed of light. Again, sound familiar? The evidence for what could reside in a black hole is compelling. Look to your left, look to your right. Pinch yourself. A black hole might have originated in another universe. But we may be living in it. j Black HOles are BasIcally tIme macHInes. Superheated by the massive black hole at the center of galaxy M87, a jet of gas shoots out across several thousand light-years. naSa/huBBle heritaGe teaM tune in to the national Geographic Channel on March 10 for the series premiere of Cosmos: A SpaceTime Odyssey.