The trek in this book has been toward what may be the capstone Copernican correction. Our universe itself may not be central to any cosmic order. Much as with our planet, star, and galaxy, our universe may merely be one among a great many."
After the jump, my review.
If your understanding of science was formed in, say, the 1960s, you probably learned that the Big Bang was the beginning of everything. And by everything I mean not just all matter, but matter, energy, even space and time. Asking what came *before* the Big Bang was as futile as asking what's north of the North Pole. It's not just that the answer is nothing; it's that the question itself makes no sense. There's no there there. The word "before" is meaningless unless time itself exists.
Well, a lot has happened in the last fifty years. Science now has more theories than it can comfortably wrestle with. Unfortunately, none of the theories have ways to empirically test. So all the theories are highly speculative at this time. Brian Greene does a better job of collecting, simplifying, and summarizing these different theories than any other popular science writer I know.
A collection of multiple universes is called a multiverse. Hidden Reality describes current thinking about nine such multiverse theories. In some theories, the multiverse is infinite and eternal, spawning bubble universes like bubbles in Swiss cheese; in another theory, the multiverse is cyclic (universes collide, returning both to a Big Bang-like stage); in another, driven by quantum uncertainty, every possible outcome of an event is real in a universe of its own; in another, our own universe is likely to be only a simulation run by an advanced civilization (think something like SimUniverse).
One thing many of the multiverse theories have in common is that communication between universes in the multiverse is impossible by the laws of physics, even in theory. Needless to say, that makes proving the reality of any of this extremely difficult. Still, Greene lays out how to approach the challenge and doesn't rule out the possibility of finding experimental results that grow our confidence in the reality of one or more of these theories.
Science has come a long way since the 1960s and Brian Greene is just the guide to show how far.
The ebook in Kindle format is available for free from the Richardson Public Library.