Which Universe Are You In?
"Get used to the idea of an infinite number of universes, says superstring theorist Brian Greene in his new book, The Hidden Reality. . . .
Extra dimensions are old news. The newest mind-bending descriptions of reality dreamed up by the world’s smartest physicists, and explained by superstar superstring theorist Brian Greene in his latest book The Hidden Reality, include untold numbers of extra universes. A million universes isn’t cool. You know what’s cool? Ten to the 500th power universes. . . .
In his new book, Greene takes us down the rabbit hole yet again, this time setting a course for the terra incognita of parallel universes, hidden worlds, alternate realities, holographic projections, and multiverse simulations. Greene likes to drop you into the middle of the action first and then explain the backstory (and sometimes it does feel like a full-scale intellectual invasion is happening), but he has an elegant knack for anticipating questions and immediately dealing with any confusion or objections.
Greene describes nine different theories which imply that we are living in a vast multiverse. He’s pretty confident that some of them are true, but less sanguine about others (chances are small that we’re living in a vast simulation with other universes running as parallel processes on some higher-order cosmic computer). One important takeaway, though, is what he calls the 'Copernican pattern': over the past 500 years, each new cosmological discovery has removed us from being in a privileged position in the universe. First, we realized that the sun, not the earth, was the center of the solar system; then we discovered that our sun is just an ordinary star in the Milky Way, and that our galaxy is just an ordinary galaxy among about 80 billion or so that are visible. Greene takes this further: what we call our universe is only one piece of an unbelievably vast multiverse." More