Rick B. (bup) -
This book wouldn't be great without his first two. Or maybe it would, but it would seem like a fantasy ride in some bologna-artist's woo-science book. It's basically a survey of the different multiverse ideas out there - all the different ways people have dreamed up multiple universes.
Given the scientific gravitas Brian Greene is able to bring, though, one has to take these ideas seriously. At least, as seriously as one can. I'm not a physicist, but I have taken a statistics course or two, and the thinking about how we can test some ideas of multiple universes by looking at our own universe make absolutely no sense to me. Our universe is one data point. It gives you zero degrees of freedom. There is no hypothesis one could reject by theorizing, as Greene seems to do, that multiverses where a universe like ours would be more likely, and then turning around and looking at the data from our universe.
Whether or not he's right about testability, though, even constructing hypotheses is a portion of science. Science is the process of developing and testing hypotheses. There's nothing wrong with developing hypotheses you have no idea how to test, and calling it a scientific step. OK, so we have no idea how to test, or if we can. Don't let that limit the process of developing hypotheses.
Two more nitpicks (I gave this 5 stars, too - why am I only complaining? I guess I found the book so intriguing and engaging that I want to talk back to it):
1) He never talked about the fact that many of these multiverse theories are not mutually exclusive - bubbles in the expansion of space and simulated multiverses could obviously coexist, as could many of the others.
2) In the ultimate universe model, the universe with nothing in it obviously exists - inasmuch as it needs to. We have to accept that one, just like we have to accept the empty set in every set of subsets ever.
Anyway, good book. I recommend "The Elegant Universe" and "Fabric of the Cosmos" before this, but I guess it would work on its own, too.
Given the scientific gravitas Brian Greene is able to bring, though, one has to take these ideas seriously. At least, as seriously as one can. I'm not a physicist, but I have taken a statistics course or two, and the thinking about how we can test some ideas of multiple universes by looking at our own universe make absolutely no sense to me. Our universe is one data point. It gives you zero degrees of freedom. There is no hypothesis one could reject by theorizing, as Greene seems to do, that multiverses where a universe like ours would be more likely, and then turning around and looking at the data from our universe.
Whether or not he's right about testability, though, even constructing hypotheses is a portion of science. Science is the process of developing and testing hypotheses. There's nothing wrong with developing hypotheses you have no idea how to test, and calling it a scientific step. OK, so we have no idea how to test, or if we can. Don't let that limit the process of developing hypotheses.
Two more nitpicks (I gave this 5 stars, too - why am I only complaining? I guess I found the book so intriguing and engaging that I want to talk back to it):
1) He never talked about the fact that many of these multiverse theories are not mutually exclusive - bubbles in the expansion of space and simulated multiverses could obviously coexist, as could many of the others.
2) In the ultimate universe model, the universe with nothing in it obviously exists - inasmuch as it needs to. We have to accept that one, just like we have to accept the empty set in every set of subsets ever.
Anyway, good book. I recommend "The Elegant Universe" and "Fabric of the Cosmos" before this, but I guess it would work on its own, too.
