I finished Brian Greene’s Fabric of the Cosmos over the weekend but had to let it sit a bit so my head could shrink back to a more normal size. Hard stuff? You bet. But Greene is very good at explaining and each chapter builds on the one before which makes it imperative that you pay attention to the early chapters, especially the one on Einstein and relativity, because he constantly refers back to them.

The book made my head hurt but it was a good hurt, the kind that comes from thinking hard. And sometimes I thought I grasped what Greene was talking about when I closed the book and then the next day when I picked it up I realized I only understood a little bit. I’d only re-read a few paragraphs before the place I left off before moving ahead. But it was okay, and if you read this book I recommend not getting worked up about being lost and confused but just enjoy the journey. More things than you expect will stick and some things that didn’t make sense in chapter four will suddenly make sense–mostly–in chapter thirteen. There might be times you want to give up on the book, but don’t. The pay off comes in the final chapters when he starts talking about all the various unproven theories of the universe. Let me just say, they are so weird.

String theory is pretty cool. In a nutshell, string theory says that the smallest particles of the universe are strings. The thing that determines that an electron is an electron is how the strings that make up that electron vibrate. There is a lot more too it than that, and string theory is unproven. One of the interesting things about string theory though is that it requires eleven dimensions in order to make the math work. That’s ten physical dimensions and time as the eleventh. So where are all these extra dimensions? That’s when things get really weird. Some suggest they are so small we can’t even see them. Another suggests that one of the dimensions is so big we can’t see it. This big dimension is a membrane (brane) in which the universe resides.

The thing with branes is that some physicists think that there are other branes outside of ours and that we are connected to one of them. They think the big bang was really a big splat when our brane collided with the other brane. And they think this is a cyclical thing and we have about a trillion years before it will happen again. The likelihood of me being alive in a trillion years is very small, but I can’t help but be disturbed by the idea of our universe being destroyed when it splats into another one.

The second to last chapter deals with time travel. Is it possible? Theoretically it is. Teleportation is also theoretically possible but the thing with that is, matter will not be transported. What happens is that the object on one end is analyzed down to the last particle and reassembled on the other end from the already existing particles in the space at the second location. To me this is duplication not transportation but Greene insists that there would be no possible way to tell the difference between the two objects. Having Scotty beam me up suddenly takes on implications I never thought about before and that I find rather bothersome.

The final chapter is about the possibility that our idea of space and time being fundamental concepts, might be wrong. Time might actually be made up of something else that when combined creates the effects of time. Same thing for space. One of these ideas is that we are living in a hologram. That everything is happening out there and we are a projection of it. Greene uses Plato’s cave as an analogy, only it’s backward. The shadows on the cave wall would be what was real and the three-dimensional things we think are real would be nothing but a projection of the two-dimensional shadows. All I can say is, whoah.

I’ll be thinking about this book for awhile and I might read it again sometime. I’ve not read Elegant Universe but now I’m going to have to. But first I have to let my brain rest a bit. In the back of Fabric of the Cosmos Greene also kindly includes a list of suggestions for further reading. I think I’m going to have to look into some of those too.