String theorists: We've got the Standard Model, and it works great, but it doesn't include gravity, and it doesn't explain lots of other stuff, like why all the elementary particles have the masses they do. We need a new, broader theory.
Nature: Here's a great new theory I can sell you. It combines quantum field theory and gravity, and there's only one adjustable parameter in it, so all you have to do is find the right value of that parameter, and the Standard Model will pop right out.
String theorists: We'll take it.
String theorists (some time later): Wait a minute, Nature, our new theory won't fit into our driveway. String theory has ten dimensions, and our driveway only has four.
Nature: I can sell you a Calabi-Yau manifold. These are really neat gadgets, and they'll fold up string theory into four dimensions, no problem.
String theorists: We'll take one of those as well, please.
Nature: Happy to help.
String theorists (some time later): Wait a minute, Nature, there's too many different ways to fold our Calabi-Yao manifold up. And it keeps trying to come unfolded. And string theory is only compatible with a negative cosmological constant, and we own a positive one.
Nature: No problem. Just let me tie this Calabi-Yao manifold up with some strings and branes, and maybe a little duct tape, and you'll be all set.
String theorists: But our beautiful new theory is so ugly now!
Nature: Ah! But the Anthropic Principle says that all the best theories are ugly.
String theorists: It does?
Nature: It does. And once you make it the fashion to be ugly, you'll ensure that other theories will never beat you in beauty contests.
String theorists: Hooray! Hooray! Look at our beautiful new theory.
By Peter W. Shor
No comments:
Post a Comment