Sometimes a new scientific idea can be like the punch line of a very long joke: You need to keep the whole setup in mind to appreciate the humor, but it's worth the effort.
There's a fledgling idea I'm working on with physicist Lee Smolin that requires quite a setup, but it's worth it. The idea is that the flow of time comes from the way that mathematics is never complete and always gets weirder the more you understand it. That sentence should not make sense yet, but it will by the end of this column.
The first part of the setup is to recap some recent physics history. Only two theories from the 20th century have matched the results of experiments so well that they seem perfect, at least thus far. These are quantum field theory and general relativity. The annoying catch is that the two great theories conflict with each other at the margins, so they can't both be completely correct.
