what is m-theory, toe 0?

A version of String Theory

http://www.pbs.org/wgbh/nova/elegant/program.html

http://www.damtp.cam.ac.uk/user/gr/public/qg_ss.ht...

An embarrassment in physics is when there are more than one theory for the same phenomenon. There should be but one true theory per phenomenon. String theory had five. Proposed by Ed Witten, M theory unifies the five string theories that have been proposed.

M theory resolved that multiplicity of theories by showing all five were really just five different views of the same thing. As an analogy, two string theories were something like looking at a car in two mirrors, one on each end of the car.

So when the observer using one mirror describes the car, she talks about the sleek grill and headlights. And when another observer using the other mirror describes the same car, he talks about the ample trunk size and the tail lights. Same car, just different perspectives. M theory put up a third mirror so both observers could see the reflections in the other two mirrors and confirm they were talking about the same car... the same strings.

I recommend getting "The Elegant Universe" by Brian Greene, Ph.D. for some easy and fun reading about string and M theories, higher dimensions, alternate universes, and other weird science. Greene also does "The Elegant Universe" on PBS; if you have a chance, try to watch it, the visuals are great.

Another good book that discusses the subject is Michio Kaku's "Parallel Worlds." Entertaining read, written well for the non-egghead.