I don't know if String Theory solves all of our problems, or whether it is nothing more than a mathematical model for understanding things at the Planck Scale, but I appreciate the simplicity of the theory, and the beauty it introduces to the universe. But I have two major problems with it that I was hoping some of you could answer. Forgive me if I misstate things and for my obvious over-simplification! 1. Strings are supposed to represent different particles by vibrating at unique frequencies in eleven dimensions with specific tensions and sizes. My first problem is that I find it hard to believe that a particle could be vibrating at the EXACT same frequency with the exact same properties for billions of years without changing at all, whether through some property affecting strings, or interaction with other strings, collision with gravitons, merging and unmerging with other strings, etc... So many things can happen to a string, and yet for billions of years a string vibrating as a particle will continue to vibrate as that particle no matter how long it lives. In light of how dynamic and violent the quantum universe is, I just fail to see how things can remain so "perfect" for billions of years to allow these particles to exist forever without changing. 2. Regardless of the above, what keeps strings vibrating forever without stopping? I'm guessing there is no friction or resistance to slow them down, but collisions and other effects would extract energy, wouldn't they? I know I've oversimplified the problem, but I can't formulate it any better!