Well, I guess they say that the one's who can't do, teach. And last time I checked everybook at the local library about physics was written by a physics teacher... I don't see how that makes them a non-scientist, I feel that comment in itself is an uneducated opinion. Any book on string theory isn't very descriptive on how the theory actually works and tends to be a small foot note in the back of the book, a very generalized description. I think it keeps people from really being able to talk about it and how and why it works, because honestly I think no one really knows. But I do know that none of them claim that 11 dimensions is prefered in any way to any other amount of dimensions, and the "prediction of the string framework" in itself would be what adds extra dimensions since it would take extra dimensions in order to create that framework. It isn't testable because it doesn't predict anything that would act differently than any other theory that is testable. No significant difference, if it did predict a significant difference I would hope that they would be able to run a test to distiguish it.