What the string theorists do is arguably physics. It deals with the physical world. They're attempting to make a consistent theory that explains the interactions we see among particles and gravity as well. That's certainly physics, but it's a kind of physics that is not yet testable.

I think that we scientists are seeking an understanding of the natural world. We come in various types - chemists and physicists and biologists and such - and we all have the same goal. We are making progress.

There are physicists, and there are string theorists. Of course the string theorists are physicists, but the string theorists in general will not attend lectures on experimental physics. They will not be terribly concerned about the results of experiments. They will talk to one another.

Sheldon Lee Glashow Quotes