I quite liked string theory when I first met it, but frustration in the face of its untestability doesn't help. I suppose it would be naïve to wonder if the ultimate bits of matter and energy could be strings without necessarily involving all the other by-products.

I never did care for string theory. I heard about it and didn't pay much attention to it for a while. Then I read Brian Greene's "The Elegant Universe" and my interest took a deep dive. At that time they had been working on string theory for a long time, and there was still no way to actually attach it to the universe as we know it. They had a theory with an extremely large number of solutions, and no way to figure out if any of them would match what we see around us. And since then it hasn't improved any. The best that they can come up with is that there are an infinite number of different universes, one for each solution. And we just happen to be living in one where we are possible. That is a cop-out if I ever heard one.

One thing about it, the search for a string theory that works has led to the development of a lot of mathematical tools that work great for other areas of physics.

Bill Gill