Is String Theory Still Our Best Hope?

Prior to this and in other contexts, we don't have a mathematical framework where you can, in this relatively elegant way, connect the other three forces with gravity.

Like gravity is always kind of the problem here in developing a theory of everything.

But people look at it and say, okay, this actually, if we think about this as a vibrating string instead of a point, and we are able to do things like connect the ends of it, mathematically, it does describe everything that we want it to describe.

So what's the problem?

Well, there's a couple of problems.

One is the strings themselves would be so small that we just have no hope of ever seeing them.

We're talking basically if an atom was made of atoms that were equivalently small as atoms are to us, and those atoms had atoms, that would be the size of strings.

Okay.

We're never going to see them.

That's a big problem.

It's a big problem.

That stops us from making predictions and then testing them on the basis of this theory.

Yeah, yeah.

Okay.

Another problem is, very early on again, it was realized that in order for the math of string theory to really make sense, there have to be, initially it was 26 dimensions of spacetime, and then later it changed to 10 because of an extra symmetry wasn't recognized originally.

So there have to be 10 spacetime dimensions, which means that we have to swallow the idea that there are six hidden dimensions of space.

That was a bitter pill.

You know, it's...

Still probably one of the main criticisms of string theory is that's just a lot of people would say, well, it's a 10-dimensional theory, therefore it's not the theory of our world.

Because our world has four dimensions.

That

we can perceive.

We don't know that there aren't six dimensions.

other dimensions.

But it is a complicated thing to say that in order for this to work, there has to be six other dimensions that are too small or in some direction that we can't ever possibly see.