I really hope so. But it’s possible we won’t. There’s no reason to believe that our brains have evolved far enough to be able to comprehend the Universe. Our brains have basically evolved for scavenging on the African savannah, so it’s actually pretty amazing that we’ve got this far.
The Universe does show signs of impressive elegance and simplicity in its laws. A lot of physicists do think we are tantalisingly close to a Grand Unified Theory, certainly the laws we have describe the Universe remarkably well. If only we could find some way to fit the pieces of the jigsaw together…
On the other hand, some physicists think the Universe might be infinitely complicated.
Like the others, I hope so. I’m not sure that we will — but there’s a bigger trouble than ‘merely’ just writing down something that describes everything: we’ve got to use it.
At the moment, we’ve got a pretty good understanding of three of the four fundamental forces in nature — everything except gravity. We can use that understanding to predict quantities we can measure to phenomenal accuracy…but actually doing that calculation is really, really hard. It’s so hard, in fact, that to work out exactly what happens to a single particle moving in free space requires maths of the type that won Feynman his nobel prize.
The world around us is a lot more complicated than a single particle moving in a straight line. I think that for a ‘theory of everything’ to justify the name, it has to be able to be used to explain everything — and most things we see on an every-day basis require a theory that’s more geared to explaining them. It’s very unlikely that we’ll ever develop either enough computing power or clever enough mathematics to be able to actually solve a ‘theory of everything’ to explain complex systems, or something more complicated than a subatomic particles interacting.