I've never understood the desire for beauty in a theory of everything. Reality clearly isn't beautiful through and through, but at its corners it is awfully complex and arbitrary. If anything, reality is much like the outcomes of an evolutionary process, a mere hack of various mechanisms that happen to give rise to the relatively stable patterns we experience. Of course, fundamental research needs the optimism that we can compress all of that in ever smaller formulae, but I think there is no unambiguous evidence that we should actually expect that to be possible. The most striking piece of counter evidence is actually the kind of reality we experience in the first place. Imagine a universe in which its inhabitants would be able to figure out its fundamental principles. These inhabitants would likely immediately conquer all available space and use it to maximize the reward signals that evolution has equipped them with and thus transform everything into something completely different from the world we are experiencing. A universe with a reality like ours and that is fully understandable at the same time is thus (together with various other assumptions) a logical impossibility.
"I've never understood the desire for beauty in a theory of everything."
It comes from the history of physics. A few equations define classical dynamics. Maxwell's four equations describe electromagnetism. A few short equations define quantum electrodynamics. High-energy physicists have been looking for something equally terse. It just isn't happening.
Once we properly understood it we realized Maxwell's equations could be reduced to one equation (the d'Alembert operator applied to the electromagnetic tensor gives 4-current scaled by a constant).
I'm sure whatever turns up for quantum gravity will be hideous to begin with, but then eventually we'll understand it.
The Mandelbrot set is very complex, but is generated by an absurdly simple rule. There are many instances in math and physics where complex behavior is an emergent property of simple rules.
You're also confusing understanding with logical omniscience and omnipotence. I know all the rules of chess, but I do not know every fact those rules entail, and I do not know how to win every chess game. Even if I did know those things, certain moves are impossible even though I know everything about chess.
It's not just about beauty, but experience. Imagine you have a spreadsheet with infinite rows where each row contributes to the Higgs mass. It also turns out that by and large each row contributes less than the previous. You can't calculate all of them, but calculating the bigger ones you can do pretty well. Now imagine someone plops in infinity into one of the rows, sure the rest could all just happen to contribute a small amount and conspire to add up and cancel that out (because the mass isn't infinite), but it just doesn't seem like the world we live in. However, if you add another column to your spreadsheet for super symmetry and suddenly that column naturally cancels out the discrepancies from the first column. It's a simplistic example, but hopefully gives a better idea why Physicists were hopefull for some kind of new physics.
Just because you can understand the thing doesn't mean that you can completely control it. Just because we know about the speed of light doesn't mean that we can travel faster than it, just because we know math doesn't mean that we can make 1 plus 1 equal 3.
Knowing fundamental principles wouldn't make us all powerful.
I was about to say something similar, just checking out if someone had already said it.
I just don't dig the obsession with "aesthetics". It just doesn't compute. I understand the need for simplicity, but there's JUST NO PLACE for aesthetics in science. We need simple verifiable experiments and results, no "my model is more beautiful than yours" stupidity.
One important thing: scientists need to recognize where science ends and passion/preference begins. Scientism is the greatest foe of science.
