Sean Carroll explores why the universe obeys simple equations. He considers whether this compressibility is a brute fact, whether we're selecting among possible worlds, or whether simplicity itself is maximized. He also distinguishes between emergent descriptions like tables and atoms versus fundamental quantum fields.
Again, an unanswerable question. Why do you think our world is so easily compressible into beautiful equations? Yeah, I mean, like I just hinted at. I don't know if there's an answer to that question. There could be. What would an answer look like? Well, an answer could look like if you showed that there was something about our world that maximized something, you know, the, the mean of the simplicity and the powerfulness of the laws of physics. Or maybe we're just generic. Maybe in the set of all possible worlds this is what the world would look like. I don't really know. I tend to think not. I tend to think that there is something specific and rock bottom about the facts of our world that don't have further explanation, like the fact that the world exists at all and furthermore the specific laws of physics that we have. I think that in some sense we're just going to, at some level we're going to say, and that's how it is. And I can't explain anything more. I don't know how if we're anywhere close to that right now, but that seems plausible to me. And speaking of rock bottom, one of the things, so your book kind of reminded me or revealed to me, is that what's fundamental and what's emergent. It just feels like I don't even know anymore what's fundamental in physics. If there's anything. It feels like everything, especially with quantum mechanics is revealing to us is that most interesting things that I would, as a limited human would think are fundamental can actually be explained as emergent from the more deeper laws. I mean, we don't know, of course, you had to get that on the table. We don't know what is fundamental. We do have reason to say that certain things are more fundamental than others. Right? Atoms and molecules are more fundamental than cells and organs. Quantum fields are more fundamental than atoms and molecules. We don't know if that ever bottoms out. I do think that there's sensible ways to think about this. If you describe something like this table as a table, it has a height and a width and it's made of a certain material and has a certain solidity and weight and so forth. That's a very useful description as far as it goes. There's a whole other description of this table in terms of a whole collection of atoms strung together in certain ways. The language of the atoms is more comprehensive than the language of the table. You could break apart the table, smash it to pieces, still talk about it as atoms, but you could no longer talk about it as a table. Right. So I think that this comprehensiveness, the domain of validity of a theory gets broader and broader as the theory gets more and more fundamental. Sam.
