Math and Magic

[Yazata]

iai.tv/assets/videos/linked/HTL … RSE.SD.mp4

INTRO: Since Newton, we have assumed that the universe is governed by unchanging laws, and Stephen Hawking once even argued that we were close to uncovering them in their entirety. But are these laws really eternal features of the universe? If so, how do they emerge and how do they act? Or are they merely human ways of codifying the world, which remains somehow unknowable and inexplicable?

I think that they are both of those things (in a way). Physics is a human construction that seeks to model how physical reality seems to us to behave. So in one sense it is something we made. But in another sense it captures and reflects something beyond itself.

Physics isn’t just literary fiction, it isn’t pure creative anything-goes. You really can use the mathematics of theoretical physics to predict what future observations will be. And quite often those future observations are almost precisely what physicists predicted they will be.

So how is that possible unless the mathematics is somehow isomorphic with some formal aspect of reality? (The no-miracles argument and ontic structural realism.)

iai.tv/assets/videos/linked/HTL … nce_SD.mp4

INTRO: Has modern physics outgrown the need for evidence? New York philosopher Massimo Pigliucci argues for a new age of explanation.

I have a lot of respect for Massimo Pigliucci, but (without watching his video) have to disagree with that idea. Physics still needs evidence, in the absence of evidence physics runs the risk of turning into speculative metaphysics.

I think that contemporary theoretical physics is increasingly moving in that direction. The always outspoken Sabine Hossenfelder, author of the recent Lost in Math seems to think so. The problem seems to be that many recent theoretical physicists proposed theories based on their mathematical elegance and their potential ability to solve various outstanding problems. (String-theory, supersymmetry, and whatnot.) The only problem with that, is that experimental evidence that might be expected to confirm them doesn’t seem to.

blogs.scientificamerican.com/cr … -thinking/

She quotes the famous physicist Frank Wilczek, who appears to agree with her: “But I don’t think we should compromise on this idea of post-empirical physics. I think that’s appalling, really appalling… If there was any bit of experimental evidence that was decisive and in favor of the theory, you wouldn’t be hearing these arguments. You wouldn’t. Nobody would care. It’s just a fallback. It’s giving up and declaring victory. I don’t like that at all.”

math.columbia.edu/~woit/wordpress/?p=10314

Sabine Hossenfelder’s chapter titles are something to behold. A few examples:

Chapter 6: The Incomprehensible Comprehensibility of Quantum Mechanics – In which I ponder the difference between math and magic.

Chapter 8: Space, the Final Frontier – In which I try to understand a string theorist and almost succeed.

Chapter 9: The Universe, All There Is, and the Rest – In which I admire the many ways to explain why nobody sees the particles we invent.

Chapter 10: Knowledge is Power – In which I conclude the world would be a better place if everyone listened to me.

(I can’t help it. I just gotta like this woman.)

[pood]

I agree with your take on Sabine and read her blog regularly. I’m no scientist but I do read and study this stuff a lot, because it’s so darned fascinating. The physicist Max Tegmark, for one, thinks that maths are literally isomorphic with reality and that every mathematical structure is instantiated in a different universe. This is mathematical Platonism. I see no evidence for it — I’m not sure it’s something you can get evidence for — but it’s a beguiling idea, and raises the question of whether there are aspects of reality to which we cannot have access even in particular. But if that is so, arguing for these untestable-even-in-principle ideas seems pretty unscientific, as Sabine argues. Why not just argue for God or fairies in the bottom of the lake and be done with it?

Sabine, for example, rejects the MWI, deeming it unscientific. At the same time, she plumps for Superdeterminism, deeming it a deeper theory of the world than QM from which QM is derived. She says she has developed a test for Superdeterminism, but I don’t get it myself. The thing about superdeterminism is it suggests that the whole universe has conspired, beginning at the Big Bang, to interfere with our measurements in the here and now in such a way that we can never run a test that shows QM to be fully deterministic rather than indeterministic. I find this crazy, personally, but my respect for Sabine is such that I labor to understand her reasoning.

I also find her repudiation of free will to be problematic, as I discuss in another thread, posing her view on the matter with the view of a physicist who disagrees with her.

String theory is another situation where the maths are beautiful but there is no evidence and so far as I understand, it may not be possible to get evidence for the extra spatial dimensions that string theory requires even in principle.