For the context, the video this is a follow up to is helpful (they're both short) - https://www.youtube.com/watch?v=ZlHvW6k2bcM

John Carlos Baez thinks Sabine has a point.

https://mathstodon.xyz/@johncarlosbaez/113285631281744111

>Despite the silly clickbait title of this video, Sabine says a lot of interesting stuff in it: her criticism of claimed deviations from Lorentz invariance in loop quantum gravity is about as good as you'll get from anyone who hasn't actually worked on loop quantum gravity. I worked on it for about 10 years, and the situation is even a bit worse than she makes it sound.

My understanding of the situation (which may be wrong, in which case please let me know) is that physics is stuck at a local optimum.

There are two obvious ways to get out

(1) Surprising physical observations, or

(2) Mathematical advances

Way (1) is what kicked off quantum mechanics. Way (2) is what kicked off Newtonian mechanics.

I see string theorists and loop quantum gravity people as working on (2). Their models are mathematically interesting and aren't totally understood from a mathematical perspective. But they're different enough that studying them may break the impasse.

I see (1) as largely limited by the budgets and technology needed to build things like particle accelerators and spacecraft.

For (2) you have to decide whether to only explore mathematics that defines physical reality, or whether to also allow exploration of non-physical systems. For example, you might explore a universe that is almost physical but has time machines. Restricting the search space to only physically realistic systems is a significant constraint, so there's a debate to be be had about how much weight to give it.

If LQG turns out to be unworkable, we're back at string theory as the only renomalizable description of quantum gravity.

Quantum gravity research amounts to one professor per university faculty on average. Even in the worst case this would not be the crisis of unmet expectations it is made out to be... QG researchers are very brave because they are risking everything on the possibility that existing data constrains quantum gravity in a way that hasn't yet been understood. I doubt there is even a single person making that gamble unaware that the Planck energy density is something like 20 orders of magnitude above present-day experiments.

The fundamental reason for this is simple. Humans are prone to cognitive dissonance. Meaning, we do absurd things to avoid painful thoughts. And anything that questions our sense of identity, is a painful thought.

So if my self-image is, "I've advanced our understanding of the fundamental nature of reality," then the idea that my contributions weren't useful becomes painful. So we avoid thinking it, challenge people who question our past contributions, and so on.

The natural result of this cognitive dissonance is a feeling of undue certainty in our speculations. After all certainty is merely a belief that one idea is easy to believe and its opposites are hard to believe. We imagine that our certitudes are based on fact. But they more easily arise from cognitive biases.

And this is how a group of intelligent and usually rational people descend into theology whose internal contradictions can't be acknowledged.

> What's even more insane is that the only two people I can think of who have pushed back against this are Peter Woit and Eric Weinstein, and both of them are trying to sell you their own theory of everything

Sabine forgot Stephen.

https://writings.stephenwolfram.com/2021/11/the-concept-of-t...

I think in this an other videos, what she says is "they are not even wrong" and she does have a point there.

As a non-physicist, it’s hard to understand if she has a point or not.

Any physicists care to weigh in?

I've said this before in not the same words, and I am always downvoted here on hackernews: people need to understand theory of knowledge before they understand science. Physics and physicists are the worst offenders.

Theoretical physics are theoretical; that seems to be the crux of her problem. And in that light it makes sense that she's become an influencer who makes content instead of someone who devotes most of their time to advancing the science. Yes, oftentimes people will be paid to work on problems, and they'll end up in a cul-de-sac. That will be the case for the majority of the field in the case of something like quantum physics. But if we pay enough of these people to sit in rooms and work on problems, maybe one of them will figure something out. That's how science progresses.