Backreaction

(I'm not a theoretical physicist).

20 years ago, I read "The Elegant Universe" by Brian Greene, as an introduction to string theory. I was initially impressed by the brilliance of the theories it presented. What really threw me for a loop, though, was realizing (as far as I understood or remember) that string theory isn't one neatly packaged theory. Instead, it's this colossal family of theories, with so many parameters that it's hard to make predictions, and to justify "why this one and not the other ones?".

Then, over the last 20 years, I read the 3 following books, which confirmed my initial impression.

- "Not Even Wrong" by Peter Woit, a deep-dive critique of string theory for the mathematically inclined. Woit's basically saying, "If we can't test it, can we even call it science?"

- "The Trouble With Physics" by Lee Smolin, which zooms out a bit. Smolin's beef with string theory isn't just about the science; it's about how this obsession is hogging resources and blocking other potentially groundbreaking ideas (including, but not limited to, his own). Think of it as a mix of a science critique and an insider's look at the politics and sociology of physics.

- "Lost in Math" by Sabine Hossenfelder, which asks if physicists' quest for beauty in equations and theories is leading them astray. This one's the most accessible, mixing in history, interviews, personal stories, and a bit of philosophy.

All three books are good, so if you have to chose one:

- Woit's book is…

I'm awaiting Jean Pierre Petit's analysis. He's developed a twin universe theory involving negative mass/energy using bimetric relativity (without the runaway effect). At one point in the development of his theory in the mid 2010s, he stumbled upon: Hossenfelder, S.: A bimetric theory with exchange symmetry.

He contacted her but she refused to collaborate on a common paper, calling him a plagiarist and a crank. She did the same to Tim Palmer (a Royal Society meteorologist) when he approached her with ideas on superdeterminism:

> But Tim Palmer turned out to not only be a climate physicist with an interest in the foundations of quantum mechanics, he also turned out to be remarkably persistent. He wasn’t remotely deterred by my evident lack of interest. Indeed, I later noticed he had sent me an email already two years earlier. Just that I dumped it unceremoniously in my crackpot folder.

http://backreaction.blogspot.com/2019/12/the-path-we-didnt-take.html

Back to Petit and plagiarism: compare:

https://link.springer.com/article/10.1007/s10509-014-2106-5

https://januscosmologicalmodel.com/cptsymmetry

with Julian Barbour's Janus Point book blurb:

> In a universe filled by chaos and disorder, one physicist makes the radical argument that the growth of order drives the passage of time -- and shapes the destiny of the universe. Time is among the universe's greatest mysteries. Why, when most laws of physics allow for it to flow forward and backward, does it only go forward?…

> That's an uncharitable interpretation. People have an objection to speculations like many-worlds because they aren't corroborated by observation, and by nature can't be (iiuc), and are therefore unscientific (though not necessarily untrue). Well-established physicists like Sabine Hossenfelder hold this position and it's not as clear-cut as "the facts don't care about your feelings" like some make it out to be.

The disagreement with MWI and the general disdain for QM are separate issues. MWI is an interpretation that doesn't necessarily invalidate the framework, but attempts to extend it. However there's also been a general disdain for QM from various folk who attempt to completely replace it.

Whether Sabine Hossenfelder likes a theory or not is not really an argument, given you're arguing from authority. As an example of her clickbaity title where she doesn't really seem to respect QM:

https://backreaction.blogspot.com/2019/05/quantum-mechanics-is-wrong-there-ive.html

I think it's well known in the theory community QM can be updated for a more complete framework (carefully obviously), but the idea that QM is "completely wrong" because it's incomplete or introduces some complexities she doesn't like, is completely laughable. It's akin to saying classical mechanics is "completely wrong" because it doesn't predict quantum behavior (despite many anti-QM people claiming QM is wrong because they want to impose their classical understanding onto the quantum world) and then…

Several of her first-or-sole-author minimal length quantum gravity phenomenology papers have more than a hundred citations:

https://scholar.google.com/citations?user=NaQZcyYAAAAJ&hl=en

and if nothing else, that's strong evidence that she has made a contribution to academic dialogue in that area.

Hossenfelder et al. 2003 in particular, is quite striking for an early career researcher: <https://scholar.google.com/citations?view_op=view_citation&hl=en&user=NaQZcyYAAAAJ&cstart=100&pagesize=100&sortby=pubdate&citation_for_view=NaQZcyYAAAAJ:ns9cj8rnVeAC>. Also noteworthy are several early publications on either side of her 2003 doctoral thesis on microscopic black holes in large extra dimensions. In that period numerous co-authors, reviewers, and editors supplied indirect evidence against your claim that her papers "were pretty bad".

Quite a lot of strong constraints on large extra dimensions came out of the LHC work eight to twelve years after these publications. Her old link-rotting written blog captures some of that: <https://backreaction.blogspot.com/2011/06/extra-dimensions-at-lhc-status-update.html>, for instance.

There is an enormous difference between being wrong and publishing nonsense.

> at least those I read

You could have usefully supplied a short annotated bibliography. It would certainly make your final sentence

> She is pure show

less likely to be seen as nonsense and more likely to be seen as wrong.

Whatever she has become in the past couple of…

Prof. Sabine Hossenfelder has a great article on the lack of progress in fundamentals of physics: "The present phase of stagnation in the foundations of physics is not normal " [1]

Choice quotes:

>We know this both because dark matter is merely a placeholder for something we don’t understand, and because the mathematical formulation of particle physics is incompatible with the math we use for gravity. Physicists knew about these two problems already in 1930s. And until the 1970s, they made great progress. But since then, theory development in the foundations of physics has stalled. If experiments find anything new now, that will be despite, not because of, some ten-thousands of wrong predictions.

>Ten-thousands of wrong predictions sounds dramatic, but it’s actually an underestimate. I am merely summing up predictions that have been made for physics beyond the standard model which the Large Hadron Collider (LHC) was supposed to find: All the extra dimensions in their multiple shapes and configurations, all the pretty symmetry groups, all the new particles with the fancy names. You can estimate the total number of such predictions by counting the papers, or, alternatively, the people working in the fields and their average productivity.

According to her, and many other physicists, there hasn't been any major progress in phenomenology since 1970s when Higgs boson was postulated.

[1] https://backreaction.blogspot.com/2018/11/the-present-phase-of-stagnation-in.html

Sabine's argument has been frequently bad faith after the fact and currently. Just skimming some of her written work:

"Before the Large Hadron Collider turned on, particle physicists claimed that it would either confirm or rule out supersymmetry. ... The answer is that the LHC indeed did not rule out supersymmetry, it never could."

https://backreaction.blogspot.com/2022/04/did-w-boson-just-break-standard-model.html

"I hope they’ll finally come around and see that they have tried for several decades to solve a problem that doesn’t exist"

https://backreaction.blogspot.com/2018/02/what-does-it-mean-for-string-theory.html

Here she says physicists will just keep building bigger colliders because they can and not on merit

https://www.scientificamerican.com/article/the-world-doesnt-need-a-new-gigantic-particle-collider/

Here she said CERN's push for an FCC is "full of lies"

http://backreaction.blogspot.com/2018/12/cern-produces-marketing-video-for-new.html

When people are accused of ignoring or dismissing credible points where a program is legitimately problematic is exactly an accusation of operating "bad faith". "Good faith" means doing legitimate and believable science with the best information. These are claims it was done to the contrary.