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by sojuz151 826 days ago
This theory is trying to justify MOND, and MOND by itself has many problems. It has problems with explaining the bullet cluster, CMB spectrum, and rotation curves of some galaxies. This paper was not even peer reviewed. This is almost certainly nothing burger
3 comments

The theory is not trying to justify MOND. That's a gross mischaracterization.

LCDM has it's own share of problems, including CMB spectrum issues and nearly zero predictive power for rotation curves.

This theory is absolutely NOT trying to justify MOND
The reason you think that this theory is trying to justify MOND is likely because hossenfelder spends about a third of the article discussing it instead of discussing the current theory.

MOND is hossenfelder's pet theory - they've done work on a version of it called Covariant Emergent Gravity

It's fine to say that any given new physical theory is almost certainly a nothingburger.. I agree with that. But please reread the article and confirm for yourself that what I say is true.

From the arxiv pdf after eq125:

> This presents a testable deviation from classical general relativity, potentially observable when the other terms are small, such as at low acceleration. The absence of such terms is likely to falsify this model. On the other hand since diffusion of the metric can result in stronger gravitational fields when we might otherwise expect none to be present, it raises the possibility that diffusion may explain galaxy rotation curves and galaxy formation without the need for dark matter

It certainly doesn't seem like an extreme reading to call this a MOND theory.

The issue is not calling it a MOND theory, it's with saying this theory is trying to justify MOND, as if that was it's primary purpose. The primary purpose was actually to unify GR with quantum mechanics and this MOND part just fell out.
This is the second time you wrote a comment claiming it's a third of the essay.

This time around, I feel like I should point out I went back and checked and it's in 6 sentences across 3 paragraphs in a 18 paragraph article.

I don't know why you started a new account to make wildly exaggerated claims about a pretty good article, but here we are

I'll grant that I was exaggerating. That's my bad. It's only 1/6th of the essay.

Re: making two comments:

I made the first point to criticize the low quality of the article. It is a low quality and dismissive article that misses an opportunity to talk about the technical meat of the theory, even through analogy. That's still true.

In the second comment I mentioned the mond thing it because it was directly related to a reader's misunderstanding, and because I felt introducing mond into the article was a red herring that had contributed to this misunderstanding. They reader thought this was specifically a MOND theory, and was therefore dismissing it out of hand. I don't think we should dismiss this theory so easily as that.

Re: Alt account

This is my only account. I lost the credentials to my old account, and it wasn't linked to my email.

Re: criticism

I drop stink bombs on things that I think are likely to misinform, and if I am wrong, I'm happy to correct myself.

Re: correction

I thank you for your comment and your correction. I know it was probably not very pleasant to write, and I know my self correction is not to the extent that you wanted, but your paragraph count helped me see I was exaggerating the MOND claim. Overcoming my own tendency to exaggerate things is very important for me, since it gets me in trouble, or gets my otherwise good arguments dismissed. I sincerely thank you for helping me with that.

Re: changing my opinion about the article

I still regard this article as an opaque and low effort treatment of the work at hand. Perhaps you could express how a particularly clear point in the article helped you understand more from the paper when you were reading it? That kind of testimony could help me understand how to see this as a good article, and to see where the value is. Thanks!

Sending Regards