The Crisis in String Theory Is Worse Than You Think | Hacker News Reader

The Crisis in String Theory Is Worse Than You Think

math.columbia.edu

43 pointsbobismyuncle35 comments

Been following this via proxy, i.e. Sabine Hossenfelder, for a few years. The charges are very solid afaict.

As a layman who has been following this topic for decades and has read many popularizations by leading physicists, and had a good undergraduate education in math and physics ... I have no clue how solid the charges are. My background on this is way too weak to justify holding an opinion. I generally don't hesitate in opining about things I'm mostly clueless about but in this case my ignorance is so vast that it is obvious even to me. If the greatest physicists can't agree on an abstruse physics topic I can't imagine what the opinion of a rando web dev might add.

I am a big fan of Sabine. Recent video on her by prof dave explains made me think though. https://travisporter.bearblog.dev/new-post/

That video in turn, has a great and extensive comment from @throwaway4179-s7d that raised Sabinne credibility, and actual decreases the one from Professor Dave Explains.

He attacked her and her audience, it was hardly an indictment on her arguments. Dripping with ad hominem.

Would you recommend following only Sabine to be a good way to get a thoughtful and unbiased view of the issue?

Not only of course, but I find is a good reference point, as somebody that was right in the middle of it, got out, and has nothing to loose saying what she thinks is true. She could very well be doing videos explaining all the models she does not believe, and have much more subscribers.

The question was to the person above where it seemed like that's what they were doing and then expected us to take their view as something worth considering. It was giving them an opportunity for them to explain their position and give themselves credibility.

Your credibility is also suffering, as you failed to explain where Sabine is wrong...

Was I attacking Sabine or was I saying trusting a single source to inform the entirety of a view of a non-expert about a debatable topic is perhaps not responsible?

I can't speak to the merits (or lack thereof) of string theory. That's well beyond my physics knowledge.

It must however be daunting to be a theoretical physicist right now. It seems like the field has been in a standstill for years. The advances in the 20th century were just eye-watering. The Standard Model is a mixed bag of stunningly accurate prediction (eg electron monopole moment [1]) vs the wildly inaccurate (eg the so-called "vacuum catastrophe" [2]).

And there are so many unanswered questions, like nobody really seems to know what particle generations are or why they exist. Or that particle masses can't be derived from first principles (or that the math can't be solved, I'm honestly not sure).

It seems like we have no intuition for a lot of this stuff because there's no analog in the real world. So we give names to things (eg color, spin) that are just abstract properties. Electromagnetism is tantalizingly simple. The strong nuclear force interacts with its own carrier particles so is far from simple. The mediating particles of the weak nuclear force were, I believe, the first evidence of the Higgs field (because they have mass) but again, not my speciality.

But here's the interesting part (to me): the human systems surrounding it. When progress slows in a field, you'll find the tendency of people to coalesce around certain ideas that may border on dogma because careers are built on reputation and nobody wants to be "wrong". Likewise, string theory has a lot of investment in it. People have built careers on it. Nobody wants to throw that away.

The LHC gave experimental evidence to the Higgs boson, which was one of its goals. It's also managed to disprove a lot of theories, which is useful. But it hasn't given any hint of where to go. There's already talk of a successor but nobody really knows what to look for so it's hard to imagine that'll go anywhere.

So string theory seems to be like physics orthodoxy now.

j[1]: https://cfp.physics.northwestern.edu/documents/PhysicsToday-...

[2]: https://en.wikipedia.org/wiki/Cosmological_constant_problem

> It must however be daunting to be a theoretical physicist right now. It seems like the field has been in a standstill for years.

The general public don't really understand where most physicists work. The largest subfield of Physics is really in condensed matter, where (depending on how you count it) somewhere like 30-50% of physicists work, and where there is plenty of interesting theory work. High energy physics is the next biggest subfield, but much of it is experimental, and then you get into "classical physics" like acoustics, optics, etc. Astrophysics is relatively smaller. There's also nuclear, plasma, fusion and then a whole host of interdisciplinary work like biophysics, materials science, etc. Especially with interdisciplinary work, people often do bits and pieces throughout their career, not everyone sticks strictly to a single subfield.

There's plenty of interesting theoretical physics work in pretty much all of these fields. Not everyone works on grand problems of the universe!

The second link reignited my bias for Zeldovich as not having sufficient public recognition. I previously knew him as the originator of the idea of Hawking radiation (he predicted it around Kerr black holes, and told Hawking about that), but it looks like he also had major contributions to both the Soviet nuclear project and the vacuum energy problem (as you say still unsolved).

Seems like a lot of the big unanswered questions are locked away until we figure out a unified theory that bridges that gap between the relativity and quantum scales, and opens up the necessary fundamentals. I know progress is incremental, but it's hard to not get the impression that we're putting all our eggs into the wrong basket, so to speak.

I'm beginning to like Sabine more and more. She is pro-nuclear, but she's not afraid to criticize the issues, like she did recently with small nuclear reactors.

The most optimistic view I've heard on string theory is that the Ads/CFT correspondence actually can move to de-sitter space one day. String theory proponents actually believe this. They do believe the Ads/CFT correspondence is one of the crowning achievements of string theory.

The most pessimistic view I've heard is that we're waiting for the people who have made string theory their life's work since the 1980's to retire and allow new funding efforts to go to different ideas.

Sabine wasn’t mentioned in this article at all. Why is this the top comment?

But as a side note, Sabine has the annoying habit of speaking authoritatively in matters outside her expertise (i.e. physics) in her YouTube videos. You catch someone doing that once in a scripted presentation, in a subject area where you have expertise and you know they are being superficial at best and wrong at worst, and you basically tune out.

Is part of it that we just can’t test any of this because we can’t either examine a black hole or run an accelerator the diameter of the Moon’s orbit?

Maybe planet nine if it exists will turn out to be a small primordial black hole within probe range, or we will locate a micro primordial black hole within the solar system.

Would building an even bigger deeper into time gazing JWST help?

I’ve gone down the black hole rabbit hole lately and personally I’d love to see an ultra sensitive fish eye X-ray and gamma ray telescope to hunt for the weak signatures that might be emitted by tiny accretion discs in or near our solar system. Find us a lovely marble to go examine and chuck stuff into.

No, because an untestable theory is just a useless theory (i.e. it is not meaningfully predictive). There are more difficult and confrontable issues such as predictions models will make like "supersymmetry", "the proton decays", and "early universe signatures in CMB" which could be, but have not been, observed.

You can sometimes make models which can put these under various parts of the proverbial rug and, sure, claim we just need to build the next generation of experiment, but at that point what are you really doing? I suspect this is what "worse than you think" is trying to get at.

Many testable theories started as untestable theories, including some of the most famous theories of all like evolution and atomic theory.

This is a valid point. Some other theories that were originally thought of as radical and untestable were plate tectonics and germ theory.

On the other hand, I think the reason why this gets brought up so often for string theory is the degree to which it appears untestable. Multiple curled up dimensions and something like 10^500 possible versions of the theory, and with everything operating below the Planck length, which according to other widely accepted theories is the smallest possible measurement. How do you measure something smaller than the smallest measurable thing?

I think the only comparably untestable theory was atomic theory when first suggested by the Greeks 2000 years ago. Germ theory and evolution were relatively tame by comparison.

> Peculiar individuals, no matter how famous they are, no matter how brilliant they are, if they’re off that consensus, and they’ve been off that consensus for a long time, they’re probably wrong.

So this guy works on string theory and has never heard of Einstein?

Why not use science to check what makes sense? - Because anyone would instantly notice that string theory is bs.

I think there should be a system, that when scientists act in bad faith (wasting money on questionable ideas because they personally profit) should retire.

I suspect when Susskind was talking about ideas away from the consensus _usually_ being suspect, he was talking about what the general public or non-practitioners should think about, especially since they are not usually in a position to judge those ideas. As a practitioner you certainly can’t ignore non mainstream ideas, or else no new ideas would ever become mainstream.

I don’t know the particulars of this debate, but as it is written, the claim is (IMO) trivially true: most people offering “out there” views are wrong. The hypothesis space is infinite. On the other hand, it’s useful to have epistemic practices that help distinguish true from false. A good one is experimental confirmation. That seems to be challenging to acquire here.

The quote continues with "That doesn’t mean for sure that they’re wrong".

> anyone would instantly notice that string theory is bs.

People said that about this wonky BS from Einstein too. And Einstein himself had some issues with that wonky BS of quantum mechanics (and he was not alone).

The whole String Theory affair is amusing but also a sad spectacle.

These people convinced the world they were geniuses, but ended up fleecing funding agencies and universities for millions with zero accountability and scientific progress.

Do you have an example where funding was given out with zero accountability? I've worked at a number of universities and national laboratories for particle research and they all had multiple layers of accountability. At the top of any public funding structure is congress and the president and bigger initiatives will even be line items in public agency budgets. At the bottom are the required regular reports (I had biannually) to grant monitors and often independent review panels and committees (for one big project I had to do that annually on top of reports). In the middle are people who make it their jobs to find ways to save money, get money to the most promising projects, and communicating up to elected/presidentially appointed officials and down to researchers to keep this together. Both DOE and NSF funding are structured this way and represent virtually all federal channels to get money for particle physics, both experiment and theory.

What's the funding you're referring to with zero accountability?

The question, I think, is “how many alternative theories were dismissed by no funding?” IF there was other people asking for funding for other topics or theories were dismissed because “strings are cool” then I expect some explanation. And boy there were other theories and projects asking for funding!

Do not read "the system is perfect" or even "good" from my post. I'm focusing only on the claim from the post above that there is "zero accountability". The people accountable are everyone in the chain I described and the whole thing hinges on people that ultimately answer to elections.

> how many alternative theories were dismissed by no funding

it's an interesting question - you should be able to request this information from the funding bodies!

Do you think you can't? It's all covered under FOIA. Bureaucratic stuff like this is in fact FOIA's wheelhouse.

No I was suggesting that he should ask for it, instead of assuming there weren't good reasons for the choices that were made.

>Do you have an example where funding was given out with zero accountability?

Yes, this article and the whole crisis it references.

Will people be removed from their position? Prosecuted, even? No.

That's what zero accountability means.

Well, that people are really smart. Also I do bot think is bad faith. It just seems to not deliver all the answers we would like.

I think it just goes to show how desperate we are to find a unified theory after all this time and effort.

The worst of it reminds me of cryptocurrency schlock and how it has drained capital from our industry with little to show for it.

The pattern is similar: an infinitely fascinating puzzle to solve full of interesting math with potentially revolutionary implications if only… if only… but not enough people ask if it’s the right math solving the right problems in the right way or if it’s even applicable.

This phenomenon of smart people being nerd sniped to this degree reminds me of that episode of Star Trek TNG where they figured out a way to possibly destroy the Borg by giving them an infinitely fascinating unsolvable geometry problem to ponder until they lost their minds.

I also see some similarity to how people get triggered and sucked into and addicted to spirals of culture war and political rage or fear mongering or other media driven mind traps. This is less intellectual but seems similar in that you’ve got this meme that hooks us and creates a discourse around it that hooks us more and not enough people poke their heads out of the vortex and say “hey everyone is this really this big of a deal?”

We should become skeptical when we see a big idea accrete a lot of sound and fury around it but it’s not producing much and the main focus of the community circling it is self referential fascination with the idea itself.

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