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Fundamental physics is dying? [video]

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Re: Fundamental physics is dying? [video]

#101
post #86

I have a pet conspiracy theory for why there has been so little progress in physics for so long. The invention of the nuclear bomb scared a lot of people, it made them scared of physics. What else might physicists turn up that could change the world in dramatic ways? Anti-gravity? Ray guns? Other dimensions? Travel to other worlds? All bad for business, no one is going to buy your airplanes or air craft carriers if t…

What time frame are you talking about here? Starting in 01950, 01995, 02010?

If we're talking about 01995, it's conceivable that, say, the US and CERN could coordinate to suppress research into hafnium bombs, AVLIS, antigravity, or whatever. If we're talking about research much prior to that point, though, you'd have to include the Russians in the conspiracy. Probably not just any Russians, either; probably Khrushchev, Brezhnev, Andropov, Tsar-Bomba-era Sakharov, and his successors. And, on the other side, people like J. Edgar Hoover, JFK, McNamara, Kissinger, Johnny von Neumann, and Teller.

I don't want to say it's literally impossible for Brezhnev or his underlings to have made a secret agreement with Kissinger and Teller to suppress the development of theoretical physics in order to keep the world predictable. But I do think it's pretty implausible, and there would have been an enormous incentive to cheat on any such secret agreement.

In the 01990s, though, it could have become plausible. But, remember that that's also when Pakistan became a nuclear weapons state, shortly followed by North Korea in 02006. And the People's Republic of China has had nuclear weapons since 01964, so they evidently had significant physics capabilities that they were willing to use for warfare (which was a huge priority; Mao reorganized the country's economy to resist an anticipated US invasion), and they dominated the TOP500 supercomputer list until this year, when they withdrew from it in apparent protest against the efforts of the USA to reverse their technological progress with a worldwide system of export controls.

So I think there's maybe a ten-year window when this could have happened somewhat, about 01992 to 02002. Both before and after that, there are too many countries with strong physics communities that are too bitterly opposed to make such cooperation plausible.

Re: Fundamental physics is dying? [video]

#102
post #88

If you want to reply to https://news.ycombinator.com/item?id=41811140 or say something Sabine-adjacent, please do it here. (This is so https://news.ycombinator.com/item?id=41808143 doesn't get too offtopic)

I don't like Sabine Hossenfelder's videos because they're too short. When I want to relax after work by playing a game while listening to someone drone on on youtube on a deep and esoteric subject, her videos end way too soon, and with an advertisement for her sponsor. I just want to hear some rambling boffin expound for an hour in the background on some matter that can't possibly raise more than a few hundred views.…

Sean Carroll is my go to guy for long form physics and philosophy discussions that have some depth but are still accessible. His October AMA on the Mindscape podcast is over 4 hours, but I haven't listened to it yet.

Re: Fundamental physics is dying? [video]

#103
post #85

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…

> physics is stuck at a local optimum. I think I heard somewhere that the trouble with string theory is it can describe anything if you tune it just in a right way. It reminds me of epicycles, they also had this property, you can add more and more epicycles to describe literally any observation data. > Way (1) is what kicked off quantum mechanics. Way (2) is what kicked off Newtonian mechanics. Hmm... What was the wa…

My understanding as a layman:

1. Copernicus figured out that if you put the sun at the center, then epicycles weren't necessary, and the math got easier --- because epicycles were based on a mis-understanding of the actual state of the universe --- I don't believe that anyone has identified such a non-alignment of fact and reasoning and observation for contemporary physics.

2. The problem is, modern physics is arguably getting boxed into a corner by approaching an end game state where the fundamental particles are getting identified, but are so small and difficult to separate out, that measurements are challenging to the point that while one can speculate and do math, actually proving out the speculations experimentally and taking actual measurements is expensive or so difficult to reason about that there doesn't seem an obvious path to an experiment, e.g., it looks as if the electron may be a fundamental particle, which is a sufficiently difficult concept to parse that it led to "The one-electron universe"/"The single electron hypothesis" and if that is the case, it walls off a not insignificant portion of particle physics at a size/state which can't be gotten smaller than.

Re: Fundamental physics is dying? [video]

#104

Earlier quoted context omitted.

The theory stops working imho if you take competition into account. The world is not aligned as a single bloc of power. While it’s not completely unthinkable (but extremely unlikely, imho) that some scientists plus some decision makers from, say, the liberal west might collude to achieve this kind of suppression, their counterparts from one or multiple other blocs might not, because they want to dominate and anti-gra…

You'd be amazed how quickly powerful discoveries find military purpose.

An important thing to consider here is that the first engineering project which had to make use of Einstein's Theory of Relativity was GPS --- the time/position calculations to triangulate location based on satellites is so exacting that it has to take into account gravimetric distortions based on the receivers being further down in the gravity well than the GPS satellites:

https://xkcd.com/808/

Re: Fundamental physics is dying? [video]

#105
post #60

Earlier quoted context omitted.

Sounds like this criticism would be valid for fundamental physics but there are many other physics fields with experimental results that become technology.

Yes, there's definitely some interesting fields that are making progress that are still in the purview of "physics". Materials science, or condensed matter physics, is doing a lot of fascinating work with quasiparticles: https://en.wikipedia.org/wiki/Quasiparticle There's a number of fields you could call "quantum engineering" where physics and engineering work together on the cutting edge. Some of the output of that…

> Since people on the internet frequently seem to operate on the silly theory that someone pointing out a problem has some sort of obligation to propose a solution

The issue with Sabine is she tends to yell about anyone proposing any solution. CERN would like to build a bigger particle accelerator, but since it's not her favored variant of accelerator they are obviously lying to the public and wasting your tax payer dollars which could be spent instead on the (implied) guaranteed discoveries if people would just listen to her.

(note also that this is a false dichotomy: any realistic analysis any set of potentially competing projects would generally conclude they're unlikely to be in competition if they are in fact viable - we usually have plenty of money to do both things provided they're likely to pay off. But the under-developed, under-timelined thing is a lot easier to promise the world with, yet far more likely to wind up just as "clearly blown out it's budget!" as the project being built).

Re: Fundamental physics is dying? [video]

#106
I know that this will probably be down-voted to death but I don't like these hyperbolic takes. I know that Sabine did use this title for click-bate purposes that she is now mostly doing YouTube videos (she had horrible experience that unfortunately not rare in scientific community [1]). I understand that the field of particle physics which is the corner stone in fundamental physics is not showing the great advances that it used to have a couple of decades ago. But I think people really don't understand that the field is still advancing and although these advances are less catchy to be reported in mainstream (and don't get traction if posted on HN) it is not dead or dying.

There is a reason why we had a particle data group updating the PDG [2] each two years (you can order physical copies for free but please don't do if you don't need one). People were writing about that since after the big discovery of Higgs boson (that was 12 years ago). We still have a lot of measurement and puzzles that is less about unification theory that people usually would talk about. Theory people are coming up with all different ideas even if some are not testable now but that job of theorist is mainly come up with ideas and help bridge the gap later.

I would suggest everyone interested in this topic to read the electroweak current chapter of the book called "How experiments End" [3] to understand a historical example to how we approached the standard model when it was first proposed. Most of the particle physicists will not work on supersymmetry, string theory and these catchy theories that people will hear about. Most of the work is advancing and answering (and raise questions) piece by piece. Here is an example of interesting results that help us answer some questions [4]. Also I'm not saying that the field had its own problems and can improve on many aspects. I'm just against these extreme and hot takes that claims it is in a crisis or dying.

for people who posted the comment from John Carlos, I like this toot/tweet/comment by Sven Geier [5] which was what John replied.

Disclaimer: I'm a particle physicist and have a skin in the game.

[1]https://www.youtube.com/watch?v=LKiBlGDfRU8

[2] https://pdg.lbl.gov/

[3] https://press.uchicago.edu/ucp/books/book/chicago/H/bo596942...

[4] https://www.symmetrymagazine.org/article/new-results-from-th...

[5] https://mathstodon.xyz/@SvenGeier/113284011925646281

Re: Fundamental physics is dying? [video]

#107
post #65

Earlier quoted context omitted.

After this much time and that much work, how is it possible for a physics theory to not have a single testable/falsifiable prediction without it being intentional? It has been over 80 years . [ https://en.m.wikipedia.org/wiki/History_of_string_theory ]. The evidence is in the absence.

It predicted supersymmetry, which has been experimentally disproved.

The kind of supersymmetry you’re referring to (global spacetime supersymmetry) is not required by string theory; this is a common misconception. Looking for super partners in a collider is actually only telling you about global supersymmetry, which unlike local supersymmetry is not a universal feature of string theory at low energy, in fact the opposite, it is probably non-generic. It so happens that a class of appealingly simple vacua do have this property, which led to some inappropriate optimism among string theorists that has entirely abated with more experiments. Unfortunately this has been widely misunderstood to rule out the whole enterprise of string theory, which is unreasonable for the reason stated above, it is much more likely to not see SUSY below the Planck scale. [0] (Unless you just like to mock string theorists for hoping that the universe would be kind to them.)

Also global supersymmetry has not been experimentally disproved (how would you do this, even?) but it is true that current or even near-term experiments are not nearly sensitive enough to get close enough to answering this definitively, which is obviously upsetting.

[0] https://ncatlab.org/nlab/show/string+theory+FAQ#DoesSTPredic...

Re: Fundamental physics is dying? [video]

#108
post #85

Earlier quoted context omitted.

> physics is stuck at a local optimum. I think I heard somewhere that the trouble with string theory is it can describe anything if you tune it just in a right way. It reminds me of epicycles, they also had this property, you can add more and more epicycles to describe literally any observation data. > Way (1) is what kicked off quantum mechanics. Way (2) is what kicked off Newtonian mechanics. Hmm... What was the wa…

My understanding as a layman: 1. Copernicus figured out that if you put the sun at the center, then epicycles weren't necessary, and the math got easier --- because epicycles were based on a mis-understanding of the actual state of the universe --- I don't believe that anyone has identified such a non-alignment of fact and reasoning and observation for contemporary physics. 2. The problem is, modern physics is arguab…

> Copernicus figured out that if you put the sun at the center, then epicycles weren't necessary

Actually, his model assuming circular orbits still required epicycles to explain retrograde motion etc. A major reason it never caught on was that it was less accurate than the Ptolemaic model but was more of a mathematical curiosity rather than a serious contender.

Re: Fundamental physics is dying? [video]

#109
post #86

I have a pet conspiracy theory for why there has been so little progress in physics for so long. The invention of the nuclear bomb scared a lot of people, it made them scared of physics. What else might physicists turn up that could change the world in dramatic ways? Anti-gravity? Ray guns? Other dimensions? Travel to other worlds? All bad for business, no one is going to buy your airplanes or air craft carriers if t…

There are some good comments here, thanks! There has been an international component to physics research cooperation. It seems not inconceivable that physicists in many countries, meeting at paper conventions and such might have agreed and recruited each other to try to prevent the next atomic bomb type invention. So while competition between countries is certainly real, competition between scientists might be somewhat different. You'd think there would be some people who would pursue it regardless, but they'd probably have to work with a team, and not everyone on the team may have supported the goals. It's just a theory, but it has some plausibility. Perhaps there are people everywhere who have decided not to be part of endeavors that could be disruptive and they've done us all a favor or have kept us from discovering the secrets of the universe. Who knows? The ethics of science has been mostly left to chance and individual decisions.

Re: Fundamental physics is dying? [video]

#110

Earlier quoted context omitted.

Exactly. Consistently untestable and unfalsifiable claims for decades has to be seriously questioned at some point, and I think we're well beyond that point. This is especially true for string theory. I'm particularly fond of how Angela Collier laid out the timeline of string theory in her video on it[0] as well as the consequences that science communication is now facing as a result. [0] = https://www.youtube.com/wa…

The same could've been said of atomic theory, neutrinos, gravitational waves, the higgs boson, cmb radiation, plate tectonics, and quantum mechanics at various points in time.

No you couldn’t. And it’s been 80 years now!!

All of those things you name came directly out of attempts to create testable hypotheses from experimental observations, and all of them were tested as soon as anyone could build an experiment apparatus or gather the data to do it. Which didn’t take that long considering the extreme engineering difficulties in actually building the apparatus for some of them.

String theory has avoided testability it’s entire existence, nearly a century now, and no one that I’ve seen is even attempting to make an experiment to try to test it - because at this point it’s clear that no one on the theory side is interested in making a testable hypothesis. That isn’t luck, that’s talent and hard work.

It’s one of the most absurd grifts I’ve personally seen play out so far.

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