13 ms·

Fundamental physics is dying? [video]

154 points by nabla9 2y ago

nabla9 2y ago
John Carlos Baez thinks Sabine has a point. https://mathstodon.xyz/@johncarlosbaez/113285631281744111 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.
- deleted 2y ago
  [deleted]
- dang 2y ago
  I know people have strong reactions to her and her sensational style, but that is a serious recommendation from a knowledgeable person, so I think we can give this thread a second chance. (Someone emailed and asked us to.) All: please let's keep the comments on topic and substantive (and avoid the sensationalism and personality aspects). Edit: this subthread was getting too off-topic so I moved the replies to https://news.ycombinator.com/item?id=41814764 https://news.ycombinator.com/item?id=41814764. Feel free to reply there if you want.
- notamy 2y ago
  > John Carlos Baez For those like me who didn't know, https://en.wikipedia.org/wiki/John_C._Baez https://en.wikipedia.org/wiki/John_C._Baez > John Carlos Baez (/ˈbaɪ.ɛz/;[2] born June 12, 1961) is an American mathematical physicist and a professor of mathematics at the University of California, Riverside (UCR)[3] in Riverside, California. He has worked on spin foams in loop quantum gravity, applications of higher categories to physics, and applied category theory. Additionally, Baez is known on the World Wide Web as the author of the crackpot index.
  - dang 2y ago
    And https://news.ycombinator.com/user?id=johncarlosbaez https://news.ycombinator.com/user?id=johncarlosbaez! Perhaps he'll contribute to this thread (or perhaps it would waste his time)
  - lamontcg 2y ago
    And he was known on Usenet and sci.physics before the World Wide Web was invented...
  - AdamH12113 2y ago
    He was also a long-time maintainer of the Usenet Physics FAQ and has been writing about physics and mathematics on the internet for decades. So not only is he the real deal in terms of knowledge, he also has a long history of communicating that knowledge to the public, albeit typically for a more advanced audience.
  - btilly 2y ago
    He is better known within physics as the author of This Week's Finds in Mathematical Physics, an archive of which is at https://math.ucr.edu/home/baez/TWF.html https://math.ucr.edu/home/baez/TWF.html. His more current blog is available at https://johncarlosbaez.wordpress.com/ https://johncarlosbaez.wordpress.com/.
- hggigg 2y ago
  30 years ago I spoke to a fairly well known and regarded physicist who said something rather interesting along the same lines. Quoting as accurately as I can "physics looks sexy from the outside due to some celebrities but inside it's mostly worse than anyone wants to admit.". He also suggested I go and study mathematics instead because at least there will likely be some applications for it. I did and I am glad I did.
  - Gooblebrai 2y ago
    Sounds like this criticism would be valid for fundamental physics but there are many other physics fields with experimental results that become technology.
    - retrocryptid 2y ago
      if you want to do applications, engineering will get you a 10% higher salary for the same job.
    - jerf 2y ago
      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 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 is why our TVs are so good. There's a lot of work to be done on how big systems, where "big systems" can be as small as hundreds or even dozens of atoms, behave, where you can't "just" throw the whole wavefunction into a computer and crunch away on it. It's particle physics that seems to be stuck in a rut. Fundamentally, they're starved for useful data. Until that is resolved, the science really isn't going anywhere. 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, let me say outright I have no more clue how to resolve this than anyone else does, except to hope that some sort of other progress in other fields creates new opportunities for new experiments.
deleted 2y ago
[deleted]
btilly 2y ago
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.
- ricksunny 2y ago
  This is beautifully articulated. And reinforces my general below-the-line (layperson) fear about the state of physics today (as reinforced ofc by the likes of Sabine Hossenfelder & Eric Weinstein).
  - btilly 2y ago
    Thank you for the compliment. I've been working on how to formulate that idea clearly for a while. It is a problem that goes well beyond physics. For example I believe that the same cognitive error is behind the fact that experts do significantly worse than chance in actually predicting the world, and the more certain the expert sounds, the less likely they are to be right. See https://www.amazon.com/Expert-Political-Judgment-Good-Know/dp/0691128715 https://www.amazon.com/Expert-Political-Judgment-Good-Know/d... for data demonstrating that fact. Depressingly, this means that we consistently put public policy in the hands of people who are demonstrably incompetent.
    - phkahler 2y ago
      >> I've been working on how to formulate that idea clearly for a while. It is a problem that goes well beyond physics. It's a really fundamental thing in psychology. The solution is something like the destruction of the ego, and many people who push hard enough to be a PhD tend toward larger ego to start with. Meditation and practicing martial arts can help. Apparently psychedelics can as well. It's a real pain because if you try to tell someone their ego is preventing them from seeing things clearly... Well that's going to trigger the same problem. So yes, it's good to find ways to articulate the message so it can get through to those that suffer from it the most.
f1shy 2y ago
I think in this an other videos, what she says is "they are not even wrong" and she does have a point there.
FredPret 2y ago
As a non-physicist, it’s hard to understand if she has a point or not. Any physicists care to weigh in?
- lamontcg 2y ago
  Follow the links to John Baez's thoughts ("the situation is even a bit worse than she makes it sound"): https://news.ycombinator.com/item?id=41808143 https://news.ycombinator.com/item?id=41808143
farts_mckensy 2y ago
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.
- lazide 2y ago
  [flagged]
  - farts_mckensy 2y ago
    There is no evidence to suggest that string theorists designed the theory to be untestable.
    - lazide 2y ago
      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 https://en.m.wikipedia.org/wiki/History_of_string_theory]. The evidence is in the absence.
      - seanhunter 2y ago
        It predicted supersymmetry, which has been experimentally disproved.
        zachf 2y ago
        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#DoesSTPredictSupersymmetry https://ncatlab.org/nlab/show/string+theory+FAQ#DoesSTPredic...
pvg 2y ago
For the context, the video this is a follow up to is helpful (they're both short) - https://www.youtube.com/watch?v=ZlHvW6k2bcM https://www.youtube.com/watch?v=ZlHvW6k2bcM
whatshisface 2y ago
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.
- naasking 2y ago
  > we're back at string theory as the only renomalizable description of quantum gravity. I think you mean, we're back at "we're not sure if string theory is a viable theory of anything real". Quantized gravity is not necessarily the right answer, and an insistence on this fundamental assumption might be the origin of these difficulties, eg. see Oppenheim's semi-classical gravity.
m101 2y ago
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.
- feoren 2y ago
  If by "theory of knowledge", you mean they need to have read a bunch of philosophical musings on epistemology, then I strongly agree with the downvoters, because that's utter nonsense. If you mean anything else by that, then you're being way too vague to contribute to a technical discussion, so again I agree with the downvoters. Try defining what you mean by "theory of knowledge" and explain why you think that's required to "understand science" (and you might want to explain what you mean by that too) and I suspect you'll see a lot fewer downvotes.
  - m101 2y ago
    Theory of knowledge "is a branch of philosophy that examines the nature, origin, and limits of knowledge". Scientists need to understand the limits of knowledge which may be acquired by science. Scientists think they are in the unique possession of tools which ascertain truths - this is misled.
- btilly 2y ago
  This strongly depends on what you mean by "theory of knowledge". If you mean the practical importance of self-honesty, and a historical awareness of how easily we slip into self-delusion, then I agree. See, for instance, https://calteches.library.caltech.edu/51/2/CargoCult.htm https://calteches.library.caltech.edu/51/2/CargoCult.htm for a very famous speech on exactly this topic. A lot of Feynman's writing touches on the same issue. If you mean the musings of philosophers on epistemology, then I emphatically disagree. The philosophers in question generally have failed to demonstrate that they understand science. And when they venture into science, they generally fail to live up to the ideals that they proclaim that scientists should follow. As an example I direct you to the sight of Karl Popper arguing to the end of his days that quantum mechanics cannot be a correct scientific theory. An opinion that began because a probabilistic theory cannot in principle be falsified. In fact QM is a scientific theory, and it stands as an example falsifying Popper's criterion for science! I find it very ironic that Feynman is so disliked by philosophers for having been honest about how irrelevant they are to science. And philosophers in turn have failed to recognize Feynman's explanations of how to do science as a key topic that should be included in any proper philosophy of science.
ants_everywhere 2y ago
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.
- slashdave 2y ago
  (1) is also limited by imagination
  - tines 2y ago
    Isn't it (2) that's limited by imagination? Nobody imagined quantum theory, they observed it first.
- Ma8ee 2y ago
  Those mathematical advances weren't developed in a vacuum, but made to solve some very specific problems which came from better measurements. So even Newtonian mechanics originated in solving problems trying to explain measurements, not that someone sat in their chamber and dreamed up cool math that happened to be very useful.
  - ants_everywhere 2y ago
    I agree. Generally, the scientific method has mutually recursive turns of theory and observation. And I don't mean to imply that exist independently. I'm just saying that if you get stuck, the two clearest ways out are to provide more observations or perturb the theory.
lagpskd 2y ago
> 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-the-ruliad/ https://writings.stephenwolfram.com/2021/11/the-concept-of-t...
- btilly 2y ago
  Not exactly. She's just admitted that he isn't someone she thought of. And that's likely because she's far more aware of the contributions of physicists to this field, than the attempted contributions of non-physicists. It's not that she's not aware that they exist - in fact she's painfully aware that there are a great number of them saying all sorts of things - its that she's not individually aware of them. That said, if she had thought of him then she would have merely increased her sample size from 2 to 3, and still had the exact same conclusion.
  - lupire 2y ago
    What absurd definition are you using that makes Stephen Wolfram not a physicist? Wolfram is more of a physicist than most physicists. Wikipedia: He entered St. John's College, Oxford, at age 17 and left in 1978[17] without graduating[18][19] to attend the California Institute of Technology the following year, where he received a PhD[20] in particle physics in 1980.[21] Wolfram's thesis committee was composed of Richard Feynman, Peter Goldreich, Frank J. Sciulli and Steven Frautschi, and chaired by Richard D. Field.[21][22] In the mid-1980s, Wolfram worked on simulations of physical processes (such as turbulent fluid flow) with cellular automata on the Connection Machine alongside Richard Feynman[29] and helped initiate the field of complex systems.[citation needed] In 1984, he was a participant in the Founding Workshops of the Santa Fe Institute, along with Nobel laureates Murray Gell-Mann, Manfred Eigen, and Philip Warren Anderson, and future laureate Frank Wilczek.[30] In 1986, he founded the Center for Complex Systems Research (CCSR) at the University of Illinois at Urbana–Champaign.[31] In 1987, he founded the journal Complex Systems.[31] From 1992 to 2002, Wolfram worked on his controversial book A New Kind of Science,[4][33] which presents an empirical study of simple computational systems. Additionally, it argues that for fundamental reasons these types of systems, rather than traditional mathematics, are needed to model and understand complexity in nature. Wolfram's conclusion is that the universe is discrete in its nature, and runs on fundamental laws which can be described as simple programs. He predicts that a realization of this within scientific communities will have a revolutionary influence on physics, chemistry, biology, and a majority of scientific areas in general, hence the book's title
retrocryptid 2y ago
i love sabine. she's speaking the lived experience of quite a few of us who lost faith in the academy.
- phkahler 2y ago
  I like her message, but some of her recent videos have me a little worried about her. She seems on the edge of a breakdown at times.
  - retrocryptid 2y ago
    yeah. she does seem like she's on the edge of throwing down f-bombs, flipping tables and screaming "i'm out of here." guess it's to her credit she hasn't done that.
  - antegamisou 2y ago
    > She seems on the edge of a breakdown at times. Academia does this to you. She's a really well controlled case.
- deleted 2y ago
  [deleted]
rapjr9 2y ago
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 they can buy an anti-gravity machine. So physics was suppressed by both business and government. Physicists were given "safe" work to do (ITER, quants) that would occupy them and keep them from exploring wild stuff. Grant financing was controlled so that only safe research would be conducted. It would be fairly invisible to the world, just a few high level decisions would determine how the funding was directed. I get the impression that if this was indeed a conscious decision that it's starting to fall apart as younger generations take over and become frustrated with the direction of physics. They weren't there when the A-bomb was invented, and nuclear weapons have not been on peoples minds much for a long time, most people have not lived in a time when one was used. So they see interesting topics and want to explore them and encounter resistance from more established scientists. It's a conspiracy theory because it would involve some buy-in from a fair number of physicists to make it work, but a lot of physicists when I was getting my BA in physics were very loudly saying "never again" about atomic weapons and felt it had tarnished the whole profession. It's very difficult to say what humanity would be capable of handling in terms of radical new inventions. Anti-gravity could solve many large problems, but it might make it even easier to destroy Earth. Once new knowledge exists it is hard to suppress it. Stopping it from from ever existing seems easier. I guess we'll find out if physics has been suppressed if the dam breaks and new ideas start proliferating. The nature of the new physics would be a big clue as to whether research in it was suppressed. I'm reminded of Elon Musk, he seems to have had really radical success in some very stagnant industries, just by trying instead of accepting limits, and being able to fund his ideas himself.
- ManuelKiessling 2y ago
  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-gravity guns surely give you some nice advantage.
dang 2y ago
If you want to reply to https://news.ycombinator.com/item?id=41811140 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 https://news.ycombinator.com/item?id=41808143 doesn't get too offtopic)
- gizajob 2y ago
  She was ripping on the valuations and economics of quantum computing companies the other week, and her critiques were such that they could be levelled against capitalism itself and basically any company in the market. Was an obvious and clear step way out of her area of expertise.
  - lamontcg 2y ago
    That doesn't have anything to do with her criticism of Loop Quantum Gravity, and is precisely the derailing of the topic that dang is asking you to avoid.
    - skhunted 2y ago
      When people don’t have expertise in an area they are prone to making really dumb comments. She has a history of this on other topics. As such I think it’s appropriate to mention so that people can evaluate how much weight/time they want to spend on her video and views.
      - lostmsu 2y ago
        Do you have expertise in the area of deciding source trustworthiness or relevancy in certain fields?
        skhunted 2y ago
        I do not. I do have a sense of the notion and make decisions for myself on whether or not something is worth my time. While her video might be accurate in this case her past casts doubt in my mind and as such I’ve decided not to watch it. Other people might find it useful to know about her past errors when deciding whether or not to watch this video.
throwaway14356 2y ago
long ago i coin: scientific physics an analogy with astrology and astronomy fits perfectly. Remember those great men who did groundbreaking work that completely changed the fabric of society? Consensus my a, their work is self evident. If you need someone to tell you something is a great accomplishment it apparently isn't obvious. If there is no revolution triggered by [say] relativity theory it doesn't qualify for the list of great discoveries. You need people to tell you how great it is. funny as hell
sega_sai 2y ago
Physicist here.. I will not give Sabine more YouTube views, justifying clickbait titles. Below is just my opinion. There are certainly issues in theoretical physics. I think particularly string theory was a massive waste of effort in physics and to some degree illustration of failure of the whole system. Despite that most of other physics I would say in sensible shape, it is just harder to make progress given that we have to push to higher energies, more accurate measurements etc. The question whether there will be major advance in fundamental physics to some degree depends on new discoveries. Many people are pushing, but it is not guaranteed.
elashri 2y ago
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 https://www.youtube.com/watch?v=LKiBlGDfRU8 [2] https://pdg.lbl.gov/ https://pdg.lbl.gov/ [3] https://press.uchicago.edu/ucp/books/book/chicago/H/bo5969426.html https://press.uchicago.edu/ucp/books/book/chicago/H/bo596942... [4] https://www.symmetrymagazine.org/article/new-results-from-the-cms-experiment-put-w-boson-mass-mystery-to-rest?language_content_entity=und https://www.symmetrymagazine.org/article/new-results-from-th... [5] https://mathstodon.xyz/@SvenGeier/113284011925646281 https://mathstodon.xyz/@SvenGeier/113284011925646281
- randomNumber7 2y ago
hindsightbias 2y ago
What if String Theory is a Sophon Virus?
- js8 2y ago
  Then it's not really all that well made, frankly, because one of the most popular YT physicists is immune to said virus. But - I have always dismissed cryptocurrencies thinking "people can't be that stupid". If I had not, I could have made some money. So maybe Sophons didn't expect Youtube to be a thing, either.
herodotus 2y ago
This might be too weird to be true, but when I heard that Geoff Hinton got the Nobel prize for Physics, I wondered if the prize committee was having trouble finding "real" physicists who had made fundamental advances.... This is not meant to knock Prof Hinton. These are his own words: “I’m not a physicist, I have very high respect for physics,” Hinton said. “I dropped out of physics after my first year at university because I couldn’t do the complicated math. So, getting an award in physics was very surprising to me. I’m very pleased that the Nobel committee recognised that there’s been huge progress in the area of artificial neural networks.”
- atmosx 2y ago
  It is evident that they need more than five categories. Awarding Nobels to individuals who are not particularly (if at all) well-versed in the subject at hand, even if they contributed to a breakthrough in the field, directly or indirectly discredits the prize. Indeed, the online memes about Hinton and Hassabis being "a bit of a <physicist|chemist> myself!" are justified, in my opinion.
- matusp 2y ago
  I agree with you. What is also telling is that there is no particularly strong reaction from the physics community that someone obvious was wrongfully omitted.
  - aleph_minus_one 2y ago
    > What is also telling is that there is no particularly strong reaction from the physics community that someone obvious was wrongfully omitted. A few days before the announcement of the Physics Nobel Prize Sabine Hossenfelder created a video about her predictions for the Physics Nobel Prize. Likely all mentioned researchers in this video did more for the advancement of physics research than John Hopfield and Geoffrey Hinton: > Who Will Win This Year’s Nobel Prize in Physics? My Speculations > https://www.youtube.com/watch?v=KMTNHqEpTnw https://www.youtube.com/watch?v=KMTNHqEpTnw
randomNumber7 2y ago
I think the problem is more fundamental. Newtonian mechanics is a science based on observation. Mathematics is just used to build a model that describes _how_ the reality behaves, not why. Now Einstein is very special, because he proved that our human perception of space and time is wrong. When we think about the allegory of the cave, we got a glimpse of the reality we couldnt see before. Nowadays every phyiscist wants to be the next einstein that uses mathematics to show us something about reality. The problem is that einstein had good reasons for his ideas. The constant speed of light didn't really work with maxwells equations. The model at that time didn't correctly describe the observations and the maths he used to solve that is rather elegant and simple.
mnky9800n 2y ago
This seems like a narrow view given that there are plenty of unanswered questions in chaos theory, etc. but physicists who think about quantum stuff typically don't like to consider the other physics Revolution of the 20th century as equivalent to theirs.
meindnoch 2y ago
I knew from the title it's gonna be Sabine Hossenfelder. Her videos are just clickbait at this point.
davidgerard 2y ago
Is this Dang turning titles into Betteridge questions again? The original does not have a question mark.
teekert 2y ago
You know how some people seem knowledgeable until they talk about your field? Well for me (molecular biology and genomics) this never happens with Sabine. So, even though much of this is over my head, I grant her much credence. FWIW.
Ono-Sendai 2y ago
Sabine is often right, but I think she's wrong here about Lorentz invariance being a problem, or at least a problem in the way she's saying. Lorentz transformations are never going to length-contract the underlying fabric of space/spacetime. Relativistic length contractions contract moving objects, not the underlying spacetime. In fact it's a strange and basic misunderstanding to have.
- auggierose 2y ago
  Depending on your reference coordinate system, space is transformed. That is the entire point of relativity theory. You might be misunderstanding things here.
  - Ono-Sendai 2y ago
    Coordinates are transformed, not the actual space. Objects are length-contracted due to the electric field being length contracted.
    - auggierose 2y ago
      You seem to be of the same opinion as Sabine when it comes down to distinguishing between mathematical modelling, and reality. In mathematics though, coordinate transformation and space transformation are the same thing. How that plays out for the actual physics happening, might be a different thing, but note that you still describe it mathematically.
- naasking 2y ago
  Sabine is correct. All objects in a spacetime are anchored to that spacetime, so if spacetime has a minimum length, then length contraction of moving objects has a detectable lower limit, thus violating Lorentz invariance.
  - Ono-Sendai 2y ago
    She seems to be talking about spacetime itself being Lorentz contracted though. it's true that a sufficiently fast moving object would be length contracted so much that it started interacting with the minimal LQG length, which would violate Lorentz invariance. Depending on how big the LQG loops are, that could be a fanstastically high speed that isn't achievable in the universe though.
openrisk 2y ago
Her choice of background for this video and the matching imprint on her blouse gives us maybe a hint that "fundamental" physics is too broad a field to actually die :-) I.e., there are ongoing and deep puzzles e.g., in dark matter / dark energy where observational data keep accumulating and at some point a critical mass (pun) of evidence may reshape our ideas about how the universe fundamentally works. The new ideas need have nothing in common with pre-existing mind sets of how things work. Now about the string theory / quantum gravity furore, after decades of work by arguably extremely bright people its pretty clear that Nature in the current juncture is not giving us enough clues to proceed. This should not be stressful - Nature is not a Hollywood production studio that needs to churn gee-wow "experiences" every season. But Sayre's law applies rather well [1] "In any dispute the intensity of feeling is inversely proportional to the value of the issues at stake.". What is at stake here is the ego of a few individuals that assumed otherwise (i.e., that a post-Einstein revolution is imminent) and the (relatively minor in the scheme of things) research funding of this particular niche of physics. Theoretical physics is not the only domain bouncing regularly between "hypes" and "winters", as the recent Nobel prize for Physics clearly demonstrates. [1] https://en.wikipedia.org/wiki/Sayre's_law https://en.wikipedia.org/wiki/Sayre's_law
drpossum 2y ago
I'm not hot on what fundamental physics looks like now or in the future, but there's an attitude that Sabine promotes that I see echoed in a lot of comments here which feeds into problems with research. I don't think the work put into studying fundamentals was "a waste of time" thus far. It's dangerous to label experiments and ideas that were acted on in good faith as the best options at the time but didn't yield positive results as missteps. Scientists need to be allowed to do work like this without fear because to do so otherwise leads to perverse incentives and you end up with things like lots of studies that can't be reproduced because of p-hacking or worse. Arguing bad faith after the fact is awfully hard without real evidence and if you're going to discount anyone with enthusiasm for their research proposal based on enthusiasm alone you're not going to be left with a healthy program. I don't blame anyone who supported things like supersymmetry as an example for something which hasn't panned out. we're still left with a major mystery and big questions and it says we need to rethink things in more difficult directions.
- Log_out_ 2y ago
  The whole of human society is a combustion engine for life, barely held from going full self destruction by a science driven economy consuming resources in a unsustainable way. Science is what kept us peaceful and nice since WW2. And the breakthroughs are needed not some time far far away ,they are needed now. This is not about the purity of approach or some hypocritical game. This is a dependancy of life and death on the results ..
- BoiledCabbage 2y ago
  I'm not in any way an expert in this area, but here is what I see. I don't think the argument is that it's being said as "bad faith after the fact". I think the argument is that the approach was told it had fundamental flaws. Those were ignored / denied. People continued to invest in it and suck up all of the research and bright minds in the field. Decades later it still has those fundamental flaws and has taken over all other possible avenues of progress as it has all grant money and and the majority of all departments working on it. It's more "you were told this is broken before. It's decades later and it's broken in the same way. At what point to you admit that this approach isn't working so try something else?" And the answer is "No, we're going to keep digging deeper". Fundamentally, approaches need to be falsifiable. If your theory is "falsifiable" in the small scale but ultimately unfalsifiable in the large scale then it's is fundamentally unfalsifiable and we can't use it to lead experimentation. It's a breadth vs depth search question. We've lost all breadth of search in physics, because a little ways back we stumbled upon a branch that happened to have a (for practical purposes) infinite number of subbranches relating to ways to roll up string dimensions. So physics is stuck exploring all of those sub-branches instead of backtracking one level and exploring any other parts of the tree. The argument is that everyone is looking under the lamppost for the keys. After 4 decades of searching there, maybe it's time to search somewhere else. And the argument is made even strong when decades back they were told, "Hey, I didn't drop by keys by the lamppost. I dropped them somewhere else". And yet most people keep looking there.
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yusufmotiwala 2y ago
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wwarner 2y ago
I'm way too late for this to be meaningful, but here's what I think! tl;dr -- gravity is the problem, we should focus on experiments and observations for a while, bring in some better mathematics, and continue the long range program of developing quantum theories that include or even produce GR. I'm just a physics enthusiast. When I became interested in physics, I was initially a sort of partisan in the "realist" camp -- pro Einstein, anti Bohr; liked Verlinde's entropic gravity, distrusted the graviton -- but have come full circle to the opposite view. GR has massive explanatory and predictive power, and an extremely satisfying aesthetic quality, but obviously breaks down behind the curtain of a black hole's event horizon, where we cannot make observations. I say obviously because it predicts a singularity, which is just another way of saying it makes no prediction at all. On the other hand, many of my complaints about QM I now look at as unanswered questions, opportunities for inquiry. QM is based 100% on experimental observations. The theory came together in a rather ad hoc fashion at the beginning of the last century, but as it was more carefully studied theoretically and experimentally, also proved to be highly predictive, even more that GR. Yes there are big ugly, outstanding questions -- measurement collapse, the transition from microscopic quantum behavior to macroscopic classical behavior, the intractability of all but the simplest calculations -- but those are huge areas of knowledge that the future will gradually (or suddenly) fill in, as our understanding moves forward. So, gravity, not QM, is the problem. We should start with the axioms of quantum mechanics, and look for ways to observe where QM and GR can be measured at the same time. LIGO offers opportunities like this, as the sensitivity of the instrument is well within the quantum regime. Continued study of QCD could make a testable prediction for what exists inside of a black hole. Or continue to study the very fine transitions between energy levels in the nucleus. Mathematically, maybe the Langlands program, with its rather weird, Fourier-like sums of L functions will allow us to model non-linear behavior. And yes, string theory sort of "jumped the shark" at some point. I'm sure Ed Witten regrets saying that other pursuits were a waste of time. But the thing is, the string theory program is centered on QM, and has shown that QM can naturally produce GR, given certain unrealistic assumptions. That's mathematical progress.

154 points by nabla9 2y ago

John Carlos Baez thinks Sabine has a point. https://mathstodon.xyz/@johncarlosbaez/113285631281744111 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.

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dang 2y ago
I know people have strong reactions to her and her sensational style, but that is a serious recommendation from a knowledgeable person, so I think we can give this thread a second chance. (Someone emailed and asked us to.) All: please let's keep the comments on topic and substantive (and avoid the sensationalism and personality aspects). Edit: this subthread was getting too off-topic so I moved the replies to https://news.ycombinator.com/item?id=41814764 https://news.ycombinator.com/item?id=41814764. Feel free to reply there if you want.
notamy 2y ago
> John Carlos Baez For those like me who didn't know, https://en.wikipedia.org/wiki/John_C._Baez https://en.wikipedia.org/wiki/John_C._Baez > John Carlos Baez (/ˈbaɪ.ɛz/;[2] born June 12, 1961) is an American mathematical physicist and a professor of mathematics at the University of California, Riverside (UCR)[3] in Riverside, California. He has worked on spin foams in loop quantum gravity, applications of higher categories to physics, and applied category theory. Additionally, Baez is known on the World Wide Web as the author of the crackpot index.
- dang 2y ago
  And https://news.ycombinator.com/user?id=johncarlosbaez https://news.ycombinator.com/user?id=johncarlosbaez! Perhaps he'll contribute to this thread (or perhaps it would waste his time)
- lamontcg 2y ago
  And he was known on Usenet and sci.physics before the World Wide Web was invented...
- AdamH12113 2y ago
  He was also a long-time maintainer of the Usenet Physics FAQ and has been writing about physics and mathematics on the internet for decades. So not only is he the real deal in terms of knowledge, he also has a long history of communicating that knowledge to the public, albeit typically for a more advanced audience.
- btilly 2y ago
  He is better known within physics as the author of This Week's Finds in Mathematical Physics, an archive of which is at https://math.ucr.edu/home/baez/TWF.html https://math.ucr.edu/home/baez/TWF.html. His more current blog is available at https://johncarlosbaez.wordpress.com/ https://johncarlosbaez.wordpress.com/.
hggigg 2y ago
30 years ago I spoke to a fairly well known and regarded physicist who said something rather interesting along the same lines. Quoting as accurately as I can "physics looks sexy from the outside due to some celebrities but inside it's mostly worse than anyone wants to admit.". He also suggested I go and study mathematics instead because at least there will likely be some applications for it. I did and I am glad I did.
- Gooblebrai 2y ago
  Sounds like this criticism would be valid for fundamental physics but there are many other physics fields with experimental results that become technology.
  - retrocryptid 2y ago
    if you want to do applications, engineering will get you a 10% higher salary for the same job.
  - jerf 2y ago
    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 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 is why our TVs are so good. There's a lot of work to be done on how big systems, where "big systems" can be as small as hundreds or even dozens of atoms, behave, where you can't "just" throw the whole wavefunction into a computer and crunch away on it. It's particle physics that seems to be stuck in a rut. Fundamentally, they're starved for useful data. Until that is resolved, the science really isn't going anywhere. 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, let me say outright I have no more clue how to resolve this than anyone else does, except to hope that some sort of other progress in other fields creates new opportunities for new experiments.

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btilly 2y ago

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.

ricksunny 2y ago
This is beautifully articulated. And reinforces my general below-the-line (layperson) fear about the state of physics today (as reinforced ofc by the likes of Sabine Hossenfelder & Eric Weinstein).
- btilly 2y ago
  Thank you for the compliment. I've been working on how to formulate that idea clearly for a while. It is a problem that goes well beyond physics. For example I believe that the same cognitive error is behind the fact that experts do significantly worse than chance in actually predicting the world, and the more certain the expert sounds, the less likely they are to be right. See https://www.amazon.com/Expert-Political-Judgment-Good-Know/dp/0691128715 https://www.amazon.com/Expert-Political-Judgment-Good-Know/d... for data demonstrating that fact. Depressingly, this means that we consistently put public policy in the hands of people who are demonstrably incompetent.
  - phkahler 2y ago
    >> I've been working on how to formulate that idea clearly for a while. It is a problem that goes well beyond physics. It's a really fundamental thing in psychology. The solution is something like the destruction of the ego, and many people who push hard enough to be a PhD tend toward larger ego to start with. Meditation and practicing martial arts can help. Apparently psychedelics can as well. It's a real pain because if you try to tell someone their ego is preventing them from seeing things clearly... Well that's going to trigger the same problem. So yes, it's good to find ways to articulate the message so it can get through to those that suffer from it the most.

f1shy 2y ago

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

FredPret 2y ago

As a non-physicist, it’s hard to understand if she has a point or not. Any physicists care to weigh in?

lamontcg 2y ago
Follow the links to John Baez's thoughts ("the situation is even a bit worse than she makes it sound"): https://news.ycombinator.com/item?id=41808143 https://news.ycombinator.com/item?id=41808143

farts_mckensy 2y ago

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.

lazide 2y ago
[flagged]
- farts_mckensy 2y ago
  There is no evidence to suggest that string theorists designed the theory to be untestable.
  - lazide 2y ago
    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 https://en.m.wikipedia.org/wiki/History_of_string_theory]. The evidence is in the absence.
    - seanhunter 2y ago
      It predicted supersymmetry, which has been experimentally disproved.
      - zachf 2y ago
        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#DoesSTPredictSupersymmetry https://ncatlab.org/nlab/show/string+theory+FAQ#DoesSTPredic...

pvg 2y ago

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

whatshisface 2y ago

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.

naasking 2y ago
> we're back at string theory as the only renomalizable description of quantum gravity. I think you mean, we're back at "we're not sure if string theory is a viable theory of anything real". Quantized gravity is not necessarily the right answer, and an insistence on this fundamental assumption might be the origin of these difficulties, eg. see Oppenheim's semi-classical gravity.

m101 2y ago

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.

feoren 2y ago
If by "theory of knowledge", you mean they need to have read a bunch of philosophical musings on epistemology, then I strongly agree with the downvoters, because that's utter nonsense. If you mean anything else by that, then you're being way too vague to contribute to a technical discussion, so again I agree with the downvoters. Try defining what you mean by "theory of knowledge" and explain why you think that's required to "understand science" (and you might want to explain what you mean by that too) and I suspect you'll see a lot fewer downvotes.
- m101 2y ago
  Theory of knowledge "is a branch of philosophy that examines the nature, origin, and limits of knowledge". Scientists need to understand the limits of knowledge which may be acquired by science. Scientists think they are in the unique possession of tools which ascertain truths - this is misled.
btilly 2y ago
This strongly depends on what you mean by "theory of knowledge". If you mean the practical importance of self-honesty, and a historical awareness of how easily we slip into self-delusion, then I agree. See, for instance, https://calteches.library.caltech.edu/51/2/CargoCult.htm https://calteches.library.caltech.edu/51/2/CargoCult.htm for a very famous speech on exactly this topic. A lot of Feynman's writing touches on the same issue. If you mean the musings of philosophers on epistemology, then I emphatically disagree. The philosophers in question generally have failed to demonstrate that they understand science. And when they venture into science, they generally fail to live up to the ideals that they proclaim that scientists should follow. As an example I direct you to the sight of Karl Popper arguing to the end of his days that quantum mechanics cannot be a correct scientific theory. An opinion that began because a probabilistic theory cannot in principle be falsified. In fact QM is a scientific theory, and it stands as an example falsifying Popper's criterion for science! I find it very ironic that Feynman is so disliked by philosophers for having been honest about how irrelevant they are to science. And philosophers in turn have failed to recognize Feynman's explanations of how to do science as a key topic that should be included in any proper philosophy of science.

ants_everywhere 2y ago

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.

slashdave 2y ago
(1) is also limited by imagination
- tines 2y ago
  Isn't it (2) that's limited by imagination? Nobody imagined quantum theory, they observed it first.
Ma8ee 2y ago
Those mathematical advances weren't developed in a vacuum, but made to solve some very specific problems which came from better measurements. So even Newtonian mechanics originated in solving problems trying to explain measurements, not that someone sat in their chamber and dreamed up cool math that happened to be very useful.
- ants_everywhere 2y ago
  I agree. Generally, the scientific method has mutually recursive turns of theory and observation. And I don't mean to imply that exist independently. I'm just saying that if you get stuck, the two clearest ways out are to provide more observations or perturb the theory.

lagpskd 2y ago

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

btilly 2y ago
Not exactly. She's just admitted that he isn't someone she thought of. And that's likely because she's far more aware of the contributions of physicists to this field, than the attempted contributions of non-physicists. It's not that she's not aware that they exist - in fact she's painfully aware that there are a great number of them saying all sorts of things - its that she's not individually aware of them. That said, if she had thought of him then she would have merely increased her sample size from 2 to 3, and still had the exact same conclusion.
- lupire 2y ago
  What absurd definition are you using that makes Stephen Wolfram not a physicist? Wolfram is more of a physicist than most physicists. Wikipedia: He entered St. John's College, Oxford, at age 17 and left in 1978[17] without graduating[18][19] to attend the California Institute of Technology the following year, where he received a PhD[20] in particle physics in 1980.[21] Wolfram's thesis committee was composed of Richard Feynman, Peter Goldreich, Frank J. Sciulli and Steven Frautschi, and chaired by Richard D. Field.[21][22] In the mid-1980s, Wolfram worked on simulations of physical processes (such as turbulent fluid flow) with cellular automata on the Connection Machine alongside Richard Feynman[29] and helped initiate the field of complex systems.[citation needed] In 1984, he was a participant in the Founding Workshops of the Santa Fe Institute, along with Nobel laureates Murray Gell-Mann, Manfred Eigen, and Philip Warren Anderson, and future laureate Frank Wilczek.[30] In 1986, he founded the Center for Complex Systems Research (CCSR) at the University of Illinois at Urbana–Champaign.[31] In 1987, he founded the journal Complex Systems.[31] From 1992 to 2002, Wolfram worked on his controversial book A New Kind of Science,[4][33] which presents an empirical study of simple computational systems. Additionally, it argues that for fundamental reasons these types of systems, rather than traditional mathematics, are needed to model and understand complexity in nature. Wolfram's conclusion is that the universe is discrete in its nature, and runs on fundamental laws which can be described as simple programs. He predicts that a realization of this within scientific communities will have a revolutionary influence on physics, chemistry, biology, and a majority of scientific areas in general, hence the book's title

retrocryptid 2y ago

i love sabine. she's speaking the lived experience of quite a few of us who lost faith in the academy.

phkahler 2y ago
I like her message, but some of her recent videos have me a little worried about her. She seems on the edge of a breakdown at times.
- retrocryptid 2y ago
  yeah. she does seem like she's on the edge of throwing down f-bombs, flipping tables and screaming "i'm out of here." guess it's to her credit she hasn't done that.
- antegamisou 2y ago
  > She seems on the edge of a breakdown at times. Academia does this to you. She's a really well controlled case.
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rapjr9 2y ago

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 they can buy an anti-gravity machine. So physics was suppressed by both business and government. Physicists were given "safe" work to do (ITER, quants) that would occupy them and keep them from exploring wild stuff. Grant financing was controlled so that only safe research would be conducted. It would be fairly invisible to the world, just a few high level decisions would determine how the funding was directed. I get the impression that if this was indeed a conscious decision that it's starting to fall apart as younger generations take over and become frustrated with the direction of physics. They weren't there when the A-bomb was invented, and nuclear weapons have not been on peoples minds much for a long time, most people have not lived in a time when one was used. So they see interesting topics and want to explore them and encounter resistance from more established scientists. It's a conspiracy theory because it would involve some buy-in from a fair number of physicists to make it work, but a lot of physicists when I was getting my BA in physics were very loudly saying "never again" about atomic weapons and felt it had tarnished the whole profession. It's very difficult to say what humanity would be capable of handling in terms of radical new inventions. Anti-gravity could solve many large problems, but it might make it even easier to destroy Earth. Once new knowledge exists it is hard to suppress it. Stopping it from from ever existing seems easier. I guess we'll find out if physics has been suppressed if the dam breaks and new ideas start proliferating. The nature of the new physics would be a big clue as to whether research in it was suppressed. I'm reminded of Elon Musk, he seems to have had really radical success in some very stagnant industries, just by trying instead of accepting limits, and being able to fund his ideas himself.

ManuelKiessling 2y ago
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-gravity guns surely give you some nice advantage.

dang 2y ago

If you want to reply to https://news.ycombinator.com/item?id=41811140 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 https://news.ycombinator.com/item?id=41808143 doesn't get too offtopic)

gizajob 2y ago
She was ripping on the valuations and economics of quantum computing companies the other week, and her critiques were such that they could be levelled against capitalism itself and basically any company in the market. Was an obvious and clear step way out of her area of expertise.
- lamontcg 2y ago
  That doesn't have anything to do with her criticism of Loop Quantum Gravity, and is precisely the derailing of the topic that dang is asking you to avoid.
  - skhunted 2y ago
    When people don’t have expertise in an area they are prone to making really dumb comments. She has a history of this on other topics. As such I think it’s appropriate to mention so that people can evaluate how much weight/time they want to spend on her video and views.
    - lostmsu 2y ago
      Do you have expertise in the area of deciding source trustworthiness or relevancy in certain fields?
      - skhunted 2y ago
        I do not. I do have a sense of the notion and make decisions for myself on whether or not something is worth my time. While her video might be accurate in this case her past casts doubt in my mind and as such I’ve decided not to watch it. Other people might find it useful to know about her past errors when deciding whether or not to watch this video.

throwaway14356 2y ago

long ago i coin: scientific physics an analogy with astrology and astronomy fits perfectly. Remember those great men who did groundbreaking work that completely changed the fabric of society? Consensus my a, their work is self evident. If you need someone to tell you something is a great accomplishment it apparently isn't obvious. If there is no revolution triggered by [say] relativity theory it doesn't qualify for the list of great discoveries. You need people to tell you how great it is. funny as hell

sega_sai 2y ago

Physicist here.. I will not give Sabine more YouTube views, justifying clickbait titles. Below is just my opinion. There are certainly issues in theoretical physics. I think particularly string theory was a massive waste of effort in physics and to some degree illustration of failure of the whole system. Despite that most of other physics I would say in sensible shape, it is just harder to make progress given that we have to push to higher energies, more accurate measurements etc. The question whether there will be major advance in fundamental physics to some degree depends on new discoveries. Many people are pushing, but it is not guaranteed.

elashri 2y ago

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 https://www.youtube.com/watch?v=LKiBlGDfRU8 [2] https://pdg.lbl.gov/ https://pdg.lbl.gov/ [3] https://press.uchicago.edu/ucp/books/book/chicago/H/bo5969426.html https://press.uchicago.edu/ucp/books/book/chicago/H/bo596942... [4] https://www.symmetrymagazine.org/article/new-results-from-the-cms-experiment-put-w-boson-mass-mystery-to-rest?language_content_entity=und https://www.symmetrymagazine.org/article/new-results-from-th... [5] https://mathstodon.xyz/@SvenGeier/113284011925646281 https://mathstodon.xyz/@SvenGeier/113284011925646281

randomNumber7 2y ago

hindsightbias 2y ago

What if String Theory is a Sophon Virus?

js8 2y ago
Then it's not really all that well made, frankly, because one of the most popular YT physicists is immune to said virus. But - I have always dismissed cryptocurrencies thinking "people can't be that stupid". If I had not, I could have made some money. So maybe Sophons didn't expect Youtube to be a thing, either.

herodotus 2y ago

This might be too weird to be true, but when I heard that Geoff Hinton got the Nobel prize for Physics, I wondered if the prize committee was having trouble finding "real" physicists who had made fundamental advances.... This is not meant to knock Prof Hinton. These are his own words: “I’m not a physicist, I have very high respect for physics,” Hinton said. “I dropped out of physics after my first year at university because I couldn’t do the complicated math. So, getting an award in physics was very surprising to me. I’m very pleased that the Nobel committee recognised that there’s been huge progress in the area of artificial neural networks.”

atmosx 2y ago
It is evident that they need more than five categories. Awarding Nobels to individuals who are not particularly (if at all) well-versed in the subject at hand, even if they contributed to a breakthrough in the field, directly or indirectly discredits the prize. Indeed, the online memes about Hinton and Hassabis being "a bit of a <physicist|chemist> myself!" are justified, in my opinion.
matusp 2y ago
I agree with you. What is also telling is that there is no particularly strong reaction from the physics community that someone obvious was wrongfully omitted.
- aleph_minus_one 2y ago
  > What is also telling is that there is no particularly strong reaction from the physics community that someone obvious was wrongfully omitted. A few days before the announcement of the Physics Nobel Prize Sabine Hossenfelder created a video about her predictions for the Physics Nobel Prize. Likely all mentioned researchers in this video did more for the advancement of physics research than John Hopfield and Geoffrey Hinton: > Who Will Win This Year’s Nobel Prize in Physics? My Speculations > https://www.youtube.com/watch?v=KMTNHqEpTnw https://www.youtube.com/watch?v=KMTNHqEpTnw

randomNumber7 2y ago

I think the problem is more fundamental. Newtonian mechanics is a science based on observation. Mathematics is just used to build a model that describes _how_ the reality behaves, not why. Now Einstein is very special, because he proved that our human perception of space and time is wrong. When we think about the allegory of the cave, we got a glimpse of the reality we couldnt see before. Nowadays every phyiscist wants to be the next einstein that uses mathematics to show us something about reality. The problem is that einstein had good reasons for his ideas. The constant speed of light didn't really work with maxwells equations. The model at that time didn't correctly describe the observations and the maths he used to solve that is rather elegant and simple.

mnky9800n 2y ago

This seems like a narrow view given that there are plenty of unanswered questions in chaos theory, etc. but physicists who think about quantum stuff typically don't like to consider the other physics Revolution of the 20th century as equivalent to theirs.

meindnoch 2y ago

I knew from the title it's gonna be Sabine Hossenfelder. Her videos are just clickbait at this point.

davidgerard 2y ago

Is this Dang turning titles into Betteridge questions again? The original does not have a question mark.

teekert 2y ago

You know how some people seem knowledgeable until they talk about your field? Well for me (molecular biology and genomics) this never happens with Sabine. So, even though much of this is over my head, I grant her much credence. FWIW.

Ono-Sendai 2y ago

Sabine is often right, but I think she's wrong here about Lorentz invariance being a problem, or at least a problem in the way she's saying. Lorentz transformations are never going to length-contract the underlying fabric of space/spacetime. Relativistic length contractions contract moving objects, not the underlying spacetime. In fact it's a strange and basic misunderstanding to have.

auggierose 2y ago
Depending on your reference coordinate system, space is transformed. That is the entire point of relativity theory. You might be misunderstanding things here.
- Ono-Sendai 2y ago
  Coordinates are transformed, not the actual space. Objects are length-contracted due to the electric field being length contracted.
  - auggierose 2y ago
    You seem to be of the same opinion as Sabine when it comes down to distinguishing between mathematical modelling, and reality. In mathematics though, coordinate transformation and space transformation are the same thing. How that plays out for the actual physics happening, might be a different thing, but note that you still describe it mathematically.
naasking 2y ago
Sabine is correct. All objects in a spacetime are anchored to that spacetime, so if spacetime has a minimum length, then length contraction of moving objects has a detectable lower limit, thus violating Lorentz invariance.
- Ono-Sendai 2y ago
  She seems to be talking about spacetime itself being Lorentz contracted though. it's true that a sufficiently fast moving object would be length contracted so much that it started interacting with the minimal LQG length, which would violate Lorentz invariance. Depending on how big the LQG loops are, that could be a fanstastically high speed that isn't achievable in the universe though.

openrisk 2y ago

Her choice of background for this video and the matching imprint on her blouse gives us maybe a hint that "fundamental" physics is too broad a field to actually die :-) I.e., there are ongoing and deep puzzles e.g., in dark matter / dark energy where observational data keep accumulating and at some point a critical mass (pun) of evidence may reshape our ideas about how the universe fundamentally works. The new ideas need have nothing in common with pre-existing mind sets of how things work. Now about the string theory / quantum gravity furore, after decades of work by arguably extremely bright people its pretty clear that Nature in the current juncture is not giving us enough clues to proceed. This should not be stressful - Nature is not a Hollywood production studio that needs to churn gee-wow "experiences" every season. But Sayre's law applies rather well [1] "In any dispute the intensity of feeling is inversely proportional to the value of the issues at stake.". What is at stake here is the ego of a few individuals that assumed otherwise (i.e., that a post-Einstein revolution is imminent) and the (relatively minor in the scheme of things) research funding of this particular niche of physics. Theoretical physics is not the only domain bouncing regularly between "hypes" and "winters", as the recent Nobel prize for Physics clearly demonstrates. [1] https://en.wikipedia.org/wiki/Sayre's_law https://en.wikipedia.org/wiki/Sayre's_law

drpossum 2y ago

I'm not hot on what fundamental physics looks like now or in the future, but there's an attitude that Sabine promotes that I see echoed in a lot of comments here which feeds into problems with research. I don't think the work put into studying fundamentals was "a waste of time" thus far. It's dangerous to label experiments and ideas that were acted on in good faith as the best options at the time but didn't yield positive results as missteps. Scientists need to be allowed to do work like this without fear because to do so otherwise leads to perverse incentives and you end up with things like lots of studies that can't be reproduced because of p-hacking or worse. Arguing bad faith after the fact is awfully hard without real evidence and if you're going to discount anyone with enthusiasm for their research proposal based on enthusiasm alone you're not going to be left with a healthy program. I don't blame anyone who supported things like supersymmetry as an example for something which hasn't panned out. we're still left with a major mystery and big questions and it says we need to rethink things in more difficult directions.

Log_out_ 2y ago
The whole of human society is a combustion engine for life, barely held from going full self destruction by a science driven economy consuming resources in a unsustainable way. Science is what kept us peaceful and nice since WW2. And the breakthroughs are needed not some time far far away ,they are needed now. This is not about the purity of approach or some hypocritical game. This is a dependancy of life and death on the results ..
BoiledCabbage 2y ago
I'm not in any way an expert in this area, but here is what I see. I don't think the argument is that it's being said as "bad faith after the fact". I think the argument is that the approach was told it had fundamental flaws. Those were ignored / denied. People continued to invest in it and suck up all of the research and bright minds in the field. Decades later it still has those fundamental flaws and has taken over all other possible avenues of progress as it has all grant money and and the majority of all departments working on it. It's more "you were told this is broken before. It's decades later and it's broken in the same way. At what point to you admit that this approach isn't working so try something else?" And the answer is "No, we're going to keep digging deeper". Fundamentally, approaches need to be falsifiable. If your theory is "falsifiable" in the small scale but ultimately unfalsifiable in the large scale then it's is fundamentally unfalsifiable and we can't use it to lead experimentation. It's a breadth vs depth search question. We've lost all breadth of search in physics, because a little ways back we stumbled upon a branch that happened to have a (for practical purposes) infinite number of subbranches relating to ways to roll up string dimensions. So physics is stuck exploring all of those sub-branches instead of backtracking one level and exploring any other parts of the tree. The argument is that everyone is looking under the lamppost for the keys. After 4 decades of searching there, maybe it's time to search somewhere else. And the argument is made even strong when decades back they were told, "Hey, I didn't drop by keys by the lamppost. I dropped them somewhere else". And yet most people keep looking there.

deleted 2y ago

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yusufmotiwala 2y ago

[dead]

wwarner 2y ago

I'm way too late for this to be meaningful, but here's what I think! tl;dr -- gravity is the problem, we should focus on experiments and observations for a while, bring in some better mathematics, and continue the long range program of developing quantum theories that include or even produce GR. I'm just a physics enthusiast. When I became interested in physics, I was initially a sort of partisan in the "realist" camp -- pro Einstein, anti Bohr; liked Verlinde's entropic gravity, distrusted the graviton -- but have come full circle to the opposite view. GR has massive explanatory and predictive power, and an extremely satisfying aesthetic quality, but obviously breaks down behind the curtain of a black hole's event horizon, where we cannot make observations. I say obviously because it predicts a singularity, which is just another way of saying it makes no prediction at all. On the other hand, many of my complaints about QM I now look at as unanswered questions, opportunities for inquiry. QM is based 100% on experimental observations. The theory came together in a rather ad hoc fashion at the beginning of the last century, but as it was more carefully studied theoretically and experimentally, also proved to be highly predictive, even more that GR. Yes there are big ugly, outstanding questions -- measurement collapse, the transition from microscopic quantum behavior to macroscopic classical behavior, the intractability of all but the simplest calculations -- but those are huge areas of knowledge that the future will gradually (or suddenly) fill in, as our understanding moves forward. So, gravity, not QM, is the problem. We should start with the axioms of quantum mechanics, and look for ways to observe where QM and GR can be measured at the same time. LIGO offers opportunities like this, as the sensitivity of the instrument is well within the quantum regime. Continued study of QCD could make a testable prediction for what exists inside of a black hole. Or continue to study the very fine transitions between energy levels in the nucleus. Mathematically, maybe the Langlands program, with its rather weird, Fourier-like sums of L functions will allow us to model non-linear behavior. And yes, string theory sort of "jumped the shark" at some point. I'm sure Ed Witten regrets saying that other pursuits were a waste of time. But the thing is, the string theory program is centered on QM, and has shown that QM can naturally produce GR, given certain unrealistic assumptions. That's mathematical progress.