16 ms·

String Theory Does Not Win a Nobel, and I Win a Long Bet

298 points by Osiris30 7y ago

scottlocklin 7y ago
FWIIW, Horgan is a well known science writer and author of a 1996 book called "the end of science" which pointed out that science in general and physics in particular has reached a point where there is no appreciable forward progress and is obsessed with non falsifiable woo like string theory. It's a provocative book; and people have raised the issue that Kelvin said something similar 120 years ago, but it's really worth reading. He was 100% on the money that Noodle Theory was a lot of non-scientific mathematical baloney; a super unpopular position at the time (1996); pretty much the only prominent person in agreement with him was Nobel Prize Winner Phil Warren Anderson, who disagrees with him in many other respects. Ultimately many other writers came out in agreement on this issue at least; Woit and Smolin most notably, though others agreed. At this point I'm pretty sure even the physics establishment is a little nervous about hiring new noodle theorists. He's basically right about stuff like "complexity theory" as well. I had a couple buddies who were prominent string theorists; some involved in its inception. One in particular retired a very disappointed man.
- haolez 7y ago
  What’s wrong with complexity theory? I remember seeing a talk about it a long time ago and the concepts were super interesting, but I didn’t (I don’t) have the mathematical maturity to understand it in depth.
  - jessriedel 7y ago
    I don't think it ever congealed into a coherent field, say, with an established canon of techniques and a heirarchy of results that built on itself.
  - deleted 7y ago
    [deleted]
  - knzhou 7y ago
    It hasn't become concrete enough to make sharp, striking, correct predictions. It turns out the real world is extremely messy. Complexity theory can produce specific predictions ("disease spread will follow a power law with a critical exponent of...") but they won't be quantitatively correct. Or it can produce correct predictions ("airplanes increase disease spread because they increase the global network's connectivity") but they're generally obvious, and certainly don't require the full formalism of complexity theory to get.
- meowface 7y ago
  There are still a lot of prominent, respectable theoretical physicists who work on string theory. Leonard Susskind, for example. While no evidence of it has been found so far, is calling it "Noodle Theory" and a bunch of baloney really fair? There are plenty of big theories for which there's no evidence, but that doesn't necessarily mean we're certain yet that they're pseudoscience or unfalsifiable. Supersymmetry, Many Worlds, etc.
  - jessriedel 7y ago
    I don't think Susskind works on string theory proper at all anymore. He works on the AdS/CFT stuff, which is compatible with and motivated by stringy approaches, but is logically quite independent. Related: https://www.math.columbia.edu/~woit/wordpress/?p=6252 https://www.math.columbia.edu/~woit/wordpress/?p=6252
  - kelnos 7y ago
    IMO calling it "noodle theory" is just a juvenile means to make fun of people who study it. If you want to tell people something is wrong, tell them why; don't invent childish names to put other people down by association.
- jessriedel 7y ago
  I like Horgan a lot, but it's notable he also made a very wrong prediction that traditional proofs in math would start losing out to less rigorous means of collecting evidence for correctness. https://blogs.scientificamerican.com/cross-check/okay-maybe-proofs-arent-dying-after-all/ https://blogs.scientificamerican.com/cross-check/okay-maybe-... Although being a string theory skeptic was certainly a minority position in both academia and journalism in 1996, I think it's somewhat of an exaggeration to characterize it as a "super unpopular position" and Horgan and Anderson as the only prominent holders.
- Merrill 7y ago
  There seems to be lots of forward progress in physics, e.g. in condensed matter physics, quantum computing, etc. Grand unified theories are sort of irrelevant so long as there are not measurable phenomena that cannot be explained without them.
  - sampo 7y ago
    > There seems to be lots of forward progress in physics, e.g. in condensed matter physics, quantum computing The theory of quantum computing is based on real physics, unlike string theory. But we have no idea if or when we will be able to build a quantum computer that actually calculates something useful. So far the progress has been only in theory. Edit: To downvoters, let's make a bet: In the next 18 years, no one will have used a quantum computer to break any encryption that hasn't also been broken by traditional computers?
    - chrisdirkis 7y ago
      Progress does not mean "Commercial success". Your bet is like hearing "my kid seems to be making lots of progress on their bike", and responding with "I bet he'll never cycle around the world in 18 years".
      - sampo 7y ago
        The bet in the posted news was also about winning the Nobel prize, not about making just lots of progress.
    - comicjk 7y ago
      Breaking a cryptosystem is not a good metric for whether quantum computers have become useful. Calculating energy levels of molecules, for example, is a much easier problem in the near term, and is of benefit to humanity. Breaking a cryptosystem takes vastly more and higher-quality qubits, and the end result is just that everyone upgrades to different math. As a computational chemist, I assign 50% probability to the idea that quantum computers will be able to do useful molecular calculations cheaper than classical computers (for large batches) within 18 years. For small batches, classical computers will remain cheapest much longer because of overhead.
- knzhou 7y ago
  > a super unpopular position at the time (1996); pretty much the only prominent person in agreement with him was Nobel Prize Winner Phil Warren Anderson, who disagrees with him in many other respects. Ultimately many other writers came out in agreement on this issue at least; Woit and Smolin most notably, though others agreed. Ugh, almost everything about this narrative is wrong; see my other comment. Science writers didn't invent skepticism of string theory, that was in good supply among physicists even 50 years ago. You only think they did because, well, you rely on them to tell you what happened, and they puff up their own roles. They turn it into "me vs. the establishment" while cribbing off conversations that are already happening within the field. For example, Glashow, one of the architects of the Standard Model, tried to bar string theorists from ever being hired at Harvard, but you never hear about that.
  - scottlocklin 7y ago
    Thousands of grad student careers, faculty appointments, glowing documentaries and ruined lives later and "oh, we knew that all along." They sure didn't act like they knew it at the time. Horgan deserves credit for making the right call. Even more credit because he wasn't even a physicist. Credit to Glashow, and apologies for forgetting him, but Horgan deserves his victory lap.
    - knzhou 7y ago
      I mean, do you think literally everybody was doing string theory? There have always been plenty of theorists focused on more concrete things -- string theorists are not and have not been the majority. Grad students entering even in the 90s knew they had to make a choice between concrete, more easily testable physics and a long-shot approach to quantum gravity. String theorists have stories of faculty going out of their way, back in grad school, to discourage them from going into it. (It wasn't just Glashow, either, it was most of the Harvard physics department.) To say that string theory comprises all of theoretical physics is to uncritically accept the "me vs. the establishment" narrative some pop scientists put out. I think it does real damage inside the field, too, because it distorts the perspectives people have coming in.
- anon1m0us 7y ago
  oh, I wonder if this is fitting with my current obsession with truth and lies. Not only are we increasing the number of lies in the world, using lies to get what we want has become more and more acceptable through social media, politics, capitalism, etc... But we are increasing the number of things you can't prove are lies. You can't falsify me, therefore I am right. OMG, this is very religious. This is all because of postmodernism! Prior to today, you couldn't prove that my religion was wrong. The more people I could get to believe my lie about the origins of the universe, the more powerful I was. Tribalism requires agreed upon unfalsifiable lies. I am with you because I believe the same thing you do. Postmodernism has done this to us. With religion and an omniscient being watching us, heaven for the good, hell for the bad, we had a -- conscience. Now, it's the internet. The internet is omniscient. Facebook is watching us. Google is watching us. The CIA and FBI are watching us through the internet. We've replaced god with ... the internet. The internet is the new god. And thus, we are evolving toward the biblical God that created us in his image. We are walking down the path to omniscience via the internet.
  - undershirt 7y ago
    I wonder if you might try the subtler word myths instead of lies. Reality is formless, and we reason about it through what Foucault called grids I think, where every structure that we impose on it to bring something new into view necessarily obscures something else. This is a bit like what Alan Watts talks about when saying that stories are like music, in which it wouldn’t have any form unless there were notes left out. I think of a fact as a compressed statement of experience in service to some story. This is like the surprising observation that bits of information seem to always have some color that cannot be captured[1]. And there is the type of myth I like to call Fruith, as opposed to Truth. Most myths comprising culture might be these—in that we pretend things are true in the belief that it brings something more important to fruition, and that is the truth which overrides the seminal “lie”. I see your despair, but I think it’s bigger than what you may be suggesting. [1] https://ansuz.sooke.bc.ca/entry/23 https://ansuz.sooke.bc.ca/entry/23
    - anon1m0us 7y ago
      When you say, "... it's bigger than what you may be suggesting." What is ... "it"? My despair? I understand your point about lies vs myths. If I substitute the two words in my mind according to your explanation of myths and their purpose, then everything actually does seem to make more sense and is more acceptable in my mind. If someone tells a lie the connotation is that it's meant to harm others to their own benefit. If it's a myth, then they need that ... not accurate portrayal of the world in order to keep going... to survive, perhaps as an individual or group.
- secraetomani 7y ago
  > noodle theorists Lovely name
- deleted 7y ago
  [deleted]
- agota 7y ago
  Thank you for mentioning the book, it sounds interesting!
whatshisface 7y ago
>Gaining access to the infinitesimal microscales where superstrings supposedly wriggle would require an accelerator 1,000 light years around. Has anyone ever proven that there aren't any better accelerator technologies left to be discovered? What about natural accelerators like the charges that build up and produce cosmic rays?
- krastanov 7y ago
  This is a common suggestion and it is used more and more. The problem is the data rate: with LHC you have a flood of interesting events to record in a very controlled environment. On the other hand, super-high-energy cosmic rays are very rare and frequently you do not know many of the initial parameters necessary to interpret the measurement. Cosmological measurements seem to be promising (akin to looking for footprints in the cosmic background from extremely high-energy phenomena from the early universe). And excitingly, extreme precision "table top" experiments are also promising. Check stuff like the recent work on measuring the (nonexistent) dipole moment of the electron.
- magicalhippo 7y ago
  > What about natural accelerators like the charges that build up and produce cosmic rays? As mentioned the benefit of artificial accelerators are that you can make the collisions happen right in the middle of the detectors, which is quite nice. You can also generate a lot of collisions, which is good because statistics require it. That said, there are projects, such as this[1], utilizing natural accelerators. There's a technical talk about their results here[2]. The first part explains the system in more detail. [1]: https://www.auger.org/index.php/cosmic-rays/detection https://www.auger.org/index.php/cosmic-rays/detection [2]: http://pirsa.org/17120007 http://pirsa.org/17120007
  - smueller1234 7y ago
    Thanks for posting that reference to the (Pierre) Auger Observatory with links and all. We loved to point out that at current accelerator tech, our high energy events would need a ring with about the same radius as the Earth's distance from the sun. What also blows my mind is that there aren't really credible/supported theories about what process or effect may be able to put as much energy into a single particle. Whatever it is, my money is on that is a process that happens at large scales (just like Fermi acceleration), so the "giant accelerator" bit remains somewhat true, except we don't have to build it. :)
raspasov 7y ago
Quantum computers might be able to perform simulations which will be indistinguishable from reality. Many theories can be tested that way once we have a sufficiently powerful quantum computer.
- jessriedel 7y ago
  You can't test string theory with a quantum computer.
- krastanov 7y ago
  While I agree on the promise of quantum computing, the way you phrased it is somewhat misleading (hides plenty of complications (even theoretical ones) under the rug). Moreover, even if we can simulate a theory efficiently, we can not use that simulation to learn the value of a (hyper)parameter, without being able to make an observation. And this is the main problem: it is infeasible to make observations in the parameter regime of interest. The difficulty of simulating the theory is borderline inconsequential in this case.
  - raspasov 7y ago
    Is observing a parameter not allowed by quantum mechanics or a current fundamental law? I am aware of the difficulty involved but an optimistic view is that anything is possible until fundamentally proven otherwise. As far as I’m aware, quantum computers would be able to simulate an entire universe in theory. Sorry if my initials comment seemed to disregard the enormity of the problem. I realize we might be decades/centuries before any of this is testable. Not unlike how Newton was compared to our current understanding of physics.
    - krastanov 7y ago
      The parameter regime of interest is monumentally out of reach to experiments. We can already derive things on paper about that regime, and with better computers we would indeed be able to make more complicated calculations about that regime. But to get something useful we also need to "fit" these calculations to observations. We do not have observations not because of a fundamental constraint, rather because it is engineeringly impossible to reach these energy scales with anything we can imagine. So the roadblock is experimental and a quantum computer would not be particularly helpful with it.
knzhou 7y ago
It's important to avoid conflating string theorists with all theoretical physicists. Plenty of people in particle physics either don't believe in string theory or don't think it can make useful predictions any time soon, even if it were assumed true. Furthermore, the vast majority of people called "string theorists" don't even work on traditional string theory day to day, but on more concrete ideas that have been partly inspired by it, such as holography and amplitudes. This needs to be pointed out because there is a huge narrative bias out there. Science popularizers will endlessly frame things like "this whole field has no idea what they're doing, and only I, the brave contrarian outsider, can see through the fraud", even though they're only pointing out things that are already well known in the field. These narratives are completely wrong, but uncritically eaten up by people who think of themselves as contrarians. Despite what the current top comment claims, you're not reading this article about Horgan because he was the first to think string theory would have trouble making predictions. Physicists have made this criticism since the beginning. Feynman pointed it out continually, and Glashow, one of the architects of the Standard Model, tried to bar string theorists from Harvard for the same reason. You're reading Horgan's take, and not Feynman's or Glashow's, because Horgan is popular, and that's because he puts all his energy into expanding his popular reach. Only nonphysicists can do that, because physicists spend the majority of their time doing, well, physics.
- Ma8ee 7y ago
  String theory has completely dominated the field of theoretical high energy physics for decades. There have been some notable contrarians, e.g., Smolin and Woit with their books. But those haven't changed the fact that it has been very hard to get a faculty position in theoretical hep for decades without being a string theorist. It is only the last few years that has changed. In other words, it's not a biased view that string theory has completely dominated the field for more than 30 years. Btw, the reason we aren't reading Feynman's take is that he died in 1988, not that he's too busy doing physics. He was very successful in doing both high quality physics and expanding his popular reach.
  - knzhou 7y ago
    That's just not true. Look at the statistics for hiring faculty in theoretical high energy physics [1]. String theory was never more than half, and usually much less than that. (It is true, though, that for a while they had a near monopoly on pop physics. But that's totally different from physics.) [1] http://www.particle.physics.ucdavis.edu/rumor/doku.php?id=statistics http://www.particle.physics.ucdavis.edu/rumor/doku.php?id=st...
dmix 7y ago
Michio Kaku has long been my least favourite of the celebrity talking head scientists. And he has some good competition for that label. His pop-science books tend to read more like coming from a Hollywood screenwriter than a careful and thoughtful scientific mind.
- AprilArcus 7y ago
  Remember when he literally sued to block the launch of the Cassini probe?
  - scarejunba 7y ago
    For others reading, this appears to be because he believed that in an accident the radio-thermal isotope generator on board Cassini would spread radioactive material all over the place.
    - eth0up 7y ago
      ...all over the place A small, but possible chance of Pu-238 spreading over Florida. I just read that 238 (half-life 87 years) emits mostly alpha, which is said to be easily blocked, even by paper. In FL, many go about half naked, so I'm not sure if this matters. I wonder how thoroughly Kaku considered everything. Seems his concern was based partially on NASA's (small but not null) history of failures. I don't know, but doubt he was being deliberately unreasonable. Maybe his Japanese (distant) ancestry was a factor? Publicity would be a surprising motive. So would general ignorance.
      - yongjik 7y ago
        Actually, alpha emitters are very dangerous when ingested, for the same reason they are readily blocked by paper - your body will absorb all the radiation. This is why Polonium 210 is one of the most toxic material known to us. (Not agreeing with Michio Kaku, by the way.)
      - namarie 7y ago
        > Maybe his Japanese (distant) ancestry was a factor? Why would it be?
ErotemeObelus 7y ago
Maybe physicists should just stop. There has to be a bottom to the barrel and we probably reached it.
beloch 7y ago
"The Nobel prize judges have always been sticklers for experimental proof." One of the big challenges of devising a grand-unifying theory of everything is that, if it doesn't make different predictions than existing theories do in any context, it's experimentally unverifiable. We can hope for a unifying theory that makes everything simpler, but it's far more likely that a theory that deals with all things at once will makes dealing with special cases harder. If such a theory is harder to work with and does not differ from special case theories that are easier to apply, why bother? Of course, a unifying theory probably will differ from existing theories in at least some contexts. They may be extremely high energy, gravity, etc. contexts that are beyond our current technology to test. String theory likely falls into this category. The question is, how much resources should we pour into developing a theory before demanding that its differences with currently accepted theories become testable? Quite frankly, answering this question is above my pay-grade. Scientific history is full of both dead-ends and things that were initially thought to be useless that have since become the foundations of entire fields. How do we know which string theory is? If we cut funding to string theory development, are we cutting off a field that will one day be essential? By continuing to pour funds into string theory, are we funding a dead end and starving several other things that might have been revelations?
- JumpCrisscross 7y ago
  > if it doesn't make different predictions than existing theories do in any context, it's experimentally unverifiable Given the number of holes in and between our theories, this seems unlikely. And there are still a lot of experiments yielding surprising results in fundamental physics.
- SolarNet 7y ago
  > One of the big challenges of devising a grand-unifying theory of everything is that, if it doesn't make different predictions than existing theories do in any context, it's experimentally unverifiable. Yea, but then it isn't a unifying theory it's basically just a giant case statement of "if relativistic motion, use relativistic motion equation". That isn't a unifying theory, that's more like a programming library that does everything. A unifying theory would have to allow one to unify all of the existing equations we have as well as synthesize new ones; not just the ones we already have. It probably doesn't exist. It smacks too much of an NP-hard compression problem, where if we have enough output of the function we can find the minimal representation of it, but applied to everything in the universe.
the-pigeon 7y ago
I can't wait until String Theory dies. As a couch scientist it seems to very clearly be a dead end. They keep massaging it to make it fit any new objective discoveries but an accurate theory matches new data, it doesn't need to be forced to fit with it constantly.
Animats 7y ago
This can happen in academia. I went through Stanford CS, finishing in 1985. That was about when it was clear that "expert systems" were not going to lead to Strong AI Real Soon Now, or, indeed, much of anywhere. But many faculty were in deep denial about that. The "AI Winter" followed. There was little progress until machine learning finally took off about two decades later.
- perl4ever 7y ago
  I still remember reading an article about Doug Lenat and Cyc a long time ago in some pop sci publication and thinking, surely you can't be serious... I don't understand how people ever thought such things could become equivalent to human minds, but I don't think that's my insight, but that others' thinking was blinkered for some reason.
  - namarie 7y ago
    Makes you think about what we think today that will be seen likewise by future people.
    - thanatropism 7y ago
      You're being downvoted, but we' re basically drunk on these amazing successes in Computer Vision and apply at least some magical thinking when expecting them to extend to general (e.g. reinforcement learning) domains.
      - Animats 7y ago
        AI is doing a lot better now than in the 1980s. AI back then was groups at MIT, Stanford, and CMU, and a few small groups elsewhere. Almost all the 1980s AI startups went bust. This time, there's enough success that the field is self-funding. Cynically, because mediocre machine learning is good enough for ad targeting.
        thanatropism 7y ago
fabiosussetto 7y ago
"It would culminate the ancient human quest for knowledge, which began when the first of our ancestors asked, "Why?"" I'm always baffled when I read these kind of quotes, especially coming from such smart people. Do they just forget that our theories are models of reality? I personally believe that there are no wave functions or vibrating membranes out there, as there are no "triangles". These are just names for our mental models on which we map reality the best we can. Fitting models are very useful, but they certainly don't answer the big "Why?" and are doomed to be superseded by more accurate ones, when progress is made. Is it just me thinking this?
- dilippkumar 7y ago
  > here are no wave functions or vibrating membranes out there, as there are no "triangles". I wish you'd added "There is no spoon" here. Opportunity missed.
  - fabiosussetto 7y ago
    Haha, indeed, missed opportunity :)
- im3w1l 7y ago
  Your perspective is a popular one, but a lot of people also think there is a "true" theory that will perfectly explain how the universe evolves.
  - wuliwong 7y ago
    >a lot of people also think there is a "true" theory that will perfectly explain how the universe evolves Doesn't Godel's incompleteness theorems make this doubtful? Logic was not my area of focus but I thought the basic idea was that there is always going to be some un-answerable question(s) or un-provable answers in any consistent theory[1]? I'm pretty sure there is not significant work using non-axiomatic math, I'm honestly not even sure what that looks like. I'd actually be quite interested to find out about some theoretical physics work that did not fall under the auspices of the incompleteness theorem. [1] There are certainly caveats to "theory" but I believe all those caveats are satisfied by any version of String Theory be actively researched.
jsnk 7y ago
Whether you get it right or wrong, I really appreciate people making verifiable predictions about the future publicly. On the other hand, I am less and less interested in post hoc analysis done by journalists and academics judging after the fact, what should've happened.
NotAnEconomist 7y ago
Why aren't TQFTs evidence for string theory? If we know you can build quasiparticles and non-local effects out of braiding/knotting dynamics -- wouldn't the minimal assumption be that other things that can be explained by the same mechanism at a different resolution are? Perhaps I don't understand the distinction between say, string theory and loop quantum gravity.
max_zhou 7y ago
Correct me if I am wrong. i think string theory is searched not just because of its beauty, but also because of existing problems in general relativity. For example, the center of black hole is predicted to be `infinite` in terms of many metrics . But the center is also part of the spacetime, it should bear some measurable values. The answer might require quantum physics since it is microscopic. Therefore, the unifying of general relativity and quantum mechanics is asked for.
- sanxiyn 7y ago
  Yes, quantum gravity is searched for. String theory is not quantum gravity, it is a specific approach to quantum gravity that has not been very fruitful.
  - max_zhou 7y ago
    Ah, thanks for pointing that out!
Mugwort 7y ago
It's very likely a unified theory will win a prize maybe even the Nobel Prize but it isn't going to happen anytime soon. FWIW I'm about as convinced of the truth of string theory as I am of the truth of General Relativity. Sure a better version of M-theory or something else is sure to be discovered but it will be an outgrowth of the current enterprise. The problem is even if we had the correct theory right now it probably would not do us much good at all. It would be a puzzle box we couldn't even open or get answers from it. People underestimated the difficulties involved and the theory was over hyped. Now begins the long "string theory winter". Decades from now, some diehard whose career is foundering will make a significant breakthrough, enough to compel everyone's attention. Until then, there's plenty of interesting physics problems to work on that have been unjustly neglected for too long. Einstein's theory of GR could end up being "wrong" but it would live on as a very good approximation to a more fundamental theory. String theory could very well turn out to be completely wrong but it would fail in a very different manner. If ST is wrong, it's no longer useful. If GR is "wrong" people will still use it. For various reasons which are by no means proof or even evidence I think ST is basically correct but we're simply unable to make proper sense of it. Anyway, we're here at the string theory winter. Careers are ruined, people disappointed etc. That's just how it goes. Sometimes, things work out and sometimes they just don't. We didn't exactly walk away from all of this with ZERO but we're very far from the ultimate PRIZE or GOAL. In hindsight we'll probably look back on this and realize we were hopelessly unable to succeed given the tools and ideas of the day. Expert systems were simply unable to deliver and people were crushed. Careers were ruined. Hopes dashed. Naysayers vindicated then along comes this crazy guy who just won't give up on neural networks. I think the future looks much brighter for unified physics now that string theory as we knew it has clearly failed. I don't want to leave these guys out too so let me add that loop quantum gravity has failed too, much more gracefully I might add. I think these guys were on to something and their ideas aren't going to completely disappear. I've thrown away about 10,000 hours of my life on this stuff. Thanks for spending 3 minutes on my meager insights.
heroHACK17 7y ago
String theory is probably the one scientific topic I spend the most of my free time learning about. It is fascinating. I have read Brian Greene's 'The Hidden Reality' over five times, I think. I recently watched his conversation with Sam Harris and was intrigued by a point Brian made, albeit about quantum mechanics and the 'many worlds' theory. Brian claims that he doesn't think the many worlds theory holds water because it makes an assumption about what happens before some object is measured (A) and after that same object is measured (A'): while many worlds claims that all possibilities are indeed realized, Brian claims that we just don't know for sure what happens between events (A) and (A'); he claims that a unified theory would explain what happens between those events. In any case, that's just me rambling about it. Thanks for the post :)
- madhadron 7y ago
  Sadly, popular discussions about topics like these are usually not worth spending any time on. There is no shortcut for digging into the math. > while many worlds claims that all possibilities are indeed realized That's...a problematic statement since you have to define "realized" without resorting to any classical concepts. Once you manage to excise the classical concepts you end up with something that is perfectly reasonable. > Brian claims that we just don't know for sure what happens between events (A) and (A'); he claims that a unified theory would explain what happens between those events. I suspect that this was a communications breakdown. It's hard to imagine a quantum physicist today postulating this in the face of the last few decades of experimental and theoretical work on the foundations of quantum mechanics.
m0zg 7y ago
Can it even win a Nobel? I thought the Nobel is not awarded for math, and string theory is just math, with no verifiable real-world side effects or consequences that I'm aware of.
- rsj_hn 7y ago
  Nobel prizes skew heavily towards experimental physics and theory prizes require experimental verification. That's why Higgs had to wait until 2013 even though absolutely everyone was convinced that a Higgs boson existed for decades before that. Even Einstein didn't win the Nobel for GR, but for the photoelectric effect. Back in the day when high energy physicists kept discovering new particles and there was a short delay between theory and experiment, there were more Nobels awarded to theorists for this, and I think that golden age of grand unification progress created a false impression that theory work is expected to win Nobel prizes just for being good theory work. But if you look at the last dozen or so Nobels, they are all for describing observable phenomena or conducting novel experiments: (lasers, discovering exoplanets, detecting gravity waves, theoretical descriptions of phase transitions of matter, LEDs, mass of the Neutrino, etc.) It would take very convincing experimental confirmation before String theory wins a Nobel, but there are lots of other prizes awarded to string theorists, and Witten even won a Fields medal, which is more prestigious than a Nobel to the math community.
  - mhh__ 7y ago
    My history of physics is probably simplified, but I think Einstein got it for (mainly) the photoelectric effect in part because relativity was still (despite having been verified to some extent already) too weird.
    - madhadron 7y ago
      Yes, it was given for the photoelectric effect and other work (which was nudge nudge, wink wink, relativity). Everyone forgets just how much physics Einstein did besides relativity. Brownian motion, for example. Turns out that the photoelectric effect as described by Einstein was possible to get out of classical physics, though, so it took a few more iterations in the later 20th century to really nail that one down again. See 'The Quantum Challenge' by Zajonc.
avip 7y ago
Mandatory string theory introduction for the novice https://xkcd.com/171/ https://xkcd.com/171/
edmqkk 7y ago
the whole time I just kept thinking, "but... when they put up their money in 2002 it was invested right?? The charity got something more like $2880? why aren't they telling us!?"
ttctciyf 7y ago
As a long-time antagonist of Kaku and string theory / supersymmetry, Peter Woit naturally has a blog entry[1] on this that's worth a look. He points out Prof Gordon Kane upped[2] the ante: > By 2020 there will be a Nobel Prize for a string- or unification- or supersymmetry-based theory or explanation or experimental discovery. And goes on to give us some insight into Kaku's current point of view. Spoiler: he thinks string theory will give us the "God Equation" when it reaches its final form! 1: http://www.math.columbia.edu/~woit/wordpress/ http://www.math.columbia.edu/~woit/wordpress/ 2: http://longbets.org/12/#comment-166313625 http://longbets.org/12/#comment-166313625
steelframe 7y ago
> characteristic radiation from black holes and Creation Wait, did the author just refer to the Big Bang as "Creation" with a capital 'C'? Since when did Judeo-Christian mythology (or whatever mythology you think "Creation with a capital 'C'" means in the author's culture, inferring some creative agent in the "beginnings" of the known universe) become relevant in this article's context?
- agota 7y ago
  I also noticed that.
didibus 7y ago
So is all this about the fact that String Theory just didn't turn out to be practically useful? Or is the theory no longer believer to hold weight given current observations?
- sanxiyn 7y ago
  It is not about being useful, it is about there being zero experimental evidence for string theory.
  - didibus 7y ago
    I'm really a commoner when it comes to physics, so indulge me if I don't make sense. As I gather then, there's been no experiment showing evidence to String Theory, but all experimental result are also not contradicting it and fitting inside its models? If so, I don't really understand how both these thing can be true at the same time. Is it that people criticize String Theory for kinda being too broad, so in a way, it allows too many things to be possible, but that also renders it useless for prediction, because it's not close enough to exactly what happens? Like saying that the weather on any day must be between -100 and 100 celcius. It will be hard to find evidence to the contrary, but it's so broad that it's useless for any valuable predictions?
braindead_in 7y ago
Is there a clear boundary where string theory ends and Standard Model starts?
hoseja 7y ago
This guy really hates the search for grand unified theory, wow. What a miserable fellow.
- tim333 7y ago
  I don't think he hates it so much as being pessimistic about finding it in a hurry.
kashyapc 7y ago
Two weeks ago I heard a very interesting EconTalk podcast[1] by Sabine Hossenfelder on Physics, Reality, and Lost in Math. Hossenfelder herself is a theoretical physicist, and researches quantum gravity. And a Research Fellow at the Frankfurt Institute for Advanced Studies. She has a refreshing tone and frankness, and I appreciated learning about her work. Quoting the podcast's abstract: "Hossenfelder argues that the latest theories in physics have failed to find empirical confirmation. Particles that were predicted to be discovered by the mathematics have failed to show up. Whether or not there is a multiverse has no observable consequences. Hossenfelder argues that physicists have become overly enamored with the elegance and aesthetics of their theories and that using beauty to evaluate a model is unscientific. The conversation includes a discussion of similar challenges in economics." [1] https://www.econtalk.org/sabine-hossenfelder-on-physics-reality-and-lost-in-math/ https://www.econtalk.org/sabine-hossenfelder-on-physics-real...
virgakwolfw 7y ago
I'm shocked that Kaku even accepted that bet. That's the easiest no ever. Even if you assume that string theory/a unified theory gets completely worked out and a consensus is reached by 2020, the nobel does not give out awards without experimental evidence. Both of those things happening before 2020 was never going to happen.
35787 7y ago
Kaku also incorrectly predicted HEVs.
dkrich 7y ago
Other than for fun and to donate to a good cause, I'm not sure why anyone would ever take the other side of a bet like this or the follow up one for the case of wine. The author is basically betting against an unlikely outcome and the challenger is betting on it, with no adjustment for the likelihood. This would be like offering a bet that a particular college football team won't win a national championship and getting even money that they will. I realize this is outside the scope of the article, but I think it's worth noting because the author gets outsized credit for being correct despite not really offering an alternative. To be fair the author should have had to bet an alternate area that would win a Nobel prize before 2020, otherwise it's a push and each person's stake goes to charity.

298 points by Osiris30 7y ago

FWIIW, Horgan is a well known science writer and author of a 1996 book called "the end of science" which pointed out that science in general and physics in particular has reached a point where there is no appreciable forward progress and is obsessed with non falsifiable woo like string theory. It's a provocative book; and people have raised the issue that Kelvin said something similar 120 years ago, but it's really worth reading. He was 100% on the money that Noodle Theory was a lot of non-scientific mathematical baloney; a super unpopular position at the time (1996); pretty much the only prominent person in agreement with him was Nobel Prize Winner Phil Warren Anderson, who disagrees with him in many other respects. Ultimately many other writers came out in agreement on this issue at least; Woit and Smolin most notably, though others agreed. At this point I'm pretty sure even the physics establishment is a little nervous about hiring new noodle theorists. He's basically right about stuff like "complexity theory" as well. I had a couple buddies who were prominent string theorists; some involved in its inception. One in particular retired a very disappointed man.

haolez 7y ago
What’s wrong with complexity theory? I remember seeing a talk about it a long time ago and the concepts were super interesting, but I didn’t (I don’t) have the mathematical maturity to understand it in depth.
- jessriedel 7y ago
  I don't think it ever congealed into a coherent field, say, with an established canon of techniques and a heirarchy of results that built on itself.
- deleted 7y ago
  [deleted]
- knzhou 7y ago
  It hasn't become concrete enough to make sharp, striking, correct predictions. It turns out the real world is extremely messy. Complexity theory can produce specific predictions ("disease spread will follow a power law with a critical exponent of...") but they won't be quantitatively correct. Or it can produce correct predictions ("airplanes increase disease spread because they increase the global network's connectivity") but they're generally obvious, and certainly don't require the full formalism of complexity theory to get.
meowface 7y ago
There are still a lot of prominent, respectable theoretical physicists who work on string theory. Leonard Susskind, for example. While no evidence of it has been found so far, is calling it "Noodle Theory" and a bunch of baloney really fair? There are plenty of big theories for which there's no evidence, but that doesn't necessarily mean we're certain yet that they're pseudoscience or unfalsifiable. Supersymmetry, Many Worlds, etc.
- jessriedel 7y ago
  I don't think Susskind works on string theory proper at all anymore. He works on the AdS/CFT stuff, which is compatible with and motivated by stringy approaches, but is logically quite independent. Related: https://www.math.columbia.edu/~woit/wordpress/?p=6252 https://www.math.columbia.edu/~woit/wordpress/?p=6252
- kelnos 7y ago
  IMO calling it "noodle theory" is just a juvenile means to make fun of people who study it. If you want to tell people something is wrong, tell them why; don't invent childish names to put other people down by association.
jessriedel 7y ago
I like Horgan a lot, but it's notable he also made a very wrong prediction that traditional proofs in math would start losing out to less rigorous means of collecting evidence for correctness. https://blogs.scientificamerican.com/cross-check/okay-maybe-proofs-arent-dying-after-all/ https://blogs.scientificamerican.com/cross-check/okay-maybe-... Although being a string theory skeptic was certainly a minority position in both academia and journalism in 1996, I think it's somewhat of an exaggeration to characterize it as a "super unpopular position" and Horgan and Anderson as the only prominent holders.
Merrill 7y ago
There seems to be lots of forward progress in physics, e.g. in condensed matter physics, quantum computing, etc. Grand unified theories are sort of irrelevant so long as there are not measurable phenomena that cannot be explained without them.
- sampo 7y ago
  > There seems to be lots of forward progress in physics, e.g. in condensed matter physics, quantum computing The theory of quantum computing is based on real physics, unlike string theory. But we have no idea if or when we will be able to build a quantum computer that actually calculates something useful. So far the progress has been only in theory. Edit: To downvoters, let's make a bet: In the next 18 years, no one will have used a quantum computer to break any encryption that hasn't also been broken by traditional computers?
  - chrisdirkis 7y ago
    Progress does not mean "Commercial success". Your bet is like hearing "my kid seems to be making lots of progress on their bike", and responding with "I bet he'll never cycle around the world in 18 years".
    - sampo 7y ago
      The bet in the posted news was also about winning the Nobel prize, not about making just lots of progress.
  - comicjk 7y ago
    Breaking a cryptosystem is not a good metric for whether quantum computers have become useful. Calculating energy levels of molecules, for example, is a much easier problem in the near term, and is of benefit to humanity. Breaking a cryptosystem takes vastly more and higher-quality qubits, and the end result is just that everyone upgrades to different math. As a computational chemist, I assign 50% probability to the idea that quantum computers will be able to do useful molecular calculations cheaper than classical computers (for large batches) within 18 years. For small batches, classical computers will remain cheapest much longer because of overhead.
knzhou 7y ago
> a super unpopular position at the time (1996); pretty much the only prominent person in agreement with him was Nobel Prize Winner Phil Warren Anderson, who disagrees with him in many other respects. Ultimately many other writers came out in agreement on this issue at least; Woit and Smolin most notably, though others agreed. Ugh, almost everything about this narrative is wrong; see my other comment. Science writers didn't invent skepticism of string theory, that was in good supply among physicists even 50 years ago. You only think they did because, well, you rely on them to tell you what happened, and they puff up their own roles. They turn it into "me vs. the establishment" while cribbing off conversations that are already happening within the field. For example, Glashow, one of the architects of the Standard Model, tried to bar string theorists from ever being hired at Harvard, but you never hear about that.
- scottlocklin 7y ago
  Thousands of grad student careers, faculty appointments, glowing documentaries and ruined lives later and "oh, we knew that all along." They sure didn't act like they knew it at the time. Horgan deserves credit for making the right call. Even more credit because he wasn't even a physicist. Credit to Glashow, and apologies for forgetting him, but Horgan deserves his victory lap.
  - knzhou 7y ago
    I mean, do you think literally everybody was doing string theory? There have always been plenty of theorists focused on more concrete things -- string theorists are not and have not been the majority. Grad students entering even in the 90s knew they had to make a choice between concrete, more easily testable physics and a long-shot approach to quantum gravity. String theorists have stories of faculty going out of their way, back in grad school, to discourage them from going into it. (It wasn't just Glashow, either, it was most of the Harvard physics department.) To say that string theory comprises all of theoretical physics is to uncritically accept the "me vs. the establishment" narrative some pop scientists put out. I think it does real damage inside the field, too, because it distorts the perspectives people have coming in.
anon1m0us 7y ago
oh, I wonder if this is fitting with my current obsession with truth and lies. Not only are we increasing the number of lies in the world, using lies to get what we want has become more and more acceptable through social media, politics, capitalism, etc... But we are increasing the number of things you can't prove are lies. You can't falsify me, therefore I am right. OMG, this is very religious. This is all because of postmodernism! Prior to today, you couldn't prove that my religion was wrong. The more people I could get to believe my lie about the origins of the universe, the more powerful I was. Tribalism requires agreed upon unfalsifiable lies. I am with you because I believe the same thing you do. Postmodernism has done this to us. With religion and an omniscient being watching us, heaven for the good, hell for the bad, we had a -- conscience. Now, it's the internet. The internet is omniscient. Facebook is watching us. Google is watching us. The CIA and FBI are watching us through the internet. We've replaced god with ... the internet. The internet is the new god. And thus, we are evolving toward the biblical God that created us in his image. We are walking down the path to omniscience via the internet.
- undershirt 7y ago
  I wonder if you might try the subtler word myths instead of lies. Reality is formless, and we reason about it through what Foucault called grids I think, where every structure that we impose on it to bring something new into view necessarily obscures something else. This is a bit like what Alan Watts talks about when saying that stories are like music, in which it wouldn’t have any form unless there were notes left out. I think of a fact as a compressed statement of experience in service to some story. This is like the surprising observation that bits of information seem to always have some color that cannot be captured[1]. And there is the type of myth I like to call Fruith, as opposed to Truth. Most myths comprising culture might be these—in that we pretend things are true in the belief that it brings something more important to fruition, and that is the truth which overrides the seminal “lie”. I see your despair, but I think it’s bigger than what you may be suggesting. [1] https://ansuz.sooke.bc.ca/entry/23 https://ansuz.sooke.bc.ca/entry/23
  - anon1m0us 7y ago
    When you say, "... it's bigger than what you may be suggesting." What is ... "it"? My despair? I understand your point about lies vs myths. If I substitute the two words in my mind according to your explanation of myths and their purpose, then everything actually does seem to make more sense and is more acceptable in my mind. If someone tells a lie the connotation is that it's meant to harm others to their own benefit. If it's a myth, then they need that ... not accurate portrayal of the world in order to keep going... to survive, perhaps as an individual or group.
secraetomani 7y ago
> noodle theorists Lovely name
deleted 7y ago
[deleted]
agota 7y ago
Thank you for mentioning the book, it sounds interesting!

whatshisface 7y ago

>Gaining access to the infinitesimal microscales where superstrings supposedly wriggle would require an accelerator 1,000 light years around. Has anyone ever proven that there aren't any better accelerator technologies left to be discovered? What about natural accelerators like the charges that build up and produce cosmic rays?

krastanov 7y ago
This is a common suggestion and it is used more and more. The problem is the data rate: with LHC you have a flood of interesting events to record in a very controlled environment. On the other hand, super-high-energy cosmic rays are very rare and frequently you do not know many of the initial parameters necessary to interpret the measurement. Cosmological measurements seem to be promising (akin to looking for footprints in the cosmic background from extremely high-energy phenomena from the early universe). And excitingly, extreme precision "table top" experiments are also promising. Check stuff like the recent work on measuring the (nonexistent) dipole moment of the electron.
magicalhippo 7y ago
> What about natural accelerators like the charges that build up and produce cosmic rays? As mentioned the benefit of artificial accelerators are that you can make the collisions happen right in the middle of the detectors, which is quite nice. You can also generate a lot of collisions, which is good because statistics require it. That said, there are projects, such as this[1], utilizing natural accelerators. There's a technical talk about their results here[2]. The first part explains the system in more detail. [1]: https://www.auger.org/index.php/cosmic-rays/detection https://www.auger.org/index.php/cosmic-rays/detection [2]: http://pirsa.org/17120007 http://pirsa.org/17120007
- smueller1234 7y ago
  Thanks for posting that reference to the (Pierre) Auger Observatory with links and all. We loved to point out that at current accelerator tech, our high energy events would need a ring with about the same radius as the Earth's distance from the sun. What also blows my mind is that there aren't really credible/supported theories about what process or effect may be able to put as much energy into a single particle. Whatever it is, my money is on that is a process that happens at large scales (just like Fermi acceleration), so the "giant accelerator" bit remains somewhat true, except we don't have to build it. :)

raspasov 7y ago

Quantum computers might be able to perform simulations which will be indistinguishable from reality. Many theories can be tested that way once we have a sufficiently powerful quantum computer.

jessriedel 7y ago
You can't test string theory with a quantum computer.
krastanov 7y ago
While I agree on the promise of quantum computing, the way you phrased it is somewhat misleading (hides plenty of complications (even theoretical ones) under the rug). Moreover, even if we can simulate a theory efficiently, we can not use that simulation to learn the value of a (hyper)parameter, without being able to make an observation. And this is the main problem: it is infeasible to make observations in the parameter regime of interest. The difficulty of simulating the theory is borderline inconsequential in this case.
- raspasov 7y ago
  Is observing a parameter not allowed by quantum mechanics or a current fundamental law? I am aware of the difficulty involved but an optimistic view is that anything is possible until fundamentally proven otherwise. As far as I’m aware, quantum computers would be able to simulate an entire universe in theory. Sorry if my initials comment seemed to disregard the enormity of the problem. I realize we might be decades/centuries before any of this is testable. Not unlike how Newton was compared to our current understanding of physics.
  - krastanov 7y ago
    The parameter regime of interest is monumentally out of reach to experiments. We can already derive things on paper about that regime, and with better computers we would indeed be able to make more complicated calculations about that regime. But to get something useful we also need to "fit" these calculations to observations. We do not have observations not because of a fundamental constraint, rather because it is engineeringly impossible to reach these energy scales with anything we can imagine. So the roadblock is experimental and a quantum computer would not be particularly helpful with it.

knzhou 7y ago

It's important to avoid conflating string theorists with all theoretical physicists. Plenty of people in particle physics either don't believe in string theory or don't think it can make useful predictions any time soon, even if it were assumed true. Furthermore, the vast majority of people called "string theorists" don't even work on traditional string theory day to day, but on more concrete ideas that have been partly inspired by it, such as holography and amplitudes. This needs to be pointed out because there is a huge narrative bias out there. Science popularizers will endlessly frame things like "this whole field has no idea what they're doing, and only I, the brave contrarian outsider, can see through the fraud", even though they're only pointing out things that are already well known in the field. These narratives are completely wrong, but uncritically eaten up by people who think of themselves as contrarians. Despite what the current top comment claims, you're not reading this article about Horgan because he was the first to think string theory would have trouble making predictions. Physicists have made this criticism since the beginning. Feynman pointed it out continually, and Glashow, one of the architects of the Standard Model, tried to bar string theorists from Harvard for the same reason. You're reading Horgan's take, and not Feynman's or Glashow's, because Horgan is popular, and that's because he puts all his energy into expanding his popular reach. Only nonphysicists can do that, because physicists spend the majority of their time doing, well, physics.

Ma8ee 7y ago
String theory has completely dominated the field of theoretical high energy physics for decades. There have been some notable contrarians, e.g., Smolin and Woit with their books. But those haven't changed the fact that it has been very hard to get a faculty position in theoretical hep for decades without being a string theorist. It is only the last few years that has changed. In other words, it's not a biased view that string theory has completely dominated the field for more than 30 years. Btw, the reason we aren't reading Feynman's take is that he died in 1988, not that he's too busy doing physics. He was very successful in doing both high quality physics and expanding his popular reach.
- knzhou 7y ago
  That's just not true. Look at the statistics for hiring faculty in theoretical high energy physics [1]. String theory was never more than half, and usually much less than that. (It is true, though, that for a while they had a near monopoly on pop physics. But that's totally different from physics.) [1] http://www.particle.physics.ucdavis.edu/rumor/doku.php?id=statistics http://www.particle.physics.ucdavis.edu/rumor/doku.php?id=st...

dmix 7y ago

Michio Kaku has long been my least favourite of the celebrity talking head scientists. And he has some good competition for that label. His pop-science books tend to read more like coming from a Hollywood screenwriter than a careful and thoughtful scientific mind.

AprilArcus 7y ago
Remember when he literally sued to block the launch of the Cassini probe?
- scarejunba 7y ago
  For others reading, this appears to be because he believed that in an accident the radio-thermal isotope generator on board Cassini would spread radioactive material all over the place.
  - eth0up 7y ago
    ...all over the place A small, but possible chance of Pu-238 spreading over Florida. I just read that 238 (half-life 87 years) emits mostly alpha, which is said to be easily blocked, even by paper. In FL, many go about half naked, so I'm not sure if this matters. I wonder how thoroughly Kaku considered everything. Seems his concern was based partially on NASA's (small but not null) history of failures. I don't know, but doubt he was being deliberately unreasonable. Maybe his Japanese (distant) ancestry was a factor? Publicity would be a surprising motive. So would general ignorance.
    - yongjik 7y ago
      Actually, alpha emitters are very dangerous when ingested, for the same reason they are readily blocked by paper - your body will absorb all the radiation. This is why Polonium 210 is one of the most toxic material known to us. (Not agreeing with Michio Kaku, by the way.)
    - namarie 7y ago
      > Maybe his Japanese (distant) ancestry was a factor? Why would it be?

ErotemeObelus 7y ago

Maybe physicists should just stop. There has to be a bottom to the barrel and we probably reached it.

beloch 7y ago

"The Nobel prize judges have always been sticklers for experimental proof." One of the big challenges of devising a grand-unifying theory of everything is that, if it doesn't make different predictions than existing theories do in any context, it's experimentally unverifiable. We can hope for a unifying theory that makes everything simpler, but it's far more likely that a theory that deals with all things at once will makes dealing with special cases harder. If such a theory is harder to work with and does not differ from special case theories that are easier to apply, why bother? Of course, a unifying theory probably will differ from existing theories in at least some contexts. They may be extremely high energy, gravity, etc. contexts that are beyond our current technology to test. String theory likely falls into this category. The question is, how much resources should we pour into developing a theory before demanding that its differences with currently accepted theories become testable? Quite frankly, answering this question is above my pay-grade. Scientific history is full of both dead-ends and things that were initially thought to be useless that have since become the foundations of entire fields. How do we know which string theory is? If we cut funding to string theory development, are we cutting off a field that will one day be essential? By continuing to pour funds into string theory, are we funding a dead end and starving several other things that might have been revelations?

JumpCrisscross 7y ago
> if it doesn't make different predictions than existing theories do in any context, it's experimentally unverifiable Given the number of holes in and between our theories, this seems unlikely. And there are still a lot of experiments yielding surprising results in fundamental physics.
SolarNet 7y ago
> One of the big challenges of devising a grand-unifying theory of everything is that, if it doesn't make different predictions than existing theories do in any context, it's experimentally unverifiable. Yea, but then it isn't a unifying theory it's basically just a giant case statement of "if relativistic motion, use relativistic motion equation". That isn't a unifying theory, that's more like a programming library that does everything. A unifying theory would have to allow one to unify all of the existing equations we have as well as synthesize new ones; not just the ones we already have. It probably doesn't exist. It smacks too much of an NP-hard compression problem, where if we have enough output of the function we can find the minimal representation of it, but applied to everything in the universe.

the-pigeon 7y ago

I can't wait until String Theory dies. As a couch scientist it seems to very clearly be a dead end. They keep massaging it to make it fit any new objective discoveries but an accurate theory matches new data, it doesn't need to be forced to fit with it constantly.

Animats 7y ago

This can happen in academia. I went through Stanford CS, finishing in 1985. That was about when it was clear that "expert systems" were not going to lead to Strong AI Real Soon Now, or, indeed, much of anywhere. But many faculty were in deep denial about that. The "AI Winter" followed. There was little progress until machine learning finally took off about two decades later.

perl4ever 7y ago
I still remember reading an article about Doug Lenat and Cyc a long time ago in some pop sci publication and thinking, surely you can't be serious... I don't understand how people ever thought such things could become equivalent to human minds, but I don't think that's my insight, but that others' thinking was blinkered for some reason.
- namarie 7y ago
  Makes you think about what we think today that will be seen likewise by future people.
  - thanatropism 7y ago
    You're being downvoted, but we' re basically drunk on these amazing successes in Computer Vision and apply at least some magical thinking when expecting them to extend to general (e.g. reinforcement learning) domains.
    - Animats 7y ago
      AI is doing a lot better now than in the 1980s. AI back then was groups at MIT, Stanford, and CMU, and a few small groups elsewhere. Almost all the 1980s AI startups went bust. This time, there's enough success that the field is self-funding. Cynically, because mediocre machine learning is good enough for ad targeting.
      - thanatropism 7y ago

fabiosussetto 7y ago

"It would culminate the ancient human quest for knowledge, which began when the first of our ancestors asked, "Why?"" I'm always baffled when I read these kind of quotes, especially coming from such smart people. Do they just forget that our theories are models of reality? I personally believe that there are no wave functions or vibrating membranes out there, as there are no "triangles". These are just names for our mental models on which we map reality the best we can. Fitting models are very useful, but they certainly don't answer the big "Why?" and are doomed to be superseded by more accurate ones, when progress is made. Is it just me thinking this?

dilippkumar 7y ago
> here are no wave functions or vibrating membranes out there, as there are no "triangles". I wish you'd added "There is no spoon" here. Opportunity missed.
- fabiosussetto 7y ago
  Haha, indeed, missed opportunity :)
im3w1l 7y ago
Your perspective is a popular one, but a lot of people also think there is a "true" theory that will perfectly explain how the universe evolves.
- wuliwong 7y ago
  >a lot of people also think there is a "true" theory that will perfectly explain how the universe evolves Doesn't Godel's incompleteness theorems make this doubtful? Logic was not my area of focus but I thought the basic idea was that there is always going to be some un-answerable question(s) or un-provable answers in any consistent theory[1]? I'm pretty sure there is not significant work using non-axiomatic math, I'm honestly not even sure what that looks like. I'd actually be quite interested to find out about some theoretical physics work that did not fall under the auspices of the incompleteness theorem. [1] There are certainly caveats to "theory" but I believe all those caveats are satisfied by any version of String Theory be actively researched.

jsnk 7y ago

Whether you get it right or wrong, I really appreciate people making verifiable predictions about the future publicly. On the other hand, I am less and less interested in post hoc analysis done by journalists and academics judging after the fact, what should've happened.

NotAnEconomist 7y ago

Why aren't TQFTs evidence for string theory? If we know you can build quasiparticles and non-local effects out of braiding/knotting dynamics -- wouldn't the minimal assumption be that other things that can be explained by the same mechanism at a different resolution are? Perhaps I don't understand the distinction between say, string theory and loop quantum gravity.

max_zhou 7y ago

Correct me if I am wrong. i think string theory is searched not just because of its beauty, but also because of existing problems in general relativity. For example, the center of black hole is predicted to be `infinite` in terms of many metrics . But the center is also part of the spacetime, it should bear some measurable values. The answer might require quantum physics since it is microscopic. Therefore, the unifying of general relativity and quantum mechanics is asked for.

sanxiyn 7y ago
Yes, quantum gravity is searched for. String theory is not quantum gravity, it is a specific approach to quantum gravity that has not been very fruitful.
- max_zhou 7y ago
  Ah, thanks for pointing that out!

Mugwort 7y ago

It's very likely a unified theory will win a prize maybe even the Nobel Prize but it isn't going to happen anytime soon. FWIW I'm about as convinced of the truth of string theory as I am of the truth of General Relativity. Sure a better version of M-theory or something else is sure to be discovered but it will be an outgrowth of the current enterprise. The problem is even if we had the correct theory right now it probably would not do us much good at all. It would be a puzzle box we couldn't even open or get answers from it. People underestimated the difficulties involved and the theory was over hyped. Now begins the long "string theory winter". Decades from now, some diehard whose career is foundering will make a significant breakthrough, enough to compel everyone's attention. Until then, there's plenty of interesting physics problems to work on that have been unjustly neglected for too long. Einstein's theory of GR could end up being "wrong" but it would live on as a very good approximation to a more fundamental theory. String theory could very well turn out to be completely wrong but it would fail in a very different manner. If ST is wrong, it's no longer useful. If GR is "wrong" people will still use it. For various reasons which are by no means proof or even evidence I think ST is basically correct but we're simply unable to make proper sense of it. Anyway, we're here at the string theory winter. Careers are ruined, people disappointed etc. That's just how it goes. Sometimes, things work out and sometimes they just don't. We didn't exactly walk away from all of this with ZERO but we're very far from the ultimate PRIZE or GOAL. In hindsight we'll probably look back on this and realize we were hopelessly unable to succeed given the tools and ideas of the day. Expert systems were simply unable to deliver and people were crushed. Careers were ruined. Hopes dashed. Naysayers vindicated then along comes this crazy guy who just won't give up on neural networks. I think the future looks much brighter for unified physics now that string theory as we knew it has clearly failed. I don't want to leave these guys out too so let me add that loop quantum gravity has failed too, much more gracefully I might add. I think these guys were on to something and their ideas aren't going to completely disappear. I've thrown away about 10,000 hours of my life on this stuff. Thanks for spending 3 minutes on my meager insights.

heroHACK17 7y ago

String theory is probably the one scientific topic I spend the most of my free time learning about. It is fascinating. I have read Brian Greene's 'The Hidden Reality' over five times, I think. I recently watched his conversation with Sam Harris and was intrigued by a point Brian made, albeit about quantum mechanics and the 'many worlds' theory. Brian claims that he doesn't think the many worlds theory holds water because it makes an assumption about what happens before some object is measured (A) and after that same object is measured (A'): while many worlds claims that all possibilities are indeed realized, Brian claims that we just don't know for sure what happens between events (A) and (A'); he claims that a unified theory would explain what happens between those events. In any case, that's just me rambling about it. Thanks for the post :)

madhadron 7y ago
Sadly, popular discussions about topics like these are usually not worth spending any time on. There is no shortcut for digging into the math. > while many worlds claims that all possibilities are indeed realized That's...a problematic statement since you have to define "realized" without resorting to any classical concepts. Once you manage to excise the classical concepts you end up with something that is perfectly reasonable. > Brian claims that we just don't know for sure what happens between events (A) and (A'); he claims that a unified theory would explain what happens between those events. I suspect that this was a communications breakdown. It's hard to imagine a quantum physicist today postulating this in the face of the last few decades of experimental and theoretical work on the foundations of quantum mechanics.

m0zg 7y ago

Can it even win a Nobel? I thought the Nobel is not awarded for math, and string theory is just math, with no verifiable real-world side effects or consequences that I'm aware of.

rsj_hn 7y ago
Nobel prizes skew heavily towards experimental physics and theory prizes require experimental verification. That's why Higgs had to wait until 2013 even though absolutely everyone was convinced that a Higgs boson existed for decades before that. Even Einstein didn't win the Nobel for GR, but for the photoelectric effect. Back in the day when high energy physicists kept discovering new particles and there was a short delay between theory and experiment, there were more Nobels awarded to theorists for this, and I think that golden age of grand unification progress created a false impression that theory work is expected to win Nobel prizes just for being good theory work. But if you look at the last dozen or so Nobels, they are all for describing observable phenomena or conducting novel experiments: (lasers, discovering exoplanets, detecting gravity waves, theoretical descriptions of phase transitions of matter, LEDs, mass of the Neutrino, etc.) It would take very convincing experimental confirmation before String theory wins a Nobel, but there are lots of other prizes awarded to string theorists, and Witten even won a Fields medal, which is more prestigious than a Nobel to the math community.
- mhh__ 7y ago
  My history of physics is probably simplified, but I think Einstein got it for (mainly) the photoelectric effect in part because relativity was still (despite having been verified to some extent already) too weird.
  - madhadron 7y ago
    Yes, it was given for the photoelectric effect and other work (which was nudge nudge, wink wink, relativity). Everyone forgets just how much physics Einstein did besides relativity. Brownian motion, for example. Turns out that the photoelectric effect as described by Einstein was possible to get out of classical physics, though, so it took a few more iterations in the later 20th century to really nail that one down again. See 'The Quantum Challenge' by Zajonc.

avip 7y ago

Mandatory string theory introduction for the novice https://xkcd.com/171/ https://xkcd.com/171/

edmqkk 7y ago

the whole time I just kept thinking, "but... when they put up their money in 2002 it was invested right?? The charity got something more like $2880? why aren't they telling us!?"

ttctciyf 7y ago

As a long-time antagonist of Kaku and string theory / supersymmetry, Peter Woit naturally has a blog entry[1] on this that's worth a look. He points out Prof Gordon Kane upped[2] the ante: > By 2020 there will be a Nobel Prize for a string- or unification- or supersymmetry-based theory or explanation or experimental discovery. And goes on to give us some insight into Kaku's current point of view. Spoiler: he thinks string theory will give us the "God Equation" when it reaches its final form! 1: http://www.math.columbia.edu/~woit/wordpress/ http://www.math.columbia.edu/~woit/wordpress/ 2: http://longbets.org/12/#comment-166313625 http://longbets.org/12/#comment-166313625

steelframe 7y ago

> characteristic radiation from black holes and Creation Wait, did the author just refer to the Big Bang as "Creation" with a capital 'C'? Since when did Judeo-Christian mythology (or whatever mythology you think "Creation with a capital 'C'" means in the author's culture, inferring some creative agent in the "beginnings" of the known universe) become relevant in this article's context?

agota 7y ago
I also noticed that.

didibus 7y ago

So is all this about the fact that String Theory just didn't turn out to be practically useful? Or is the theory no longer believer to hold weight given current observations?

sanxiyn 7y ago
It is not about being useful, it is about there being zero experimental evidence for string theory.
- didibus 7y ago
  I'm really a commoner when it comes to physics, so indulge me if I don't make sense. As I gather then, there's been no experiment showing evidence to String Theory, but all experimental result are also not contradicting it and fitting inside its models? If so, I don't really understand how both these thing can be true at the same time. Is it that people criticize String Theory for kinda being too broad, so in a way, it allows too many things to be possible, but that also renders it useless for prediction, because it's not close enough to exactly what happens? Like saying that the weather on any day must be between -100 and 100 celcius. It will be hard to find evidence to the contrary, but it's so broad that it's useless for any valuable predictions?

braindead_in 7y ago

Is there a clear boundary where string theory ends and Standard Model starts?

hoseja 7y ago

This guy really hates the search for grand unified theory, wow. What a miserable fellow.

tim333 7y ago
I don't think he hates it so much as being pessimistic about finding it in a hurry.

kashyapc 7y ago

Two weeks ago I heard a very interesting EconTalk podcast[1] by Sabine Hossenfelder on Physics, Reality, and Lost in Math. Hossenfelder herself is a theoretical physicist, and researches quantum gravity. And a Research Fellow at the Frankfurt Institute for Advanced Studies. She has a refreshing tone and frankness, and I appreciated learning about her work. Quoting the podcast's abstract: "Hossenfelder argues that the latest theories in physics have failed to find empirical confirmation. Particles that were predicted to be discovered by the mathematics have failed to show up. Whether or not there is a multiverse has no observable consequences. Hossenfelder argues that physicists have become overly enamored with the elegance and aesthetics of their theories and that using beauty to evaluate a model is unscientific. The conversation includes a discussion of similar challenges in economics." [1] https://www.econtalk.org/sabine-hossenfelder-on-physics-reality-and-lost-in-math/ https://www.econtalk.org/sabine-hossenfelder-on-physics-real...

virgakwolfw 7y ago

I'm shocked that Kaku even accepted that bet. That's the easiest no ever. Even if you assume that string theory/a unified theory gets completely worked out and a consensus is reached by 2020, the nobel does not give out awards without experimental evidence. Both of those things happening before 2020 was never going to happen.

35787 7y ago

Kaku also incorrectly predicted HEVs.

dkrich 7y ago

Other than for fun and to donate to a good cause, I'm not sure why anyone would ever take the other side of a bet like this or the follow up one for the case of wine. The author is basically betting against an unlikely outcome and the challenger is betting on it, with no adjustment for the likelihood. This would be like offering a bet that a particular college football team won't win a national championship and getting even money that they will. I realize this is outside the scope of the article, but I think it's worth noting because the author gets outsized credit for being correct despite not really offering an alternative. To be fair the author should have had to bet an alternate area that would win a Nobel prize before 2020, otherwise it's a push and each person's stake goes to charity.