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.
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.
It's kind of cute how some people now are trying to rewrite history when it is more and more obvious that it was a dead end.
I would not say 'all', but this bet fits the claim. If he had lost, his position as a prescient naysayer would be gone anyway, while a win could be used to boost it, even though, as it happens, no decisive case against string theory (or for an alternative) has emerged in the interim. In a sense, this bet is a columnist's hedge against there being no news.
For any counterparty, however, a win would have been completely overshadowed by the science itself. A person might be happy to accept the bet as a form of harmless entertainment, but for Horgan, it was more than that.
But for someone focused on mathematics, string theory, quantum loop gravity (if that is what it's called) and all the others become tools and objects of study on their own that have a unique perspective to offer in their own right. Whether you study one or the other then becomes a personality inspired preference. Just because I don't study number theory, doesn't by default scorn the field (or perhaps I just can't do number theory).
In any case, ideally the framework should touch on geometry eventually as well, but I am not aware of concrete ways to do it. Toposes are considered geometric, but I don't know whether geometric in the sense of GR. The eventual or at least, hopeful, end point is something like  where your mathematical framework should ideally in the language of categorical or functorial duality express physical dualities. I don't know how to get to GR, as I say, and should read maybe this  but there are many ways to get to QM. One example is through entropy: the generalised abstract set subobjects are partitions and partitions encode entropy through "distinctions", i.e, elements in separate equivalence classes of the partition. The category of sets itself is a model for QM theories via it's inspiration for (symmetric) monoidal categories so perhaps one would want to express in the self-dual language that as well. It's one thing to point to multiple uses of category theory in physics, but it is another to keep track of it in your personal, internal intuition strategy.
Pure theoretical physicist might be in a comparable budget, but I think it is true that the lower expectations on math research is partly due to how cheap it is to fund.
You can go one step further. If you regard string theory as an attempt to answer questions about quantum gravity, then this criticism applies to the whole question, not just to any particular school of thought about answering it. This was known since approximately the time when physicists first had access to Planck's constant, Newton's constant, and a spare envelope to write on.
But, as you say, this is far from all that people who get called string theorists work on. A great pile of mathematical tools have been developed, to the point where deliberate ignorance of all of them would be a very strange position. Not for all fields of theory, obviously, but for quite a few.
For example, for QGP, holography can paint a nice picture, but we don't know a holographic dual for Nc=3 QCD.
EDIT: yup, I am not knowledgable enough to be in this conversation.
A hypothesis is ideally 'atomic': it's making a single assertion that should be falsifiable by experiment.
A theory provides a specific way of modeling the elements of some field of study, and how those elements interact with one another.
It should be structured in such a way that it can describe the components of any experiment that might be set up to confirm/reject a hypothesis in this field.
And once an experiment is described in the terms of some theory, the theory should provide a systematic way of calculating what the result of the experiment should be.
That's where the connection between hypotheses and theory comes in: actually conducting experiments assigns either Acceptance or Rejection to a set of hypothesis; ideally, the theory assigns the same Accept/Reject values to the same hypotheses in its predictions (this is probably never 100% the case in practice though—esp. not in an active field of study).
The structure of String Theory is much closer to theory than hypothesis. (It may have limitations in how much it models physical 'experiments,' but it's at least much more of a 'system description' than an atomic assertion.)
Whether in science or police work, etc. a theory is a holistic framework, while a hypothesis is truth-valued.
We should also complicate this idea that something can be 100% proven, but baby steps.
From the view of a philosopher of science string theory isn’t even a
hypothesis as a hypothesis needs to be testable
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.
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.
Credit to Glashow, and apologies for forgetting him, but Horgan deserves his victory lap.
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.
They were encouraged to do things like condensed matter physics, not trying to find some alternative to string theory.
I often wish Feynman (or anyone of his kind really) was still here. Science nowadays seems more and more like one big appeal to authority...
When I was in physics in the early 2000's, the general feeling was that it's a probably nonsense, but having someone out at the far end of the mathematical spectrum like that in your theory group was a good investment. And even if they were doing string theory, there's a good chance they were using it as a vehicle, a kind of generalized, more flexible version of field theory, to poke at some mathematical rabbit hole.
The majority of physicists are not in HEP. The majority of HEP physicists are experimentalists. The majority of HEP theorists are phenomenologists. But phenomenologists aren't generally good fodder for science journalists because statements like, "I'm calculating scattering cross sections in the kaon sector for CP violation measurements" isn't going to get clicks. And the experimentalists are even worse: "I've been working eight hour night shifts for the past two years. I'll probably go back to my home university and spend another couple years processing data to get an estimate for this parameter in this scattering calculation. It might be a fraction of a percent off what we expected!" Faced with that, "I'm playing with a high dimensional extension of quantum field theory to see if I can generate a spin 2 field in an expanding spacetime" sounds really sexy.
I think what I’m objecting to is that as the discoveries within physics become less and less impactful, the “field” seems to turn more and more inwards. Also, egos seem to expand approximately proportionally to the inverse of the utility of their work...
I don't understand why that deserves kudos. I would very much prefer top scientists to listen to people who know what they're talking about, instead of paying heed to the less informed on the off chance their wild speculation bears fruit.
I will only accept the correct answer from people I choose. Experts in the field should provide the most insight overtime but don't ignore non-experts. That's foolish and limiting.
It preposterous to think that all the physicists were on board with string theory. Do you really think the experts in the field didn’t have doubts and it took an non physicist to work it out?
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.
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?
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.
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.
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.
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.
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.
Who's connotation? I think that's a very myopic take on lying. Insofar as people care for others, people frequently lie to benefit those they care about. Some people believe the truth is more important than sparing the feelings of somebody you care about, and that's totally fine. But that point of view is not universal to humans and many people believe lying for the benefit of others to be reasonable or even obligatory.
I won't bore you with examples of such lies; I think you can probably imagine a few. Some are trivial, and others far more substantial. Whether or not those lies are justifiable under your personal system of ethics (or my own) is beyond the point; the point is that to some people those lies are justifiable and for those people, lying is motivated by a desire to benefit others.
The book Sapiens covers this well, that you cannot escape the prison of a myth without being contained by one larger.
If one takes “myth” to mean something that is itself believed without being falsifiable, it is true by necessity of any belief system with any content beyond statements about the subjective experience of the believer
I have a copy of Kaku's Quantum Field Theory book on my shelf, but no Chopra (thank god)
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.
(Not agreeing with Michio Kaku, by the way.)
Why would it be?
Certainly there are some people in/from Japan who are enthusiastic about the future of nuclear energy. But I think it's fair and reasonable to say that cultural trends exist and a randomly chosen person with a personal connection to Japan is more likely to be critical of nuclear energy than a randomly chosen person from the rest of the general population.
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?
> 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?
Some people have a relationship with "science" that bears a strong resemblance relationship some other people have with various religions and/or religious concepts. I get a strong vibe of that from the quote you cited.
> Is it just me thinking this?
No, it isn't. I agree and generally think of science is basically a kind tool-making activity. Mathematical wrenches, so to speak.
This is historical nonsense. There's an interesting book called Curiosity by Philip Ball that looks at the history of curiosity going from being a vice to being an epistemic virtue.
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? 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.
 There are certainly caveats to "theory" but I believe all those caveats are satisfied by any version of String Theory be actively researched.
I'm not so sure about this. It reminds me of the quote "If our brains were simple enough for us to understand them, we'd be so simple that we couldn't".
I asked multiple questions, I'm not sure which one you are responding to.
If you don't understand what the incompleteness theorems say, be wary of citing them.
There will - let there be no doubt - be a final theory of physics (Humanity will end at some point), but determining whether that theory is truly "perfect" is probably impossible within the bounds of measurements known to us at the moment.
I wish you'd added "There is no spoon" here. Opportunity missed.
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."
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.
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.
This time, there's enough success that the field is self-funding. Cynically, because mediocre machine learning is good enough for ad targeting.
I’m bearish on reinforcement learning right now. Is there good stuff happening in a comparable front? (Will a blocks world solver ever play Super Mario?)
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?
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.
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.
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.
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.
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?
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.
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, utilizing natural accelerators. There's a technical talk about their results here. The first part explains the system in more detail.
He points out Prof Gordon Kane upped 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!
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 :)
> 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.
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?
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?
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.
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.
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.
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.
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.