Compare the number of articles on string theory and physics beyond the standard model to those on exotic materials, advances in turbulence, orbital mechanics, modern elasticity, solar system formation, or foundations of quantum mechanics. Is it that there is no tradition of popular writing that makes people think that they have any insight beyond the wall of knowledge necessary to understand these fields?
One thousands years from now when humanity is building star-bridges out of beyond-standard-model particles, I guarantee that there will be a Journal of Taychon Engineering whose articles never make it on PBS.
This is still a 'social' network.
Woit's critiques are of string theory as an extension of the Standard Model. But most string theorists are not working on string theory trying to get predictions about current energy frontiers. Rather, they are working on understanding the mathematical structure of string theory and seeing what it can teach us about analogous mathematical structures in quantum field theory. (A now classic example: The first calculable models of 4-dimensional confinement came out of string theory.)
Unfortunately, a fully fleshed out theory with centuries of matching experimental data is still called a theory.
Even in mathematics, there are different definitions of "theory". One is that a theory is a body of knowledge, like set theory or automata theory. This is where I would group string theory as well.
Another definition from mathematical logic is that a theory is a set of axioms and deduction rules. Fascinatingly, those have in common with scientific theories that they can (if sufficiently complex) only ever be falsified, not verified.
For example, (going from memory here, so don't quote me), your basic (Von Neumann's?) formulation of quantum mechanics was basically a generalization of Newtonian physics that specified an unreasonable number of non-real possibilities, and you can only recover meaningful results by taking Newtonian physics as an axiom a la the 'classical limit'. This would have just been mathematical over-complication had it not been for the fact that this model predicted things that differed from Newton physics in measurable ways.
So to reiterate, if your theory is unfalsifiable, it is not impressive that it agrees with every measurement. All you'd have achieved is restating what is already known in a language nobody wants to use.
Doesn't that also mean that (in such a hypothetical situation) our best theory says that our previously best theories will give accurate predictions up until the point at which we observe something equivalent to a galactic-scale collider? If so, that doesn't sound so bad to me.
On the bright side, if there was a single particle that didn't move like a string, string theory would be falsified. On the dim side, it's difficult for anything to not move like a string, because string theory is so powerful as a framework that you can get it to make just about anything consistent. What you really want in physics is a brittle framework that only allows you to slot in a few different behaviors.
It's kind of funny because programmers want the opposite thing that physicists do. When your client asks for a behavior that you have painted yourself into a corner against ever implementing your software has been "falsified," an expensive disaster that you work very hard in advance to prevent! If you made universes for a living, strings would be an ideal framework.
(I sure hope that's not wrong.)
I think most physicists probably have a reasonable intuitive idea what a diffeomorphism is, since most have probably learned something about relativity.
Well I have, and even though I'm not too keen on superstring theory I just couldn't dismiss it like this. It makes sense, it's important and it's a possibility worthy enough to be explored. Will people here just try to understand that they're talking about another profession with a really high skill access barrier that takes many years of hard work to become just acquainted with? Can we please just admit that if we don't know what we're talking about, we really don't know what we're talking about?
Poster you're replying to admits they're a layman. As am I.
Perhaps the people writing articles for the laymen should do a better job explaining the redeeming aspects of String Theory. Because like the OP, I too have been left with the impression (from reading articles targeting laymen) that String Theory is clever math in search of a reality it can describe.
So for example from the current thread:
(someone with training in the field): "It makes sense, it's important and it's a possibility worthy enough to be explored."
(admittedly uninformed person): "As a layman from a distance, [...] it's total garbage."
Is there any nearer term benefit that may come out of string theory ? I am honestly curious. Somehow I find it hard to believe that so many very intelligent people are chasing something misguided.
That said, we're not devoting the kind of resources to string theory that we devote to engineering ready problems. Probably somewhere in the ballpark of $10M/year worldwide funding provided by various governments, with a similar amount provided by private donors. This is rounding error. In the US, we spend about 10x this on the National Endowment for the Arts.
You can make an argument that all money spent on extensions of the Standard Model (and there are a lot of them besides string theory) has been wasted. But string theory at least has taught us far more about the structure of the mathematical models we use to describe physics than any of its competitors. This is why people continue to study it, even in the absence of experimental confirmation.
I know everybody has an opinion about everything under the Sun, me having an opinion about theirs is only natural. I'm just pointing out the fact that laypersons feel increasingly entitled to dismiss not only the professional work of experts, but whole bodies of knowledge available to them but that they can't be bothered to study. As I don't know whether the professional fields of these people allow for winging it, I'm assuming that maybe they think that you can do that in physics. Well you can't, so if you have a problem with some physical theory the proper way is to engage like everybody else, not trying to kill whatever you don't like because how it sounds from the proudest and laziest outside.
This new sense of entitlement from the opinionated laypersons is actually an antiscience stand, this is what gets you anti-vaxxers and shuts down funding of honest research.
The theories are all falsifiable in that they make lots of testable predictions.
The problem is that there is a family of related theories which all produce the same testable predictions at energies we can probe and there’s no way to use an experiment to rule any of them out.
Currently the theory "predicts" around 10^500 vacuum models, all of which have different properties.
That's quite a large number, and makes specific predictions rather difficult.
There was a vague hope that maybe something stringy would fall out of the LHC. That didn't happen. There's now an even more vague hope that it might fall out of Son Of LHC instead.
Outsiders might wonder if this is really just throwing string at the wall and hoping some of it sticks.
It hasn't yet, but it's always possible it might.
Isn't that part of it? Smash particles together at increasingly higher energies, see what happens. I don't think we can pretend to predict everything that will happen.