An angry rant on the subject of superstring theory

[Flameblade]

Source.

Superstring theory is hot with scientists trying to understand the entire nature of the universe (as opposed to, say, inventing a way to block cellphone reception in cinemas). The idea is that all the particles and forces in the universe are different notes on appallingly tiny strings. A key tenet of this theory is that there are at least ten dimensions, that’s six more than the four we can access, but that the others can’t be measured or in any way observed because they’re too small. Seriously, that’s the entire argument. And an invisible and untouchable dog ate their homework. Also, the dog cannot be smelled.

One of the main arguments in favor of string theory is that it correctly predicts the existence of the graviton; this would be the graviton that nobody has ever actually detected, by the way. The graviton we only “know” about at all because another theory (Quantum Field Theory) says it exists. Oh, but that theory stops working if you actually try to use the gravitons in it. It’s like saying elves have to exist otherwise there’d be nobody to make toys for Santa.

The problem is that gravitons are points, and as soon as you bring the field theory down to a point the probabilites of something or other become infinite. Since it’s only actually possible for something to be 100% probable, you don’t have to be a mathematician to understand that an answer of 101% is probably wrong, 200% is definitely wrong, and infinity-% is indescribably moon-bendingly wrong.

Superstring theory solves this by saying that gravitons aren’t points; they (and everything else) are little strings around those points, so you never get there. That’s right. The geniuses, the guys who would have been rocket scientists a couple of generations ago, the frontline in humanities quest for cosmic knowledge solved a problem in the theory by drawing a little string circle around the point and saying “Don’t go here or our stuff breaks”. Good thing they weren’t rocket scientists or we’d have star charts marked “Don’t go this way because planes stop working”.

After that the evidence gets even weaker, as if that was possible. Some starry-eyed scholars who may have spent a little too much time indoors point to the inherent symmetry and beauty of the mathematics, and how it fits in with the other graceful theories that describe the universe. I have two things to say:

1) Anybody who thinks mathematics is pure art and elegance simply hasn’t done enough integration.

2) The concept that all particles and forces are made up of different notes on the same string all throughout the grand totality is very nice, but given the choice on how to arrive at it, I’ll choose a joint and a bean bag over ten years of fiendishly difficult mathematics.

Of course the real support for superstring theory is that it would be really nice if it was true. Alas, the same factor has not given my “Lots of hot cheerleaders doing my bidding” theory the same financial and public support. But when you can’t provide a shred of evidence for your belief system (other than the fact you like it better than the alternatives), and certain parts of that system actually refuse the idea of being experimentally tested - well, there’s only one thing to say:

Welcome to the Church of Superstring.

[Darth Wong]

Is that supposed to be interesting for some reason? Superstring is a fringe theory and will remain one until there is some particular reason to believe that it is necessary. Nobody would even know about it if not for the fact that self-described "science geeks" (most of whom comically have no more than a high-school science education in my experience) love to talk about it, as well as many other things they don't really understand. Having said that, there's nothing in that article which refutes it. It's still one of those "might be true, might be bullshit, nobody cares at this point" fringe theories.

[Starglider]

That is a worthless critique. Yes superstring theory has been overhyped, mostly by people who just can't wait for science to actually reach a 'theory of everything' and like to pretend we're closer than we are (though we've come a hell of a long way). It's true that a few attention-seeking scientists are guilty of helping that along.

However this critique has been 'dumbed down' so much it says nothing useful about the theories themselves, and worse it comes off as dismissing theorising as entirely useless. It isn't of course, because coming up with a good set of detailed hypotheses is essential to maximising the utility (i.e. discriminatory power) of upcoming experiments. We're long past the point where you can just go down to the lab from a position of complete ignorance, measure random properties of some physical processes that look interesting, and expect to discover a new physical law by trying some simple algebra on the results.

[drachefly]

It would help if he actually portrayed string theory accurately.

I'm not attached to it. I don't even think it's particularly cool. Just, don't say it's wrong for reasons that don't apply to it.

[SirNitram]

Wasn't superstring passed by a little while ago, into M-theory? Most appropriately named theory in fringe. M is either for Membrane or Magic.

But yea. That's just a whine. Why do we care?

[Surlethe]

As I understand it, string theory is more an esoteric branch of math than anything else. It occupies that same place Riemannian geometry did a century and a half ago, but depending on whether or not the theory pans out, it might just stay math.

[Fingolfin_Noldor]

It would help if he actually portrayed string theory accurately.

I'm not attached to it. I don't even think it's particularly cool. Just, don't say it's wrong for reasons that don't apply to it.

Well, a long while ago, there was quite a publicity campaign for it, and I think back then some thought it cool to do String Theory.

These days though, most professors I have met advice against going into that field as it is quite a dead end as it is.

[Flameblade]

The main reason why I'd posted this here is because I deal with a lot New-Age types, who try to default to string theory or quantum mechanics to explain their delusions, and I had wondered if this was a simple, yet accurate bit of information to start disabusing them of that.

Granted, I probably should have said something about that in the initial post...

That'll teach me to post at 4:00 am.

[Darth Wong]

The main reason why I'd posted this here is because I deal with a lot New-Age types, who try to default to string theory or quantum mechanics to explain their delusions, and I had wondered if this was a simple, yet accurate bit of information to start disabusing them of that.

Simple rebuttal to all New Age quantum theory/string theory bullshit: "As long as you're explaining quantum theory to me, could you show me the calculations you used in order to arrive at your conclusions? I know some people who are into this sort of thing and I'd like to show your calculations to them. Oops, you don't have any calculations? Just how much quantum mechanics do you know, anyway?"

[Eris]

There was a book published recently, The Trouble With Physics written by Lee Smolin, whose main point is a critique of the string theory mentality that has taken over a lot of modern cutting edge physics.

From what I understand - I only skimmed bits of the book at the store - he takes issue with the amount of money and effort that goes towards developing string theory on the grounds that it's elegant of beautiful, instead of actual work that's backed by evidence, and further brings up some troubling cases for string theory such as the existence of dark matter to back up his point. He lays into it as a conjecture without the support or completeness needed to be a theory yet, and argues the the physics community is being harmed by how much its gripped the public and scientific imagination.

In a vaguely related theme, I've heard that the LHC coming online will help either confirm or deny some of the claims of string theory. Does anyone know if this is true?

[Starglider]

he takes issue with the amount of money and effort that goes towards developing string theory on the grounds that it's elegant of beautiful, instead of actual work that's backed by evidence

Bloody mathematicians, insinuating their way into other fields and trying to make them more like the pure maths they know and love. We have this problem a lot in computer science. Can't live with them, can't live without them.

[drachefly]

I had a colloquium on this subject yesterday, so this information is up-to-date.

Wasn't superstring passed by a little while ago, into M-theory? Most appropriately named theory in fringe. M is either for Membrane or Magic.

Membrane. M-theory isn't 'passing' string theory in that it replaces it; it's just another variant. A somewhat more complex variant.

In a vaguely related theme, I've heard that the LHC coming online will help either confirm or deny some of the claims of string theory. Does anyone know if this is true?

The LHC should find or rule out a class of events which are consistent with supersymmetry. String theories are a subset of the supersymmetric theories. So, if the LHC does not find events consistent with supersymmetry, string theories are in deep trouble.

If it does find supersymmetric-compatible events, then the fun begins... because there are other non super-symmetric theories which predict similar-looking events, and sorting out the difference is going to be a major technical challenge.

That determination might have to wait for the 100km long electron-positron linear collider that's on the drawing boards.
This is because electron-positron collision is about the cleanest collision particle physics has to offer: the only thing you start with is energy and two half-quanta of angular momentum.

Colliding protons, like the LHC, has been reasonably accurately described as throwing garbage cans at each other.
If you want to see if an effect exists, a proton collider will help since you can get high energy and collision rates relatively easily. Good for scanning large ranges of energies for something when you aren't exactly sure what it is. Which, at this point, is exactly what we're doing.

[Starglider]

Colliding protons, like the LHC, has been reasonably accurately described as throwing garbage cans at each other.

In that case what's your metaphor for colliding heavy ions? Two garbage trucks hitting each other head-on at 100mph?

But collision energy on the LHC is 1,150 TeV for lead ions as opposed to 14 TeV for proton-proton, which is presumably useful otherwise the capability wouldn't have been added.

[SirNitram]

Wasn't superstring passed by a little while ago, into M-theory? Most appropriately named theory in fringe. M is either for Membrane or Magic.

Membrane. M-theory isn't 'passing' string theory in that it replaces it; it's just another variant. A somewhat more complex variant.

I was intending to illustrate the general place M-Theory occupies: M technically stands for Membrane, but it might as well be for Magic; it's so fringe we can't take observations at all. It's solved alot of interesting equations, though.

[drachefly]

Colliding protons, like the LHC, has been reasonably accurately described as throwing garbage cans at each other.

In that case what's your metaphor for colliding heavy ions? Two garbage trucks hitting each other head-on at 100mph? :)

Sounds about right, except substitute 'at a gamma of 100' for 100 mph. As in, 99% of their energy is kinetic, not rest mass.

But collision energy on the LHC is 1,150 TeV for lead ions as opposed to 14 TeV for proton-proton, which is presumably useful otherwise the capability wouldn't have been added.

I'm not sure how much it cost to enable the LHC to throw ions around. Protons are generally slipperier. All I can think of that permitting ions would require is not hard-coding in certain timing instructions, and of course a source of ions.


SirNitram, I looked it up and found that we were both right.
Membrane is what people consider it to mean more seriously, but the originator never specified, so other possibilities are equally valid; and 'magic' is a very popular alternative.


Also, to nitpick myself, not all string theories are supersymmetric, though the nonsupersymmetric variant (the original) couldn't represent reality, since it only contains bosons.

[Eris]

In a vaguely related theme, I've heard that the LHC coming online will help either confirm or deny some of the claims of string theory. Does anyone know if this is true?

The LHC should find or rule out a class of events which are consistent with supersymmetry. String theories are a subset of the supersymmetric theories. So, if the LHC does not find events consistent with supersymmetry, string theories are in deep trouble.

If it does find supersymmetric-compatible events, then the fun begins... because there are other non super-symmetric theories which predict similar-looking events, and sorting out the difference is going to be a major technical challenge.

An excuse to build an even bigger particle accelerator! It gives me the giggles just thinking about it. Let's just admit it; half of the reason we built it was to further science, and the other half is that the very notion of playing skeeball with protons is just so wicked awesome.

Bloody mathematicians, insinuating their way into other fields and trying to make them more like the pure maths they know and love. We have this problem a lot in computer science. Can't live with them, can't live without them. Wink

*nods sagely* In this day and age, pure mathematics are in greater and greater danger of being applied.

We in chemistry are thusfar more fortunate. Unlike you poor sods, we don't need to understand number theory to do our work. I'm convinced it's only a matter of time, though. Any day now I'll walk into organic lab and they'll inform me that my 1-ethyl-2,4-methylcyclohexane is now only able to be characterised by complex values generated via a system of linear equations...

[drachefly]

the other half is that the very notion of playing skeeball with protons is just so wicked awesome.

The inner hoop of that skeeball range better be pretty narrow; the engineers say they'll be able to focus the electron and positron beams down to a beam width of one nanometer. Unless it gets smaller than that, you're going to be handing out a lot of free game tokens.