/sci/ - Science & Math

[Anonymous No.11004494]

I hate string theory and string theorists so goddamn much.

Can someone post things wrong with it so I can know how to tear it apart when I see it?

[Anonymous No.11004503]

>>11004494
it's theoretical, it's the mathematician's version of a girlfriend, which is also theoretical.

[Anonymous No.11004544]

>give me talking points

You'll make a wonderful politician OP

[Anonymous No.11004546]

>>11004503
String Theory is the physicists' Canadian Girlfriend?

[Anonymous No.11004635]

>>11004494
Well, supersymmetry has pretty much been backed into a corner experimentally. SUSY fans would disagree and say it's still very feasible, but there's no doubt that the nicest candidate theories have been ruled out, and the supersymmetric partners that the LHC was 'almost certain' to reveal didn't show up.

[Anonymous No.11006082]

>>11004494
bump

[Anonymous No.11006090]

>>11004635
OP said string theory. SUSY is only necessary for m-theory.

[Anonymous No.11006099]

>>11004635
So the only thing we can say now is that SUSY wasn't discovered at an extremely early stage of the experiment - which many people have hoped for but this possibility has never been supported by anything else than a wishful thinking. Whether the LHC may see SUSY may remain an open question for several years - unless the LHC will see it much sooner than that. It's an experiment that may continue to 2020 and beyond.

I think that in the case of no SUSY at the LHC, the LHC will remain some distance away from "completely disproving" SUSY particles as the source of dark matter because this role may work up to 10 TeV masses or so, and much of this interval will remain inaccessible to the LHC.

[Anonymous No.11006105]

>>11006090
SUSY is a natural - and mostly inevitable - consequence of string theory

[Anonymous No.11006162]

>>11004494
String theory is one of the most beautiful fields of mathematics of the past century anon. Why do you hate it?

[Anonymous No.11006205]

>>11004635
>Well, supersymmetry has pretty much been backed into a corner experimentally.

Nope, plenty of space between LHC and Planck energy for SUSY to hide.

[Anonymous No.11006207]

>>11004494
>Can someone post things wrong with it so I can know how to tear it apart when I see it?

You are not qualified to even have an opinion on the matter.

[Anonymous No.11006555]

>>11004494
>Hates something
>Yet doesn't understand it
The fuck?

[Anonymous No.11007054]

bump

[Anonymous No.11007061]

>>11006090
wrong, superstring theory is what is needed to describe fermions. without susy (the “super” in superstring) there would be only bosons in string theory, no electrons or quarks or neutrinos or etc

[Anonymous No.11007063]

>>11004494
*adds dimensions arbitrarily until it works*

[Anonymous No.11007079]

>>11004494
the best criticism of string theory imho, is that it’s too speculative and has too much wiggle room to be compatible with anything that could conceivably falsify it. theories need to be predictive and only by a “miracle” could we observe something stringy observationally. no chance experimentally, with our current understanding. such a “miracle” would need to be something like LIGO seeing gravitational waves characteristic of a cosmic string...

however math bozos like yukari TQFT anon have a point
>>11006162
it is a wonderfully beautiful theory mathematically. but so was Vortex Theory back in the late 1800s. so meh. and if you really want to argue with someone like that, just point out that it can’t generate the de Sitter universe we see, so far as we know, without endowing it with horridly ugly crap like dubious KKLT or other ugly nonsense like quintessence

[Anonymous No.11007101]

>>11007079
cosmic strings are different than the strings from string theory

[Anonymous No.11007104]

>>11004494
If you don't understand it well enough to 'tear it apart' without help, then how do you even know enough about it to have a legitimate reason to hate it?

[Anonymous No.11007113]

>>11007101
not really, string theorists think they are another plausible prediction of string theory. gimme one minute to find the youtube video where David Gross says this....

[Anonymous No.11007134]

>>11007113
here
https://youtu.be/beQ9fZ0jVdE
big brain stringmeister Gross says it at ~11:50

[Anonymous No.11007141]

>>11007134
>mfw Rob Laughlin is still alive
Also thanks for the ASMR video

[Anonymous No.11007143]

>>11007063
>adds [____] until it works
That's the same problem people have with dark matter. Ad-hoc hypothesis is really starting to tear apart public faith in science.

[Anonymous No.11007144]

>>11007134
but maybe the context is better if you start at 10:00

[Anonymous No.11007148]

>>11007104
The people promoting it are dicks and don't make any sense when they talk

[Anonymous No.11007150]

>>11007143
as if the public knew what adhoc is

it is tearing apart the scientific faith on science

[Anonymous No.11007159]

>>11007141
>calls Robert Laughlin “Rob” instead of “Bob”
nice try 1st year

[Anonymous No.11007240]

>>11007113
>>11007134
yeah but there's plenty of other models that admit string-like solutions. Axion strings are a thing, and they're understood in the sense that the axion is an extension of the standard model. No string theory involved.

[Anonymous No.11007245]

>>11004494
How about you read a book OP or research for yourself. God forbid you actually have to think for yourself.

[Anonymous No.11007247]

>>11007240
well then take it up with Dr. Gross. i’m sure if LIGO detects a cosmic string then string theorists will basically use it to reload their clips. and rightfully so, since it would be their first empirical “success”

it’s not going to happen though, come on. total wishful theorist thinking. even cosmologists don’t take that seriously

[Anonymous No.11007248]

>>11004494
it's a gay theory made by gay people. lel gay
also NOT MATH OR SCIENCE

[Anonymous No.11007253]

>>11004494
The problems are well known, you just hate it because you're not smart enough to understand the basics and people needlessly hold it as the bar of intelligence forcing you to face your inconsistencies between your beliefs and reality.

[Anonymous No.11007261]

>>11007248
>ed witten and his wife and kids pity you

[Anonymous No.11007262]

>>11007247
The reason nobody thinks we'll detect axion cosmic strings with LIGO is because the expectation is that they've radiated away their energy into light axions already. The only ones that have a chance of being observed still are the infinitely long ones - these cannot radiate away. Cosmologists don't believe such a thing will be found because the axion field solution associated with a string of this sort has a very large tension, and would have already been found in CMB data.

There may be reason to think the tension actually isn't very large but rather small due to quantum corrections. This is all speculative though. If a gravitational wave came from cosmic string collisions, the signal profile is going to be model dependent, so we should be able to verify if they are fundamental strings or just topological solitons.

[Anonymous No.11007274]

>>11007262
good post. interesting stuff. is there a GUT or BSM theory you think is a good candidate for describing these expectations (particle physics-wise)?

my assumption is that you may be very right, in whatever theory(theories) you are considering, but at the same time, since string theory is incredibly flexible in fitting any observation, any cosmic string observation would equally or even better be touted as a triumph of string theory. and i’m not trying to support ST but rather point out how predictively ambiguous it is

[Anonymous No.11007315]

>>11007274
I believe you when you say the string theorists would try to co-opt any such discovery. I don't think they'll be very successful. I only bring up axions as a candidate because I'm overly familiar with them, but to me it seems they're a very popular candidate for dark matter. Any string theory resurgence will be absolutely drowned out by the dark matter phenomenology community trying to fit their models to the discovery. String theory's flexibility is actually dangerous here: they would risk a lot by claiming these things to be fundamental strings when they're incapable of predicting their exact behavior. The pheno community can make very sharp predictions in the axion case though, so their claim would have much stronger evidence.
That's just my 2 cents on this hypothetical matter...

> is there a GUT or BSM theory you think is a good candidate for describing these expectations (particle physics-wise)?
I'm not sure what you mean. There's many version of the axion that can be used to amend the standard model. The most "natural" one is the QCD axion, but there are others that have nothing to do with QCD (for example, ones that exist in a sector weakly mixed with electromagnetism. In this model, the axion can actually turn into photons and vise-versa in strong magnetic fields. Some people have argued this explains fast radio bursts).

[Anonymous No.11007326]

>>11004635
that's the thing. SUSY was sooo hyped and now it's like a desert.

I think the biggest "discovery" of the last few decades will be the LHC not finding evidence of SUSY.

[Anonymous No.11007345]

>>11007315
well, i can’t argue with much besides the QCD axions. at the LHC there is not much that can be done to rule out e.g. Peccei-Quinn axions. that’s why there are some bizarre “telescope”-like experiments designed for them. so basically it is good that axion theories are more falsifiable, but the problem arises when and if they get falsified.

OTOH string theory is permanently immune to falsification but at the same time can claim credit for any real observation

it’s a very weird scenario but i am much more interested in PQ axions than stringy folks. but the stringy folks won’t and can’t be killed.

the only real way forward is to find evidence of something that works. and then get, say, 3 confirmations of that experimentally. then, even if strings hills can say “oh we can explain that too”, only then will people start to move past the string meme

[Anonymous No.11007351]

>>11007345
*string shills
not string hills

[Anonymous No.11007458]

>>11004494
String theory is the truth. You can bitch about it all you want, it won't change the truth.

[Anonymous No.11007652]

>>11006090
m-theory is string theory.

[Anonymous No.11007681]

>>11007652
true. but there used to be a few different versions of string theory until based ed unified them

[A Question for Yukarianon but (...) No.11008798]

So what fields of mathematics do I have to study to understand String theory/M-theory?

[Anonymous No.11008830]

>>11007079
>it is a wonderfully beautiful theory mathematically. but so was Vortex Theory back in the late 1800s

Nah, string theory is much more elegant, deep and beautiful mathematically than Vortex theory. Regardless of it's reality.

[Anonymous No.11008833]

>>11007148
>The people promoting it are dicks
not an argument
> and don't make any sense when they talk
you are not knowledgeable enough to know who is making sense and who isn't when it comes to high energy physics

[Anonymous No.11009112]

>>11007104
That's why I hate it DESU. I tried reading Wittens book and other sources but I don't understand the logic behind what they are trying to do while they vomit a bunch of math out in seemingly random directions, and then when I get frustrated and try to ask string theorists what is actually going on they either immediately jump into minute technical details or say "you don't understand it, read more."

It feels like gaslighting desu. I'll keep an open mind in case I run into someone or a book that can finally explain it in a way that makes me appreciate it more, but so far that hasn't happened, and not for lack of trying.

I might just be too brainlet but I'd much rather be an honest brainlet and say "this makes no sense to me" than be shamed into pretending to understand something I really don't or end up a defensive dickhead because I sunk 5+ years into studying this.

[Anonymous No.11009197]

>>11004494
It is pretty bad because it disagrees with observational evidence and they keep modifying it in ways to make it work theoretically but no knew knowledge has been gained in the past 20 years. It seems to only make some sense in 5+ dimensional space which leads to many worlds and other such nonsense theories.

The main problem is that everyone engaged with it seems to think that math and logic have some sort of transcendental qualities that they would be true in all possible universes/outside of the observable universe. That is the most retarded leap of faith for any scientist.

[Anonymous No.11009249]

>>11008798
Of course you'll have to know the physics first, starting with Baez and Polchinsky.
Assuming you know the basics (classical alg. top. and alg. geo.), it'd be good to know about CFTs, SUSY, HYMs, symplectic geo. of hyperkahlers, modern alg. geo (mainly over [math]\mathbb{C}P^n[/math]), and a bit of arith. geo. Also read aout homological mirror symmetry since that's where string theory is most useful.
I'm sure I've missed some stuff since my area of expertise isn't on string theory. Others can fill in the blanks.

[Anonymous No.11009265]

>>11009197
What alternative do you suggest?

[Anonymous No.11009285]

>>11007061
Superstring theory isn't strong theory

>>11007652
Wrong. m-theory contains string theory as an approximation.

Wow you fags act like you know it all and actually know jack shit. Embarrassing.

[Anonymous No.11011222]

Legitimate string theorist here. AMA (physics related)

[Anonymous No.11011271]

>>11006555
that's how it works, stupid but true

[Anonymous No.11011309]

>>11011222
Are you a believer in string theory? Why?

[Anonymous No.11012163]

>>11011222
Is it a good refutation of materialism? Is up to 11 dimensions what we are talking about afterall. Considering the Strings create the matter through the energy and vibration they produce, all because of a Fundamental unseen Force.

[Anonymous No.11012732]

>>11011222
how does morse theory matter in ST?

[Anonymous No.11012978]

>>11004635
String theory only requires worldsheet SUSY, and spacetime SUSY in certain backgrounds only. We could be in a background with no SUSY and would only see her effects at the Planck scale.
>>11007061
Only worldsheet SUSY is needed to get spacetime fermions, just like how the worldline theory of a fermionic particle is supersymmetric.

[Anonymous No.11013037]

BTW, is Cumrun plopping down all these papers because he's about to drop a real bombshell? it seems like this latest ~200 page paper is just some classification of CFTs, which i doubt could be the "main point" of all his stuff lately

[Anonymous No.11013044]

>>11007079
Eh, to be fair to vortex theory, it was actually a useful idea that sort of came back in condensed matter physics in which vortecies do show up and are connected with quasi particles. The real issue was the belief in the aether, so in some sense the beautiful part of the theory has remained, but the incorrect part was replaced by the more beautiful special relativity. That's the thing about peoples' claims about beauty has led physicists astray in the past, because usually the theories were replaced by something even more beautiful, or aspects of that beauty remained and the issue was some other assumption.
>>11007113
It's also really worth mentioning that despite the fact that people have studied string theory for decades it is still a somewhat immature field in that there' s a whole lot of basic questions that have yet to be answered. Part of that is the fact that the mathematical questions one has to grasp with to make progress are at the forefront of mathematics, so it's not easy to just plow ahead.

[Anonymous No.11013047]

>>11004494
OP is a string theorist, this is bait. He knows there is nothing wrong with it and just wants to read some experimentalist non-falsifiable Woit-Hossenfelder lost-in-math bullshit for lulz.

[Anonymous No.11013051]

>>11006162
>appeal to beauty in science

go back to comment sections of the NDG episodes of JRE

[Anonymous No.11013058]

>>11013047
here is a classic string theory lulz if that's what you're looking for:
https://youtu.be/k7EnQd-VGqU

unzicker is like the all-out pseud version of woit/hosstardfelder, crazy++. he also promotes a conspiracy theory that CMS and ATLAS hoaxed the higgs boson....

[Anonymous No.11013107]

>>11013037
I don't follow Vafa's non-categorical/cosmological stuff but his work in general won't be something that's significant only in the scope of string theory, and I doubt that's his motivation to begin with.
The only bombshell I could imagine him putting out in my limited expertise is some extremely powerful [math]C[/math]-theorem for (2,0) interacting 6D superconformal that characterizes all of its compactification IR fixed points and unifies every SuGra under the sun, which I definitely wouldn't put it past him.

[Anonymous No.11013283]

>>11013107
you don’t think there’s any chance he’s working on F theory+M theory unification?

[Anonymous No.11013296]

>>11013283
I am unable to answer as I am not Vafa and therefore do not know.

[Anonymous No.11013835]

>>11004503

[Anonymous No.11014152]

>>11013296
my whole impression of Vafa (Witten's PhD advisee) and Witten naming the theories M and F (mother and father) Theory was that they would one day try to put them into the same framework. that's why i suspect that

[Anonymous No.11014285]

>>11014152
That might as well be the case but I don't see how it can be done, or at least with the technology Vafa is currently developing. That requires a lot more geometric details that I'm not very familiar with, but it (or some kind of no-go divorce theorem) might as well be the long term goal.

[Anonymous No.11014348]

>>11014285
interesting. at least you are acknowledging that M+F theory is in principle doable