/sci/ - Science & Math

>>11417384
What does it say about consciousness

>>11417393
nothing, obviously
physical ToE =/= philosophical ToE

>>11417393
Conciousness doesn't exist.

>>11417384
What has it predicted?
And what does it predict?
Daily remind me :P

>>11417539
>t. NPC

>>11417548
t. humanities brainlet

>>11417544
You probably want a conclusive result of string theory as a theory of everything. So far, because we don't have our vacuum, we are limited here to results of a very general nature. But there is at least one such result: the mass of the lightest charged particle must always be less than it's charge in natural units. The units mean that two such particles should repel electrostatically more than they attract gravitationally. This is demanded from general principles of black hole decay within a holographic theory....

>>11417544
>>11417595
... It is my opinion that there is still at least one more major model-independent prediction that one can make uniquely string theory which does not require us to get lucky, like find a small black hole or a monopole by accident. This prediction is simply the one for the emissions of highly rotating or highly-charged near extremal black holes.

In both classical GR and in string theory, such black holes look shiny and reflective. In classical GR, if you throw something into a rotating or highly charged black hole, it just bounces out after travesing the interior, but it bounces out into a classically disconnected "other universe". In string theory, there is no other universe, so it either never comes out (unjustified consensus), or else, it comes out in our universe later. I am sure it's the latter, but I can't calculate exactly how much later. This is something you can only calculate using string theory as a theory of gravity.

The gluing of such black hole universes together requires that rotating black holes can emit stuff reflected as anti-matter, and this might explain the signature anti-matter signal at the galactic center. The issue with this prediction is that nobody has worked out the details yet, it is a personal idea of mine that I am pretty confident is true from putzing around, but until I know the precise gluing, I won't persuade anyone else.

The evidence that string theory is correct is that it obeys the holographic principle, so that it is consistent with Hawking's entropy law. The entropy law is firmly established, and it creates the information paradoxes that can only be resolved by an S-matrix point of view. From a theoretical perspective, this clinches it, string theory is correct. From a practical view, it is likely that the low-energy theory is not supersymmetric, and this might be a tremendous clue, because such vacua with small cosmological constant might be very restricted.

String theory, like all quantum gravity models, is in a difficult position, because the natural place to test it is in scattering at enormous energies. This doesn't mean that it is untestable, it means it is prohibitive to test technologically. The philosophical criterion that makes a theory untestable is not when it is too expensive to test. The theory that there is a rock at the Lagrange point of the Earth and the sun is also prohibitively expensive to test, less so than string theory, but still more expensive to test than to propose. But it is not unscientific, it's scientific, it's just probably wrong, there probably is no rock there. String theory needs cleverness to test, because the direct tests are out of reach. This cleverness means figuring out our vacuum, by making models of it using the theory.

There are model independent predictions of string theory, the swampland constraints, and the emissions of black holes, that allow the theory to make certain astrophysical predictions and rule out certain models even without knowing our vacuum. It has made solid contact with strong interaction physics, and it will never be overthrown in the domains where it is already tested, which are in QCD, especially RHIC nucleus-nucleus scattering. As a theory of quantum gravity, it is also likely to be the only possibility, in that any other possibility is a vacuum of the theory, since this has been true so far. The way to disprove it is to show it is inconsistent theoretically (it isn't) or inconsistent with observations, which means ruling out our universe by showing it isn't a vacuum. That's not infeasable to do, there are only so many vacua (with reasonable assumptions), but you just won't do it, if you search, you'll find our vacuum.

>>11417595
How do you know that result?
Which experiment was that the result of?
How do we know that?

>>11417597
Black holes are just a more powerful version of something like a neutron star.
It's just a mini singularity of mass and gravity. Black holes absorb light because light is an electromagnetic waveform using background cosmic radiation. As a medium. Light has no mass. It is unaffected by gravity. Black hole act as big broadband antennas absorbing this background EMF. That's why they absorb light.
There is no need for magic in physics.

>>11417638
>There is no need for magic in physics.
If your intuition is from field theory, you think that you can just make up whatever you want. This is just not so in string theory. You can't make up anything without geoemtry, and you only have so much geometry to go around. The theory should be able to, from the qualitative structure of the standard model, plus the SUSY, plus say 2-decimal place data on 20 parameters (that's enough to discrimnate between 10^40 possibilities which are qualitatively identical to the SM), it should predict the rest of the decimal places with absolutely no adjustible anything. Further, finding the right vacuum will predict as much as can be predicted about every experiment you can perform.

>>11417652
These equations only work with with vectored mathematics.
They don't apply to real physics.
It's pure fantasy.
What do you mean by vacuum?

Good thread except for the schizo

OP when we get our quantum PC's hooked up we'll grind out a few new advanced materials and get you those DBZ energy levels you need.

>>11417384
the obvious point is that string theory lacks a nonperturbative formulation and witten showed us that a unified theory of strings based on manifolds underlies string theory, and no decent formulation of that whatsoever exists so far. after 15 years! this is the reason why AdS/CFT is hot—because it is the only way string theorists are able to even approach some sort of real M theory. and even Witten himself is stumped on M theory after 15 years.

i have two scenarios:
1) somebody actually does formulate M theory and it is a huge boon, maybe even settling the multiverse/swampland ambiguity. great
2) some einstein type thinks the whole situation over and makes a conceptual leap that brings the thing to a whole new context. (like maybe they rethink whether 1+2+3+4+... = -1/12 like polchinski assumes in chapter 1 when deriving that bosonic string theory must live in 26 dimensions...) that would probably be even better

>>11417652
>string theory
>only have so much geometry to go around
Yeah, what can you do with 10^272000 possible vacua?

>>11417384
String theory makes zero testable predictions. It’s best achievement is not being incompatible with current experimental evidence, which isn’t an achievement.

>>11418275
What the fuck. You haven't read a single post in this thread. Get the fuck off my board.

>>11418190
>like maybe they rethink whether 1+2+3+4+... = -1/12 like polchinski assumes in chapter 1
>assumes
please do not opine on string theory until you have a couple post-calculus math classes under your belt, it will save you time and future embarrassment

>>11417384
Can string theory get me a gf

>>11417384
>This should be enough to make severe testable predictions
Do it. We've been waiting for 40 years or so.

>rope theory

>>11418535
>Do it. We've been waiting for 40 years or so.
I've already done it. There are some predictions discussed in this very thread. Didn't you notice?

>>11417384

Go to the right ways but wrong imagination
String theory dont need extra +space +time dimension Tobe 26 bosonic string.

Just 24
It is so perfect.

>>11417384
Good thread. Brainlets often think that string theory is merely yet another attempt at ToE, with academia being unsure about it's validity. This is not the case. We basically know that theory of everything, while incomplete, will have to be stringy. The mathematical evidence is just too good.

You will even find many subpar physicists believing this misconception, as they do not really understand string theory. But such physicists disappear at the higher end. Physicists smart enough to get string theory almost never choose to work on something else.
Another misconception is that we are looking for a theory of quantum gravity, trying to make GR and QM compatible. Nope, we already have the correct theory of quantum gravity for low energies. We are looking for very high energy quantum theory (of gravity but also other forces). This is why tabletop quantum gravity experiments (such as proposed by that dumbass Hossenfelder) will lead to no advances in the field. There is no substitute for pushing the energy frontier.

>>11418352
>hurr durr infinity=-1/12 obviously, just watch numberphile

>>11418275
This. It's cumbersome formalism that has no place in standard physics education UNTIL and only until, it manages to predict new physics that can be experimentally verified. Literally le not even wrong.

Enjoy wasting your life, OP.

bump so more but lasted brainlets reeee pathetically about “nooo all the top physicists are wrong because it makes my tiny brain feel sad!!!”

Is there a good intro textbook? Have degree in math but never took any physics.

>>11419343
see >>11418561

>>11420264
There really aren't so many prerequisites, the difficulties in string theory are the alien physics, not the mathematics. Aside from standard topics for physics, you need to know all the Lie Algebras well, not just SO(3), SU(3), SU(5). The natural path here is through the SU(5) SO(10) E6 guts, and you can learn this from Green-Schwarz-Witten. You need to know homology/cohomology intuitively, and a small amount of algebraic geometry, just to relate the compactification geometry to the physics. But the barriers to learning the theory are developing a physical intuition for such alien things as strings.

For this, you need to learn the complex analytic things that motivated the original discovery. You need to an intuition for analytic continuation, this is standard undergraduate stuff, but the physicist intuition is more developed--- you can read Gribov's book "The Theory of Complex Angular Momentum", along with Mandelstam's articles on the Analytic S-matrix, and those of others throughout the sixties. This is the most difficult thing--- understanding the analytic S-matrix stuff, and this is not something that rigorous mathematics is going to help very much with, and it is not even current in physics departments anymore, it is just buried.

After this. the remaining mathematics of string theory is developed most straightforwardly by learning the theory from physics sources. The Kac-Moody algebras, the conformal algebras, the mirror symmetry, even the Ricci flow, these are all things that were developed first within string theory. The flow of ideas here has been nearly entirely from physics into mathematics, with a few exceptions that are still more clearly described in the physics literature.

>>11420264
yes, there are good intro textbooks, but don't listen to this guy:
>>11420294
green-schwarz-witten is out of date and is too obscure for an intro. i would recommend starting by going through zwiebach but if that is too easy you can move right to polchinski

>>11417384
>string theory
not science nor math
back to >>>/x/

>>11420372
lol that anon again. how about for once you make an argument instead of being a troll who always says the same absolutely retarded shit in every string thread?

>>11420278
There are no predictions. If you think so, then you are completely oblivious to the current state of confusion even among the most prominent string theorists themselves. The negative sign of the cosmological constant renders even the "SM derived from String theory" (actually N=4 supersymmetric yang mills which was completely blown out of the water with LHC, oopsie) absolutely useless. String theory might generate quantum gravity, but not in this universe. You would be wise to realize this sooner before you waste your time with it.

>>11420384
>There are no predictions.
the standard model predicts that gravity is impossible. string theory predicts gravity as a historical accident.

string theory also has made some (albeit arguable) predictions about things like quark-gluon plasmas, since there is a way to formulate an analogue system using black branes.

>?If you think so, then you are completely oblivious to the current state of confusion even among the most prominent string theorists themselves. The negative sign of the cosmological constant renders even the "SM derived from String theory" (actually N=4 supersymmetric yang mills which was completely blown out of the water with LHC, oopsie)
that is a stupid thing to say. there is a difference between the MSSM and SYM theory. you know like massive particles existing. get your shit straight before larping
> absolutely useless.
no, there are stringy mechanisms to get the cosmological constant positive. look up KKLT.
>String theory might generate quantum gravity, but not in this universe. You would be wise to realize this sooner before you waste your time with it.
i am not advocating that people who want to be practical take up string theory, but saying that it is a waste of time is like telling cosmologists they are wasting their time on thinking about the big bang. it's a poor argument. and all your other arguments are complete nonsense so it fits with your generic "i read too much sabine hossenfelder" normie mindset.

>>11417618
>it has made solid contact with QCD
Lmao, like reproducing asymptotic symmetry, am I right bruv? Get a grip.

>>11420394
no, he is referring to quark gluon plasma stuff. like jet substructure and jet splitting in the final states of QGPs:
https://quark.phy.bnl.gov/~pisarski/talks/Colloquia/Gubser.pdf

>>11420398
PS: RIP steve gubser, taken at such a young age

>>11417384
>actually falling for the string meme on life support in 2020

>>11420409
>actually making a meme post to accuse something top physicists work on of being a meme
i hope you are a chemistry undergrad or something acting like a /b/ troll, since usually genuine /b/ trolls can usually post a funny meme or insert humor instead of just trolling

>>11420415
That one struck a nerve. Also
>top physicists
>string theory
>physicists

I think you are confusing occupations.

>>11420426
honestly i would be fine if they moved to calling themselves "applied mathematicians" but i just go by what their titles are and the departments they work in.

heck, even Witten started out doing normal ass field theory, wrote some papers on the QFT of pions and shit and worked with Weinberg on some QFT stuff. he also spent time working with Sidney Coleman who was a QFT master.

there are some other prominent string theorists who crossed over from particle theory too, but not as famous. gabriele veniziano literally invented string theory and he was a hot theorist working on CERN stuff. lenny susskind dabbled in particle theory for a long time even after he was crowned one of the subsequent co-inventors of string theory. yoichiro nambu also was a co-inventor of string theory and made massive contributions to QCD like the chiral anomaly.

so if you want to say that "string theorists aren't physicists" then you are factually wrong, since some of them actually are physicists who started out working out quarks and leptons and bosons, and almost all of the original generation of string theorists were real physicists like that too

the fact that it has diverged somewhat is not their fault. nature didn't work out the way everyone hoped. even experimentalists cracking away at their hodoscopes wanted supersymmetry to come true and the particle zoo to continue to increase. but nobody can tell reality what to do

>>11420447
just to prove witten started out in normal particle physics, pic related, his first two papers

Speaking of strings have you seen THAT FUCKING [math] \mathbb{ PHENOTYPE?} [/math]? Oh my god he's banging! Those powerfully wise but at the same time soft and kind facial features, that strong, like a Moai statue, forehead. Fucking incubus. Listening to this cranial giant preach always gets me weak at the knees. How lucky we are to bask in his masterful elocution and intonation, the way he relaxes into a vowel; crisps a consonant; divines, for each syllable, a richness, conveying wisdom and strength. That's the truth, bloke! Sling it at 'em! O Gorbli'me, that was grand! His might be the most fuckable voice yet. Gives me a righteous wangbone.

>>11421681
Of course, he's a jew

They seemed to have found a bear in the middle of integers recently.

>>11421681
>posts current witten
>not prime witten

>>11422968
Magnificent.