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Theoretical physics and Mathematical physics

Anonymous Mon 02 Dec 18:47:24 2019 No.11193491 View Reply Original Report

Quoted By: >>11194644 >>11194906 >>11196935

What exactly makes these different? Ive read a bit about them and it seems that the mathematical physicists care more about the maths involve in the physical problems, but thats pretty much it. So are they the same, is it just that one is in the math dept. and the other is in the physics dept.?

Anonymous

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Anonymous Mon 02 Dec 2019 19:00:26 No.11193510 Report

Quoted By: >>11193630 >>11196304

No, both are in the physics department.

- A theoretical physicist generally builds theory that is tied to contemporary experiment (think theoreticans making models to make predictions for a particle accelerator, or how to design a quantum computation chip, or how to compose gas for this and that theomodynamcal behavior.)
- A mathematical physicist is more interested in the theories themselves. This often means putting working but mathematicall ill-defined theories on more solid ground or, when trying to embed stronger frameworks for models, reframing theories borrowing heavy formal machinery that a theoretical physicist wouldn't want to spend much time on (e.g. being very formal w.r.t. operator analysis involved). A mathematical physicist is generally more willing to spend a few years on theories that are well established and considered being long beyond having low hanging fruits.

Anonymous

Anonymous Mon 02 Dec 2019 19:53:04 No.11193630 Report

Quoted By: >>11193645 >>11193655 >>11193658 >>11195965

>>11193510
Ok. So mathematical physicists don’t really come up with much new stuff beyond better mathematical understanding of old models?

Anonymous

Anonymous Mon 02 Dec 2019 20:00:28 No.11193645 Report

Quoted By:

>>11193630
That's a bit harsh and I'd not say that from better grounding doesn't come a new understanding - but yeah the quantitative output on the theoretical physics side is bigger and hipper.

Anonymous

Anonymous Mon 02 Dec 2019 20:03:41 No.11193655 Report

Quoted By: >>11193678 >>11196304

>>11193630
Not necessarily. I think Ed Witten is the stereotypical example of a mathematical physicist, and he's coming up with all sorts of new advances to whatever the fuck it is he works on (string theory, topological QFT).
Xiao-Gang Wen (one of Ed's students, actually) is, IMO, sort of at the interface between the two. He thinks about physics which can be probed and tested (fractional quantum Hall effect, high temp. superconductors), but also has done a lot of work in classifying topological phases of matter via generalized cohomology, supercohomology, stuff like that.

Anonymous

Anonymous Mon 02 Dec 2019 20:04:40 No.11193658 Report

Quoted By:

>>11193630
Not the other guy but yes; a mathematical physicist would, for example, spends his time trying to rigorously define the notion of a measure in QFT. A theoretical physicist would simply gloss over these issues and use it to calculate stuff.

Anonymous

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Anonymous Mon 02 Dec 2019 20:09:42 No.11193678 Report

Quoted By:

>>11193655
I don't think string theorists think of themselves as "out of the theoretical physics crew". When I think of a mathematical physicist then I think of the guys who study the theory of thermodynamics by framing it with notions such as lattice theory, or using the more fancy *-algebra spaces with this and that topology on it to really cast some classical electrodynamics potential questions on solid ground. Or studying the causal structure of spacetime in a way that looks less like Riemannian geometry but more like formal logic+topology.

El Arcón

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El Arcón Tue 03 Dec 2019 00:35:25 No.11194368 Report

Quoted By: >>11194422 >>11194429

I noticed when Penrose gave his Twistor lecture at my university, he was repping the letter Z quite strongly, pointing to the letter Z on his slides when he was saying stuff like, "...and if you know what's really going on in the world..."

What is the letter Z?

https://smartech.gatech.edu/handle/1853/27625

Anonymous

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Anonymous Tue 03 Dec 2019 01:02:10 No.11194422 Report

Quoted By: >>11194429

>>11194368
I don't see any slides on that link, but I'd guess Z was the partition function, which in practice is a power series who's coefficients are the expectation values/observables of your theory of interest.

Anonymous

Anonymous Tue 03 Dec 2019 01:04:27 No.11194429 Report

Quoted By: >>11194496

>>11194368
>>11194422
I now took a glimpse at the video and no, seems like it was just some point in some (twistor) space

El Arcón

El Arcón Tue 03 Dec 2019 01:24:20 No.11194496 Report

Quoted By:

>>11194429
You are missing the point and you should be more careful not to make posts that irk me.

Anonymous

Anonymous Tue 03 Dec 2019 02:12:17 No.11194644 Report

Quoted By: >>11194786 >>11194882

>>11193491
im in mathphys and from what I can see, math is the best tool you have for physics. all the niggers you see saying 'i hate math' and they are in physics, dont expect to see them make it to third year because they are likely better suited in gender studies. Mathematical physics, at least in my university, is much more interesting in my view. I find the math much more elegant and enlightening than a few blabbers by some faggot who you take their word for. With math, you can simply confirm it on your own. As a plus, you can take more interesting math courses. Im also taking a math minor but just a mathphys degree requires real analysis which theoretical phys doesnt have.

Anonymous

Anonymous Tue 03 Dec 2019 03:12:06 No.11194786 Report

Quoted By: >>11197557

>>11194644
So would you say that mathphys peeps are superior theophys peeps?

Anonymous

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Anonymous Tue 03 Dec 2019 04:12:48 No.11194882 Report

Quoted By: >>11197557

>>11194644
If you are still in uni (and sounds like you are), then a "mathematical physics" course will probably just cover PDEs. This has nothing to do with actual modern mathematical physics which requires much better understanding of maths than an engineer-level PDE course you happened to take.

Saying "theoretical phys" doesn't have real analysis just shows that you are studying at a shithole as well as your ignorance. Much of the modern theoretical physics is rigorous maths - if you are just an undergrad and don't don't know better, maybe you shouldn't be giving advices.

Anonymous

Anonymous Tue 03 Dec 2019 04:21:06 No.11194906 Report

Quoted By: >>11194909

>>11193491
Obviously, there is a lot of overlap, but theoretical physicists are generally interested in the frontiers that mathematical knowledge can explain in physics, while mathematical physicists focus more on rigorous underpinnings of models, often finding insightful consequences of solutions that are more ambiguously explained in the first pass.

Anonymous

Anonymous Tue 03 Dec 2019 04:22:53 No.11194909 Report

Quoted By: >>11194944 >>11195110

>>11194906
To add, mathematical physicists are primarily concerned with using rigorously derived mathematics to consider physical problems. Such mathematical rigor is not necessarily provided or expected in all theoretical physics work generally.

Anonymous

Anonymous Tue 03 Dec 2019 04:45:03 No.11194944 Report

Quoted By: >>11195002

>>11194909
>Such mathematical rigor is not necessarily provided or expected in all theoretical physics work generally.
The fuck kinda theoretical physics are you reading on arxiv? Definitely not the one that I do, or the one that's there.

Anonymous

Anonymous Tue 03 Dec 2019 05:15:17 No.11195002 Report

Quoted By: >>11195024

>>11194944
Theoretical physics is mostly poorly justified math. There are thousands and thousands of papers, and a scant few actually contain a valuable idea developed in a significant way.

Anonymous

Anonymous Tue 03 Dec 2019 05:35:07 No.11195024 Report

Quoted By: >>11195076

>>11195002
He literally provided a screenshot. Are you dumb?

Anonymous

Anonymous Tue 03 Dec 2019 06:25:44 No.11195076 Report

Quoted By:

>>11195024
Who did? This shit is anonymous, dipshit.

Anonymous

Anonymous Tue 03 Dec 2019 06:50:19 No.11195110 Report

Quoted By:

>>11194909
Mathematics is an unqualified field which means regardless of any equation you do its just whatever there is no black and white in life you see the real world when you stop doing math and start mixing dish soap in a bucket. That's why major academic organisations across the globe are ditching instruments in favour of coloured signs. A green sign means dog for example, a yellow sign means 2. This is the industry standard and therefore this method is the only way of producing accurate results. Any other way of practicing mathematics is an extreme threat not only to yourself but those around you.

Anonymous

Anonymous Tue 03 Dec 2019 16:33:27 No.11195965 Report

Quoted By: >>11196169

>>11193630
Mathematical physics is why we have maxwell’s equations. A lot of progress in physics has been done by looking at established theories, extending or fixing them, or reformulating them. It’s less glamorous than theoretical physics on surface level inspection, but as an activity it’s hard to do. However in reality there’s more overlap than you’d think, and at best the core differences between the two groups are the journals they publish, the departments they employ them, and their methods - there are plenty of people interested in “recent” physical theories

Anonymous

Anonymous Tue 03 Dec 2019 18:30:40 No.11196169 Report

Quoted By: >>11196358

>>11195965
desu it sounds like you guys are just theoretical physicists janitors. You gotta go through the mess that they are too busy to deal with. Theoretical physicists get all the glory for coming up with new discoveries while math phys get to clean up their theories for them. Imagine being such a beta male you want to become a mathematical physicist

Anonymous

Anonymous Tue 03 Dec 2019 19:24:16 No.11196304 Report

Quoted By: >>11196324 >>11196358 >>11196389

>>11193510
This is wrong. We call a theoretical physicist that is tied to experiment a "phenomenologist." The kind of physicist that actually makes advances is just called a "theoretical physicist." The type of physicist that gets all picky about an axiomatic formulation of quantum field theory that ends up being irrelevant anyway is a "mathematical physicist." The kind of physicist that was not good enough to work on anything interesting so decided to retreat to a different department we call an "applied mathematician"

>>11193655
Ed Witten is a theoretical physicist. A "mathematical physicist" is someone like Rudolph Haag or Arthur Jaffe

Anonymous

Anonymous Tue 03 Dec 2019 19:32:09 No.11196324 Report

Quoted By: >>11196327 >>11196358

>>11196304
wow, mathematical physicists are faggots, I never suspected, I actually thought they had bigger cocks before I was enlightened.

Anonymous

Anonymous Tue 03 Dec 2019 19:33:44 No.11196327 Report

Quoted By:

>>11196324
Not sure what you're being sarcastic about but the two posts I replied to were not using the term the way physicists themselves actually use it

Anonymous

Anonymous Tue 03 Dec 2019 19:53:17 No.11196358 Report

Quoted By: >>11196374 >>11196403

>>11196169
If it's an ego thing for you, you're never gonna make it
>>11196304
As far as I can tell, at least in my department, mathematical physicists aren't concerned with wholly irrelevant things, as I've seen many will "play the game" as physicists do but with a lot more rigor, so their work is more abstract and less pragmatic in understanding the physics immediately (ie tying back to experiments). However, especially based on what I've seen on the mathematical physics work in statistical mechanics, I think mathematical physicists still offer valuable and fairly insightful work to physics, but it certainly isn't as "mainstream" if that makes any sense. I like to reference this answer
https://physics.stackexchange.com/questions/56293/difference-between-theoretical-physics-and-mathematical-physics
>>11196324
Do you want to do physics because you like physics, or do you want to stroke yourself off on the achievements of others in a field you happen to share?

Anonymous

Anonymous Tue 03 Dec 2019 20:04:43 No.11196374 Report

Quoted By: >>11196476

>>11196358
High energy physics has been stuck on the standard model for approaching 50 years now. Essentially all theoretical high energy physics work has very little direct connection to experiment, and would be what you call "mathematical physics", but that is not how we actually use the term.

Take a look at the difference between papers on arxiv hep-th and math-ph and you will see the difference

El Arcón

El Arcón Tue 03 Dec 2019 20:11:57 No.11196384 Report

Quoted By: >>11196386 >>11196390

Mathematical physics is theoretical physics with rigor.

Anonymous

Anonymous Tue 03 Dec 2019 20:13:02 No.11196386 Report

Quoted By: >>11196390

>>11196384
keep on coping

Anonymous

Anonymous Tue 03 Dec 2019 20:15:28 No.11196389 Report

Quoted By: >>11196407

>>11196304
How is what you respond to wrong then? In that there's a third branch called "phenomenologist"?

Anonymous

Anonymous Tue 03 Dec 2019 20:15:35 No.11196390 Report

Quoted By:

>>11196384
>>11196386
Why? It's one of the most sensible things I've ever seen him post.

Anonymous

Anonymous Tue 03 Dec 2019 20:27:38 No.11196403 Report

Quoted By: >>11196470 >>11196476

>>11196358
The answer in the link doesn't strike me as very correct, though. For example, it says that mathematical physics is a field of math... I think neither would the mathematical physicists call themselves mathematicans, nor would all mathematican agree that those are their like-minded coworkers.
I did my Masters in a dept with a well known mathematical physicist and author (in the physics dept., to be sure), and while he was into stuff nobody was into there, he was also somewhat surprised (dare I say confused) about many modern mathematical tools and language.

Anonymous

Anonymous Tue 03 Dec 2019 20:29:05 No.11196407 Report

Quoted By: >>11196414

>>11196389
What they said about "theoretical physicist" was completely off the mark. They were describing a phenomenologist. Theoretical physicists examine mathematically complex theories in a non-rigorous way. Witten is the paradigm example. Other examples include Seiberg, Vaffa. These guys are looking at theories which usually have absolutely nothing to do with the real world, and often these theories have been around for decades, but they happen to see something new by considering it in a different way.

Mathematical physicists are doing roughly what that post I responded to said, but the key is rigor. That is the main difference between the two groups. If you force yourself to be rigorous, you usually can't work on quite as interesting things. Arthur Jaffe is probably the best example of a mathematical physicist. John Baez is another that is well known on the internet

Anonymous

Anonymous Tue 03 Dec 2019 20:35:05 No.11196414 Report

Quoted By: >>11196428

>>11196407
But, then, aren't the phenomenologists not theoretical physicist?
Aren't they at least closer to being a theoretical physicist than string theorists?

Anonymous

Anonymous Tue 03 Dec 2019 20:41:37 No.11196428 Report

Quoted By:

>>11196414
Phenomenologists are considered theoretical physicists too. There is a big gap between a phenomenologist and a string theorist, but neither is considered a mathematical physicist.

You have to understand that something like string theory has things like path integrals at its foundation, and these are difficult to define rigorously

Anonymous

Anonymous Tue 03 Dec 2019 21:01:54 No.11196470 Report

Quoted By:

>>11196403
Then it probably depends from department to department, because the math-ph people at my school are definitely mathematicians who work in the math department, teach both math and physics courses, etc.

Anonymous

Anonymous Tue 03 Dec 2019 21:03:47 No.11196476 Report

Quoted By: >>11196500

>>11196403
Also, look at Shor's answer down below
>>11196374
Not exactly. You seem to be throwing away all concerns for rigor as irrelevant and put under the umbrella of mathematical physics. I'm arguing that while there's meaningful distinction, it isn't to the point where one does relevant work and the other does irrelevant work.

Anonymous

Anonymous Tue 03 Dec 2019 21:10:40 No.11196500 Report

Quoted By: >>11196506

>>11196476
I think Shor blurs the line far too much there, there's subjects so old that I can't see a non-mathematical-physics guy write papers about, while those do.

Any interesting physicist to follow on LinkedIn/youtube/twitter, apart from the nLab guys?

Anonymous

Anonymous Tue 03 Dec 2019 21:12:48 No.11196506 Report

Quoted By:

>>11196500
Sure there's distinction, but is it really fair to say every mathematical physics person studies old subjects?

Anonymous

Anonymous Tue 03 Dec 2019 22:27:30 No.11196670 Report

Quoted By:

what are the stats oriented physicists considered? I noticed in astronomy for example, there's a lot of work coming from a statistical and machine learning direction in order to deal with the epistemic uncertainty of astronomic observational data.

Anonymous

Anonymous Tue 03 Dec 2019 23:44:16 No.11196935 Report

Quoted By: >>11197613

>>11193491
Depends on the work. In the last century, mathematical physicists indeed did stay behind about a decade or two as far as theories go, but these days there's more cross communication due to how large research efforts have become. Seiberg, Witten, Candelas, Baez, etc. are pretty prolific examples. It comes down to your long term goals, since if you're in the field or adjacent, there's little actually stopping you from just jumping into what you want to do. In math-ph, you'll have enough rigor to jump into hep-th but need to work your ass off to get respected at all, and vice versa.

Anonymous

Anonymous Wed 04 Dec 2019 01:28:20 No.11197221 Report

Quoted By: >>11197476

I think the real question, is which one is more interesting? Seems like theoretical is more interesting based on reading this.

Anonymous

Anonymous Wed 04 Dec 2019 03:09:06 No.11197476 Report

Quoted By: >>11197539

>>11197221
Depends. Why would math ph be less interesting?

Anonymous

Anonymous Wed 04 Dec 2019 03:32:39 No.11197539 Report

Quoted By: >>11197613

>>11197476
Not that guy, but it would seem that finding new things is more interesting than reformulating old theories that are already pretty much known as true and proven

Anonymous

Anonymous Wed 04 Dec 2019 03:42:49 No.11197557 Report

Quoted By: >>11197588 >>11197765 >>11197989

>>11194786
from experience yes but I wouldnt know really beyond my experience so im really just joking.

>>11194882
>Saying "theoretical phys" doesn't have real analysis just shows that you are studying at a shithole as well as your ignorance
>if you are just an undergrad and don't don't know better, maybe you shouldn't be giving advices.
wow I never knew theoretical physicists could cope so hard. If anything, your reply says more about your reading comprehension and ability (or lack thereof) to put together a coherent sentence. I clearly stated that all I had said was based off my experience only. After all, theoretical physics, by definition, is less rigorous than mathematical physics but more than this tongue-in-cheek fact, mathphys presses much more on the math than autistic 'i love fucking science' garbage that belongs more in a biology class of memorization and taking for granted than a respectable physics class.

Anonymous

Anonymous Wed 04 Dec 2019 03:53:38 No.11197588 Report

Quoted By:

>>11197557
>'i love fucking science' garbage that belongs more in a biology class of memorization and taking for granted than a respectable physics class.
what do you mean by this?

Anonymous

Anonymous Wed 04 Dec 2019 04:02:04 No.11197613 Report

Quoted By:

>>11197539
I mean, mathematical physicists also find new things. Look at the scientists mentioned in >>11196935

Anonymous

Anonymous Wed 04 Dec 2019 05:03:51 No.11197765 Report

Quoted By:

>>11197557
>more on the math than autistic 'i love fucking science' garbage that belongs more in a biology class of memorization and taking for granted than a respectable physics class.

...and now it's clear you have no clue what you're talking about

Anonymous

Anonymous Wed 04 Dec 2019 07:23:09 No.11197989 Report

Quoted By:

>>11197557
incredibly based

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