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For the morbidly curious, that nightmare math is someone's quantum field theory notes which they typeset in TeX:

https://rohankulkarni.me/files/notes/heidelberg_qft/12_2.pdf ("12.2 Diagrammatic expansion of partition function for Yukawa theory")



I was looking for "nightmare math" in the README and was confused because I didn't find any. I guess that's what a theoretical physics degree does to you: that formula looks very harmless to me.


Yeah, I was also let down when I found the "nightmare math" was simply integral of a generic Lagrangian density...


you're a simple integral of generic density


wow, please folks, keep it civilized! :D


Looks like a horror show to me. Makes me feel embarrassed at leaving my math bs behind and going into cs. I have an insane retirement idea of retiring to some fun mountain town and going to grad school in physics. Where's the best place to go skiing with a college that takes old washed up programmers as students?



Good suggestion, but maybe shooting too high. Checks off the "in the mountains" part of my fantasy life. But a place that has seminars for grad students and working physicists and has many Nobel laureates who attended as students may be above my intellectual grade.


Close by is Grenoble. You can take the bus from the main station to arrive at the nearest ski stations within 45mins. :)


U of NM maybe? You can go skying just outside of Albuquerque and play golf on the same day.


Well now you have to show us something you would consider nightmare math


https://petapixel.com/2019/07/05/goodbye-aberration-physicis...

Another example is standard model of particle physics. There’s a way to write down the Lagrangian of the standard model very compactly: https://visit.cern/content/standard_model_formula_t_shirt

But if you expanded all the implied sums and terms, it probably would be monstrous. After all it is supposed to contain all the terms that this figure contains for example: https://commons.wikimedia.org/wiki/File:Standard_Model_of_El...

Also, ask string theorists to show you calculations that they need to find the largest paper to perform. I’ve heard people doing calculations where a single line is the width of an A1 paper.


Surely he could have defined some sensible quantities and notations or exploit some symmetry to make that monstrosity a bit more compact, no? I mean the Einstein field equations in its simplest form is something like G=k*T for suitable definitions of G and T. But if you wrote each component of G in terms of the metric tensor, it would become huge. This is just one component of the Riemann tensor: https://i.stack.imgur.com/xkrq9.png


You are not wrong. Eg the original Maxwell equation is so ugly (I think 20 of them) but the ones that are taught nowadays looks so elegant.

The language is important. The more you “understand” something, the simpler it is (over simplification here.) eg I would not consider the Einstein equation expanded out to be natural after understanding it. (Well Maxwell’s equation can be summarized in 1 single elegant equation as well.)

But the reason I’d consider that optics formula to be monstrous is that no matter how you group it into smaller pieces (ie refactoring it), there’s no way to hide the fact that it is not elegant at all. There’s no “understanding” there, it is just so happen the exact solution looks like that.

To put it that way then, often fundamental “master equation” are simple in some ways, but exact solutions to some particular manifestation of that master equation is often quite ugly and monstrous. In that sense then rather than quoting Einstein equation I’d quote its solution eg one with mass and spin and electric charge.

P.S. the solution of quartic equation is also a good example of this category


There is a ton of repetition, so you could probably replace it with like five relatively small equations. Still...glad I didn't get into optics lol.


I'm pretty sure I used to get nightmares from Christoffel symbols and Riemannian geometry: https://i.stack.imgur.com/Njf17.png


Yeah that didn't look much more nasty than most problem sets


three dimensions over time, with vector components?


I recall dimly a period of months during engineering school when I would have been able to parse those symbols and perhaps make a joke about something in the lunch room. Those days are long behind me.


I would argue that it is a nightmare in general, a viewpoint of someone who actually shared this pain before.


Quantum is a trip. Pages of math to describe... 4 straight lines.


Quite the opposite, the 4 straight lines represent all that math. Notation is very powerful and get you quite far.


Understood, and that was exactly my (poorly made) point. Crazy how powerful quantum notation is!




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