#serious-discussion

1 messages · Page 358 of 1

split basin
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this makes sense

foggy meadow
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What's a filtered vector space?

split basin
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like is there a naive interpretation of what “pt/C*” should mean that makes this evident

vivid halo
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intuitively if BC*=pt/C* is meant to be a single point with internal group of symmetries C*, then a vector bundle on this should just be a vector bundle on the single point pt which is C*-equivariant, meaning it carries an action of this internal group of symmetries C*

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stuff on X/G is G-equivariant stuff on X

foggy meadow
foggy meadow
split basin
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oh

vivid halo
split basin
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so you dont think of some coset space

vivid halo
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morally this is a coset space but you are meant to remember the actual equivalence data between members in a given coset, not just collapsing them down to a single equivalence class

split basin
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i guess that makes sense

vivid halo
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that is the difference between these stacky quotients versus classical quotients

split basin
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that this would be the right way to generalize classical quotients

vivid halo
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like you want to remember why things are isomorphic not just that they are isomorphic

split basin
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i see

vivid halo
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remembering why things are isomorphic is a structure rather than a property

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the difference between these is the difference between sets and groupoids

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stacks generalize sheaves in exactly the same way

split basin
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btw is this pt/C* example analogous to some fourier transform?

vivid halo
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the usual gluing axiom for sheaves must accordingly be more complicated to capture this additional structure

foggy meadow
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Man, this is wacky. Very different from like the topological view.

foggy meadow
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Bruh.

split basin
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idk why it just seems like it

foggy meadow
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Yeah, I need to learn more about orbifolds I think.

vivid halo
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this is exactly the right intuition and this is a very general phenomenon, captured by the Fourier-Mukai transform and Cartier duality

foggy meadow
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I only get the general flow of what's happening, but not the exacts honestly.

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But getting the flow down is how I start to learn things.

vivid halo
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Gaitsgory has two very nice recorded lectures on this notion of Cartier duality and Fourier transforms, and discusses a more general version of this one category level higher

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the example I described above and many others like it are explained very nicely in the first lecture

foggy meadow
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I'm going to step back for a moment to something really simple is a mod b an orbifold of just R/Z_{n}?

vivid halo
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but yes for example the quotient R/Z for Z acting on R by the usual translation action happens to be a classical object which is probably what you have in mind

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sometimes these stack quotients are classical objects, in general they are not

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whenever they are classical the intuition for stacks agrees with your usual intuition for quotients by equivalence relations

foggy meadow
vivid halo
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maybe a richer example related to this which is no longer classical would be taking the quotient of R by the slightly larger group acting both by translation and negation

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some semidirect product of Z and Z/2Z or whatever

split basin
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why does BS^1 appear here?

vivid halo
split basin
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ok

vivid halo
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the S^1 is maybe more evocative of why Z appears by the usual Fourier transform

foggy meadow
split basin
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yeah

vivid halo
foggy meadow
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Which then is what I was understanding, okay cool.

vivid halo
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you can keep generalizing this notion to higher notions of stacks but this is maybe a bit much to swallow for one conversation lol

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anyways the point is these things are very useful and they unlock for you things which are very hard to talk about classically

foggy meadow
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I mean, I'm still on orbifolds probably, but I was really curious about Artin Stacks. I now have a name for blah/So(3) or whatever now.
Also, thanks btw.

vivid halo
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this example around filtered/graded vector spaces is very nice because it is often very useful to interpret various linear algebraic constructions like structures on various cohomology theories, in terms of bundles over stacks like this

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there is an interesting "transmutation" one can perform which interprets all sorts of very different cohomology theories as actually the same cohomology theory but each is interpreted over some different stack like this

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this is very useful because then you can just prove once and for all certain abstract properties of this single cohomology theory and then offload the actual differences in detail of different cohomology theories onto differences in detail between these different stacks

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definitely takes a fair bit of stacky machinery to get this idea to work, but in the long run this is much more efficient compared to like, proving hard technical theorems a dozen times over and over in different contexts

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also just very clarifying because you can start to view the actual "reasons" for deep theorems about cohomology theories and the relations between them in much more geometric terms

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you can interpret all of Hodge theory and its p-adic counterpart in these terms for example

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in fact this perspective is honestly the only sane way to understand p-adic Hodge theory lol

foggy meadow
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I still need to finish reading about Geometric Algebra.

torpid bay
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pandapopcorn if i were to read some books about the topics for the things y'all said ot learn about it from scratch, what would be the topics?

vivid halo
foggy meadow
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I know it's probably a must.

vivid halo
foggy meadow
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I'm just happy lattices have helped me this far.

torpid bay
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i got no background, other than like calc 3, some linear algebra stuff + currently doing real analysis by tao (a small bit of recognizing some specific groups and some tensors calc basics)

vivid halo
split basin
vivid halo
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but yes also this perspective I am advocating literally does not make the slightest bit of sense until you finish the usual first course in abstract algebra, and also kind of does not make sense until you finish a first graduate course in algebraic geometry at the level of Hartshorne

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I'll be here if you have any questions like 2-3 years from now

split basin
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surely it takes a lot more than just a course in algebra

foggy meadow
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I'm still surprised my head knew what a Modular curve was.

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I also realize, if I decided to do signum matrices and do something similar. I would need to define them using this type of language.

vivid halo
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if you cover commutative algebra at the level of something like Atiyah-MacDonald then in principle you could use Adeel Khan's notes as an intro to AG, but this is only a good idea if you have bran damage of a very particular kind

vivid halo
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maybe good if you have the undergrad category theory nlab reader kind of brain damage and at least want to turn that into something useful

split basin
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just like take core algebra topology analysis geometry classes for a few years

vivid halo
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like this approach is ultimately the cleanest and most powerful approach to algebraic geometry when all is said and done, but it is not the approach that most people would actually benefit from learning first

foggy meadow
split basin
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sure but less of a priority as an undergrad i think

vivid halo
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this sort of thing makes sense to study if you are a grad student and know that you would benefit from these techniques, most people do not stand to benefit relative to the amount of machinery this approach requires

foggy meadow
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I'll probably end up making my own sauce, and doing silly stuff again with a partial understanding. But talking like this makes that partial understand a little more full. That or I reinvent the wheel and start making chariots.

vivid halo
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also depends on the department you are in, there are a handful of departments where this is just kind of the way that everyone learns algebraic geometry and how people talk about things, at most departments this is very much the case and not knowing more pedestrian ways of talking about geometry basically makes it impossible to talk with other people which is a big disability to voluntarily acquire

foggy meadow
vivid halo
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yeah Arun's notes on this stuff are very nice

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covers a lot of interesting material in somewhat vague but still useful terms

foggy meadow
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Why are forms everywhere and show up where and when I don't expect.

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Even with my own silly math they come up.

latent edge
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I might get cancelled if I said it

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hint: it's not number theory sotrue

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I find esoteric logic boring idk

ocean robin
vivid halo
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log log log log log log

hallow plume
vivid halo
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analytic number theory heads really be like "I will take the most rich and interesting subject in all of mathematics, and study it in the most dry and boring way I can possibly imagine"

vivid halo
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wait no

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as an intro to Hodge theory yes

latent edge
vivid halo
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reading that paper is like eating glass

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like it's such a brilliant paper but holy fuuuck

junior turtle
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one example that comes to mind is logic

pure hollow
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Logic is cool if you're autistic enough.

hallow plume
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numerical analysis

vivid halo
hallow plume
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you write a program to simulate stuffs
oh compile failed have a good luck next time!

junior turtle
vivid halo
pure hollow
foggy meadow
vivid halo
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understanding why is the actual important part lol

foggy meadow
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Just change the "it's true" into the important and meaningful part some how. Then use the inverse transform to transform it back.

vivid halo
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lol

foggy meadow
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You got this I believe.

latent edge
foggy meadow
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Make every "this is true" meaningful by inventing a new language or something so it's meaningful. trollface

junior turtle
hallow plume
foggy meadow
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@torpid bay what are you working on today?

torpid bay
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i was mostly just at work

torpid bay
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but

pure hollow
torpid bay
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ig i had 2 ideas

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one was about bivectors actually

foggy meadow
latent edge
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Geometric Algebra

torpid bay
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im thinking, suppose there is a space S (lets say 2 dimensional), and we can ig define bivectors on it. if I can take this bivector, and move it along a closed path, and when it comes back to the starting point, but ends up with a negative orientation as what we started with, then it's a nonorientable surface thne(iff)? i dunno the official rigorous def of non orientiable surface so im just going off of intutiion

junior turtle
zealous garden
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Yo

junior turtle
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yoo

zealous garden
junior turtle
latent edge
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to summon you obviously

zealous garden
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Boring? No, it was just ignored

zealous garden
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Geometric Algebra (as in Grassman's work) underlies all of exterior algebra, clifford algebra, gibbs-heaviside vector algebra, and more

latent edge
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just realized this is discussion 2

zealous garden
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But props on you for realizing it was Grassman and not Clifford. Not many get this right

pure hollow
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High school math.

zealous garden
torpid bay
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the second idea I had was about integration over closed spaces

junior turtle
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ohhh wait, probability is a good candidate

foggy meadow
agile fiber
zealous garden
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I guess?

torpid bay
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ye

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but like iff

zealous garden
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Is that easier than showing directly that no smooth pseudoscalar field exists?

torpid bay
zealous garden
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Well hold on now

zealous garden
torpid bay
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ye

zealous garden
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Yeah this should work out

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The pseudoscalar field is basically the geometric algebraic definition of the orientation of the manifold

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So if transporting your orientation around in a loop changed it, something is awfully fishy

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Like the orientation not existing

torpid bay
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does this mean you can't do GA on a klein bottle or just that orientation cant be defined?

foggy meadow
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~~I feel like it's just that orientation couldn't be defined, but maybe I'm wrong 🤷‍♂️. ~~

torpid bay
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^

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anyway, the second idea was I saw a vid by 3b1b, and it had flux, which i had forgotten about, but that whole 0 flux if source/sink is outside of closed surface reminded me quite a lot about the 0 = closed integral curve in the complex plane if no roots or poles inside it

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i feel like they're just two special cases of something more

pure hollow
foggy meadow
junior turtle
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i dont even know why lol

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but i have been avoiding it for a long time

pure hollow
foggy meadow
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Me working with stochastic values and graphs.

neat lintel
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Hello

junior turtle
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i mean i dont really care about probability, at least not for now. So imo its reasonable that i havent studied it yet

pure hollow
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I'm eventually gonna learn graph theory but I don't see the appeal for it rn

junior turtle
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i am prioritizing many things over it

latent edge
junior turtle
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rn its at the bottom of an infinite list of things that i want to study

foggy meadow
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I'm trying to learn more about GA and some other things.

junior turtle
neat lintel
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I want to learn group theory

latent edge
torpid bay
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one other thing is that I figured out what went wrong in my previous bad lower bound for primes, and it came down to counting fractions when I should've used floor after each time, which ended up overestimated the nummber of primes within a certain inverval

pure hollow
junior turtle
neat lintel
foggy meadow
vivid halo
junior turtle
foggy meadow
junior turtle
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i recommend lang's algebra for a friendly introduction

junior turtle
junior turtle
vivid halo
junior turtle
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scroll down till you see a message with a list of books about abstract algebra

junior turtle
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people usually recommend D&F, its probably good as a start but i dont really like it so i wont recommend it myself

latent edge
foggy meadow
junior turtle
foggy meadow
neat lintel
vivid halo
foggy meadow
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yes.

junior turtle
neat lintel
latent edge
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#arabic

junior turtle
junior turtle
neat lintel
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Ok back to English so we don’t get banned

junior turtle
vivid halo
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mom pick me up I can't read the moon runes

foggy meadow
junior turtle
neat lintel
pure hollow
junior turtle
neat lintel
latent edge
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incoming talk about falafel:

junior turtle
zealous garden
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There's so much snow

junior turtle
neat lintel
junior turtle
latent edge
neat lintel
foggy meadow
junior turtle
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I mean in Iraq you see people eat like kafta and so on for breakfast

foggy meadow
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That makes sense.

junior turtle
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Tho it's nice to do this ngl

foggy meadow
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I feel like if you live where it's arid then yes.

neat lintel
neat lintel
junior turtle
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I don't remember ever eating hummus with falafel, but actually I don't even remember the last time when I ate falafel so my memory might be failing me

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But I am almost sure that I have never done that tbh

neat lintel
junior turtle
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But yeah hummus is peak if it's done in the right way

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It's tasty on its own

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like you can make a sandwich of hummus, tomato and olive oil or something like that for example

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It will have a very good taste if the hummus is done in the right way trust

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Ah I miss manakish 🥀

neat lintel
junior turtle
neat lintel
junior turtle
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Currently in brazil

neat lintel
junior turtle
junior turtle
neat lintel
junior turtle
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Ohhhh nice

neat lintel
# junior turtle Ohhhh nice

But Brazil is kind of niche tbh, most Arabs when they leave the Middle East they usually go to Europe or the US, but it is interesting to see Latin American countries as destinations for some

junior turtle
hallow plume
# vivid halo a group is:

a group is an object whose delooping BG is a 1-truncated ∞-groupoid whose higher homotopies are contractible? sotrue woke

upbeat kraken
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Hello

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What kind of proofs should I be able to do before I go to learning calculus proofs

I am learning basic proofs and want to know when it is ok to learn calculus proofs

vivid halo
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if you have covered some portion of basic intro to proofs material then that's more than enough to get started

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you can also get started with absolutely none of that material as long as you have basic reading comprehension skills and a brain

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the only function that intro to proofs serves as a course is to sort prospective mathematics students into two camps, the first camp is "students who understand what words like "and" and "or" and "if/then" mean intuitively and without much conscious effort" versus "students who can mimic this understanding only with a great deal of concentration and conscious effort"

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all the students in this latter group get removed from the pipeline and end up doing something else more worth their time, all the students in this former group probably didn't need this course in the first place

acoustic zealot
timid cypress
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yo

severe steppe
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The "intro to proofs" course is basically a filter for logical intuition. Most of what you learn there is just formalizing things you already do when you solve a puzzle.

vivid halo
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I wouldn’t say I’m going out of my way to be elitist here just being a bit brutally honest about the overall role of these courses

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That said these courses are not entirely useless and their main merit is that they give you a bit of time to just start working on basic mathematical writing skills which takes time for anyone to develop and is slightly orthogonal to the skill of coming up with logically valid proofs

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sometimes it feels like these skills can be quite poorly correlated, loads of incredibly technically skilled mathematicians are also absurdly bad at writing clearly

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most good intro to proofs courses end up feeling like courses on technical writing and most bad intro to proofs courses end up being courses on mathematical logic in a way that really misses the overall point

severe steppe
vivid halo
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Most mathematicians are really bad at this it’s a really huge cultural issue which I could absolutely continue to bitch about

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Like it’s a hard skill to write or deliver lectures with clarity but the bar is so absurdly low here and so many people constantly make such easily avoidable mistakes about this

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Shit like “oops I forgot to think for a single minute about the intended audience”

vast wraith
vast wraith
vast wraith
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idk all the aspiring logicians i know are currently hospitalized

vivid halo
severe steppe
# vivid halo Like it’s a hard skill to write or deliver lectures with clarity but the bar is ...

I don't blame them that much, because once most people understand something complex, they will forget what it's like to be confused by it.You see this in CS all the time too, the documentation that is written by engineers for engineers are usually unreadable garbage because they skip the obvious steps.

One of the easiest ways to get ahead currently is to explain a concept without confusing the hell out of the reader, because by that point you will be already ahead of most PhDs.

vast wraith
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admittedly i know just two

vivid halo
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Well I would imagine that the feeling of struggling with logical connectives and their manipulation would be like, kind of a bad sign for anyone trying to become an expert in the topic which deals most heavily with precisely this

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It’s like trying to become a low dimensional topologist while also having incredibly poor spatial reasoning skills or being blind

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Like you can overcome those things with a lot of work but more often than not it is a bad omen of sorts

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likewise just because someone stuggles quite a lot earlier in mathematics with something like this doesn't mean it is impossible for them to become a good mathematician, there are fields medalists for whom this sort of thing is true, but generally speaking it just shifts the odds against you

vivid halo
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most people do not become marathon runners if they find it hard to enjoy running

vast wraith
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Weil has an interesting discussion on this in the introduction to hos foundations of algebraic geometry, he talks about two kinds of mathematicians, which he calls “creative” and “critical,” having in mind someone like Segre versus Peano

vivid halo
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ah that's an interesting dichotomy I haven't heard before

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people often talk about the dichotomy between "theory builders" versus "problem solvers" which is not unrelated in some ways

vast wraith
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i love math astrology

vivid halo
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one thing I have noticed about people who are like, really really good at mathematics usually at the PhD level is like, they tend to be able to read mathematics texts rather quickly without getting stopped constantly by the voice of skepticism

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obviously one has to be a little careful about just instantly accepting things as true this often leads to bad mistakes, it's not quite like that

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usually once you are closer to finishing a PhD thesis you can read papers in that area at some incredible speed and everything feels very natural and obvious, while papers outside that area will still often be a slow stuggle to understand

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but like some people develop this sense of intuition much more quickly than others

vast wraith
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i dont think i have ever managed to read any math of some complexity quickly cat_happycry

acoustic zealot
vast wraith
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i meant just the introduction bnuuychristmas

acoustic zealot
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Ah

onyx reef
vivid halo
vivid halo
vast wraith
vivid halo
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yeah sometimes that can be a factor monkey

onyx reef
vivid halo
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what is your cutoff on time spent being stuck on those sorts of proofs before looking up any hints which might help with them?

onyx reef
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I somehow never tried to actually analyze why though.. I'll try to pay more attention to it next time and see if I can find rooms of improvement where the solution isn't just "do more math and git gud"

vivid halo
onyx reef
vast wraith
vivid halo
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people are often given the advice that you should try to prove a bunch of things completely on your own and that you shouldn't "cheat" with any hints or whatever but this is generally quite poor advice, it is usually very counterproductive and leads to massive slowdowns which aren't worth the benefit this advice is trying to get at

onyx reef
onyx reef
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Ig yeah if I want to cut down on the time I should stop doing that

vivid halo
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you probably don't want to have such a low tolerance for frustration that you immediately google everything that takes more than 10 seconds to think through carefully, and ideally you should not be looking up the same things over and over and over again without internalizing them

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in most cases it is most productive to not waste too much time on these things, look up hints if things feel like they are taking too long, or just move on and skip some things and return to them later if you want

onyx reef
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Yeah makes sense, I'll try to apply that advice next time

vivid halo
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people seem to have this idea that you should work through a textbook completely linearly and work all the details to completion and you will somehow emerge from the other end having completely internalized all the content, but this literally never actually happens in practice

onyx reef
vivid halo
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like another thing to keep in mind is that often it is impossible to actually have the proper context for completely understanding the mathematics in textbooks like this, like loads of exercises do not have obvious importance until you encounter some version of the same problems in actual research and then you see why people actually care about them

onyx reef
vast wraith
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as a sort of opposite extreme to this idea of having a complete understanding of a theory, is conway’s idea that math is not about theorems, but rather about examples catcutethink having a deep understanding of particulars

vivid halo
onyx reef
vivid halo
#

right yeah this happens a lot

vivid halo
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at some point everyone is forced into this sort of strategy of being fast and loose with it as soon as actual research is happening

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if we had unlimited cognitive ability it would be nice in principle to like, understand literally every definition and every theorem you are citing as input to something you are doing in research, but realistically no human can actually do this

onyx reef
onyx reef
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ok sorry but I need to go study rn

vivid halo
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good luck

onyx reef
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Thanks for the advice kannawave

vivid halo
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try to get in the habbit of skimming and see how it feels for a bit

onyx reef
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Yeah, I'll let you know how it goes thumbsupanimegirl

vivid halo
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very good exercise at some point is to try and read some math books at the same speed you would read a novel and just see what happens

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very very useful skill to develop

hollow ivy
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Hello to everybody, I'm still thinking about what career I can choose to study, I was investigating a little bit about maths and I really like the option, however, when I get into a "Jornada a puertas abiertas", that is like a meeting where professors explain you about the different professions, I saw a obscure and boring path to deal with maths. Besides, my current tearcher of maths is heavily into maths, and talk just about maths. What is the real deal for studying maths an why it can be so interesting, in addition to the bare prejudice about that graduating from maths is to be professor or to study for the rest of your life like a investigator about abstracts things that maybe will never come out of anything. I don't mean to bother, just asking if the career is worth.

limber thunder
# hollow ivy Hello to everybody, I'm still thinking about what career I can choose to study, ...

for some the act of studying mathematics in itself is the interesting bit, it can be very rewarding to see your own progress in understanding things or sharing ideas with people at e.g. a conference if you're a career mathematician

for others math becomes especially interesting when it's applied or applicable, that's also valid and you can seek an applied math major or specialize in a master's or PhD after graduating in math, these days I know of a bunch of people that majored in math or physics and then did data science, or software development or statistics

junior turtle
slate beacon
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why just skim? what about almond or whole?

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no soy though

vivid halo
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Skim proofs for some idea of how detailed or involved certain proofs will turn out to be, get some sense of which parts are long tedious computation which you can skip later and which parts are genuine insights

junior turtle
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ohhh i see, this will likely not work perfectly from the first time. But it will probably save plenty of time

vivid halo
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yes it's absolutely not supposed to work perfectly on first pass that's the point

junior turtle
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usually i avoid skipping a proof/a section/a theorem etc... but i think that i should start changing that

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tho i still dont feel too much comfortable about doing that ngl

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lol

scarlet crane
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hiii

vivid halo
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lol you need to learn to get over that discomfort

junior turtle
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yea ig

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yesterday i tried leaving complex analysis and studying modular forms and then returning to complex analysis along the way when i face things that idk in it

novel void
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hey guys im thinkin bout getting into finance would getting a maths deg for bachelors be good?

vivid halo
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like the point is on first pass you are trying to figure out what is even worth revisiting in much greater detail on second pass in the first place, and figuring roughly how things are laid out and what the overall ideas you should expect to revisit

junior turtle
vivid halo
#

this is absolutely the right thing to do and there is a huge cognitive science literature which consistently points towards this being way more efficient than the alternative

junior turtle
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what made me do this step was because there are many things that look interesting to me which i want to study, specifically stuff around number theory. But then i should have quite a bit of background so eventually i couldnt wait anymore and i was like ok its time to study what i am interested in and pick up necessary tools along the way

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I had these thoughts very recently and only really started with it yesterday

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but now i might start doing it with everything and not just complex analysis

vivid halo
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yeah this strategy applies to most other academic fields this is hardly specific to math

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nothing that is genuinely difficult ever takes a single pass

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but yeah also when you start to read fewer textbooks and start to read mostly research papers this is literally the only possible way you can have any chance at reading a useful quantity of things and getting to know the rough impression of what things people have already done and what things are interesting

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even if you are very skilled as a speedreader trying to just move your eyes over a sizeable portion of decent papers in most active subjects in mathematics takes quite a long time

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obviously skimming this aggressively often means you retain very few actual details from any single paper but this does leave you with the incredibly valuable knowledge of where to look if you should ever need some detail later

junior turtle
junior turtle
vivid halo
#

yeah for a lot of research the obstruction to finding loads of very easy fruit to pick is just like, most people don't read enough papers to be able to do this

vivid halo
#

one which unfortunately doesn't work with latex documents but works very easily with any plain text document is like

junior turtle
vivid halo
#

there is some software which lets you read plain text at maybe 2x or 3x the speed you would otherwise be able to with surprisingly little loss of retention

#

it's not magic either it's such a stupid trick

vivid halo
latent edge
#

The art of pulling out different sources and jumping back and forth

junior turtle
vivid halo
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yeah unfortunately it doesn't work for math, or at least it could work in principle but you would have to write custom software for this

latent edge
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Sounds like a project I could work on (eventually give up on it)

vivid halo
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at best you could maybe get this to work for inline stuff but any display math is fucked so unfortunately that trick isn't such a good trick anymore

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but like for reading novels it's really hilarious

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I guess the other downside to that trick is you have to be like

junior turtle
vivid halo
#

REALLY LOCKED IN and can't stop locking in

latent edge
#

Tfw last midnight I was so stubborn locking in and now I feel horrible

vivid halo
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I mean there are better speed reading tricks out there anyways but they require some training, this one is just really funny because it just instantly works out of the box

junior turtle
latent edge
#

Can't be bothered to use noggin in the morning it's slow as fuck

vivid halo
#

a mildly terrifying rabbit hole to go down is like, what kinds of speeds and retention people who are REALLY GOOD at speed reading can pull off

latent edge
#

Maybe I should take amph

vivid halo
#

you act like a crackhead half the time when you are sober, you don't need meth

#

some of the best speedreaders have unlocked incredible cheats like "what if i just stopped reading the words or the lines and just took a picture of the entire page all at once with my eyeball"

pure hollow
vivid halo
# junior turtle lmao what

the people who are best in the world at this are genetic freaks and it's not really a skill that most people can actually replicate, but there are freaks out there with weird brain quirks that makes this possible lol

#

but like short of being fastest at this a lot of people can train this skill with a fair bit of effort and still get quite good at it

pure hollow
vivid halo
#

but yeah the people who are fastest at this the speed really just does not make sense and it sounds fake until you put them through cognitive tests for information retention and it still kind of makes no sense

junior turtle
pure hollow
#

I can't do 1/10th of this in a month for mathopencry

junior turtle
#

real

#

I am reading it like a novel but surprisingly i dont understand a thing

vivid halo
#

for some numbers: average reading speed is maybe around 250 WPM, most people can hit around 750 WPM comfortable with this kind of software that just flashes text in front of your eyes as quickly as you can process that stream visually

latent edge
#

Gotta have the insane picture memory for these things

dim plank
vivid halo
#

the people that can photoread entire pages at a time tend to be in the ballpark of 10k WPM to 25k WPM with varying degrees of retention

vivid halo
pure hollow
vivid halo
#

the hack is called savant syndrome and it also usually means that you are so autistic that you are functionally disabled in many other areas of life monkey

#

but it's kind of insane that this is actually possible at all even in freak cases

#

there is one very insane case of photomemory in a savant who can do fun things like

#

you take him up in a Helicopter above the NYC skyline for a few minutes

pure hollow
vivid halo
#

then proceeds to paint a perfect photorealistic recreation of the skyline

#

every window, every building, everything

latent edge
#

Yeah insane skills

vivid halo
#

I mean my iphone camera can do that but still cool I guess

junior turtle
#

you: my iphone camera
him: my brain camera

vivid halo
#

lots of other fun cases around standard tasks like "memorize deck of cards"

#

and of course people have turned this into an autistic sport

#

you have to memorize the sequence of cards and then regurgitate that sequence without any errors

#

current world record is 12.74 seconds for memorization

pure hollow
#

We need this but "memorize nlab"

vivid halo
#

of course some of this is incredibly silly and doesn't actually translate to other cognitive tasks lol

#

reminds of the whole thing about chess players being able to photomemorize chess board configurations very very easily

#

if you move a couple pieces into an illegal configuration that cannot be reached by the normal chess rules, instantly they cannot memorize it anymore

pure hollow
#

Just have extreme cognitive abilities of all kinds.

junior turtle
#

sotrue

vivid halo
pure hollow
pure hollow
vivid halo
#

I have crazy photomemory that lets me recall all the traumatic things that have happened to me in the last 27 years

vivid halo
#

the amazing cognitive ability to forget information faster than anyone else can

junior turtle
junior turtle
vivid halo
#

very fun cognitive science fact is that if you are unable to forget things then you suddenly become massively less efficient at remembering things also

pure hollow
#

I don't think the inverse is true 😔

vivid halo
pure hollow
vivid halo
#

this tends to be a measurable issue with people who have perfect recall of their day to day activities and things like this

#

like there are people who can remember in perfect chronological order every single meal they have ever eaten

#

this isn't some skill it's a memory disability

#

here is a helpful picture that explains what is going on there

pure hollow
#

Makes sense I do wonder how much efficient memory recall affects daily life, like it surely has a impact but how much or is this even a valid question?

junior turtle
split basin
pure hollow
pure hollow
vivid halo
split basin
#

i mean there is a lot of variation across fields of math in terms of problem solving vs theory building being more central

vivid halo
#

weirdly enough Chimpanzees have much better photomemory than we do

split basin
#

but idk if it’s productive for individual people to pigeonhole themselves in this way

pure hollow
#

how do we categorize the outside world
What if the outside world is extended to non commutative cases
Thoughts of the utterly deranged (me)

vivid halo
#

basic cognitive test for this is like, take a 10x10 grid of LED squares, flash some random configuration of n squares on this board for a fraction of a second, then have the person or chimp touch all the squares which were lit

#

most people can do this very easily up to some cutoff n beyond which the skill rapidly deteriorates

latent edge
#

Chimpanzees should do Langlands then I give up

vivid halo
#

chimps can do this for larger n than we can

pure hollow
latent edge
#

hmm

vivid halo
split basin
#

i thought it was more like a testament to their patience

vivid halo
#

for most short term memory tests like this there is a fundamental cutoff on the number of bits of information that you can instantly memorize and retain for short durations

pure hollow
vivid halo
#

that cutoff tends to be pretty uniform in people

split basin
#

i actually dont know though

vivid halo
#

like you will see a pretty clear correlation between outcomes on this test and general short term memory metrics which scale in a predictive way with things like eye queue and so on

pure hollow
#

Makes sense

vivid halo
#

but then you hit a cutoff beyond which people really cannot do this reliably even as eye queue scales

pure hollow
turbid ocean
#

Mathcord neuroscientists and psychometricians in discussion

pure hollow
#

and one crank(me)

turbid sedge
#

dont forget the drug addict

brazen mulch
#

🔥

upbeat kraken
upbeat kraken
# vivid halo Like it’s a hard skill to write or deliver lectures with clarity but the bar is ...

I actually had a question about this as well

I am in grade 12 I have completed pre calculus 12 which was all computational and I am now learning proofs to fix my mathematical gaps

I do not plan becoming a mathematician or publishing papers or doing anything to do with mathematics

I wanted to learn proofs so I can understand mathematics specifically calculus at a deeper level than just mechanical problem solving

Given my goal of understanding calculus deeply and not publishing math papers or being a mathematician at all

Should my goal be to write proofs as cleanly and as high quality as possible

Of course I won’t be writing gibberish, but do I have to put extra emphasis on communication my proofs because I am just doing this for myself and not trying to become a mathematician or pursue mathematics at any form after high school

torpid bay
#

There's quite a bit of math after calculus, and also quite a bit of calculus as well, you may end up going much further than it as your understanding grows

#

catthumbsup gl

placid flume
#

Hello, does anyone have any recommendations for (not wildly expensive) ereader which is good for reading textbook PDFs or ebooks?

#

I have no room to store any more books, but the ipad screen tires my eyes when I try to read

steady grotto
#

I know some e-ink devices, but I didn't have them before

placid flume
#

Hmm maybe I will look into this red-screen mode thank you

thorny wraith
#

I am currently a math major student interested in homotopy theory and higher categories but i am having a lot of problems finding professors who work in that area in europe to get some kind of a project , is there a way i can find such ppl ?

junior turtle
thorny wraith
main star
#

Fourier>>>laplace

willow juniper
rocky shuttle
vast wraith
vivid halo
foggy meadow
#

Circles are better than non circles, who knew.

shadow palm
#

hello nerds²

#

Ofc whenever I come, everyone leaves

worldly horizon
foggy meadow
#

Hi mike

shadow palm
noble tinsel
shadow palm
south orchid
#

TIMEEEEEEEE

olive fjord
#

A jewish man goes to his rabbi and says “Oh rabbi! You will not believe what happened to me! My son left the house and became a Christian!”

The Rabbi responds in frustration “Hush, Hush, YOU would not believe what happened to ME! My child left the house and they too became a christian!”

Man says “What do we do?” To which the Rabbi says “We Pray to God and ask for his guidance”

The two men started Praying, and God responds! He tells them:

“You would not believe what happened to me…”

upper vine
#

guys i have mathematics test tomorrow
and i dont know anything
Maayyy GOD Save my AZZ

peak orchid
#

@wicked cypress

#

Bhai

#

What happened

#

Tell me

old oak
#

sub-par embed

fresh comet
drifting lark
#

It's crazy that, if you pick a random positive integer, the probability of it being greater than TREE(3) is 1.

latent edge
chrome cairn
muted marlin
#

guys can you help me with my homeworks pls😭

stiff turtle
errant bone
#

can i ask for help with physics here or do i need to go to another server or what

muted marlin
stiff turtle
#

Ig

urban vigil
stiff turtle
stiff turtle
urban vigil
#

It has pre requisites of canabi yau structures

#

And QCD landau pole

stiff turtle
urban vigil
urban vigil
stiff turtle
stiff turtle
urban vigil
#

It is a vector space applied to a complex manifold

stiff turtle
stiff turtle
stiff turtle
thorn wren
foggy meadow
#

Hello

foggy meadow
#

@blazing pawn I found you're ancient language twin.

glossy wind
#

me when politics

#

anyway

crimson nebula
#

Lmao

#

Welcome to mathcord!

glossy wind
#

indeed!

#

what you up to? aside from arguing online lol

crimson nebula
#

Studying mostly

glossy wind
#

oh are you in school?

crimson nebula
#

Undergrad

glossy wind
#

what's your major?

crimson nebula
#

Math and EE

glossy wind
#

okay wait whats EE

crimson nebula
#

Electrical engineering

glossy wind
#

ohhh

#

wait thats cool

#

have you made anything cool?

crimson nebula
#

Ive built some computer architectures, and ive built a transceiver

glossy wind
#

was it for something specific?

crimson nebula
#

Hobby projects

glossy wind
#

thats fun

crimson nebula
#

Transceiver was an excuse to use maxwells

glossy wind
#

the...

#

equation?

#

me googling

crimson nebula
#

Yeah

#

Very rich math there

#

If youre into geometry and PDEs

glossy wind
#

Ah like I said before, I'm really bad at math

#

I wanna do psychology so I need calc and vectors

crimson nebula
#

I am too lol

#

Just gotta grind at the math mines if you wanna get better

glossy wind
#

joined this server cuz i was looking for direction on how to get good

#

lol

#

hello lurkers

#

👀

crimson nebula
#

Once you get to proof-based math, it actually gets really interesting

glossy wind
#

its hard on your own and idk where to start blobsweat

#

i mean im not opposed to math as a concept

#

i think its cool

#

i just have a hard time with it

crimson nebula
#

I suppose if i had to give advice, you have to read textbooks and repeatedly practice problems

#

Almost everyone is much more capable of math than they think, its just that math is hard

#

It takes a long time and discipline

glossy wind
#

what year are you?

#

did i ask that

crimson nebula
#

Senior, rising super-senior

glossy wind
#

4th year then?

crimson nebula
#

Yeah

glossy wind
#

are u american lol?

crimson nebula
#

Ill meed another year to finish both majors

#

Mhm

glossy wind
#

well good luck on your studies, what job do you want?

crimson nebula
#

Idek yet

#

Tbh

#

Ive been wanting to get into academia

#

Teach and research

#

But im constantly debating between just going to industry and making money

glossy wind
#

you could do both, one now and the other later

crimson nebula
#

Thats what im aiming for right now, but its a bit scary

glossy wind
#

why? the industry not good or... just general fear?

crimson nebula
#

Academia scares me

#

Quite a lot of downsides that come with it

glossy wind
#

really?

crimson nebula
#

The pay isnt great, its insecure, incredibly difficult, and failing a single test can throw you into debt at the worst

glossy wind
#

oh

crimson nebula
#

Among a lot of other issues

glossy wind
#

yeah thats scary

crimson nebula
#

But its a major passion

#

I love teaching and learning

glossy wind
#

im sure you can do it, just have money saved up in case of emergencies

#

i also love teaching, i wanna work in schools either has a teacher or a school psychologist

crimson nebula
#

Id like to teach college if anything, maybe AP highschool classes

#

Having gone through hs, i really dont want to put up with their immaturity

glossy wind
#

aw really? i wanna work in high schools to help kids out

crimson nebula
#

Maybe

glossy wind
#

i didnt really attend high school though

#

and when i did it was awful

crimson nebula
#

What do you wanna teach?

glossy wind
#

probably english lol. or special ed

#

special ed is such a blessing when its facilitated properly

crimson nebula
#

It takes serious patience

#

Thats good to see tho

drifting lark
lucid obsidian
#

.

glossy wind
#

@green idol What time is it for you?

green idol
glossy wind
#

Oh wow

#

Are you in Europe?

green idol
#

Switzerland

glossy wind
#

Oh cool, do you like it there?

#

Or are you neutral

#

Heh

green idol
#

Idk man, if I were to ask you that you would say “neutral” . I lived here of course its just normal 50 50 ( boring ) opencry

glossy wind
#

I’ve never been to Switzerland but yeah

#

I mean if you asked me if I like where I live I’d say no

green idol
#

So you are from Egypt ye?

glossy wind
#

Yep! But I currently live in Canada

green idol
#

Ah nice

glossy wind
#

I hear Switzerland is nice, maybe not for a Muslim idk how the tolerance is there

#

But nice nonetheless

green idol
#

🤷

glossy wind
#

Do you not have class today?

green idol
#

nah I just got home

#

my class today was 7:30 - 10:30 am

glossy wind
#

Ah so early

#

What’s your major?

frail anvil
glossy wind
#

He means in the morning

frail anvil
green idol
frail anvil
glossy wind
#

Made anything cool?

green idol
glossy wind
#

That’s respectable

#

What sort of job do you want?

green idol
#

I like transmission

glossy wind
#

Like cars and stuff?

#

Sorry if that’s a stupid question

#

Ping me if you come back I guess

quaint sky
glossy wind
#

Can it broadcast?

quaint sky
#

If I had made an antenna for it yeah

ancient hemlock
#

hello

glossy wind
#

Do you use it to listen to the radio?

quaint sky
#

Had to make a transmitter and receiver

glossy wind
quaint sky
#

But I want to modify it to listen to aviation band so I can hear local air traffic

glossy wind
#

Oh that’s fun

ancient hemlock
#

I like some fm stations

glossy wind
glossy wind
ancient hemlock
ancient hemlock
quaint sky
quaint sky
glossy wind
#

Is there a reason you didn’t use potentiometers ?

quaint sky
glossy wind
#

Ah I see. Yeah sounds like a hassle

quaint sky
#

Yeah, but if you’re just making a receiver it’s really easy

glossy wind
#

I’ll have to take your word for it

#

Anyway I think I’m heading to bed now

#

I’m super sleepy

quaint sky
#

Real I should be too

#

Rest well!

glossy wind
#

You too!

ancient hemlock
long matrix
#

,av 358704260839374868

fathom swallowBOT
#
desdemonaii's Avatar

Click here to view the image.

long matrix
#

kawaii

pastel blade
urban vigil
fallow token
#

someone help me make a money printer

limber thunder
reef carbon
#

@neat lintel so what exactly was that joke

#

i kinda don't get it

neat lintel
#

psychic -> telepathy type

#

uh forget it

#

bad framing

reef carbon
#

i... still do not understand the joke

#

what's telepathy gotta do with anything

long matrix
#

reading minds allows you to understand languages probably ?!

reef carbon
#

... what

#

confused as ever

proud copper
#

peeks into mind
hears unga bunga noises
?????

fallen quiver
#

Lots of languages. Spies. Mission impossible

reef carbon
#

yeah idk it feels like you kinda hit a sore spot with calling me a spy

pastel blade
reef carbon
#

oh yeah hi

radiant sparrow
radiant sparrow
old oak
#

Now that's the kind of content I want to see in this server

restive mirage
#

When mathematicians ran out of real problems, they literally invented numbers.
(i=\sqrt{-1})
If I told my bank my account balance was "the square root of negative one," I’d be arrested for fraud. In math, they give you a PhD for it.😂

old oak
#

Revolutionary observations, I don't think anyone came up with that point of view before

sharp mulch
#

Stunning and innovative

old oak
#

None of the supposed "natural" numbers exist anywhere in nature

mellow wedge
agile fiber
#

not true, i met a wild 2 while hiking!

old oak
#

Wild

sharp mulch
#

wild

magic python
#

Must've been the wind...

tawdry musk
#

Has FUSRP 2026 sent out offer letters?

solid yarrow
old oak
#

They do occur in pairs

rich quail
#

Lol nozoomi

drifting lark
#

I thought of an interesting way to generate huge numbers. Idk how it measures up to, say the Goodstein meta-sequence or the TREE function, but basically...

The first number is 1.

To get the next number, you take the first number (1), and you concatenate to it all of the nonnegative integers less than it, descending to 0. In this case, the only nonnegative integer less than it is 0, so the second number in this series is 10.

To get the third number, you take the second number (10) and repeat the process. You concatenate to 10 all of the nonnegative integers less than 10, descending to 0. So the third number in this series is 109,876,543,210.

To get the fourth number you take the third number, and you concatenate to it all the nonnegative integers less than it, down to 0. This number is so large that I would need some time to compute how many digits it has.

#

The study of unfathomably gigantic numbers is really interesting to me.

solar spire
#

its like more than 109876543210

#

idk how much more tho

drifting lark
#

Yeah

#

The upper bound would be 109876543210 × 12

sterile bobcat
#

ohh i got it

torpid bay
#

10^k -> ~10^(10^k)

#

ig

#

wait hm

#

k -> ~ k^k

#

a little bit less

#

but good enough

#

roughyl equal to $^{k}x$ for k iterations when starting at number x

fathom swallowBOT
#

Yeatte

rough needle
#

pop quiz: what is the binomial coefficient

mystic hill
#

Also known as the number of ways to choose k things out of n things where it's the kth terms coefficient and the power of the binomial is n

rough needle
#

yipee u got right

foggy meadow
#

Wait until they find out trinomials exists.

mystic hill
#

Multinomial coefficient cat_uwu

#

Justice for trinomials blobcry

gleaming abyss
#

I just wanna say I've been reading this series called Dungeon Crawler Carl and it is so good. Not math related really but yeah. It made me enjoy reading again.

carmine cosmos
#

hi chat

carmine cosmos
#

i think

#

you can talk something off-topic

#

also

#

i enjoy reading too

#

i like Philosophical Books

analog silo
#

Hi everyone,
I’m looking for help with a mathematical manuscript focused on dynamical systems. The core of the work involves delay differential equations, Lyapunov stability and bifurcation analysis, asymptotic methods, and center manifold reductions.

I should mention that I’m not a math student by training, which is exactly why I’m seeking help—especially from someone very strong with rigorous calculations and analytical details (Hopf bifurcation, normal forms, Lyapunov exponents, etc.).

I’m specifically looking for someone who can commit to the project and has enough available time to help build and check the proof in a sustained way, not just give quick comments.

The project is interdisciplinary, at the interface of mathematics, nonlinear dynamics, and neuroscience (EEG–fMRI (observer/operator) modeling).

If this aligns with your expertise and availability, or you know someone who might be interested, I’d really appreciate connecting. Thanks!

ionic tree
#

Just a reality check btw (as a math professor) I'm totally with your concept but the problem with your request is that solving complex equations requires time and energy that most math graduates unfortunately lack of

dull socket
#

my intuition says this server is 80% indians

long matrix
analog silo
ionic tree
#

Not very low im saying you need time to find someone like that

gritty heath
#

Its also much easier if you ask in person than online

#

Its hard to get people to commit to anything to strangers online

analog silo
# ionic tree Not very low im saying you need time to find someone like that

I am not a math student, I m more in the computational neuroscience field… this step of solving the paradox is fundamental for the développement of other measures for precision psychoatry diagnosis (that I have in mind)
This is a long lasting project that I wish to start, and whoever I will choose to work with me will probably stick along for a few years and maybe partner with me… I m looking for a student who has been doing math but isn’t able to find what to do with it explicitly. Someone who doesn’t have solid future plans and is looking for one… I want to create a team … but like you said this will take me a while but I have to start somewhere.

I could do this in many other ways formally through labs or universities but for the moment i am a medical student so I don’t have many options, I would have to wait till I graduate

I have a big Chunk of the proof ready I just need a calculations guy

analog silo
#

And we re students not just strangers, give yourself and us some crédits, I for sur don’t seem to be trying to scam anyone

mortal marsh
#

Not enough people talk about the importance of nutrients to the human body

torpid bay
fresh comet
ionic tree
urban vigil
#

@analog silo you should try in specialised channels depending on the topic of yours, since grads mostly don't check this discussion channels

#

I didn't read it yet(will do)

urban vigil
#

I am not an expert of dynamical systems tho

#

So I don't think I can help much

analog silo
#

Thank you for your guidance 🙏

foggy meadow
torpid bay
#

i got through a real analysis problem that i procrastinated on

#

nothing new other than that catthink

languid patrol
#

I'm interested in working through a math book but I don't have any list of homework problems from a course. Is there any kind of service in the math community where people can help a student chose a set of appropriate problems from each section of a book for learning?

torpid bay
#

I haven't heard of one, but depending on what subject in math you're reading through, there should be some other books or materials online for it. The earlier the math the more likely it is you'll find it

#

there will be tons of stuff calc 2 and below, a long with linear algebra

#

what book you reading through?

languid patrol
torpid bay
languid patrol
torpid bay
#

i just looked up 'func analysis problems' hopefully it would cover the same topics, but yeah always a good chance that your book covered stuff they found to be important enough but the link i gave didnt

languid patrol
torpid bay
#

in this server, tutoring and giving money for tutoring is against the rules, the best you'll find is recs

languid patrol
torpid bay
#

school maybe

languid patrol
#

Or I could just find another book, maybe.

torpid bay
boreal fulcrum
#

Helloo

fresh comet
old oak
#

<@&268886789983436800> I have no idea what this is, but it seems shady

frail lagoon
#

This sounds very dodgy, deleting

glass peak
#

But I wanted to be crypto scammed

astral bay
#

has anyone here heard of netmath at UIUC, or taken any of their courses? i am interested in their MATH 444 course. wondering if anyone has taken it or heard about it.

cinder zephyr
#

it was fine but I think I benefitted alot from there still being a teacher at the high school I could ask questions to

#

doing Math 444 completely online, idk it depends on your strengths and how good you feel you are at studying on your own (I went to UIUC so I know what 444 is, intro real analysis)

#

I mean using mathematica for calc 3 stuff was nice

#

idk how useful it is for proof based courses though

astral bay
#

nice, it's good to hear from someone with firsthand experience

#

so i am kind of going back and "filling in the gaps"... i was an engineering student, so i only had up to calc 3. since returning to school i've taken foundations, vector spaces, group theory, rings and fields, all kinds of stuff, never an analysis course.

#

or actually i had linear algebra and diffeq too

astral bay
torpid bay
#

im going through tao's analysis

#

ive procrastinated far too long with it

foggy meadow
torpid bay
#

I'm kinda liking geometric algebra less and less

#

half the notation i've seen that GA loves is just bad notation

zealous garden
torpid bay
#

well

zealous garden
foggy meadow
torpid bay
#

I was looking at geometric algebra notation for calculus, with nabla, but then 3 different obejcts end up having the same exact notation as each other, (some seem to change this slightly), and i haven't seen much complaint in various geometric algebra videos about it.

zealous garden
torpid bay
#

specifically maxwells equations

zealous garden
#

AHAHAHA

foggy meadow
#

So, actually applying GA.

zealous garden
#

That specifically is a good one, but I'll say part of the reason you won't see a complaint is that most actual sources will actually have a single consistent convention, but there isn't a standard I would say

torpid bay
zealous garden
#

I assume you mean the gradient, vector/geometric derivative, and spacetime gradient?

torpid bay
#

take the gradient of a vector field, taking the nabla geometric product vector field, and whatever he last one is called where they write the same thing being nalba F = J

zealous garden
#

and the last example is literally just the geometric derivative, but acknowledging the underlying manifold as spacetime and not just space

#

and the geometric derivative of a scalar field corresponds exactly to the gradient of a scalar field as well

#

it's actually well justified

#

and the geometric derivative squares to the laplacian as well

torpid bay
zealous garden
#

the only real confusion I see there is from the fact that people often intermix classical and relativistic ideas when discussing maxwell

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So you have a spacelike gradient and laplacian, and then separate time derivatives, or you have spacetime derivatives.

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Have you seen how GA unifies the lorentz force law?

torpid bay
#

hm

zealous garden
#

This is the fun thing, GA can, regardless of whether you chose to use a relativistic, or more classical, formulation, unify the lorentz force laws into a single form, just as they reduce maxwell to a single equation.

torpid bay
#

i think ill do that part, dont spoil it catthumbsup

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annoying how none of the actual geometric algebra sources atually explained that stuff above

zealous garden
#

Where have you been learning GA

torpid bay
#

1: youtube, 2: wiki

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flawless combinatoin i know

foggy meadow
#

Get LAGA?

zealous garden
#

There is a textbook of decent utility that I've skimmed and stolen/modified some notation from, not on my usual list of recommendations but the author has the PDF freely available on his website

torpid bay
#

i do have a question about the last nabla F = J thing

zealous garden
foggy meadow
#

AG is fun.

torpid bay
#

using $\Psi = E + B\gamma$ and $p_\Psi = p_e + p_m\gamma$ and $j_e+j_m\gamma = j_\Psi$ I have $(\partial_T+\nabla \gprod)\Psi = p_\Psi-j_\Psi$

fathom swallowBOT
#

Yeatte

zealous garden
#

they are not the same no

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Their intersection might not be trivial though

torpid bay
#

hm

zealous garden
torpid bay
#

yeah

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i let gamma = w

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originally i had them be seperate, but they always showed up together and kinda made them equal as a "what if"

zealous garden
zealous garden
# fathom swallow **Yeatte**

if gamma is the imaginary unit, then F= E+B\gamma works.
If gamma is a timelike basis vector, then F= E+B\gamma is absolutely wrong

torpid bay
#

hold on, im thinking through the question

foggy meadow
#

wick rotation?

torpid bay
#

ah yeah gamma^2 = -1

zealous garden
#

That's fine, you can do spacetime algebra in +++-

#

the square of gamma is not the issue, desu

torpid bay
#

but ye it imaginary thing

zealous garden
#

E+B\gamma cannot possibly be the correct type of quantity when gamma is a vector

torpid bay
#

for me, gamma was the way to translate magnetic vector thingy into electric vector thingy and back

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and the two 3 vectors end up as seperate spaces

zealous garden
#

If we have moved to a 4D relativistic representation, F is a bivector. E and B have to be bivectors. Furthermore, E is actually the one that picks up a factor of the timelike vector, while the magnetic bivector field B remains a product of only spacelike vectors

torpid bay
#

i just multiply by gamma to go between the 2

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E and B are the 6 bivectors in 1,4,6,4,1 then ig?

zealous garden
#

if gamma is acting as the imaginary unit in a 3D representation, it is best thought of as a trivector, where it then encodes a duality between vectors and bivectors within its subalgebra.

torpid bay
#

yep

zealous garden
torpid bay
#

another naggin reason i wasnt liking GA for maxwells, was because it felt like magnetic and electric fields were arbitrarily treated differently, (tho one could always turn their vector-bivector status into bivector-vector via a dual)

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so 4D spacetiem fixes that then

zealous garden
#

It's not arbitary at all actually

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yeah so you start from a 4D perspective

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then project!

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realize that you can't actually see along the timelike direction

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therefore, these Electric bivectors with a timelike direction, get cut down into lines

torpid bay
#

I wanted stuff to represent magnetic and electric fields as symmetrical (to the maximum extent i could)

zealous garden
#

There's a more rigorous formulation of this, the spacetime split, that allows us to see how the rotations of this 4D space project down into a particular observer's 3D reference world

torpid bay
#

also, that rotaiton is just the lorentz boost, right?

zealous garden
#

Yes

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accelerations are lorentz boosts

torpid bay
#

if i really wanted to

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I could modify maxwells equations and make the magnetric field the vector and the electric field the bivector instead right? or vice versa?

zealous garden
#

Well, vectors and bivectors in 3D are related through duality. Duality also relates the exterior and interior products, and therefore the curl and divergence. So yes, you should be able to convert all of the statements in whichever direction you want through intelligent application of the dual

torpid bay
#

oh yeah

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i never got a nice version for the lorentz

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force

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i rememer now

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or is it lorenz

gray glade
#

as in, non-physically

torpid bay
#

the best I could do was making a certain kinda of new dot product that in back then's words would be "real part of q vector multiply be real part of psi vector plus imaginary part of q vector multply by imaginary part of psi vector"

gray glade
#

just changing coordinates to some constant velocity

torpid bay
#

$F_\Psi = k_\Psi q_\psi\cdot(1+\vec{v}\wedge)\Psi$

fathom swallowBOT
#

Yeatte

zealous garden
#

tf

torpid bay
#

k is just a constant

zealous garden
#

what is that

torpid bay
zealous garden
#

what is F_psi

foggy meadow
#

What is all of it?

torpid bay
#

force due to the electromagnetic field, Psi

zealous garden
torpid bay
#

k is a constant, i would have to look up later exactly what it is, just say its 1 for now

#

as for the pseudo dot product

zealous garden
torpid bay
#

$(q_e + q_m\gamma) \cdot(E+B\gamma) = q_eE +q_mM = q_\Psi\cdot\Psi$

#

yes

#

prob some other notation for this

gray glade
#

it's amazing how many different ways you can phrase CED

zealous garden
#

I have Joot's answer in my clipboard for you

gray glade
#

and how compactly you can do it

#

almost intimidating

zealous garden
#

Lorentz force and power

fathom swallowBOT
#

Yeatte

torpid bay
#

a scalar cdot a vector, a little cursed but catshrug

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matrices i just didnt want to bother with

foggy meadow
#

Programmers ^

zealous garden