This Is The Best Resource For Studying Math That I've Found In A While! It's 300+ Pages Of Flawed/incorrect

Weaving Stereographic Projection

I made a stereographic projection by weaving paper strips!

Here's a Julia package for the computation of the shapes of the paper strips.

GitHub

GitHub - hyrodium/ElasticSurfaceEmbedding.jl: The weaving paper strips: shape optimization by geometric elasticity

The weaving paper strips: shape optimization by geometric elasticity - GitHub - hyrodium/ElasticSurfaceEmbedding.jl: The weaving paper strip

Japanese blog post about this: https://note.com/hyrodium/n/n7b7cf03a7d91

being a humanities major who’s friends with stem majors is so funny because you’ll ask your friends what they’re doing today and they’re like “UGH it’s so stressful i have to stabilize the reactor core for my nuclear power midterm and then i have to build the supercomputer from i have no mouth yet i must scream for my electrical engineering homework :/ what about you” and you’re like “oh well i have to read a fun little book and write an essay about gender.” and they still think you have it worse

12 XII 2022

I have a test at the end of this week so I am mostly grinding for that, kinda ignoring other things along the way, planning to catch up with them during the christmas break

the new update for my tablet's OS brought the option to insert pictures into the notes, so now I can paste the problem statements directly from the book. I am not sure if this is actually efficient but it surely looks better and the notes are more readable

(I can't vouch for the correctness of those tho lol I just started learning about the Rouché's theorem)

I have been trying to keep up with the material discussed in lectures on commutative algebra and agebraic methods. with each lecture there is a set of homework problems to solve and I predefined a standard for myself that this week it's alright if I don't do the homework because grinding for the test is more important

I made some pretty notes on valuation rings

during the break I need to study finite and integral ring maps and valuation rings for commutative algebra course; resolutions, derived functors and universal coefficients theorem for algebraic methods course. I feel pretty good about the test that's coming up. sure, you can never be too prepared but so far I've been able to solve a good part of the problems I tried, so I should be ok

I know we all have different skills and all and it's supposed to be complementary, but, people who can do math are so morbidly funny to me

I figure it must be like

Imagine being like only one of twelve people in your whole city who can read and write

And it's not just because everyone else is uneducated, most of them cannot even learn the sort of things you can learn. Or they could, in theory, but it frustrates them so much that they never make it past grade school reading tops, and they hate every second of it

And it's not a "luxury" skill, either, like your whole society needs the written word to function, and by extension, they need you. They need you for shit like reading labels and instruction manuals and writting 2 sentences letters, and they pay you handsomely for that, which is nice, but also feels absurd

You read a whole series of novels that rock your life and you can't even talk about it to your best friend because anything more complex than a picture book breaks their brain

welcome ✨

i'm a math student, currently persuing master's degree. this semester I'm taking courses on complex manifolds, category theory, equivariant cohomology and representation theory

my bachelor's thesis was about my partial result in the knot/link theory. right now I'm finishing that proof and hoping to publish it when (if?) I'm done. my interests include algebraic and geometric topology and the goal for this year is to get to know some algebraic geometry

I post updates of how I'm doing, photos of my ugly notes and sometimes share some study methods that proved to be useful to me

oh and math is my special interest, I take it way too seriously lol

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my posts with study tips:

tips for studying math

tips for studying math part 2: you have an exam but the course is boring

What's the beef between engineers and physicists and even mathematicians.

Why physicists mock mathematicians: Because playing 51 dimensional chess against your own brain seems silly to us when there’s a whole cosmos to explore.

Why mathematicians mock physicists: The universe can only be understood because some nerd spent the time playing 51 dimensional chess and in the process they created some useful stuff for the physicists to steal and abuse the hell out of.

Why everyone mocks the engineers: π=e=3 is an abomination before God and those pencil pushing dorks make more money than us so we feel the need to vindicate our $75000 student debt.

free recall

here I am sitting and trying to learn something from a textbook by making notes and ugh I don't think this is gonna work

what I'm writing down will probably leave my head the second I switch tasks

today I found a cool video about taking notes during lectures and a method called free recall is mentioned there:

to summarize: taking notes during the lecture is ineffective, because it requires dividing attention into writing and processing the auditory input. instead of doing that one should just listen and then try to write down the contents of the lecture from memory. I can believe that – this is how I studied for my commutative algebra exam and the whole process went really fast. I highly recommens this guy's channel, he is a neuroscientist and bases his videos off of research findings

I will try to do this with textbooks and after a while I'll share how it felt and if I plan to keep doing it. the immediate advantage of this approach is that it gives raw information for what needs the most work and what can be skipped, which is often hard to see when trying to evaluate one's knowledge just by thinking about it. another thing that comes to mind is the accountability component – it is much easier to focus on the text while knowing that one is supposed to write down as much as possible after. kinda like the "gamify" trick I saw in the context of surviving boring tasks with adhd

I'll use this method to study differential geometry, algebraic topology, galois theory and statistics. let's see how it goes

I'm reblogging this to compare it later with 1.A from Hatcher's Algebraic Topology. in that chapter he defines the topology on a graph if anyone else wants to check it out

Intuitively, it seems to me that graphs should be some sort of finite topological space. I mean, topology studies "how spaces are connected to themselves", and a graph represents a finite space of points with all the internal connections mapped out. That sounds topological to me! And of course many people consider the Seven Bridges of Königsberg problem to be the "beginning" of topology, and that's a graph theory problem. So graphs should be topological spaces.

Now, I vaguely remember searching for this before and finding out that they aren't, but I decided to investigate for myself. After a bit of thought, it turns out that graphs can't be topological spaces while preserving properties that we would intuitively want. Here's (at least one of the reasons) why:

We want to put some topology on the vertices of our graph such that graph-theoretic properties and topological properties line up—of particular relevance here, we want graph-theoretic connectedness to line up with topological connectedness. But consider the following pair of graphs on four vertices:

On the left is the co-paw graph, and on the right is the cycle graph C_4.

Graph theoretically, the co-paw graph has two connected components, and C_4 has only one. Now consider the subgraph {A, D} of the co-paw graph. Graph theoretically, it is disconnected, and if we want it to also be topologically disconnected, it must by definition be the union of two disjoint open sets. Therefore, in whatever topology we put on this graph, {A} and {D} must be open. The same argument shows that {B} and {C} must be open as well. Therefore the topology on the co-paw graph must be the discrete topology.

Now consider the subgraph {B, D} of C_4. It is disconnected, so again {B} and {D} must be open. Since {A, C} is also disconnected, {A} and {C} must be open. So the topology on C_4 must again be the discrete topology.

But these graphs aren't isomorphic! So they definitely shouldn't have the same topology.

It is therefore impossible to put a topology on the points of a graph such that its graph-theoretic properties line up with its topological properties.

Kind of disappointing TBH.

I know your thesis was about something to do with algebraic topology, may I ask what exactly it was about?

(and congrats to you getting your bachelors degree and into a masters program)

(thank you!)

my thesis was about an open question regarding a certain skein module of tangles on 2n nodes. the conjecture is that the module is free and in my thesis I constructed a generating set that is free for n=2,3 (direct calculation) but I have yet to prove that for a general n. if you are interested I can send you the paper in which the question was posed, all the details are explained there and would be hard to write down here without tex lol