Today I Learned That For A Surface With Boundary, Which I Believe We Can Say A Straw Is, The Genus Is

today I learned that for a surface with boundary, which I believe we can say a straw is, the genus is equal to that of a 2-manifold obtained from attaching disks to the boundary. hence the straw has genus equal to that of a 2-sphere, which is 0, therefore a straw has 0 holes

also a straw is not homotopic to a torus I think, but rather to S¹, as it's a product of S¹ and a closed interval, which is contractible. a torus has the fundamental group S¹×S¹, thus they cannot be homotopy equivalent. buuut that requires the straw to be infinitely thin so maybe I'm too idealistic for this claim to hold and it is in fact equivalent to a torus

lmao I love math but I can't stop laughing at the fact that it took me two years of university to be able to have this discussion

I’m really into internet discourse but only pointless and stupid internet discourse like how many holes there are in a straw (it’s 2)

Tags

More Posts from Bsdndprplplld and Others

1 year ago

Hey students, here’s a pro tip: do not write an email to your prof while you’re seriously sick.

Signed, a person who somehow came up with “dear hello, I am sick and not sure if I’ll be alive to come tomorrow and I’m sorry, best slutantions, [name]”.

1 year ago

oh i just saw, congrats on the bachelors!! im still in calc 3, i thought itd be less mundane but it is actually killing now to the point where i cant even open our stewart text. all my friends in decent math programs are doing more fun and general versions this course. i just cant wait to not use this awful book anymore (all our work is based on the books problems and methodology). all this is to say your progress is inspiring. hopefully i get to a point where i can also be having fun around structures and such, i just have to finish grinding through the filter of "do a bunch of this and don't worry about what it really means, btw good luck problem solving on your exams with 0 neither provided intuition nor rigor". i hope blogs like this stick around!

thank you for the nice message!

I'm so sorry to hear that this is how they teach you math, something like this takes away all pleasure and satisfaction. I didn't have calc 3 as such at my university, we would generally focus on theory and understanding from the start. however, we did have some courses where the mindset was like you just described and it was torture. I hope it changes for you soon so that you can finally enjoy some beautiful math!

2 years ago

(I'm reblogging this for later to really look into all the amazing accounts I follow)

Let's get a new mathblr roll call going! There's an older version but it's got a decent number of inactive people on it so let's start fresh. Reblog and/or reply tagging yourself and any other good math accounts!

Math shitposters! Math academia aesthetic blogs! Math studyblrs! Unthemed blogs owned by people who happen to be math fans! CS, stats, physics and other math-adjacent dorks too if they like hanging out with the math crowd! I want them all!

2 years ago

"Wow you're so naturally talented!" "You truly are gif-" biting you biting you biting you biting you die die die die I didn't work for thousands of hours to get called naturally talented fuck you fuck you fuck you I wasn't a particularly gifted beginner I just didn't stop doing it aaaaaaaaaaaaaaaaaaa

2 years ago

25 XII 2022

this chunk of the semester is finally over, sweet jesus I'm so exhausted. I'm getting the well-deserved rest and later catching up with all the things I put on my to-do list that I kinda learned but not really

the test I had last week went fine. frankly I expected more from it after solving more than 50 problems during my prep, but I scored 74%, which is objectively great and more than I predicted after submitting my solutions

here is my math plan for the break:

25 XII 2022

in algebraic methods I started falling behind a few weeks ago when I missed two lectures while being sick. they were about resolutions, derived functors and group homology and afterwards I wasn't really able to stay on top of my game like before. high time to get back on track. in commutative algebra I was doing ok, but there are some topics I neglected: finite and integral maps and Noether's normalization. for complex analysis everything is great until we introduced the order of growth and recently we've been doing some algebraic number theory, which btw is a huge disappointment. don't get me wrong, I understand the significance of Riemann's ζ, but the problems we did all consisted of subtle inequalities and a lot of technical details. I am doing mainly algebraic stuff to avoid these kind of things lol

when we were doing simplicial sets I stumbled upon some formulas for the simplicial set functor and its geometric realization and I thought it to be a nice exercise to probe them, so here it is:

25 XII 2022
25 XII 2022

I won't know if this proof actually works until I attend office hours to find out, but I am satisfied with the work I put into it

I already started making some notes on the derived functors

25 XII 2022

other than that I have this nice book that will help me prepare for writing my thesis, so I'd like to take a look at that too

25 XII 2022

as for the non-math plans, I am rewatching good doctor. my brain has this nice property that after a year has passed since finishing a show I no longer remember anything, the exponential distribution is relatable like that. this allows endless recycling of my favourite series, I just need to wait

I wish you all a pleasant break and I hope everyone is getting some rest like I am


Tags
3 years ago

27 IV 2022

neglected this place very much, would like to start posting again

may I start with what's new

the last semester was pretty much a failure, I passed everything but my grades were trash. had me seriously doubting my abilities

turns out studying comes easier when I am medicated correctly. I was diagnosed with adhd and asd, so now that I have proper meds and understand my brain a little bit better, things come easier

I fell deeply in love with algebraic topology. there was a notion of excitement about the whole concept of homotopy a few months ago, but now I am fiercely invested in making algebraic topo my field of choice

psychologically I am working on focusing more on the process than the results. it means that my goal is not "to be good at math" but rather to complete this homework, pass that test, etc., in hopes of reducing some of the stress coming from the fear of failure

my current semester is quite boring. ODEs are trivial, yet I have to sit on my ass for a few hours and learn how to solve them. analysis is difficult as always although differential forms are interesting. probability theory is just not my thing. only topology is the light in the tunnel

I don't have any specific plans for the next few days nor do I have any goals. maybe I want to study covering spaces and solve some problems concerning the fundamental group. other than that I need to complete my analysis homework and study de Rham cohomology

27 IV 2022

here are my category theory notes


Tags
3 years ago

8 V 2022

I am on my way home from a math conference, the first one in which I participated actively – I prepaired the talk about the Borsuk-Ulam theorem

my lecture was centered around the connection between the classic "continuous" BUT and its combinatorial analog: Tucker's lemma

I wanted to talk about this because I was amazed at how cool and "versatile" this theorem is. there is a whole book about its applications and generalizations, which is btw very well-written, I highly encourage everyone to read it:

8 V 2022

my presentation went well, although after practicing it for about a week the topic seemed really fucking boring to me, no wonder

other than that I have another recommendation to make. do you also hate how messy multivariable calculus is? I do. calculations and technical definitions everywhere, and at the end everything comes down to calculating the determinant of some jacobian. bluh. I stumbled upon a book that describes everything from a sort of algebraic perspective, smells a little bit like category theory too. very clean, very satisfying to read:

8 V 2022

I have been studying covering spaces recently and I can give some dope motivation for learning about the structure induced by the covering mapping:

8 V 2022

I will never forget that the homomorphism induced by the covering projection is injective

that would be it for my mathemathical life. my personal life, which is still closely connected to math, brings me some psychological progress. I no longer get stuck in loops of "oh I'm so bad at math. maybe I'm not? I got a good grade from X. ah but I got a shit grade afterwards". it might be because I didn't fall on my face for a while now, only decent grades, good ideas, a good presentation, this is correct. but I also do not negotiate with myself that this is supposed to be proof that I'm good enough, I just stopped paying attention to these and focused on math instead. and paradoxically when I stopped caring about being good at math I was rewarded with getting better at math???

a coincidence,

a pleasant one, nonetheless.

anyway I will have to take a fall at some point, unavoidable. and it will be the final test of my progress, becauase I used to get very elevated in my sense of self-worth after receiving a single good grade among trash ones and now I'm just ok. not the god, just ok. but back then, at some point I would no longer be god, I would get smacked in the face by some "proof that I'm actually trash" and that would be a fall from a significant altitude. so I'm hoping that the fall will also be less painful now

I think the biggest change I made was giving up, I abandoned all hope. nooow here is the moment when people interrupt me with "nooo that's horrible don't give up you're a great person you just have to notice that"

fuck off you don't understand shit

I'm doing better now precisely because I stopped hoping that one day I'll stop feeling worthless, that one day something great will happen that will prove once and for all that I'm meant for something great. I can't stand this anymore, I am disgusted by the fact that deep down I still believe that I'm supposed to be the best and that I can't enjoy anything unless I am winning. I want to puke when I'm reminded that everything I do serves the purpose of winning the negotiations I have with myself about what my actual value is

my self-hatred runs much deeper now than ever before and I have no more patience for self-victimization, no more room for "allowing myself to feel". fuck off, all I feel is rage. I want to be able to do things without the prospect of a reward, my goal is to enjoy things, not the sense of being good at doing things

so that's what I'm doing, I made peace with the fact that I will probably never feel good about myself and that I have no chance at achieving the greatness I crave. and I must say I started respecting myself more, turns out I am actually able to do things without the promise of being the best at them, the vision of bringing value to the world motivates me. and fuck the western culture with its oh you must love yourself you are a great person. no, you don't have to do that and you have no way of knowing what kind of person you are, nobody has ever defined it in a strict formal sense, people just use this phrase to trigger the feel-good in others

I am aware that all of this sounds really bad, but I don't care, it works. and my math will be better like that because now that I stopped crying over being trash I have more time to study

I just hope that the fall won't be as painful


Tags
3 years ago

30 VII – 1 VIII 2021

done some stuff

sleep: I'm on it, gonna get better soon

concentration: alright

phone time: alright

did some multivar calculus today, didn't do any topo unfortunately, finished the functionality in the coding project, finished the art comission, watched some lectures from MIT

tomorrow going to a different city, gotta wake up early so will be dead all day ugh. plan to do some coding and finish the chapter from the multivar calc book. at the end of it i will find out what the manifold actually is and some of what can be done with it, pretty excited


Tags
1 year ago

touch grassmannian

touching grass is not enough sometimes. sometimes what you actually need to touch is a math textbook

Loading...
End of content
No more pages to load
  • catrillion
    catrillion reblogged this · 1 week ago
  • partialmagic
    partialmagic reblogged this · 1 week ago
  • raepritewrites
    raepritewrites reblogged this · 1 week ago
  • raepritewrites
    raepritewrites liked this · 1 week ago
  • sundaysapphic
    sundaysapphic reblogged this · 1 week ago
  • sundaysapphic
    sundaysapphic liked this · 1 week ago
  • rustedmustard
    rustedmustard reblogged this · 1 week ago
  • rustedmustard
    rustedmustard liked this · 1 week ago
  • slytherintoyourpants
    slytherintoyourpants reblogged this · 1 week ago
  • ralaferin
    ralaferin reblogged this · 1 week ago
  • p-en
    p-en reblogged this · 1 week ago
  • postapocalypticparenting
    postapocalypticparenting reblogged this · 1 week ago
  • ximajs
    ximajs reblogged this · 1 week ago
  • stabbingcrab
    stabbingcrab liked this · 1 week ago
  • thehjolle
    thehjolle liked this · 1 week ago
  • fadingcheesecaketyphoon
    fadingcheesecaketyphoon liked this · 1 week ago
  • leftherringbailiffcash
    leftherringbailiffcash reblogged this · 1 week ago
  • leftherringbailiffcash
    leftherringbailiffcash liked this · 1 week ago
  • fab-wolf-in-the-gloom
    fab-wolf-in-the-gloom liked this · 2 weeks ago
  • dancerandfighter
    dancerandfighter liked this · 2 weeks ago
  • doofnoof
    doofnoof reblogged this · 2 weeks ago
  • mistytheghost
    mistytheghost reblogged this · 2 weeks ago
  • peaches876
    peaches876 reblogged this · 2 weeks ago
  • jahriaharley8-blog
    jahriaharley8-blog liked this · 2 weeks ago
  • youcandalekmyballs
    youcandalekmyballs reblogged this · 2 weeks ago
  • tiedpawslikeheraklescloak
    tiedpawslikeheraklescloak reblogged this · 2 weeks ago
  • artisticdissonance
    artisticdissonance reblogged this · 2 weeks ago
  • artisticdissonance
    artisticdissonance liked this · 2 weeks ago
  • sentient-forest-boy
    sentient-forest-boy reblogged this · 2 weeks ago
  • darkmoonravewolf
    darkmoonravewolf liked this · 2 weeks ago
  • buzzingbree
    buzzingbree liked this · 2 weeks ago
  • yourhollywoodsong
    yourhollywoodsong reblogged this · 2 weeks ago
  • yourhollywoodsong
    yourhollywoodsong liked this · 2 weeks ago
  • these-lavender-blues
    these-lavender-blues liked this · 2 weeks ago
  • missus-chanandler-bong
    missus-chanandler-bong reblogged this · 2 weeks ago
  • haywirehawk
    haywirehawk liked this · 2 weeks ago
  • moontyrant
    moontyrant reblogged this · 2 weeks ago
  • detectivebambam
    detectivebambam liked this · 2 weeks ago
  • coke-nail
    coke-nail reblogged this · 2 weeks ago
  • bri-of-the-shire
    bri-of-the-shire reblogged this · 2 weeks ago
  • bri-of-the-shire
    bri-of-the-shire liked this · 2 weeks ago
  • letthesunburnyourskin
    letthesunburnyourskin reblogged this · 2 weeks ago
  • traditionaleagle
    traditionaleagle reblogged this · 2 weeks ago
  • traditionaleagle
    traditionaleagle liked this · 2 weeks ago
  • incorporealbagelbeing
    incorporealbagelbeing reblogged this · 2 weeks ago
  • hololesbian
    hololesbian reblogged this · 2 weeks ago
  • carapacequeen
    carapacequeen reblogged this · 2 weeks ago
  • unironicallyresurrected
    unironicallyresurrected reblogged this · 2 weeks ago
  • unironicallyresurrected
    unironicallyresurrected liked this · 2 weeks ago
  • mimris
    mimris reblogged this · 2 weeks ago
bsdndprplplld - you can't comb a hairy ball
you can't comb a hairy ball

⁕ pure math undergrad ⁕ in love with anything algebraic ⁕

292 posts

Explore Tumblr Blog
Search Through Tumblr Tags