27 Unhelpful Facts About Category Theory

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Oliver Lugg

Oliver Lugg

2 жыл бұрын

Category theory is the heart of mathematical structure. In this video, I will drive a stake through that heart. I don't know why I made this.
Grothendieck Googling: / grothendieckg
Join my Discord server to discuss this video and more: / discord
MUSIC
Oregano
Vendla (Epidemic Sound)
Penumbra
Kevin MacLeod (incompetech.com)

Пікірлер: 982
@OliverLugg
@OliverLugg Жыл бұрын
I've kept my promise of making a serious follow-up which actually explains the details of category theory. You can find it here: kzfaq.info/get/bejne/r6eZZruIqKjPdKM.html
@louiswong921
@louiswong921 Жыл бұрын
Disclaimer: Followup may not include breaks (like fact 16)
@BS-bd4xo
@BS-bd4xo Жыл бұрын
@@louiswong921 NOOO
@petevenuti7355
@petevenuti7355 Жыл бұрын
Sometimes the Funnest part is the truth...
@mihailmilev9909
@mihailmilev9909 11 ай бұрын
Yup. Thanks! 👋👍😀👍👍👍
@mihailmilev9909
@mihailmilev9909 11 ай бұрын
And it was good indeed. I saw it first. Or at least watched it ig.
@Wolfie2TMX
@Wolfie2TMX 2 жыл бұрын
You've heard of "The mitochondria is the powerhouse of the cell", now get ready for "A monad is a monoid in the category of endofunctors"
@VincentKun
@VincentKun 2 жыл бұрын
Thats wild mate, like "a tensor is an object that transforms like a tensor"
@TheReligiousAtheists
@TheReligiousAtheists 2 жыл бұрын
@@VincentKun A vector is an element of a vector space
@hhaavvvvii
@hhaavvvvii 2 жыл бұрын
I'm pretty sure I've heard the latter way more often than the former. I never realized there's a natural transformation between them in the categories of jokes.
@markuspfeifer8473
@markuspfeifer8473 2 жыл бұрын
A monad is a category where objects are the image of some functor F and the arrows are of type A -> F(B). The requirement that a monad forms a category implied in particular that composition of those arrows (however it might work) ought to be associative and there ought to be an identity arrow, often called „pure“ (or „return“ if you look at it from the point of view of operational semantics).
@toddtrimble2555
@toddtrimble2555 2 жыл бұрын
@@markuspfeifer8473 You're referring to a Kleisli category of a monad.
@Thebiggestgordon
@Thebiggestgordon 2 жыл бұрын
You made an entire video, just to explain to *270 000* people _juuust_ enough about category theory, so you could hit them with the worlds nerdiest your mum joke. Respect.
@Sciencedoneright
@Sciencedoneright Жыл бұрын
It was never told that it was a joke ;)
@KIT8882
@KIT8882 Жыл бұрын
@@Sciencedoneright read fact 1 again (oh wait is it a liar paradox?)
@Sciencedoneright
@Sciencedoneright Жыл бұрын
​@@KIT8882 oh 😂 I forgot, haha
@lisa2052
@lisa2052 Жыл бұрын
Genius, isn‘t it
@user-pr6ed3ri2k
@user-pr6ed3ri2k 11 ай бұрын
Read this comment right after that
@oliviapg
@oliviapg 2 жыл бұрын
“A coconut is just a nut” I absolutely lost it here, I don’t know why
@mini_bomba
@mini_bomba 2 жыл бұрын
it's the moment, when you realise that the "coco" in "coconut" is a double inversion, making it redundant and can therefore be safely removed... leaving you with just "nut"
@DiracComb.7585
@DiracComb.7585 2 жыл бұрын
@@mini_bomba but I’d like to remove excluded middle please, so coco doesn’t necessarily get you back to the same place
@reo101
@reo101 2 жыл бұрын
So a cocone is just a ne?
@nonavad
@nonavad 2 жыл бұрын
@@reo101 we are the coauthors who say ne! NE! NE! NE!
@Dimiranger
@Dimiranger 2 жыл бұрын
@@DiracComb.7585 Ah, a constructivist!
@JonnyPS111
@JonnyPS111 2 жыл бұрын
As a cocreator of this video, I very much like it.
@BenRHarsh
@BenRHarsh 2 жыл бұрын
As your coposter, I couldn't agree more.
@JordanMetroidManiac
@JordanMetroidManiac 2 жыл бұрын
I see no correlation in the replies to this comment and the original comment!
@nicefloweytheoverseer7632
@nicefloweytheoverseer7632 2 жыл бұрын
Uncreator, unpostor, unrrelation, unmment
@strangeWaters
@strangeWaters 2 жыл бұрын
If category theorists were in charge of naming things, children would be called "co-parents".
@Dong_Harvey
@Dong_Harvey 2 жыл бұрын
@@strangeWaters they did start as haploid cells cooperating via copulation
@123TeeMee
@123TeeMee 2 жыл бұрын
You say category theory's one application is functional programming, but among programmers, there is a joke about asking of the applications of functional programming
@jimbocho660
@jimbocho660 2 жыл бұрын
Apache Spark is written using functional programming in Scala. Spark is the most widely used computing infrastructure for big data machine learning. Functional programming is very suited to parallel computing.
@maean7410
@maean7410 2 жыл бұрын
@@jimbocho660 yeah but thats nerd shit
@koacado
@koacado 2 жыл бұрын
have you heard of... Rust? :D
@AjaxGb
@AjaxGb 2 жыл бұрын
@@koacado Rust is many things, most of which I like, but it is not a functional programming language.
@fragileomniscience7647
@fragileomniscience7647 2 жыл бұрын
Beautiful short code. If you understand it... *IF(!)* you understand it...
@johnchessant3012
@johnchessant3012 2 жыл бұрын
A comathematician is a device that turns cotheorems into ffee.
@kyay10
@kyay10 2 жыл бұрын
Nah a comathematician turns theorems into coffee. Therefore, coffee is isomorphic to theorems, and so my proof for the Riemann hypothesis is... a half shot of Espresso
@c.a.7058
@c.a.7058 2 жыл бұрын
This is my favourite joke in mathematics, glad to see it here.
@jonasvanderschaaf
@jonasvanderschaaf 2 жыл бұрын
Wouldn’t it turn ffee into cotheorems?
@c.a.7058
@c.a.7058 2 жыл бұрын
@@jonasvanderschaaf no, arrows must be reversed! (the joke is on the common saying "a mathematician is a device that turns coffee into theorems"
@jonasvanderschaaf
@jonasvanderschaaf 2 жыл бұрын
@@c.a.7058 you're right of course, I must have been tired from trying to understand what the everliving **** the Yoneda lemma actually means
@CookieQuantum
@CookieQuantum 2 жыл бұрын
I feel like I now know less math than I did nine minutes and twenty-five seconds ago.
@koacado
@koacado 2 жыл бұрын
Every second that passes you know less math. We all do.
@user-jr7ns3bl9c
@user-jr7ns3bl9c 2 жыл бұрын
Well technically new math is developed at faster pace than you can consume, so every second you know less _part_ of totality of math whether you watch this video or not
@travcollier
@travcollier 2 жыл бұрын
There is no math. There is only maths
@tompw3141
@tompw3141 2 жыл бұрын
It's an example of coeducation. Everyone knows you learn less in a coeducational dorm.
@SeanNicholsEh
@SeanNicholsEh 2 жыл бұрын
Don't worry. I spent 4½ years studying Category Theory in grad school. I 𝘥𝘦𝘧𝘪𝘯𝘪𝘵𝘦𝘭𝘺 know less math now than I did when I started that journey.
@tristan5494
@tristan5494 2 жыл бұрын
Thanks a bunch! If i’m ever at a party where someone asks me to prove my intelligence by naming 27 facts about Category Theory, i’m set! (No, wait, I’m Class!)
@quantumchill5237
@quantumchill5237 2 жыл бұрын
You're object of an elementary topos
@tipx2master788
@tipx2master788 2 жыл бұрын
@@Salmanul_ it's stalin
@Martykun36
@Martykun36 2 жыл бұрын
cool but having a picture of a genocidal dictator as your pfp is kinda cringe
@ilonachan
@ilonachan 2 жыл бұрын
just tell them that a monad is a monoid in the category of endofunctors
@tipx2master788
@tipx2master788 2 жыл бұрын
@@ilonachan so true
@antikovt
@antikovt 2 жыл бұрын
Just admit it: this whole video's point was to teach us category theory in simplest terms possible so that we all understand the joke about the terminal object in a set of people and sexual relations.
@walterbushell7029
@walterbushell7029 2 жыл бұрын
Or just the worlds most abstract and theoretical set up for a your mum joke.
@Imperiused
@Imperiused 2 жыл бұрын
Yeah I sensed that terminal object before I even finished laughing!
@serse8455
@serse8455 2 жыл бұрын
I hope you'll remain faithful and won't forget to make the serious follow up video
@OliverLugg
@OliverLugg 2 жыл бұрын
Only if I also remain full and essentially surjective on objects. (Sorry, it’s another category theory joke, couldn’t resist.)
@mrOverYeff
@mrOverYeff 2 жыл бұрын
@@OliverLugg so if you transcend everything you just get insane? Nice Easter egg @god (just a joke this is a great video)
@nicefloweytheoverseer7632
@nicefloweytheoverseer7632 2 жыл бұрын
@@mrOverYeff this whole vid is a joke lol
@wnderer4365
@wnderer4365 Жыл бұрын
and he did....
@olivergottkehaskamp3369
@olivergottkehaskamp3369 2 жыл бұрын
This was extremely unhelpful! Thank you!
@kennethye4374
@kennethye4374 2 жыл бұрын
*cohelpful
@irrelevant_noob
@irrelevant_noob Жыл бұрын
@Oliver Gottkehaskamp i'll have to disagree... This has been EXTREMELY helpful for my facial muscles; they did some work-out during this video like they haven't done in weeks (or maybe even months). xD
@scialomy
@scialomy Жыл бұрын
@@irrelevant_noob You missed the joke I'd say. Maybe check the video title again ;)
@aloysiuskurnia7643
@aloysiuskurnia7643 Жыл бұрын
@@scialomy That fella just implied that the video is not doing its job correctly :^)
@mihailmilev9909
@mihailmilev9909 11 ай бұрын
365th like
@simka123
@simka123 2 жыл бұрын
The analogy of category theory being the "they are the same picture meme" is accurate. That is what makes category into a beautiful black whole where students fall and sometimes they never leave/recover
@VerilyVeritasValio
@VerilyVeritasValio 2 жыл бұрын
help
@groundbird4904
@groundbird4904 2 жыл бұрын
@@VerilyVeritasValio no
@eddie-roo
@eddie-roo 2 жыл бұрын
If there’s a black whole, is there a black separate?
@Dong_Harvey
@Dong_Harvey 2 жыл бұрын
@@eddie-roo that would just be a black cowhole
@drdca8263
@drdca8263 2 жыл бұрын
@@Dong_Harvey a co-whole is just a cow-hole
@quantumchill5237
@quantumchill5237 2 жыл бұрын
Finally, a video about math twitter.
@jordanweir7187
@jordanweir7187 2 жыл бұрын
"Set theorists can construct the set of all things that cause you pain" im functing dead lmao, subbed
@griof
@griof 2 жыл бұрын
The main application of category theory is to make Haskell programmers look smarter than they are.
@Rudxain
@Rudxain 8 ай бұрын
"I use Haskell, BTW" Haskell and Arch Linux are isomorphic!
@thewhitefalcon8539
@thewhitefalcon8539 5 ай бұрын
This is extremely true.
@Pablo360able
@Pablo360able 2 жыл бұрын
"It's a good idea not to upset set theorists. They can construct the set of all things that cause you pain." I'm invincible, though, because nothing causes me more pain than the set of all things that cause me pain. Well, unless they're using some model other than ZF. Then I'm screwed.
@treetheoak8313
@treetheoak8313 2 жыл бұрын
I don't know what's worse. The jokes in this video, the fact that I found them funny or the fact that I was genuinely disappointed that this was a joke video 😂
@RyanTosh
@RyanTosh 2 жыл бұрын
That coauthor joke worked on so many levels lol
@chrisprice8112
@chrisprice8112 Жыл бұрын
He just followed up with a real one!
@LarryGarfieldCrell
@LarryGarfieldCrell 2 жыл бұрын
"What do you call someone who reads a paper on category theory" is my new favorite math joke. Damn, dude. Damn.
@joriskbos1115
@joriskbos1115 2 жыл бұрын
I have been learning australian category theory for a while now, and only recently found out it is actually isomorphic to regular category theory. If you flip everything upside down, it is just category theory!
@zyaicob
@zyaicob 8 ай бұрын
It's cocategory theory
@crackedemerald4930
@crackedemerald4930 2 жыл бұрын
This was all well and good until mathematicians discovered another even more abstract field of maths where the basis of communication is flustered frustrated hand waving.
@abebuckingham8198
@abebuckingham8198 2 жыл бұрын
That's actually a proof technique in category theory called diagram chasing. You just ramble and point at parts of a diagram while pontificating about preimages and morphisms. For example that's how you prove the snake lemma and it's an incredibly annoying proof to do any other way. Like writing it down is incredibly tedious so most authors only do one part and leave the rest as an exercise.
@hughcaldwell1034
@hughcaldwell1034 2 жыл бұрын
@@abebuckingham8198 I remember the first time I saw diagram chasing. I's a frightened undergrad until that moment, when I realised I was allowed to do that sort of thing. Just draw the shapes that make sense in your mind, gesture vaguely at the blackboard, saying "See?"
@brantleyvose2205
@brantleyvose2205 Жыл бұрын
I feel like the proper way to communicate a diagram chase is a flipbook. But the journals won't let me staple one to my paper :(
@markhathaway9456
@markhathaway9456 Жыл бұрын
Economics?
@mihailmilev9909
@mihailmilev9909 11 ай бұрын
230th like
@gamerofwar99
@gamerofwar99 2 жыл бұрын
I spent 9 minutes 30 seconds watching a video learning about something I didn't know existed, and I'm pretty sure I know less now than when I started. I've since liked the video, subscribed, and hit the bell icon. Excellent stuff!
@walterbushell7029
@walterbushell7029 2 жыл бұрын
Achieving ignorance is the beginning of understanding.
@irrelevant_noob
@irrelevant_noob Жыл бұрын
@@walterbushell7029 achieving KNOWN ignorance, rather?
@nuklearboysymbiote
@nuklearboysymbiote Жыл бұрын
You co-learnt the material
@markhathaway9456
@markhathaway9456 Жыл бұрын
You are obviously therefore in the category of people who are easily trapped by theories about nothing. Bon voyage to lala land.
@atsmyles
@atsmyles Жыл бұрын
Welcome to the study of Category Theory. It's like that all the way down.
@Speykious
@Speykious 2 жыл бұрын
"A coconut is just a nut" I lost it.
@harbl99
@harbl99 2 жыл бұрын
Category Theory is the revenge of that one kid who was angry about having to show his working.
@badlydrawnturtle8484
@badlydrawnturtle8484 2 жыл бұрын
Fact 23 was a comprehension question. If you laughed, you passed. All tests should be structured like that.
@imacds
@imacds 2 жыл бұрын
the joke gets better the more you think about it
@thoperSought
@thoperSought 2 жыл бұрын
oh god I didn't get it until I saw this comment... that's hilarious
@misiraly
@misiraly 2 жыл бұрын
To be fair, you have to have a very high IQ to understand Fact 23. The humour is extremely subtle, and without a solid grasp of theoretical mathematics most of the jokes will go over a typical viewer's head. There's also Oliver Lugg's nihilistic outlook, which is deftly woven into his characterisation- his personal philosophy draws heavily from Alexander Groethendieck's literature, for instance. The fans understand this stuff; they have the intellectual capacity to truly appreciate the depths of these jokes, to realise that they're not just funny- they say something deep about LIFE. As a consequence people who dislike Fact 23 truly ARE idiots- of course they wouldn't appreciate, for instance, the humour in Oliver's existential catchphrase "What about maps between Functors ?," which itself is a cryptic reference to Samuels and Saunders paper What about maps between Natural Transformations?[Berlin 1969, Publications Mathematiques de l'Institut des Hautes Etudes Scientifiques]. I'm smirking right now just imagining one of those addlepated simpletons scratching their heads in confusion as Lugg's genius wit unfolds itself on their television screens. What fools.. how I pity them. 😂 And yes, by the way, i DO have a Fact 23 tattoo. And no, you cannot see it. It's for the ladies' eyes only- and even then they have to demonstrate that they're within 5 IQ points of my own (preferably lower) beforehand. Nothin personnel kid 😎
@nickdalfarra3887
@nickdalfarra3887 2 жыл бұрын
@@misiraly this is some of the most adept mathematical shitposting I've ever witnessed
@1224chrisng
@1224chrisng 2 жыл бұрын
Fact 17 even more-so
@THB192
@THB192 2 жыл бұрын
"A monad is a monoid in the category of endofunctors" Ahh, programming memes.
@floramew
@floramew 2 жыл бұрын
I clicked the thumbnail, thinking this would be about how coconuts have hair & produce milk and are therefore mammals. So very different content than what I thought, but somehow exactly the same vibe. Also, I had no idea category theory was a field of math before this video... not sure I learned more than the fact that monads are monoids except they look like gonads now.
@GerinoMorn
@GerinoMorn 2 жыл бұрын
As a hobbyist Haskell programmer (as opposed to a competent other things programmer) - the video made quite a lot of sense. Don't get me wrong, I did advanced maths in Uni, and had all that explained to me. And I flunked the same semester.
@shmoobalizer
@shmoobalizer 2 жыл бұрын
remind me to never touch Haskell
@cherryblossom000
@cherryblossom000 2 жыл бұрын
As a hobbyist Haskell programmer still in high school this video made some sense but I didn't understand the Yoneda Lemma stuff (heard of it but have never bothered to look into it)
@Yotanido
@Yotanido 2 жыл бұрын
@@shmoobalizer To be fair, you don't actually need to know any category theory to use Haskell. It got a lot of concept from category theory, but the theoretical background is meaningless as far as actual programming is concerned.
@markhathaway9456
@markhathaway9456 Жыл бұрын
@@shmoobalizer NEVER touch Haskell !!!!
@shmoobalizer
@shmoobalizer Жыл бұрын
@@markhathaway9456 thx
@klafbang
@klafbang 2 жыл бұрын
Functional programming is not really an application of category theory. It's at its core an implementation of lambda calculus. Since lambda calculus also has a natural representation in category theory, some (but far from all) functional languages use some terminology from category when describing higher order combinators.
@NXTangl
@NXTangl 2 жыл бұрын
Monads are very useful for encapsulating state and sequencing, and the monad operations form a category.
@SteveBobbington
@SteveBobbington 2 жыл бұрын
its also not really an application of category theory, as it is not useful itself :D
@xXJ4FARGAMERXx
@xXJ4FARGAMERXx Жыл бұрын
@@SteveBobbington i know there's a pun in there somewhere but: Just beacuse B is not useful, that doesn't mean A→B isn't an application. For example: suppose that the above statement is true. One application of math is to calculate demand for food (A→B), and one application of that calculation is to not waste food (B→C), and one application of not wasting food is increasing the amount of useable food (C→D), and one application of increasing the amount of useable food is increasing humans' lifespan (D→E), and one application of increasing humans' lifespan is making more jokes (E→F), and one application of jokes is... Well, jokes are useless things, and that makes E→F not an application, and that makes D→E not an application... and that makes A→B not an application. So now, do you believe math doesn't have any applications? I think I ran into two fallacies (if that is even the right word), 1- I conflated math having a use in calculating with math having only one use. But more importantly, 2- I measured "usefulness" of a given thing by the number of applications it has. which, you know, causes anything that is not evantually an application of itself to fail (teaching history helps students to become history teachers so that they teach students so that....) "=" useful, but things that evantually end aren't.
@SteveBobbington
@SteveBobbington Жыл бұрын
@@xXJ4FARGAMERXx *screams*
@thewhitefalcon8539
@thewhitefalcon8539 5 ай бұрын
​@@NXTangldoesn't everything form a category? Isn't that the entire point of category theory?
@mikanorlenjaderberg1993
@mikanorlenjaderberg1993 10 ай бұрын
Category has so many funny, near incomprehensible sentences like "a monad is a monoid in the category of endofunctors". My absolute favorite has to be "A double category is a category in the category of categories".
@pacotaco1246
@pacotaco1246 Күн бұрын
Should I get a phd in category theory just so I can get paid to spout silly sentences like these?
@gerardogarcia2930
@gerardogarcia2930 2 жыл бұрын
As someone who didn't even know category theory was a thing, this was a somewhat good intro to category theory. It also explains those diagrams i keep seeing but had no idea what they were
@robertschlesinger1342
@robertschlesinger1342 2 жыл бұрын
A worthwhile video. By the way, Samuel Eilenberg was a world class collector of ancient South Asian bronzes. His collection was worth tens of millions. Alexander Grothendieck's radicalization is rather interesting historically. His Russian Jewish father had an arm amputated as a Czarist prisoner. His mother was a German socialist. Both patents were active in the failed Spanish Civil War while little Alexander was in the care of others. It's no wonder he had the political views he so strongly adhered to.
@taggerung_
@taggerung_ 2 жыл бұрын
i have no idea if what you said is true but im liking this anyways for how absurd it sounds
@fredranzalot4849
@fredranzalot4849 2 жыл бұрын
Based Grothendieck
@robertschlesinger1342
@robertschlesinger1342 2 жыл бұрын
@@taggerung_ Truth is sometimes stranger than fiction and with mathematical geniuses, truth is sometimes far stranger than even Theater of the Absurd. To borrow from Hardy's comment on receiving Ramanujan's initial correspondence: I couldn't make-up such things; nobody would have the imagination to dream up such things. By the way, I have a great photo of Sammy Eilenberg reclining on his sofa, contemplating mathematics in his Greenwich Village apartment and using Chola bonzes as paperweights on his piles mathematics reprints. Those sort of Chola bronzes sell at $500,000 to $2,000,000 at auction these days, and he was well aware of their value. And Grothendieck was quite the eccentric sometimes self-publishing in mimeograph format. I have one of his rare mimeographed books (in French) and sadly, it's fading.
@DanDeebster
@DanDeebster 2 жыл бұрын
I like that in the question of one space or two between sentences that you went for the meme "why don't we have both?"
@6884
@6884 2 жыл бұрын
my favorite mathematician together with Conway
@programaths
@programaths 2 жыл бұрын
Years ago, I did a presentation about isomorphism showing how choosing the right representation can make a problem really hard to grasp to something really trivial. There were no big words, because I am not versed in really abstract mathematics. But the content was enough to get people in a WTF state ^^ One of the example was showing how to create a Gray code from a path on a cube or tesseract. Another was about how to easily win one game by playing another game which is isomorphic. Then how to translate some programming constructs into other (akin to refactoring). Too many programmers forget that computer sciences...is math. They simply make their live harder ^^
@karen-7057
@karen-7057 Жыл бұрын
Do you still have it? Maybe the slides or something? This really interested me, I would so go to a talk about this topic
@programaths
@programaths Жыл бұрын
@@karen-7057 I can't find it. I did it about 10 years ago and it's not in my GDrive, MSDrive, slides, slideshare...neither on my website. I still remember the content though. It showed the link between complex numbers, the plane and matrix. It also showed the relation between a sum number game and 3 in a row (tic-tac-toe). Also shown how to write for loops as while loops. And how grey code can be found by navigating a n-dimentional square. Also, SQL vs Set theory (But I learned that this one breaks quickly and relational algebra is a better fit). Very simple stuff, but useful to understand for future analyst developers (that was the target audience).
@RaunienTheFirst
@RaunienTheFirst 2 жыл бұрын
"What do you call someone who reads a category theory paper? A coauthor" I died
@ofsinope
@ofsinope 2 жыл бұрын
You found a practical application for category theory in Haskell, so now you just need to find a practical application for Haskell 😂
@RolandHutchinson
@RolandHutchinson Жыл бұрын
It is a well known result that the main practical application for Haskell is that it provides a practical application for category theory.
@sachs6
@sachs6 2 жыл бұрын
I've tried reading a handful bunch of books on the subject, but could never understand beyond the third page. Your video was surprisingly very helpful indeed! I've learned a lot, thanks! Sorry if I was not supposed to.
@gekixkishin4508
@gekixkishin4508 10 ай бұрын
As someone with a Master's in Algebraic Topology and Cohomology Theory, I very much enjoyed every joke in that video (especially the one with Russel) ! Great job
@BumboLooks
@BumboLooks 9 ай бұрын
Autistic weeb has a useless masters in Algebraic Topology and Cohomology Theory? Not surprising. The period after WW2 has certainly been fruitful in the production of bullshit from pure mathematics and philosophy. Although some of the crap from the likes of Gregory Cantor came way earlier. Mathematics that doesn't describe numerical or value relationships in reality simply isn't mathematics.
@fahrenheit2101
@fahrenheit2101 9 ай бұрын
@@BumboLooks Jesus christ, who hurt you? The first sentence of that reply was random baseless ad hominem attacks, and the rest just seems like pure speculation and one hell of an odd, bold take about what constitutes mathematics. Maths needn't inherently relate to reality. But almost any field of maths does somehow link in anyway, even if in a really obscure fashion. Maths isn't even easy to define - but I'd say "study of patterns", is good for a concise definition. Which essentially means anything goes, provided it's defined consistently. You can still look down on it, but it's mathematics nonetheless. Honestly you sound like somebody who got salty about not being able to understand some math once upon a time, and took that to mean that whoever came up with it was confused, rather than perhaps the person looking into it, and then that spiralled into a hatred for any and all modern mathematics, which seems to even have extended to philosophy because why the hell not? The only thing missing is a "back in my day" quip. Let people learn what they wanna learn - it's often not helping anyone, but it definitely ain't hurting anyone, either. Throwing insults at people can hurt, though - it's not a chore to just be nice, or at the least not be outright rude if unprompted? Or, you're just trolling - but I know you aren't, I just like to leave that option open as a catch-all.
@user-pi1vz1de3u
@user-pi1vz1de3u 8 ай бұрын
​@@BumboLooksShouldn't you be pumping my septic tank right now? Maybe filling some potholes? 🤣
@BumboLooks
@BumboLooks 8 ай бұрын
@@user-pi1vz1de3u What does that have to do with mathematics?
@shiina_mahiru_9067
@shiina_mahiru_9067 2 жыл бұрын
1. To my surprise, the word "pentagonator" is officially recognized by KZfaq subtitle auto-generator. (Basically, in an ordinary monoidal category, associativity of a certain operation (formally called tensor product) is only satisfied up to isomorphism, so we get this thing called "associator" describing this mathematically. The associator itself satisfies the so-called pentagon axiom, which is a commutative diagram and hence an equality. A pentagonator is just weakening this equality in the same sense as before but in a higher categorical setting. Disclaimer: I know nothing about it, but it is a very educated guess if you know how category theory work.) 2. What are the morphisms in the category of edible food? and how composition work? or is it just a discrete category? 2. Joke 28: If you want to see real-world applications of category theory, just go to n-Category Cafe
@kitty1230100
@kitty1230100 2 жыл бұрын
As somebody who graduated with a pure (not applied) mathematics degree this made me giggle and have some serious flashbacks to abstract algebra. Thank you for the laugh
@mastershooter64
@mastershooter64 Жыл бұрын
Only a pure math student would feel the need to put "(not applied)" lmao
@dcqin
@dcqin 2 жыл бұрын
Thanks so much for this--very much appreciate the sarcastic and deadpan presentation of a really really confusing subject! Contrary to the title, this was actually very helpful as it reminded me of how much I love talking to and hearing from others about whatever math they've been up to. Hope you make some more math/CS related videos (parodies or non-parodies!) and keep up the great work : )
@davidhesson5036
@davidhesson5036 2 жыл бұрын
A monad is a monoid in the category of endofunctors
@123TeeMee
@123TeeMee 2 жыл бұрын
I've never studied category theory and I've still found myself trying to read that somewhere
@christopherbroms2508
@christopherbroms2508 2 жыл бұрын
A monad is a monoid in the category of endofunctors.
@Your2ndPlanB
@Your2ndPlanB 2 жыл бұрын
it's a really good way of remembering it tho! You just write down the necessary commutative diagrams for a monoid in a strict monoidal category and then you instantiate it to End(C), and there you have it: the definition of a monad.
@jero37
@jero37 2 жыл бұрын
I'm seeing Tantacrul influences! A monad is a monoid in the category of endofunctors.
@marz8386
@marz8386 2 жыл бұрын
I'm summoning the tantacrul gang
@jarryb3837
@jarryb3837 2 жыл бұрын
This is so true #jank
@jarryb3837
@jarryb3837 2 жыл бұрын
Also my buddy MusicMelts wanted to say "Recalcitrant"
@hellomynameisjoenl
@hellomynameisjoenl 2 жыл бұрын
Categories are getting worse every year.
@marz8386
@marz8386 2 жыл бұрын
Good work, team!
@nice3294
@nice3294 2 жыл бұрын
I cracked so hard at the sudden "A coconut is just a nut"
@jakubledl1602
@jakubledl1602 2 жыл бұрын
Fact 28: assuming you really have a defined categorical structure on the quiver (graph? hypergraph?) of all people and sexual relationships, you are cordially invited to take the identity morphism and go **** yourself. (Sorry, I just could not resist after the last one. Nothing mean intended.)
@wojteksowinski248
@wojteksowinski248 2 жыл бұрын
If you wanna sound less friendly, you could say “rdially” instead of “cordially”
@zongaaa6673
@zongaaa6673 2 жыл бұрын
Category theory ➘ this exact video ➙ Terminal object ➙ *why* Math in general ➚
@Hankathan
@Hankathan 2 жыл бұрын
Correction: Category theory ➘ this exact video ➙ Terminal object ⇄ why Math in general ➚
@drdca8263
@drdca8263 2 жыл бұрын
Both of your comments are difficult to parse (at least on mobile) because of it being unclear what parts of it is due to wordwrap and such
@Axman6
@Axman6 2 жыл бұрын
Pretty sure “why” is the initial object for all maths.
@u.v.s.5583
@u.v.s.5583 Жыл бұрын
@@Axman6 The initial object for lots of modern maths is a disjunction. PUBLISH v PERISH.
@riccardoorlando2262
@riccardoorlando2262 2 жыл бұрын
"A coconut is just a nut" I died
@ndc5544p
@ndc5544p 2 жыл бұрын
that joke at 08:26 killed me
@Rintse
@Rintse 2 жыл бұрын
The co-author joke is too real...
@drstrangecoin6050
@drstrangecoin6050 2 жыл бұрын
3:03 "almost everyone" programmers diminishingly rare as they are, yes
@52flyingbicycles
@52flyingbicycles Жыл бұрын
“As soon as Mathematicians start counting they can’t stop” Why is this so true 😅
@antoniusnies-komponistpian2172
@antoniusnies-komponistpian2172 8 ай бұрын
Yes, reminds me of cardinal numbers and dimensions.
@FT029
@FT029 2 жыл бұрын
my abstract algebra professor made us prove the yoneda lemma on a homework; the professor's solution said the proof was "extremely brutal yet entirely trivial". So he's in both camps.
@JonathanMandrake
@JonathanMandrake Жыл бұрын
Now that I have actually learned a bit about category theory in my topology class, it's absurd how true this video is. Everything is either a joke or true, and it has both helped me understanding the topic a bit better and made me despair over why we had to learn this in topology, I don't ever want to see this shit in an exam
@heitortremor
@heitortremor 2 жыл бұрын
I love that I was recommended this video and really enjoy it while understanding maybe ~30% of what is being said. You present the data in a very entertaining fashion!
@nicholasiverson9784
@nicholasiverson9784 2 жыл бұрын
A real world application of category theory is teaching category theory to math students.
@MrCmon113
@MrCmon113 10 ай бұрын
Maths is a Ponzie scheme.
@samrichardson5971
@samrichardson5971 2 жыл бұрын
I put this video in my watch later list a few days ago because I also do category theory and today I saw a tumblr post about 5d chess with multiverse time travel so wanting to know more I searched it on KZfaq and stumbled on one of your videos. When I went to your channel to watch more I was so surprised to see this video at the top! Very cool selection of interest you have here.
@pocaudraphael6066
@pocaudraphael6066 Жыл бұрын
"A coconut is just a nut" is the best joke I've heard in a while
@someone16234
@someone16234 2 жыл бұрын
You’re right this was entirely unhelpful! Greatly appreciated.
@Eliza_Yump
@Eliza_Yump 2 жыл бұрын
number 20 is the equivalent of "the mitochondria is the powerhouse of the cell"
@eliasvernieri
@eliasvernieri 2 жыл бұрын
"What'd you call someone who reads a paper on category theory? a co-author"
@ivansmitt2195
@ivansmitt2195 2 жыл бұрын
the fact that you explained category Theory enough to deliever the final joke is just amazing
@__init__3493
@__init__3493 2 жыл бұрын
I didn't understand any of this but I'm just assuming that category theory is the exact same thing as set theory except they replaced all the words people already know with different words that nobody knows
@irrelevant_noob
@irrelevant_noob Жыл бұрын
Not the "exact" same, remember FACT 8 (4:04). The ALMOST exact same. ;-)
@imtryingiswear97
@imtryingiswear97 2 жыл бұрын
i wanna see someone else who also studies category theory to watch this, i feel like im missing so many inside jokes
@ilonachan
@ilonachan 2 жыл бұрын
I thought setup&payoff didn't work in internet humor anymore, but the coauthor had me wheezing
@KatzRool
@KatzRool 2 жыл бұрын
That coconut pun really paid off.
@rijaja
@rijaja 2 жыл бұрын
This is the kind of content youtube was made for
@beriukay
@beriukay 2 жыл бұрын
@1:56 wait, it wasn't invented by mathematicians Dr. Cat and Dr. Egory?
@u.v.s.5583
@u.v.s.5583 Жыл бұрын
Gory is an adjective.
@arnaudparan1419
@arnaudparan1419 Жыл бұрын
Man that video is the funniest thing I've seen in a long time X) was literally laughing doing all my appartment cleaning and all X)
@drdca8263
@drdca8263 2 жыл бұрын
Wait, what does the direction of the arrow mean in the last category mentioned? And also the identity arrows? Is this a category or (as another co-author of the video suggested) a quiver?
@estebanmarco8755
@estebanmarco8755 2 жыл бұрын
I did an internship on groupoids and this is quite useful to generalise what I learned.
@jessecook9776
@jessecook9776 2 жыл бұрын
This is the most accurate and funniest representation (pun intended) of category theory that I have ever seen. 😂🤣
@EricKolotyluk
@EricKolotyluk 2 жыл бұрын
Thank you for some great laughs... You reminded me of a line in the Hitchhikers Guide to the Galaxy, about the funniest joke in the universe of all time was a mathematical joke...
@pladselsker8340
@pladselsker8340 2 жыл бұрын
thank you, this is gonna help me relax a little if I ever follow lectures on the subject :)
@MrRyanroberson1
@MrRyanroberson1 2 жыл бұрын
1:29 actually, morphisms are also objects. Consider the set of all rational polynomials (a + bx + cx^2 ... / (n + mx + ...)), which are mappings (morphisms) from complex numbers to complex numbers. Those polynomials have morphisms as well: + - * /, which turn them into other mappings. So category theorists go super-extra meta with this, and consider all morphisms yet more objects.
@mastershooter64
@mastershooter64 Жыл бұрын
Is this demonstrated in a 2-category? like how they have morphisms between morphisms?
@MrRyanroberson1
@MrRyanroberson1 Жыл бұрын
@@mastershooter64 he made another video actually describing the various parts of category theory, but roughly: you can keep repeating this forever. every morphism is an object, so you can morph between those, and morph between those, and morph ...; idk the definition of a 2-category though
@irrelevant_noob
@irrelevant_noob Жыл бұрын
@@MrRyanroberson1 Guess you bailed out before fact 15 (6:22)? :-B
@MrRyanroberson1
@MrRyanroberson1 Жыл бұрын
@@irrelevant_noob nah i just comment as i watch the video
@irrelevant_noob
@irrelevant_noob Жыл бұрын
@@MrRyanroberson1 still, did it take you 5 months to not advance past 7 minutes? :-s
@cameronball3998
@cameronball3998 2 жыл бұрын
I’m in my last semester of a computer science degree. Glad to say I colearned because of this video
@shivChitinous
@shivChitinous 2 жыл бұрын
Australian category theorists can't be similar to marsupials because marsupials did not evolve independently in the old world and develop weirdly fascinating features which seem like wizardry to us placental muggles, but rather marsupials went extinct in most of the new world for as yet mysterious reasons leaving placentals like ourselves the only mammalian representatives in the northern hemisphere and, for reasons pertaining to swimming ability, placentals never found themselves on Australian shores. So unless Australian category theorists somehow disappeared elsewhere under mysterious circumstances and non-Australian category theorists have swimming disabilities, this would be a false equivalence...
@cefcephatus
@cefcephatus Жыл бұрын
I finally learn how to express my functiful thoughts. I whished I learned about Category Theory earlier. Belief it or not, my notes and diaries is written like these diagrams, and I'm struggling to explain any thoughts in my head. Knowing such thing exist is going to make my life easier.
@alxjones
@alxjones 2 жыл бұрын
You're wrong about one thing: I know exactly what "A monad is a monoid in the category of endofunctors" means, but I'm not going to tell *you.*
@user-jr7ns3bl9c
@user-jr7ns3bl9c 2 жыл бұрын
Sooooooo by applying Yoneda lemma I can conclude that you might as well *not* to know what it means since your lack of wish to share the knowledge makes it behavioraly undistinguishable from the state that you claim
@SpaghettiToaster
@SpaghettiToaster 2 жыл бұрын
@@user-jr7ns3bl9c That would be true if not for the fact that a monad is actually a monoid in the category of endofunctors. Classic beginner mistake.
@puppable
@puppable 2 жыл бұрын
Now I'm proudly one step further away from understanding my math friends Twitter shitposts 😊
@DaxSudo
@DaxSudo 10 ай бұрын
As someone who likes Haskell and C++ the statement, “A monad is a monoid in the category of endofunctors” is a phrase to live and die by.
@DaxSudo
@DaxSudo 10 ай бұрын
Aannddd I wrote this comment before u brought up Haskell lol
@MrCmon113
@MrCmon113 10 ай бұрын
Why not a half group or group or sth?
@ZedaZ80
@ZedaZ80 Жыл бұрын
Frickin "cobra" almost made me pee laughing, then you hit me with "coconut" hot damn 😂
@LeLa_Lu
@LeLa_Lu 2 жыл бұрын
true false or bottom describes twitter beautifully
@thinkthing1984
@thinkthing1984 2 жыл бұрын
*trying to recover from the last 4 seconds of the video
@spiralofinspiration3653
@spiralofinspiration3653 2 жыл бұрын
I'm reading category theory for computer science as well! Got the scala edition on my computer, and I've ordered the paperback. Brilliant!
@crapshoot
@crapshoot Жыл бұрын
7:39 Dammit; I misremembered this line - and here I was about to make a joke about 'corona' is known in Australia as 'rona'
@hashtagornah
@hashtagornah 2 жыл бұрын
Wouldn't an infinity category be a cyclic loop error?
@IRoIN100
@IRoIN100 2 жыл бұрын
I understand not even 3% of these jokes, yet I think this is the most hilarious vid on youtube, where do I map on the functors?
@baptistebauer99
@baptistebauer99 2 жыл бұрын
That was an aweseomely funny video, I don't know why I got recommended this several times but something in KZfaq's algorithm worked just right.
@demolisherinfinite8606
@demolisherinfinite8606 2 жыл бұрын
I sat throughout the entire video slightly confused only to be instantly one-hit-K.O.’ed by the ending. I’ve been laughing my ass off for 5 minutes!
@fanofthewrittenword7577
@fanofthewrittenword7577 2 жыл бұрын
I spent ages wondering weather or not I existed, weather my existence was true or false. Now though I see the light, the true answer is neither for I am a bottom.
@anibalismaelfermandois6943
@anibalismaelfermandois6943 2 жыл бұрын
Amazing video. Hilarious yet still gives a vibe of the field.
@jontedeakin1986
@jontedeakin1986 2 жыл бұрын
I was just learning category theory! Thanks friend :)
@tonyng8075
@tonyng8075 Жыл бұрын
Actually I'd come across a real world application of Category Theory (maybe): Proofing a set of operator replacement rules of a tensor algebra system is correct in all circumstances A PhD student who was working on deeplearning computationial graph optimization
@jobobminer8843
@jobobminer8843 2 жыл бұрын
Category theory has been keeping the world safe from global conflicts ever since. Well...
@u.v.s.5583
@u.v.s.5583 Жыл бұрын
Cozelenskyy started a cospecial cooperation and invaded Corussia.
@brandonmack111
@brandonmack111 2 жыл бұрын
That might have been the most complex mom joke I've ever heard
@innokentiybredun6660
@innokentiybredun6660 2 жыл бұрын
Loved it! The bit on co-author was really nice, thanks.
@classicalmusic1337
@classicalmusic1337 2 жыл бұрын
Why stop at 27 facts instead of adding one more and having a perfect number of facts? How could you do this to us?
@drdca8263
@drdca8263 2 жыл бұрын
cubes!
@classicalmusic1337
@classicalmusic1337 2 жыл бұрын
@@drdca8263 fair enough! :D happy new year
@AlexanderShamov
@AlexanderShamov 2 жыл бұрын
Fact #0: the very definition of a category is a lie. A category doesn't have a set (or a class) of objects. Instead it has a category of objects, or at the very least a groupoid of objects. And these kinds of lies only get bigger the further we go into the theory. This is because the set-theoretic langauge is inadequate for expressing categorical concepts, and yet it's the only one we have that is developed enough.
@marshmelo4832
@marshmelo4832 2 жыл бұрын
in fact we should think of a category of only existing of morphisms with thinking of the objects as identities
@AlexanderShamov
@AlexanderShamov 2 жыл бұрын
​@@marshmelo4832 This doesn't solve the fundamental problem I was referring to, because "all" morphisms still don't form a set. Besides, I don't think this point of view is generalizable to infinity-categories.
@SpaghettiToaster
@SpaghettiToaster 2 жыл бұрын
@@AlexanderShamov Why do all morphisms not form a set?
@AlexanderShamov
@AlexanderShamov 2 жыл бұрын
@@SpaghettiToaster If you learn the definition of a category and treat it the same way you would treat any other algebraic structure, you'll miss the all-important nuance: namely, that the naive notion of isomorphism of categories is "wrong". The "correct" notion is called equivalence of categories, and it's much weaker. Everything category theorists ever do is invariant under equivalence of categories. But neither the set of objects nor the set of "all" morphisms is invariant under it. The broader picture is that equality of elements of a set, isomorphism of objects in a category, and equivalence of categories are really just the beginning of a hierarchy of higher dimensional notions of "sameness", and the classical set-theoretic foundations only capture the first layer of this hierarchy. In order to "feel" the whole thing we will probably need to replace set theory with some version of homotopy type theory, but that is still work in progress.
@SpaghettiToaster
@SpaghettiToaster 2 жыл бұрын
@@AlexanderShamov I still don't see how elements categorized as "same" by whichever means do not form a set.
@Encysted
@Encysted 2 жыл бұрын
I like these jokes. I think jokes are good way to help make something more accessible: you need context to laugh, and context necessitates explanations.
@celticwinter
@celticwinter 9 ай бұрын
Anything outside applied mathematics is bedlam with research funding. This dogma lets me sleep snuggly at night and also explains why category theorists decided that concepts are most easily explained by adorning a hypercube with arrows.
@fariesz6786
@fariesz6786 2 жыл бұрын
i got a bit into category theory via haskell. made the mistake of introducing my big brother to it. first he argued how all of it is just hacks and rubbish, then he went deep down and it became a spiritual revelation for him. meanwhile to me a monad is a monad. maybe i'm just too zen for this world.
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