Maths

Doctor. Profile picture by Anna Podedworna.

[bagel-of-masyaf]

rarely laugh out loud at math memes but this got me

[complex-analytic-dysfunction]

[changeling-automaton]

Unironically I think this meme is really good for explaining why maths formalisms and notation are so valuable, even when they seem cumbersome/convoluted. It's an incredibly precise way to describe the interaction of a lot of related-but-meaningfully-distinct concepts, and this is a great showcase of that, thank you Lynn Chordbug you're the best.

[littjara-mirrorlake]

holy shit. holy fuck. holy shit. h

[no-sharks-on-the-sun]

[salmonella-destroyer-of-worlds]

[transgenderer]

straight edge and compass constructions really are a ritual act. the goal is not to make a perfect construction, which could never exist in real life, or could be approximated (sometimes better!) by imperfect techniques. the goal is to perform a series of movies which correspond to a series of elsewhere-moves, platonic realm moves, which are actually perfect and actually result in a perfect construction. it's genuinely like some kinds of religious ritual in a meaningful conceptual sense

[more-mathematics-mor-lam]

Not taking 0 as part of N the natural numbers is insisting we live in a fantasy world where I always have at least 1 carton of ice cream. While I wish that was true, it is tragically not the case. There are certainly times where I have 0 cartons of ice cream and while it’s egregiously unfair, it’s also by inspection natural. Because ice cream is delicious and therefore requires replenishment (eg goes to zero). If N can’t capture this, what are we even doing

[shimmeringdroplet]

the Hausdorff separation axiom, which says that any two distinct points can be "housed orf" from each other by disjoint open sets

[theunlitpath]

This is from Vickers, Topology Via Logic, p. 3.

[machine-saint]

In this house we believe:

\aleph_\alpha = \beth_\alpha

Every vector space has a basis

P != NP && P != BQP

\zeta(s) == 0 && Re(s) > 0 => Re(s) == 1/2

F_1 is real

\pi is normal

If you don't like it? LEAVE!

[machine-unlearning]

[m---a---x]

Yes, GCH ⇒ WOT ⇒ AC ⇒ Existence of basis

In particular CH(κ) + CH(2^κ) ⇒ |H(κ)| = 2^κ ⇒ κ well-orderable.

[model-theory]

It's true that GCH→WOT/AC, but it's not as simple as the one-line proof, because limit stages of the argument are not obvious.

[im-the-antonymph-of-your-mom]

The new xkcd just made me cry

[im-the-antonymph-of-your-mom]

https://xkcd.com/3184

[badjokesbyjeff]

A math professor noticed his kitchen sink at home was leaking. 

A math professor noticed his kitchen sink at home was leaking.

He called a plumber.

The plumber came the next day, tightened a couple of nuts, and the sink worked perfectly again. The professor was delighted. But when, a minute later, the plumber handed him the bill, he was shocked.

“This is a third of my monthly salary!” “Yeah, I get it…” said the plumber. “Why don’t you come work for our company as a plumber? You’ll make three times more than you do as a professor. Just remember: when you apply, say you only finished seventh grade. They don’t like hiring educated people.”

So the professor got a job as a plumber, and his life really did improve. All he had to do was tighten a nut here and there every so often, and his salary was much higher.

One day, the management of the plumbing company decided that every plumber had to attend evening classes to finish eighth grade. So our professor had to go too.

By chance, the very first class was math.

The evening school teacher, wanting to check what the students knew, asked for the formula for the area of a circle.

They called the professor up to the board, and he suddenly realized he’d forgotten it. He started frantically reasoning it out, covering the board with integrals, differentials, and all sorts of fancy formulas to re-derive the result. In the end, he got: S = –π r²

He didn’t like the minus sign, so he started again. Again he got a minus. No matter what he did, it kept coming out negative.

He cast a panicked look at the class, and all the plumbers were whispering:

“Swap the limits of integration!”

[juney-blues]

stairs are so funny. falling 100 meters will kill you. solution? fall 10 centimeters a thousand times.

[markadoo]

they invented all those neat si prefixes and people still talk like this

[395nm]

falling a hectometer will kill you. solution? fall a decimeter a kilotime.

[real-real-numbers]

choosing a PhD advisor is not unlike marriage reality shows. making a multi year commitment on the basis of only a handful of awkward, perfunctory interactions. very small pool of options. something kinda wrong with all of them

[peniswizard69]

Love how in abstract math anything can be whatever

[miscellaneousmathematics]

[bubbloquacious]

This one is really good but it always annoys me because the normal way to do it is the same thing as using Stokes' theorem. You definitely get a number!

[hama-industries]

[locally-normal]

Joke 1.2. A groupoid is a group with many objects.

Section 1.2

[hama-industries]

Not to be pedantic but is this true? How do we guarantee a unique identity element?

[locally-normal]

Good question - every object in a category has a unique (strictly! Not up to unique choice! This is a deficiency in some people's eyes that's under active development in the infinity categorical setting, where everything said here also works if you add the adjective infinity everywhere. But for us it's a feature) identity morphism, which corresponds to the identity element of the group.

[model-theory]

Surely uniqueness of identities is simply a consequence of being a left-right-identity.

[ryebreadgf]

just learned americans have different standard paper sizes than everyone else. what do you MEAN you don’t have A4 as the standard. what do you mean your standard paper size isn’t even the same size as an A4. apparently it’s like. ’letter’ and ’legal’ and whatever else. help!!!

[ryebreadgf]

this is so scary

[huggingtentacles]

That has to be false. That's misinformation hold on

[huggingtentacles]

holy fucking shit

[model-theory]

Remember to manually set paper size to A4 in LaTeX