And God Said, "Behold! I Have Created The Fourth Primordial Force: The Weak Interaction!"

So I recently stumbled on the Wikipedia article for the Grothendieck-Riemann-Roch theorem, which is an algebraic geometry thing that I'll hopefully learn some day once I actually have the prerequisite knowledge =w= But at the top of the article was this letter, which I thought was a wild thing to have at the top of a Wikipedia article about a niche abstract math thing - here's a translation:

Witches' Kitchen 1971 Riemann-Rochian Theorem: the latest craze*: the diagram

is commutatif**! To give this statement about f: X->Y some approximative meaning, I had to abuse the listeners' patience for nearly two hours. In black and white (in Springer's Lecture Notes) it seems like it will take up to about 400, 500 pages. A gripping example of how our thirst for knowledge and discovery indulges itself more and more in a(n il?)logical delirium far removed from life, while life itself is going to hell in thousandfold ways - and is threatened with absolute annihilation. High time to change our course! (6.12.1971) Alexander Grothendiek

* "der letzte Schrei" is a reasonably common German idiom meaning "the latest craze", but here it could alternatively be translated non-idiomatically as something like "the last cry". I think its more fun to imagine he means the idiom. ** I'm assuming this is a weird old-timey spelling probably taken from french but googling it I can find no examples of anybody using this spelling in German besides this letter

Note that this is 20 years before all of this happens:

A Vision of the Labour Party, 2017

Liz Kendall has returned to a quiet life as a backbencher and constituency politician, but due to border change legislation passed by a gloating Tory Government, her constituency is now Hades.

Yvette Cooper is serving a ten year sentence for the murder of her husband Ed Balls after his 167th utterance of “At least I lost to the Millibands…”

Jeremy Corbyn, in what is considered one of his more unusual leadership moves, proposes legislation to ban the word “Crown” from any and all pub names. The Labour conference that year is held in the “People and Anchor” pub in Islington.

Andy Burnham turned back into a wooden doll at the stroke of midnight after the leadership election, where he came third place, as a result of the particular brand of contractual wish magic that gave him life.

Today on the blog I start a new project: where do numbers come from?

By which I mean, mathematicians deal with lots of weird kinds of numbers. Real numbers, complex numbers, p-adic numbers, quaternions, surreal numbers, and more. And if you try to describe the more abstract types of "numbers" you sound completely incomprehensible.

But these numbers all come from somewhere. So I'm going to take you through a fictional history of numbers. Not the real history of the actual people who developed these concepts, but the way they could have developed them, cleaned up and organized. So in the end you can see how you, too, could have developed all these seemingly strange and abstract concepts.

This week in part 1, we cover the most sensible numbers. We start with the basic ability to count, and invent negative numbers, fractions, square roots, and more.

But that will still leave some important questions open—like, what is π? So we'll have to come back for that in part 2.

I have a new post up on my blog, continuing the Fictional History of Numbers series. In part 1 we started with the natural numbers and built up the algebraics, which let us solve equations. In part 2 we started asking geometric questions, and constructed the real numbers.

But the real numbers are weird and hard to define. In part 3 we see one way they're extremely strange, and then talk about why we want them anyway. In the end, we shouldn't worry about the definition of the reals; we should worry about what they allow us to do. And it turns out they're exactly what we need to make calculus function as it should.

It’s impossible to give directions in Boston. Nothing makes sense. There are inexplicable one way streets, there are streets that change their names as you move from one area to another. There’s a road in my area where the gps literally tells you to take TWO full right turns to “stay on” the same road which is at a right angle to the original. There’s like four different Massachusetts Avenues. Sometimes you have to be in the left lane to turn right. The gps can’t even get directions to my workplace correct; it tells me to take a left on a road where lefts are not allowed, and the only way to not have to go across the river and take 15 minutes to turn around is to remember this shit one block early and make the left THERE. Recently, they’ve restricted 1 of 2 lanes on each side of major thoroughfares to only allow bikes and buses, and the government officials seemed to genuinely believe that would somehow EASE traffic. Oh and don't try to drive on Memorial Drive on Sundays; they close it for pedestrians. Just because. And when you DO drive on Memorial, there's one exit that will make your gps lose its mind and start chanting random sequences of numbers for four minutes straight. You can't take a Uhaul on Storrow Drive because the bridges that go over it are too short, and every year some doofus college student ignores this rule and proceeds to "get Storrowed" when they shave off the top of the truck on the overpass and get stuck. I-93 turns into I-95 and makes a big circle around the city, so a lot of the time you'll be on I-95 north but driving east or west.

It’s not limited to driving either. The Arlington train station is not in Arlington, it’s in the middle of downtown. Harvard Square is not a square, it’s more like a pentagon. There are four different green line train routes, and they’re labeled B for Boston College, C for Cleveland Circle, D for… Riverside, and E for… Heath Street. The Silver line is listed on the train map but is entirely run on buses which have to be connected and disconnected from power lines every time you go through the route. The Blue line goes to (and I’m not joking) Wonderland. The two red lines are labeled for their southern points: Braintree line goes to Braintree, and the Ashmont line goes to… Mattapan. To be fair, the train itself stops in Ashmont and you continue to Mattapan on a trolley, but that doesn't make it better. South Station and North Station are 1 mile apart and the easiest way to get from one to the other is just to walk it because otherwise you have to travel through 4 or 5 train stops on two different lines. But make sure you memorize the route because there's a good chance your gps will lose signal in the Financial district because it can't get through the buildings. In Boston Commons there are two train stops within line of sight of each other, on the same street, and one of them screams. To get to the trains at Porter Square, you have to ride down escalators 105 feet below street level, or you could just take the 3 flights of stairs totaling 199 steps (presumably because the engineers had something against nice even numbers). The North End is south of East Boston. Castle Island is part of the mainland.

No matter where you're going or how you're getting there, it takes 45 minutes (no wrong turns) or an hour and a half (one wrong turn). It doesn't matter if you're going one stop on a train; it will take 45 minutes. If it's summer, there's a better than 50% chance you'll be in the train car that lost it's AC; if it's winter, you're guaranteed to be in the car where the heat has it up to 80 degrees and the inside of your winter coat will be a sauna. Check the Red Sox schedule before you go south of the river, or you'll be trapped in the waves of baseball fans flooding the streets and days will go by before you're found again. And just... don't go outside on September 1.

If you're thinking that this sounds eldritch as shit, you're right. The entire city is an arcane lock keeping the ghoulies and ghosties from haunting the rest of the nation. We charge it with every "fuck" we utter while we travel our labyrinthine paths and drink our Dunks. You're welcome.

This idea for an SCP article came to me in a dream, so it’s not necessarily good, but I have to get it out there. My subconscious was clearly influenced by memories of mathematical SCPs (like SCP-033 and SCP-1313) and semiotic SCPs (like SCP-4703, though I hadn’t actually read that one before, and another one I can’t for the life of me find right now but I’ll add it if I do).

Keep reading

I have a new post up on my blog, continuing the Fictional History of Numbers series. In part 1 we built on the natural numbers using algebraic operations, and got the algebraic numbers. In part 2 and part 3 we used geometric and analytic arguments to build up the real numbers.

These two sets of numbers overlap, but aren't the same; there are real numbers that aren't algebraic (as we saw in part 3) but also algebraic numbers that aren't real. So what happens if we combine the two? We get the complex numbers, which are complete and also algebraically closed. But proving this is a little tricky, and touches on the deep strangeness of complex analysis.

And in the process of adding algebraic closure to the real numbers, we lose the ability to order them, which has its own consequences.

RAHHH THE ONLY CORRECT WAY TO START 2025!!

Happy 2025!

I worked like mad to finish this but here it is – some insanely large number of words about the year that was, through the lens of Billy Joel songs with "night" in the title because they are fascinating as all get out.

Interchanges, rambles, and confluences

Sing Us A Song To Night: The Night-time Motif in Billy Joel’s Songwriting

Some reviews are so esoteric or so literal rather than musical in their outlook that they just confuse the issues involved. —Billy Joel, int

Special shoutout to @thebreakfastgenie for helping to infect me with the urge to go even deeper into the old man research.

A new post up on my blog!  Last time we talked about the algebraic numbers, and how just wanting to solve simple equations can create a ton of different numbers.  But they don’t get us everything.

So this time we start off with the idea of measurement, and wind up inventing the real numbers.  The real numbers are weird.  Real weird.  But they show up when we start asking questions about size or measurement.  And in part 3, we’ll see they’re exactly the right way to do calculus.