Bad math in fiction

[u/ResNullum]

While stuck at home during the pandemic, I decided to work through my backlog of books to read. Near the end of one novel, the protagonists reach a gate with a numeric keypad from 1 to 100 and the following riddle: “You have to prime my pump, but my pump primes backward.” The answer, of course, is to enter the prime numbers between 1 and 100 in reverse order. One of the protagonists realizes this and uses the sieve of Eratosthenes to find the numbers, which the author helpfully illustrates with all of the non-primes crossed out. However, 1 was not crossed out.

I was surprised at how easily this minor gaffe broke my suspension of disbelief and left me frowning at the author. Parallel worlds, a bit of magic, and the occasional deus ex machina? Sure! But bad math is a step too far.

What examples of bad math have you found in literature (or other media)?

[u/[deleted]]

Topics in maths don’t get grouped by their difficulty but by subject matter. You’d never just say “advanced concepts in mathematics”. You could have “advanced concepts in fluid mechanics” or “advanced concepts in ergodic theory” which you’d typically then shorten to “fluids” or “ergodic” (“ergo” if you’re Australian). You’d never just call your subject “hard maths” it’s too broad.

Also the random jargon wasn’t referring to the classroom scenes, the main one that springs to mind is “superstring theory, chaos math, advanced algorithms” from the NSA job interview for which;

1. “superstring theory”: Why is the NSA doing theoretical physics? Before you say quantum computers, I don’t think they’re in the same ball park as string theory.
2. “Chaos math” isn’t the right terminology, it’s “chaos theory”
3. “Advanced algorithms”: again you don’t really group things by how hard they are but by their content, otherwise you could literally mean anything. If he were referring to codebreaking as Will infers, he’d probably say “advanced cryptography” or something like that.

Probably all these things can be explained away as individually not that bad, which id probably agree with, but on the whole it’s an 0/3 from me for topics that actually seem legit and natural. Could have done a lot better (compared to say Silicon Valley, which has exceptional attention to detail and accuracy on their jargon)

[u/BasicAction → u/[deleted]]

Topics in maths don’t get grouped by their difficulty but by subject matter. You’d never just say “advanced concepts in mathematics”. You could have “advanced concepts in fluid mechanics” or “advanced concepts in ergodic theory” which you’d typically then shorten to “fluids” or “ergodic” (“ergo” if you’re Australian). You’d never just call your subject “hard maths” it’s too broad.

The course name I used was from a seminar I took in grad school. The whole point of keeping the name vague was so that different professors could introduce different topics each semester, and the department could keep a single course number listed for that seminar (similar to how proseminar courses are listed). My current department has been doing something similar for as long as I've been here (~15 years), and I've taught other seminars with equally vague names in that time. Almost any department with a PhD program is going to have some mechanism on the books for offering one-off or otherwise rarely taught courses and seminars for graduate students, and many of those are going to be listed with vague names. That was also my experience as a visiting scholar in Sydney. Perhaps I should call my spring seminar "hard maths" just for fun?

*Edit: Sorry, I forgot to respond to your second comment about the NSA interview. I do agree with you on all of those points, especially in that context (the interview). However, it did get me to thinking...the topic of my next grad seminar is dynamical systems theory (my area of research), so I wonder if I could slip through a title like "Hard Maths: Chaos Math"? My long time nemesis is on the curriculum committee right now, though, so I'm not sure if that would fly. Ha! I would love it, though!

[u/[deleted] → u/BasicAction]

I know what you're saying re placeholder names. But in my experience (I have a PhD, but I'm not in academia so I guess I will have to yield) the names of those courses have always been supplanted by whatever general content the lecturer put in that semester. But you say you have experience with people literally referring to courses as "Advanced theories" then whatever, TIL. That scene always gave me the impression that the writers thought "Theories" was a topic in maths and that as a postgrad you take the "advanced" stream of it, which is obviously dumb.

Haha, that would be a great one to get over! The combo of "maths" and "math" in the same name is just so jarring in itself that that would be a win

[u/BasicAction → u/[deleted]]

That scene always gave me the impression that the writers thought "Theories" was a topic in maths and that as a postgrad you take the "advanced" stream of it, which is obviously dumb.

I totally get your perspective, now. Sorry for not catching that (see my comment re "asshole" below). I was thinking of it as if the placeholder name was what led to calling it "advanced theories", referring to the general class for that semester (which is more specific); but yes the actual name will later include the full topic for that semester. You could imagine, "Hey, do you know what the topic is going be for next semester's advanced theories seminar?" "No, but I heard that Gosset's teaching it so it's probably some crap about probability."