#2945: Broken Model

XKCD comic, described below.
Transcript

[Miss Lenhart is holding a pointer to a whiteboard, indicating the last part of the last line of text.]

Miss Lenhart: Hmm, looks like I accidentally swapped the predation terms.

Miss Lenhart: If this were an ecology class, I would have to fix that.

Miss Lenhart: Unfortunately for those 20 poor foxes, this is calculus, and the math says these 400 rabbits are hungry for meat.

[There are three lines on the white board, where the '...' ellipses in the bottom line are illegible:]

Nrabbits(0) = 400

Nfoxes(0) = 20

dN0/dt = ... dN.../... = ...

[Caption below the panel:]

Every broken mathematical model is just a glimpse into a terrifying alternate universe.

(Sourced from explainxkcd.com)

In addition to eating foxes, rabbits can eat grass. The grass also eats foxes. Our equations chart the contours of Fox Hell.

ExplainOriginal