probability
Original: probability on Saturday Morning Breakfast Cereal
Transcript
Panel 1:
Bearded man (with chalk, drawing on a chalkboard): Suppose there's a square with a side length between 0 and 4 units.
[Chalkboard shows a square labeled "0 -> 4" with a question mark above it.]
Panel 2:
Bearded man: You don't know its length and you don't know the distribution of probabilities. Reasonably, you say it's equally likely to be more or less than two units long.
[Chalkboard shows a square labeled "0 -> 4".]
Panel 3:
Bearded man: You'd also like to know its area. Since area is the side length squared, you know it must be between 0 and 16, with an equal chance of being greater or lesser than 8.
[Chalkboard shows a square labeled "0 -> 4" on top and "0 -> 16" inside.]
Panel 4:
Bearded man (turning, hand raised): But a square with an area of 8 has a side length of 2-root-2 (2√2), not 2!
Panel 5:
Bearded man (shouting, leaning toward an unseen audience): So which is it, mother fuckers?
Panel 6:
Bearded man (mouth wide open, yelling): Which is it?
Panel 7 (bottom, wide):
Bearded man: I thought philosophy of probability would be the easiest in a math degree, and now I'm not even sure reality is real.
[A red-haired student and another student walk away through a doorway.]
A student (in speech bubble): "Reality"? That's just a convenient assumption for calculations.
Votey:
Text (handwritten, parenthetical): (Literally nothing is wrong with this line of reasoning, so there is no need to email me)
Bearded man (with chalk, drawing on a chalkboard): Suppose there's a square with a side length between 0 and 4 units.
[Chalkboard shows a square labeled "0 -> 4" with a question mark above it.]
Panel 2:
Bearded man: You don't know its length and you don't know the distribution of probabilities. Reasonably, you say it's equally likely to be more or less than two units long.
[Chalkboard shows a square labeled "0 -> 4".]
Panel 3:
Bearded man: You'd also like to know its area. Since area is the side length squared, you know it must be between 0 and 16, with an equal chance of being greater or lesser than 8.
[Chalkboard shows a square labeled "0 -> 4" on top and "0 -> 16" inside.]
Panel 4:
Bearded man (turning, hand raised): But a square with an area of 8 has a side length of 2-root-2 (2√2), not 2!
Panel 5:
Bearded man (shouting, leaning toward an unseen audience): So which is it, mother fuckers?
Panel 6:
Bearded man (mouth wide open, yelling): Which is it?
Panel 7 (bottom, wide):
Bearded man: I thought philosophy of probability would be the easiest in a math degree, and now I'm not even sure reality is real.
[A red-haired student and another student walk away through a doorway.]
A student (in speech bubble): "Reality"? That's just a convenient assumption for calculations.
Votey:
Text (handwritten, parenthetical): (Literally nothing is wrong with this line of reasoning, so there is no need to email me)
Alt text
A seven-panel SMBC comic. A bearded man stands at a chalkboard lecturing about probability. He says: "Suppose there's a square with a side length between 0 and 4 units. You don't know its length or the distribution of probabilities, so reasonably you say it's equally likely to be more or less than two units long." He draws a square labeled "0 -> 4." He continues: "You'd also like to know its area. Since area is side length squared, it must be between 0 and 16, with an equal chance of being greater or lesser than 8" (board now also shows "0 -> 16"). He suddenly realizes the contradiction: "But a square with an area of 8 has a side length of 2√2, not 2!" He spirals, shouting at his students: "So which is it, mother fuckers? Which is it?" In the final wide panel he despairs, "I thought philosophy of probability would be the easiest in a math degree, and now I'm not even sure reality is real," while two students walk out a doorway, one replying, "Reality? That's just a convenient assumption for calculations." Votey aftercomic: a hand-lettered parenthetical in a panel reads, "(Literally nothing is wrong with this line of reasoning, so there is no need to email me)" — the author preempting math pedants. The joke is the Bertrand-paradox-style contradiction where assuming a uniform distribution over length versus over area gives inconsistent answers, driving the lecturer to an existential breakdown.
Transcribed by Claude Opus 4.8.