What If? 10th Anniversary Edition: Serious Scientific Answers to Absurd Hypothetical Questions

by Randall Munroe

am a cartoonist. If you follow my advice on safety around nuclear materials, you probably deserve whatever happens to you.

you’re like me, when you first saw this question, you might’ve imagined the puck leaving a cartoon-style hockey-puck-shaped hole. But that’s because our intuitions are shaky about how materials react at very high speeds. Instead, a different mental picture might be more accurate: Imagine throwing a ripe tomato—as hard as you can—at a cake.

To put that in perspective, it takes about five milliseconds for the fastest nerve impulse to travel the length of the arm. That means that when your arm is still rotating toward the correct position, the signal to release the ball is already at your wrist. In terms of timing, this is like a drummer dropping a drumstick from the tenth story and hitting a drum on the ground on the correct beat. We seem to be much better at throwing things forward than throwing them upward.

Here’s a question to give you a sense of scale. Which of the following would be brighter, in terms of the amount of energy delivered to your retina: A supernova, seen from as far away as the Sun is from the Earth, or the detonation of a hydrogen bomb pressed against your eyeball?

I am alone now, truly alone, and absolutely isolated from any known life. I am it. If a count were taken, the score would be three billion plus two over on the other side of the moon, and one plus God knows what on this side.

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