Project Hail Mary

by Andy Weir

Cool thing about pendulums: The time it takes for one to swing forward and backward—the period—won’t change, no matter how wide it swings. If it’s got a lot of energy, it’ll swing farther and faster, but the period will still be the same. This is what mechanical clocks take advantage of to keep time. That period ends up being driven by two things, and two things only: the length of the pendulum and gravity.

Light is a funny thing. Its wavelength defines what it can and can’t interact with. Anything smaller than the wavelength is functionally nonexistent to that photon. That’s why there’s a mesh over the window of a microwave. The holes in the mesh are too small for microwaves to pass through. But visible light, with a much shorter wavelength, can go through freely. So you get to watch your food cook without melting your face off.

Human beings have a remarkable ability to accept the abnormal and make it normal.

The tape measure is metric, thank God. It’s going to be confusing enough using base-6 Eridian seconds. The last thing I want to throw in there is imperial units—even

Oh thank God. I can’t imagine explaining “sleep” to someone who had never heard of it. Hey, I’m going to fall unconscious and hallucinate for a while. By the way, I spend a third of my time doing this. And if I can’t do it for a while, I go insane and eventually die. No need for concern.

“Obvious I can do that! You are stupid right now. You sleep.