Project Hail Mary

by Andy Weir

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.

Gravity doesn’t just “go away” when you’re in orbit. In fact, the gravity you experience in orbit is pretty much the same as you’d experience on the ground. The weightlessness that astronauts experience while in orbit comes from constantly falling. But the curvature of the Earth makes the ground go away at the same rate you fall. So you just fall forever.