I used to be into caving. There's something transcendental about complete darkness. Not just the merely dark of an overcast, moonless night, but the truly black. Caves are the only place I've seen it. No visible-wavelength photons beyond those made by radioactive decay, maybe.
It's uncanny. Humans aren't built for it.
Most people begin to gently hallucinate after anywhere from a couple minutes to a half hour.
@starkatt I want to experience that sometime, too. :-}
@starkatt Seems like an okay thing to experience for a few minutes, after that probably not so much.
.... I am such a child of the sun.
Also, have you read The Skook? It's... quite dated now in several respects, but it deals with a guy trapped in a cave for a very long time without any light. And hallucinates, or doesn't, several things.
@Soreth I have not! Is it available online?
@starkatt Huh, nobody's selling ebooks of it... seems probably not. n..n;
A friend of mine would get scary, non-gentle hallucinations. She didn't like the lights to be out for longer than a few seconds.