Anyone heard of the cave phenomenon, "dead light"?

Question

I came across a description in a crime novel which I think was called "Dead Light" or something similar. The phenomenon is where light enters the cave and bounces of the narrow tunnel walls, "lost" in the cave, and providing very faint light when it should really be very dark.

Has anyone heard of this, and can give me the proper name for it? I think it was "dead light", "ghost light", something along those lines. Thanks!

Answer 1

Hi. Good question. As long as there is a path, no matter how convoluted, that the light can travel down it should never be completely dark.

Answer 2

I'm not sure if this is the answer you're looking for but "calcium carbonate refraction) causes light to extend into deep recesses in cavern systems and can leave the eerie impression of ghost lights. It's a common phenomenon because of the amount of calcium deposits in many caves. It can take many turns and dips and is beautiful to look at.

Answer 3

I've never heard of this really happening, but I think it is the principle of the optic fiber :)

Answer 4

For all practical purposes, the light in a cave disappears a short way in from the entrance.