[jotaen]

I find the “no light” bit in the subtitle confusing, as the article says he had “a torch as his only light source”. I get that a torch is not much light, but it’s still significantly different from “no light”. Or maybe they meant “no daylight”, but that seems hardly worth to mention for a cave.

[adammarples]

It's worth mentioning because we use daylight to regulate our circadian rhythm, and he was studying the body's circadian rhythm without daylight