It's possibly due to the fact that it's outside our respective worlds and it's simply taking persons out of said time frames. But there's a lot we don't know about it.

Nope! None whatsoever! It's rather amazing actually. The food is restocked by the people who brought us here, the Malnosso. [ Saying that with a tinge of resentment. He's not really on good terms with them after the last experiment. ]