Question: how does lackk of light affect someone's inner bodyclock?

Mike Ambler answered on 12 Nov 2018:

Hi great question!

Yes it does: we have a set of neurons in our brains that tick away like an internal clock and tell us when we should be awake vs asleep or when to eat. Interestingly the clock neurons don’t quite keep perfect time and they need information about whether it is light or dark to make sure they stay set correctly. If people are kept in a room with no windows so they don’t see when it is night time or day time the clock can drift off time a bit. Each day the clock may drift a little bit further until eventually the person may be sleeping during the day time and awake at night (although the person wouldn’t realise this because they can’t see outside).