Question: Is it true that falling into a black hole in a dream is your body waking you up because one of your organs was malfunctioning?

Alex Baxendale answered on 5 Mar 2021:

This is an interesting one! I have never heard of this before, but I can tell you what I do know about sleep and dreaming. Our brains create waste throughout the day (it ‘eats’ things, and when we eat something needs to come out afterwards) which needs to be thrown away. One of the reasons we sleep is so that we can give ourselves the chance to throw away the waste our brains create (recent research is still figuring if this is really what it going on though). During the day our brain has a lot of background activity that we’re not really aware of, this is called the ‘default mode network’, it’s the generic state your brain is in when it isn’t doing anything – Sleep is kinda like this function as well! We don’t have anything to do whilst the brain is flushing itself of nasty waste, so our brain picks random pieces of information, some of it is things that we experienced that day, or it could be random bits from whenever. This is important because our memory of something gets better (we’re less likely to forget it) the more we remember, so this is an opportunity for our brain to do something useful whilst we’re sleeping – we throw a bunch of random bits together to practice remembering things.
I haven’t seen any evidence anywhere that the content of our dreams represent anything specific at all, it’s just a general mess of stuff we put together to keep us busy whilst sleeping