Originally posted by GunsForBucks:

Until proven wrong I am just going to assume it is something like this
https://steamcommunity.com/sharedfiles/filedetails/?id=2469795907

And expect to see an elephant or turtle on the way down if I go off in the right place.

There was an old PS1 game called Discworld that explained this concept rather well, it was voiced by Monty Python's Terry Pratchett.

also apparently a comic :

https://en.wikipedia.org/wiki/Discworld

even better (the intro from the game) :

https://www.youtube.com/watch?v=Q1CtIcInJSw