CB1100 Monthly Photo Challenge

[Cormanus]

Maybe I have the term wrong? In Douglas Adams' novel, Dirk Gently's Holistic Detective Agency there's a sofa stuck half way up a flight of stairs. No-one can get it up and no-one can get it down, and nobody can figure out how on earth it got stuck there. Turns out, as the chaps were carrying the sofa up the stairs they were having trouble turning it on the landing. One of them opened a door on the landing and they partly maneuvered it using that. Turns out the door was an opening in time and space and vanished immediately after they'd used it and before they could complete the turn. Hence the sofa was stuck for ever. Well, until the police sawed it into pieces in order to get up the stairs.

It also turns out the 'moving sofa problem' is a thing in maths. See here.