| Is the impediment that there are no polar bears in
| Antarctica?:) Whatever, I was interested in what John said
| about how we know when we have the whole solution set when a
| problem may not easily reduce to a mathematically solvable
| form. Like he said when setting the riddle, you have to think
| outside the square, then maybe think outside the square beyond that.
For me, the impediment is partially that; but more so that I've heard
this one since I was a kid and was always told the answer was the North
Pole (combined probably with a northern hemisphere prejudice) all of
this combines in my head to provide a powerful disinclination to search
for other answers beyond the one given.
As an aside, both answers provide a nice example of how geometry on S2
(surface of a 3dim sphere) is different from geometry on R2 (Euclidean