overheard a joke about some topological space where one can go in but can't come out. What is the name of this space. Google just gave me black holes.
Question of name of space
1
$\begingroup$
general-topology
reference-request
1 Answers
3
Could that be a Klein bottle? One can go in, but once in, one can't come out, since the inside and the outside of a Klein bottle are the same.
-
0@MaoYiyi Certainly, but the check mark ✓, not the up-arrow ⇮, is used for accepting. If I were you, I would undo the check mark, and wait a day or two to see if any better answers come in, before accepting. – 2012-09-14