Open set Memes

The Japanese flag just got a topology upgrade. That mathematical statement translates to "Japan is an open set" - meaning for any point in Japan, there's some tiny neighborhood around it that's still in Japan. The dashed boundary on the red circle is the mathematician's way of saying "we don't include the border" - just like how mathematicians insist on making simple concepts incomprehensible to normal humans. Next semester: proving why sushi rolls are topologically equivalent to donuts.