Why Do You Know That?

Let's try this again. It's the converse of "auto mechanics to quantum mechanics," where the idea now is to contribute those bits of knowledge that seem really cool even if they are not directly applicable to anything.

Mine for this week:

In Ethiopia, 12:00 a.m. is what we think of as 6:00 a.m. (from a former student who just got back).

Ohio has the only non-rectangular state flag.

The philosopher Hans Reichenbach introduced skiing to Turkey when he fled there after the Nazi purge of 1933. He was also a great ice skater.

What do you know and why do you know it?