Time zones were created to simplify our lives. But as the saying goes, time is relative, which is part of what makes time zones around the world so fascinating.
Hair has sent cultural messages for centuries. It also sends signals about our body chemistry, including our age and health, which may be the unconscious reason some of us get so upset about "bad hair" days.
The ancient world is full of surprises. What sprawling pre-Columbian civilization had its own postal system? Where can you find the world's biggest pyramid, or the oldest mummies? (Hint: It's not Egypt.) Read on for the stories behind these and other astounding aspects of the distant past.