By any measure, the 20th century was a wild ride for the people of Earth. Between 1900 and 2000, we went from a world of about 1.6 billion to over 6 billion people, survived two world wars, squeaked through 44 years of the Cold War and 70,000 ready-to-go-at-the-touch-of-a-button nuclear missiles, unlocked the DNA code of […]