Above: a Federal Civil Defense Administration pamphlet, circa 1950s, explaining that fallout is “nothing more than particles of matter in the air, made radioactive by nuclear or thermonuclear explosions,” which you then ingest or breathe. Wow, what a bunch of alarmists we are. We thought it was something bad.
1947—Heyerdahl Embarks on Kon-Tiki
Norwegian ethnographer and adventurer Thor Heyerdahl and his five man crew set out from Peru on a giant balsa wood raft called the Kon-Tiki in order to prove that Peruvian natives could have settled Polynesia. After a 101 day, 4,300 mile (8,000 km) journey, Kon-Tiki smashes into the reef at Raroia in the Tuamotu Islands on August 7, 1947, thus demonstrating that it is possible for a primitive craft to survive a Pacific crossing.