... technologies to first enter popular consciousness as toys. In the 1st century, Heron of Alexandria invented the aeolipile: a metal ball with curved nozzles sticking out of it, perched on stilts. With water in it, and flame beneath it, the resultant ...

... diamond-pendant earrings that now belong to me. In her jewelry case, there is also a pair of small, hinged, hollow metal balls that snap closed over the diamonds to make them look like gold earrings. What was the purpose of the hollow balls ...