This and dozens of other questions are being answered athe  the New Scientist "Last Word" Column. Its one of my favorite websites. It's a mix of wit, insight and scientific curiosa. TLW's most prolific answerer by far is one Jon Richfield, a retired
computer scientist in Stellenbosch, South Africa. His first reaction to TLW's riddles is often "No clue!" or "Who cares?"
Then "the next thing you know, it's 'Oh, well, let's have a go.'" This
has happened about 300 times...