Category Science

The first snooze alarm, GE’s 1956 Snooz-Alarm, promised ten minutes, not nine. A fixed nine appears with 1970s digital clock chips, and no maker ever explained why.

Federal rules require an ashtray by every airplane lavatory door. The FAA’s reason: some people still smoke, and a lit cigarette in the paper towel bin started fires in the 1970s.

The holes, called docker holes, let steam escape while the cracker bakes. Without them the dough blisters into a lumpy pillow, as two snack and pizza patents explain.

The mirror-image word on the front of an ambulance turns the right way round in a rear-view mirror. In the US it is a written rule: federal specification KKK-A-1822 sets the letters at no less than 4 inches, in blue.

There is no universal code for scrub colours. The green in operating rooms goes back to a 1914 article by surgeon Harry Sherman, whose green sheets faded in sterilization, so he dressed his team in black.

For decades textbooks said microbes outnumber your own cells ten to one. The real figure is closer to a tie, and the story of the old number is its own lesson.

You have probably heard that medieval windows are thicker at the bottom because glass slowly drips over centuries. It is a tidy story, and it is false.