Catching up with some of the groups I lurk on, I spotted a great post from Dave Taylor, who was recently reading the very first issue of the original Eagle comic and stumbled upon an error in the Professor Brittain (sic) strip. "The Professor is explaining how radar works to Bob and Joan and as a sort of analogy uses a torch as a searchlight to find Joan's bracelet in the dark," says Dave. "He then uses a portable radio to discover the direction from which radio waves are being emitted from a radio transmitter. Bob then queries how radar can detect a plane when it doesn't emit radio waves. The Professors response is...
"Sound waves are like light waves—they even travel at the same speed..."
Not in this universe they don't.
(* My thanks to Dave Taylor for allowing me to quote his comment.)