The thermoexchanging processesbetweenthe inner and the outersurfacesoftheglass in a freezerdoor were simulated with a model oftwo infinite parallelplanes.
But if the aircraft in question, known as Trumper, Piper and Laima, make it to Benbecula in theOuter Hebrides, as their owners hope, they will be the first pilotless planes to have crossed the Atlantic Ocean and landed safely.