Bau einer leichten Reiseuhr

This clock shows how long it takes light to travel from the Earth to other planets and the sun. I got the idea from the first of six Christmas lectures that Carl Sagan gave at the Royal Institution in 1977. A clock like this is shown there in large format. The model of the Titan III-Centaur main rocket that sent the interstellar probes, Voyager 1 and Voyager 2 into space, is slightly shorter than scaled in the video. The reason is that otherwise, the clock wouldn’t fit on my bookshelf.