The first episode of Doctor Who was broadcast on the 23rd November, 1963. It was beamed into the homes of an unsuspecting British public using radio waves, which are part of the electromagnetic spectrum. These radio waves didn't just stay in our tellies, however, and will have radiated out into space at the speed of light. By now, the first episode of Doctor Who will be more than 50 light years away from the Earth. Who knows, perhaps a passing alien has managed to pick it up by now. If some lucky alien was receiving broadcasts of one of Britain's greatest exports, what would this hyper-intelligent extraterrestrial think of our scientific know how? Well, as is often the way, a lot of the science fiction in the show can actually be seen reflected in the world of science fact. Either by careful research or sheer dumb luck, the writers have managed to include many concepts that often float around the offices of theoretical physicists. Yes, perhaps even including the TARDIS itself...
