Part of the show Naked Science Question and Answer
Gordon in Huntingdon asked:
I'm curious about this digital era we've gone into. If you watch the television on digital signal, the clock that they show, especially on breakfast television, has a slightly different time than real time. This is because of the signal having to go up to the satellite and come back down again. I wondered if there was a way of solving this?
There is and they rely on Einstein's theory of relativity to get around the problem with GPS, but not really for everybody because it depends how far the signal has to travel. The only way round it is to provide local time signatures. And they're going to switch off the analogue signals so it's going to cease to be an issue and we'll all be slightly out of time. The thing is, we live in a world where the average person has their watch out by several minutes relative to Greenwich Mean Time, so a fraction of a second disparity on the television is probably not going to affect people's lives if I'm being really honest.