After watching Wonders of the Universe with Professor Brian Cox the other day I got thinking about something he said. Something I knew already but had never really thought about; the fact that when you are looking at stars you are looking into the past.
Sitting on top of Snaefell on Monday night I realised this also meant that in outer space the vision of Earth will be based on some time in history determined by the distance.
So the next question that entered my head was “How far do I need to get out into space?” There was no chance of sleeping then until I’d figured this one out so with the help of Excel I’ve done some very dirty maths and reckon I have a formula to work this out.
So, what I worked out was that if I wanted to see what was happening on earth 100 years ago I’d have to travel 945,425,495,548,800 Km away and look back with a pretty big telescope. OK not likely but it is possible! When I was trying to work this out I had no idea what the distance would be and rather naively never imagined it to be this far. To put this in perspective, which is what I needed to do, Pluto is only 5,913,520,000 in comparison. So it’s a bit of a journey.
