Ask a grown-up: how would it be possible to time-travel?

Ten-year-old Grace's question is answered by physicist-turned-comedian Ben Miller

• Ben Miller
• The Guardian, Saturday 19 January 2013

Ben Miller: 'I know a bit about this.' Photograph: Karen Robinson

Before I was a comedian, I was a physicist, so I know a bit about this. One way would be through a wormhole. We think that certain parts of space are connected to different parts, possibly at different times, and you could possibly move between them.
But there is also a simpler way. Look up at the stars at night. Because they are so far away and the light takes such a long time to reach us, in many cases you are seeing the star as it was thousands of years ago. If we had a strong telescope, we could see the planets that circle those stars, too, and that means that if there are people on those planets with really strong telescopes, they would be able to see us as we were thousands of years ago. They may be seeing the Earth as it was 1,000 years ago, when the Vikings were settling and when there was no electric light and no cities. So when you look at the stars at night, you are time-travelling with your eyes.
• Ben Miller stars in BBC1's Death In Paradise.