Monday, 8 July 2013

DIY time travel, part 3: Seeing back in time.....

Now, earlier in this series of posts, I claimed going forwards in time was easier than going backwards. And it's true - we're all going forwards in time anyway, so going forwards faster just means giving nature a helping hand.

Um.

Yes I'm trying not to admit that I've missed something obvious.

My ego's very fragile, ok?

What I had forgotten was that light travels at a very fast, but still limited, speed. Which means that we're all seeing into the past - the light that we see with has taken time to reach us, so it is arriving from the past. We see the Moon as it was a second and a half ago, the Sun as it was eight minutes ago, and Pluto as it was nine hours ago. 

The further away you look, the further into the past you see. And the Hubble Space telescope can see pretty damn far....



So we can see into the past - billions of years into it. But can we send things into it?

Weeeellll...... maybe. But here I'm going to have to drop the DIY bit: To send something into the past we're going to need some lethal radiation, and the most powerful magnets in the universe.....

To be continued...