UFOs & Aliens Fact or Fiction?

Erm, travel back in time? Can you explain the physics that will make this possible please? Travel forward in time - yes, I get that. Back?? (This obviously doesn't include going to Merthyr Tydfil).

Of course with the billions of galaxies in the known universe, it's very unlikely that this insignificant rock should be the only one to have life on it. Intelligent life is also pretty likely to have appeared elsewhere in the universe in one of the billions of galaxies over the past 13 billion years or so.

However, the likelihood of such life then being close enough to us in terms of distance, and also developing at the same time as we're around is actually pretty slim - so unlikely we'll meet any aliens.

The Sun is about 93 million miles from the earth. The star nearest to the Sun is Proxima Centauri. Proxima Centauri is 4.3 light-years from the Sun or over 25 million million miles, which is 270,000 times greater than the distance between the earth and the sun. So it would take light 4.3 years to travel that distance, at the erm... speed of light. The space ships we have would take about 10,000 years to travel a light year. The other bad news is that Proxima Centauri is a red dwarf, so unlikely to support any life in its solar system. So we'd have to go to one further out, and therefore even further away.

Not going to happen in our life-time then.