In reply to marcusinbristol:
Answers hopefully suitable for the young...
> My little girl tonight asked about the stars in the night sky and why we could see them on earth if they were really so far away.
They are very, very bright, many of them are even brighter than the sun. And there is nothing (vacuum is, by definition, nothing) to stop the light so we see it here. Light moves very fast, but it's not instant, and the light has spent years travelling to get to us.
> We talked about if we were in space with a torch and we turned it on for a couple of minutes what would happen to that light. [...] She also wants to know if she were on the far side of space and was waiting for the light to arrive from the torch what would it be like.
That light would go out into space as a long, thin beam, travelling very fast. It would spread out as it travelled, and it wouldn't take long until it was spread so thinly that it was invisible even with the most powerful of telescopes. A torch is a hundred million million million million times dimmer than our sun, and our sun is small enough to be nearly invisible from the other side of the galaxy, never mind the other side of space. Space is huge.
If instead of using a torch just blew up a bunch of big stars, then the explosion would be bright enough to see from a long way away. You could see it in the next galaxy over (which is called Andromeda by the way), but it would take 2.5 million years to travel there.
We don't know how far away the far edge of the universe is, or even if it has an edge. It's possible it wraps round on itself somehow, but that's getting complicated. If it has a far side, then the light would probably not get there before the end of the universe.
If it did get there, it would arrive as radio waves due to the cosmological redshift. That's due to general relativity, which is notoriously hard to understand, so I'm not even going to try to explain it.