We were talking, my friend and I. About things. Silly things, like how big the universe was, and how small something can be. We didn't know.

Rhys, that's my friend, reckoned there was no end to smallness. He said you could keep cutting something in half and still have something to cut in half again.

"It doesn't matter how many times you do it!" he said, "There's still something there to cut in half!"

"Where would you get a knife small enough to do the cutting?" I asked.

He didn't know. That's what I mean about silly. We couldn't figure it out.

And then I said there must be an end to the universe.

"It can't keep going on and on and on!" I said, "Its impossible for something to be that big!"

"OK," said Rhys, "What if it doesn't go on and on and on? What if you get to the last star and stop at the edge? What comes after that? Just nothing?"

"Yeah, nothing," I said uncertainly.

"Lots and lots of nothing?"

"Well that's something isn't it. Nothing is something."

"Nothing can't be something."

"Why not?"

"Because its nothing!"

"How much nothing do you reckon there is out there, where the universe stops? Maybe the nothing goes on and on? Maybe there's no limit to the amount of nothing there is when you get to the end of the universe with no edges?"

Neither of us had a clue. I thought they were stupid questions!

And sometimes we'd talk about Time, because we'd seen some movies with time-travel in them.

"What if you went back in time?" Rhys said, "And stopped yourself from being born?"

"You'd disappear!" I said.

"Would you?"