What is infinity?
Scott: Infinity is the number that no-one in the world can count to. No-one can even get to the 10 numbers before it.
How big is infinity?
Scott: So big that I can’t even say. I don’t even know how many numbers make infinity. The biggest number still isn’t big enough. Infinity is the biggest number in the world, isn’t it? Isn’t it?
Well, it’s not really a number – it’s really a concept.
Scott: What’s a concept?
Well, something that you try to understand rather than something you can touch.
Scott: So it’s a number no-one can count to, mostly?
Sort of. Space is infinite, because it’s got no beginning and no end.
Scott: How does space never begin? People have been to the moon and that’s the beginning of space.
Well, that’s part of space – not the beginning. The moon is in space, but it’s not the start of space.
Scott: The end of space?
No, it’s not the end of space either.
Scott: Somewhere in the middle? A quarter of the way through?
It’s got no beginning and no end.
Scott: How does it have no beginning? If it has no beginning, how can people go to the moon?
The moon’s in space, but it’s not the beginning – we’re in space already.
Scott: How? Yes, it is… Of course… because we can see the moon and the moon’s actually the sun, isn’t it?
The moon’s the moon and the sun’s the sun. The moon’s a planet, the sun’s sort of a planet and the Earth is a planet.
Scott: But Daddy, why don’t we float into space?
Gravity.
Scott: Yes, but there’s no gravity in space.
We’ve got gravity here and it helps us stick to the ground.
Scott: But not too sticky, because I can still jump in the air. I wish there was a little less gravity so I could jump higher.
And there is the atmosphere, which protects us and means we can breathe.
Scott: Yes, but the sun has made a hole in this atmosphere so it sometimes gets a teeny bit hotter.
But we’re still in space, does that make sense?
Scott: A teeny bit. Earth is like the second or third smallest planet. Pluto is definitely the smallest, isn’t it?
The smallest near us I think.
Scott: Are any planets smaller than Pluto? I don’t think we’d fit on any smaller than Pluto.
There are billions and billions and billions of planets in space, some of them will be smaller than Pluto.
Scott: One’s so tiny I don’t think an alien would even fit on kit. If aliens lived on Pluto, they’d be the size of tiny ones.