And in the meantime, unfortunately I used the words, in my paper in Science, 'artificial biosphere' to describe these possible alien activities, biosphere just being an inhabited region, and I called it an artificial biosphere as being something that would radiate in the infrared band. And the science fiction writers got hold of this phrase and imagined it then to be a spherical rigid object and the aliens would be living on some kind of artificial shell, a rigid structure surrounding a star, which wasn't exactly what I had in mind, but in any case that's become then a favourite object of science fiction writers. They call it the 'Dyson sphere', which was a name I don't altogether approve of. But anyway, that's... I'm stuck with it. But the idea was a good one.

[Q] But you had indicated the possibility of advanced civilisation taking planets apart, and... it's possibly that idea that, so to say, resonated with science fiction, I mean the notion...

That's also true, yes. I mean, that was a different paper. I published another paper in a Marshak memorial volume, I think...

[Q] In the Bethe Festspiele.

Oh, that's what it was. Anyway, that was about taking planets apart, demonstrating that, as far as the laws of physics are concerned, it's quite possible to take planets apart simply by spinning them up; you can... you can apply a homopolar generator to a planet and spin it up faster and faster until the equator flies away and it becomes a disc, and so in principle you can do that. I wasn't advocating that, but merely pointing out that the aliens might in fact have done that and that would be a good way of getting material if they wanted to do large scale engineering.

[Q] But it's... I mean it's... as the editors commented in the introduction, there are very few people who would have dreamt of doing something like that, except for you.

Well, Olaf... I got that idea from Olaf Stapledon. Olaf Stapledon is one of my favourite writers of science, he does... he wrote excellent science fiction and, very imaginative, and he also was a professor of philosophy, so he was thinking big.