Bob Maywood: We talked last week about black holes with you, Stephen. You said nothing, even light or time, could escape from a black hole. That sounds to me like they could be like huge cosmic bank vaults then, like giant libraries. Would it makes sense to go looking for signals there?
Stephen Appleton: I told you, nothing can escape from a black hole. Once you cross the event horizon, that’s it. There’s no coming out.
Katherine Collins: Unless you are thinking about white holes. Theoretically, if black holes are connected to white holes, then you have an exit point.
SA: Theoretically. But it’s just speculation really.
KC: It’s a mathematically viable theory.
SA: Yes, it might be, but that doesn’t mean they actually exist.
BM: But what do you think life might be like if it existed in these amazing unknown regions. That’s a possibility, right? If you believe Fermi – and it would explain why we’ve never found it.
SA: That’s the stupidest idea I’ve heard all week.
KC (laughs): Well, it is a little far-fetched, but yes, it’s theoretically possible. But I’d have to say, to survive in such an environment it would have to be very alien. So alien that we might not even realise it was intelligent at all. We might not even recognize it as life. We’d have to redefine the term.
BM: So you’re not expecting any invitations to discuss science on an extra-terrestrial radio station broadcasting out of a black hole anytime soon then?
KC: I won’t be giving up the day job, put it that way. But a good scientist should never close their mind off to anything until all of the evidence is in.
BM: Coming up next, we’ll be discussing the practical ways in which we’ve been listening for alien life – the SETI project and the plans for a bold new initiative called META. But first, more space-inspired hits from the last two decades, and coming first is another Brit, the incomparable David Bowie…