A third possibility is that there is a reasonable probability for life to form, and to evolve to intelligent beings, in the external transmission phase. But at that point, the system becomes unstable, and the intelligent life destroys itself. This would be a very pessimistic conclusion. I very much hope it isn’t true. I prefer a fourth possibility: there are other forms of intelligent life out there, but that we have been overlooked. There used
to be a project called SETI, the search for extra-terrestrial
intelligence. It involved scanning the radio frequencies, to see
if we could pick up signals from alien civilisations. I thought
this project was worth supporting, though it was cancelled due
to a lack of funds. But we should have been wary of answering
back, until we have develop a bit further. Meeting a more
advanced civilisation, at our present stage, might be a bit like
the original inhabitants of America meeting Columbus. I don’t
think they were better off for it.
That is all I have to say. Thank you for listening.