A riveting video from David Kipping at Astronomy Columbia. Is there life out there? We simply have no idea as it’s not possible to extrapolate from a single data point – Earth. It could well be that the creation of life is very difficult and we are the only example of life in our galaxy or indeed in the entire observable universe. We simply have no data to suggest otherwise. It would explain the absence of evidence of life in the radio spectrum and we have been looking for 50 years. The prospect that we are the only sentient beings within the observable universe (~30 billion light years across is both wonderful and rather terrifying.
That said it is interesting to contemplate that we and our animal relatives are likely the most complex entities on this planet and in this solar system. Given that we have seen no evidence of other sentient beings in the radio spectrum in the last 50 years or so it might also be reasonable to suggest that we are likely the most complex entities with hundreds of light years of Earth. It would however be nice if life were present in profusion elsewhere – but we simply do not know.
It might well be that it is us who are the “Aliens” and that over the next few hundred million years we will populate a vast region of this corner of our galaxy. I find this somehow very satisfying.