From Alex McDowell, London, UK
I take issue with the idea that we don’t hear from aliens because the ability to develop interstellar communication also means an ability to develop potent weapons that lead to self-destruction(24 May, p 21).
Such civilisations have the potential to last longer because they can find ways to avert natural Armageddon. We know an asteroid wiped out the dinosaurs and are looking at ways to prevent future impacts. Nuclear bombs are one way to deal with asteroids. We also have methods to mitigate climate change, and advanced societies are also more likely to colonise other worlds, giving them greater protection from annihilation.
