SETI and sci-fi expectations
In your letters page (21st Feb 2015) John Bailey concludes that since we haven’t been bombarded with self-replicating alien robots or seen huge heat signatures in space, there probably aren’t any advanced civilisations in our galaxy. He seems to think that advanced races will have a ‘more is better’ philosophy, but climate change is showing us that a ‘less is better’ philosophy is the only intelligent long-term strategy. If this is correct, then the more advanced a race is in the galaxy, the less visible they’ll be. It’s the quiet ones that are clever, not the shouters.
John Bailey's expectation that advanced alien civilisations will be huge, star-spanning confederations with big, powerful ships and zillions of self-replicating robots is, I think, because of how they're currently depicted in mainstream fiction. We pick whatever seems cutting-edge and exciting at the moment - nano-technology, robotics, ion-drives - and multiply them by a thousand or a thousand million and, voila, that's your advanced alien civilisation. A century-or-so ago, H.G.Wells came up with the idea of Cavorite, a substance that could negate gravity. Using this discovery, two Englishmen travelled to the moon. From a scientific point of view, Cavorite is just as believable as a warp drive or a hyperdrive but it's now seen as quaint, silly and unscientific. I'd bet that self-replicating robots will be seen as just as daft in a century's time.
'The Midwich Cuckoos' approach to science-fiction couldn't be more topical. Our species has reached a point where we have highly developed enlarging external abilities (engineering, constructing, organising, refining, distributing) but we desperately need to exercise internal reducing abilities (self-denial, abstinence, self-rationing, selflessness) if we are to avoid climate meltdown and centuries of social, political and environmental collapse. The challenge now is not without, but within.