When thinking about why we have not encountered intelligent aliens yet, as Adam Kirsch does (The long read, 11 August), it seems to me that one factor gets neglected: fossil fuels. Alien life could develop intelligence on myriad planets, but to develop advanced technology that would enable them to get off‑world, they need to go through an equivalent of the Industrial Revolution, and that needed first coal, then oil and gas.
There could be many intelligent alien races out there, but on planets without an easily accessible fossil fuel equivalent, they’d never get past a 17th-century level of development.
Even if we can eventually detect life on planets outside our solar system, we’d never know these civilisations existed, as their signature from afar would be indistinguishable from that of a planet with just plant-like life and a fire ecology.
It is entirely probable, as a result, that almost all alien races, if they exist, are living in an eternal equivalent of Game of Thrones’s Westeros, not Iain M Banks’s Culture, doomed never to be detected from afar.
Ian Simmons
Westcliff-on-Sea, Essex
Adam Kirsch’s article misses one possibility: that any advanced civilisation might simply be keeping its distance. Humans have long imagined such watchers. The Kayapó people of Brazil, for example, tell of Bep Kororoti, a visitor who shared knowledge and helped their ancestors build a stable and sustainable society.
It’s easy to imagine a similar conversation among distant observers today. A younger voice might look at our atomic weapons and shake its head, predicting that we’ll finish ourselves off. An older voice might reply that humans have a habit of rebuilding, and that societies like the Kayapó show we can live with balance when we choose. Their verdict might be to wait a while, and see whether we can keep our civilisation going, before attempting contact. Given our history, who could blame them?
Miland Joshi
Birmingham
Given the age of the universe, estimated at 13.8bn years, it is quite possible that many forms of life and civilisations have arisen, flourished, declined and disappeared (just as humanity seems likely to). The notion that two such phenomena might occur at the same time and thus permit mutual communication would be a mind-boggling cosmic coincidence. So one response to Fermi’s question “Where is everybody?” might be “they all left before we got here” or “they haven’t arrived yet, and we’ll be gone by the time they do”.
David Walker
Sheffield
Maybe aliens have arrived, but were too small for us to notice? Perhaps they fell down a drain, were eaten by seagulls, or ended up in an ants’ nest?
Sheila Preston
Shoreham-by-Sea, West Sussex
