Readers offer their explanations for the absence of hard evidence for extraterrestrial civilisations, in response to an article by Adam Kirsch
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 offâworld, 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, theyâd never get past a 17th-century level of development.
Even if we can eventually detect life on planets outside our solar system, weâd 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 Thronesâs Westeros, not Iain M Banksâs Culture, doomed never to be detected from afar.Ian SimmonsWestcliff-on-Sea, Essex
Adam Kirschâs article misses one possibility: that any advanced civilisation might simply be keeping its distance. Humans have long imagined such watchers. The KayapĂł people of Brazil, for example, tell of Bep Kororoti, a visitor who shared knowledge and helped their ancestors build a stable and sustainable society.
Itâs 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 weâll finish ourselves off. An older voice might reply that humans have a habit of rebuilding, and that societies like the KayapĂł 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 JoshiBirmingham
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 Fermiâs question âWhere is everybody?â might be âthey all left before we got hereâ or âthey havenât arrived yet, and weâll be gone by the time they doâ.David WalkerSheffield
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 antsâ nest?Sheila PrestonShoreham-by-Sea, West Sussex
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