omens

"Though he died decades before Sputnik, Tsiolkovsky believed it was human destiny to expand out into the cosmos. In the early 1930s, he wrote a series of philosophical tracts that launched Cosmism, a new school of Russian thought. He was famous for saying that ‘Earth is the cradle of humanity, but one cannot stay in the cradle forever.’

The mystery that nagged at Tsiolkovsky arose from his Copernican convictions, his belief that the universe is uniform throughout. If there is nothing uniquely fertile about our corner of the cosmos, he reasoned, intelligent civilisations should arise everywhere. They should bloom wherever there are planetary cradles like Earth. And if intelligent civilisations are destined to expand out into the universe, then scores of them should be crisscrossing our skies. Bostrom’s expanding bubbles of infrastructure should have enveloped Earth several times over.

In 1950, the Nobel Laureate and Manhattan Project physicist Enrico Fermi expressed this mystery in the form of a question: ‘Where are they?’ It’s a question that becomes more difficult to answer with each passing year. In the past decade alone, science has discovered that planets are ubiquitous in our galaxy, and that Earth is younger than most of them. If the Milky Way contains multitudes of warm, watery worlds, many with a billion-year head start on Earth, then it should have already spawned a civilisation capable of spreading across it. But so far, there’s no sign of one. No advanced civilisation has visited us, and no impressive feats of macro-engineering shine out from our galaxy’s depths. Instead, when we turn our telescopes skyward, we see only dead matter, sculpted into natural shapes, by the inanimate processes described by physics.

Robin Hanson, a research associate at the Future of Humanity Institute, says there must be something about the universe, or about life itself, that stops planets from generating galaxy-colonising civilisations. There must be a ‘great filter’, he says, an insurmountable barrier that sits somewhere on the line between dead matter and cosmic transcendence.

Before coming to Oxford, I had lunch with Hanson in Washington DC. He explained to me that the filter could be any number of things, or a combination of them. It could be that life itself is scarce, or it could be that microbes seldom stumble onto sexual reproduction. Single-celled organisms could be common in the universe, but Cambrian explosions rare. That, or maybe Tsiolkovsky misjudged human destiny. Maybe he underestimated the difficulty of interstellar travel. Or maybe technologically advanced civilisations choose not to expand into the galaxy, or do so invisibly, for reasons we do not yet understand. Or maybe, something more sinister is going on. Maybe quick extinction is the destiny of all intelligent life.

Humanity has already slipped through a number of these potential filters, but not all of them. Some lie ahead of us in the gauntlet of time. The identity of the filter is less important to Bostrom than its timing, its position in our past or in our future. For if it lies in our future, there could be an extinction risk waiting for us that we cannot anticipate, or to which anticipation makes no difference. There could be an inevitable technological development that renders intelligent life self-annihilating, or some periodic, catastrophic event in nature that empirical science cannot predict.

That’s why Bostrom hopes the Curiosity rover fails. ‘Any discovery of life that didn’t originate on Earth makes it less likely the great filter is in our past, and more likely it’s in our future,’ he told me. If life is a cosmic fluke, then we’ve already beaten the odds, and our future is undetermined — the galaxy is there for the taking. If we discover that life arises everywhere, we lose a prime suspect in our hunt for the great filter. The more advanced life we find, the worse the implications. If Curiosity spots a vertebrate fossil embedded in Martian rock, it would mean that a Cambrian explosion occurred twice in the same solar system. It would give us reason to suspect that nature is very good at knitting atoms into complex animal life, but very bad at nurturing star-hopping civilisations. It would make it less likely that humans have already slipped through the trap whose jaws keep our skies lifeless. It would be an omen."

there was a period, i think in year 1, where i was seriously obsessed with reading and talking about aliens and AI, and space etc. it kind of stopped, but i happened to chance upon this piece and you have no idea how excited this article made me!! i seriously have a ton to say about aliens, predictions abt the future of humanity and the like zomg i am sorry to the friend i am meeting tomorrow i am just going to talk about this the whole afternoon