British astrophysicist and cosmologist, Sir Martin Rees, warns that the first aliens that we encounter will not be little green men, but will be a race of machines. He believes that when we detect aliens, it will not be by stumbling across organic life, but from picking up a signal made by machines.
It’s likely these machines will have evolved from organic alien beings, and that humans will also make the transition from biological to mechanical in the future.
He thinks that life away from Earth has probably already gone through this transition from organic to machine. “This suggests that if we were to detect ET, it would be far more likely to be inorganic: We would be most unlikely to “catch” alien intelligence in the brief sliver of time when it was still in organic form.”
On a planet orbiting a star far older than the sun, life “may have evolved much of the way toward a dominant machine intelligence,” he writes.
He also suggests, writing in Nautilus magazine, that aliens may be so god-like that we’re currently looking for the wrong sort of signal.
He writes, “Searches for extraterrestrial intelligence typically seek some electromagnetic transmission that is manifestly artificial. But even if the search succeeded (and few of us would bet more than 1 percent on this), it would still in my view be unlikely that the “signal” would be a decodable message. It would more likely represent a byproduct (or even a malfunction) of some super-complex machine far beyond our comprehension that could trace its lineage back to alien organic beings (which might still exist on their home planet, or might long ago have died out). The only type of intelligence whose messages we could decode would be the (perhaps small) subset that used a technology attuned to our own parochial concepts.”
SETI seeks out electromagnetic transmissions thought to be made artificially, but even if it did hit the jackpot and detect a possible message sent by aliens, Sir Martin says it is unlikely we would be able to decode it.
He thinks such a signal would probably be a byproduct or malfunction of a complex machine far beyond our understanding that could trace its lineage back to organic alien beings, which may still exist on a planet, or have died out.
He also points out that even if intelligence is widespread across the cosmos, we may only ever recognize a fraction of it because “brains” may take a form unrecognizable to humans. For example, instead of being an alien civilization, aliens may take the form of a single integrated intelligence.
He mused that the galaxy may already teem with advanced life and that our descendants could “plug in” to a galactic community.
However, he says that there is a chance Earth’s biosphere may be unique and that searches will fail, meaning our planet could be the most important place in the cosmos.
“We would then be of especially great cosmic significance, for being the transient precursor to the deeper cogitations of another culture – one dominated by machines, extending deep into the future and spreading far beyond Earth.”