British physicist Stephen Wolfram believes extraterrestrial intelligent life is inevitable, but with a caveat. Although intelligent life is inevitable, we will never find it -at least not by searching in the Milky Way. Stephen Wolfram points out that in order to compress more and more information into our communication signals – be they mobile phone conversations or computer- we remove all redundancy or pattern. If anything in a signal repeats, then it can be deleted. But this process of removing any pattern from a signal makes the signal look more and more random – in fact, pretty much like the random radio “noise” that rains down on Earth coming from stars and interstellar gas clouds.
According to Wolfram, if someone beamed our own 21st-century communication signals at us from space we would be hard pressed determining whether they were artificial or natural. So what chance do we have of distinguishing an ET communication from the general background radio static of the cosmos?
In his magnum opus, A New Kind of Science, Wolfram, suggests that extraterrestrial intelligence is inevitably difficult to define and recognize “It has usually been assumed that detecting extraterrestrial signals from a sophisticated mathematical computation would provide evidence for extraterrestrial intelligence,” he writes. “But the discoveries in A New Kind of Science show that such computation can actually be produced by very simple underlying rules—of kinds that can occur in simple physical systems with nothing like what we normally consider intelligence. The result is a new view of the character of intelligence, and a collection of ideas about the nature of purpose, and recognizing it in ultimate extrapolations of technology.”
The Oumuamua Paradox
As Harvard’s Avi Loeb suggested about Oumuamua, Hawaiian for “Messenger from Afar,” the first known interstellar object detected passing through the Solar System on 19 October 2017, ET artifacts could look far more like a natural artifact. Loeb made headlines around the globe in 2018 when he suggested that Oumuamua, with an extreme oblong shape as much as 10 times as long as it is wide, might actually be an alien spacecraft. An analysis of its trajectory suggests that the object came in from a place far beyond the solar system, somewhere in the constellation Lyra, heading towards the constellation Pegasus.
Astronomers around the world attempted to detect radio signals to see if they could determine what it was. Was it a shard from an ancient asteroid, a weird comet? Or was it something else? A possibility, Loeb suggests, that is no more speculative than the existence dark energy or dark matter.
It is easy to distinguish a technological artifact such as a car from a natural object such as a tree. The tree is far more complicated. But, says Wolfram, “this is simply because our technological artifacts are primitive. As they become more complex – with computer processors enabling them to make a moment-by-moment decisions – they will begin to look just as complex as trees and people and stars.” We have slim chance, he suggests, of distinguishing an ET artifact from a natural celestial object.
If Wolfram is right and ETs are out there but we will not be able to recognize them – either in their communications or their artifacts – then of course they could be here in the Solar System and we would not have noticed.
The Computational Universe
Wolfram thinks ETs will not want to travel to Earth – or anywhere else for that matter. In Wolfram’s view, everything in the Universe is the product of a computer program. In fact, he imagines an abstract cyber-universe of all conceivable computer programs, all the way from the simplest up to the most complex. This “computational universe” contains everything from the Apple Macintosh operating system to a program for creating a faster-than-light starship.
Wolfram believes he has found nature’s big secret – how it generates the complexity of the world, everything from a rhododendron to a tree to a barred spiral galaxy by applying simple rules over and over again as a simple computer programs. Wolfram came to this remarkable conclusion in the early 1980s when he discovered that the simplest kind of computer program – known as a cellular automaton – can generate infinite complexity if its output is repeatedly fed back in as its input.
Nature’s Big Secret
Wolfram has found evidence that the kind of computer program that produces endless complexity can be implemented “not just systems of biological molecules but in all sorts of physical systems – chaotic gas clouds, systems of subatomic particles and so on. He concludes that all over the Universe life – though definitely not life as we know it – will spring up spontaneously. It is a fundamental feature of matter.”
The existence of this computational universe is the crucial thing. But the reality is it would be it easier and more efficient for an ET civilization to stay at home and use a computer to search the computational universe for useful programs rather than try to get the same information by hunting for ETs to talk to among the 200 billion or so stars in the Milky Way. “It’s a simple numbers game,” says Wolfram.
Everything is generated by computer program,”and that includes you and me,” says Wolfram. “Someone halfway across the Galaxy could have found the computer program for you and conversing with you at this very moment.”
Image credit: ESO Observatories, Chile