"Astronomers will have scanned enough star systems by 2040 that we'll have discovered alien-produced electromagnetic signals," said Seth Shostak of the SETI (Search for Extraterrestrial Intelligence) Institute in Mountain View, Calif. during a talk at the 2014 NASA Innovative Advanced Concepts (NIAC) symposium at Stanford University.
ET machines would be infinitely more intelligent and durable than the biological intelligence that created them. Intelligent machines would be immortal, and would not need to exist in the carbon-friendly “Goldilocks Zones” current SETI searches focus on. An AI could self-direct its own evolution, each "upgrade" would be created with the sum total of its predecessor’s knowledge preloaded.
ET artifacts coordinated by computers, suggests British physicist, Stephen Wolfram, would look far more like a natural artifact. 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.
SETI's chief astronomer, Seth Shostak, says that "artificially intelligent alien life would be likely to migrate to places where both matter and energy — the only things he says would be of interest to the machine-based life — would be in plentiful supply. That means the SETI hunt may need to focus its attentions near hot, young stars or even near the centers of galaxies."
Writing in Acta Astronautica, Shostak says that the odds favour detecting such alien AI rather than "biological" life. Seti researchers have long argued that nature may have solved the problem of life using different designs or chemicals, suggesting extraterrestrials would not only not look like us, but that they will not be carbon based life forms, but be bound to follow "at least some rules of biochemistry, live for a finite period of time, procreate, and above all be subject to the processes of evolution."
"If you look at the timescales for the development of technology, at some point you invent radio and then you go on the air and then we have a chance of finding you," he told BBC News."But within a few hundred years of inventing radio - at least if we're any example - you invent thinking machines; we're probably going to do that in this century. So you've invented your successors and only for a few hundred years are you... a 'biological' intelligence."
From a probability point of view, if AI-powered machines evolved, we would be more likely to spot signals from them than from the "biological" life that invented them.
"But having now looked for signals for 50 years, Seti is going through a process of realizing the way our technology is advancing is probably a good indicator of how other civilisations - if they're out there - would've progressed. Certainly what we're looking at out there is an evolutionary moving target."
Dr Shostak says that artificially intelligent alien life would be likely to migrate to places where both matter and energy - the only things he says would be of interest to the machines - would be in plentiful supply. That means the Seti hunt may need to focus its attentions near hot, young stars or even near the centers of galaxies.
"I think we could spend at least a few percent of our time... looking in the directions that are maybe not the most attractive in terms of biological intelligence but maybe where sentient machines are hanging out." Shostak thinks SETI ought to consider expanding its search to the energy- and matter-rich neighborhoods of hot stars, black holes and neutron stars.
Data centers like this generate a lot of heat, and keeping them cool is a major challenge for modern computing. Intelligent computers would likely seek out a low-temperature habitat. Bok globules (image at top of page) are another search target for sentient machines. These dense regions of dust and gas are notorious for producing multiple-star systems. At around negative 441 degrees Fahrenheit, they are about 160 degrees F colder than most of interstellar space.
This climate could be a major draw because thermodynamics implies that machinery will be more efficient in cool regions that can function as a large “heat sink”. A Bok globule’s super-cooled environment might represent the Goldilocks Zone for the AI powered machines, says Shostak. But because black holes and Bok globules are not hospitable to life as we know it, they are not on SETI's prime target list.
“Machines have different needs,” he says. “They have no obvious limits to the length of their existence, and consequently could easily dominate the intelligence of the cosmos. In particular, since they can evolve on timescales far, far shorter than biological evolution, it could very well be that the first machines on the scene thoroughly dominate the intelligence in the galaxy. It’s a “winner take all” scenario.”
According to the British physicist Stephen Wolfram, intelligent life is inevitable. But there is a hitch. Although intelligent life is inevitable, we will never find it -at least not by looking out in the Milky Way. As evidence Wolfram points out 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 clearly it can be excised. But this process of removing any pattern from a signal make it 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?
ET artifacts coordinated by computers would look far more like a natural artifact. 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.
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 programme 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. 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."
The Daily Galaxy via astrobio.net, BBC.com, M. Chown, The Universe Next Door and A New Kind of Science by Stephen Wolfram
Image credit top of page: Bok globules http://www.dl-digital.com/images/Astronomy/Nebulae/Rosette-Bok-64-Frame-Halpa-crop-v4preHDcropNew2.jpg