As the number of exoplanets rises, so should the chance of finding extraterrestrials. But the silence so far could suggest advanced civilizations have merged with technology and moved beyond our physical realm — or were destroyed by it.
Are computers the new aliens? A few friends recently expressed amusement over the question. Are recent movies like "Her" and "Transcendence," and TV shows like "Person of Interest" putting computers into the kinds of roles typically reserved for aliens (of the extraterrestrial kind)? What do you think?
There's a bigger question however, extending beyond such trends in popular entertainment, and beyond computers' growing presence in our daily lives. It is this: Could some aliens — if there are any — really turn out to be computers? And what might that mean for our own future?
In popular fiction, alien beings — while often surrounded by awesome technology — were biologic creatures at the core. But maybe this stopped too short; a growing minority of researchers propose that any extraterrestrials we find are more likely to be synthetic than organic. Stick with me here; this is not totally crazy.
It is virtually certain because of the vast time-frames involved that any intelligent extraterrestrials we detect will be not just thousands, but millions of years ahead of us in their technology. And in our infant culture, we already anticipate machines that could improve themselves, building ever better versions that we could quickly lose control of. This is becoming a real concern in many quarters. To most experts, the question of Artificial Intelligence is a matter of when, not if. If that happens, who knows where it will lead?
The question of extraterrestrial intelligence, ETI, has become more urgent as the tally of exoplanets — planets orbiting stars other than our sun — has expanded. As of May 1, the verified count was 1,786 planets outside our own solar system, with a few thousand more candidates waiting to be confirmed.
Speculation about ETI got a major boost on April 17, when scientists announced the discovery of the most Earth-like planet yet, designated Kepler-186f. It is about 10 percent larger than Earth, and orbiting in the habitable zone of a red dwarf star 500 light-years away in the constellation Cygnus. The habitable zone, also called the Goldilocks zone, is the distance from a star where it's just right — not too hot or cold — for liquid water to exist. Presently, that's where life seems most likely.
The SETI Institute even turned its Allen Telescope Array to Kepler-186f to check for possible alien signals. None were found, but they intend to look more closely. Even if the planet had a lush biosphere, that doesn't mean there'd be civilization. Our planet's biosphere thrived just fine without us here for hundreds of millions of years.
If there were a civilization on Kepler-186f, they'd need to be transmitting a 100 million watt signal in our direction through an antenna the size of a football field for us to detect it. How likely is that? Don't hold your breath.
Our emergence on this planet barely registers on the geologic time scale, and we've already spawned this "electronic age" thing. Events that led us here point to a very interesting long-term trend in Earth's history.
It took several billion years after the first living cells for the first multi-cellular life to appear, but then only a few hundred million years for more complex organisms leading to the plants and animals to spread through the sea and across the land. The drive toward more complex and intelligent life only accelerated after that, with each major jump coming more quickly than the ones before.
Now our technology seems poised for the kind of exponential growth Earth has never seen. It may already be outpacing our own biologic and cultural evolution, because we have not matured enough to control the technology we create. This may all be part of life's natural progression, but it's qualitatively new to this planet.
Our species has survived thousands of years of predators, disease, famine, earthquakes and environmental changes. The 1918 flu pandemic and two world wars have not slowed the global human population explosion. In my six decades, I've seen the number of humans more than double to top 7 billion. It's a humbling picture no matter how you slice it.
In the short-term, the risk of human extinction from asteroid impacts is small. And as appalling as nuclear destruction might be, even that probably would not eradicate us. Bioengineering, nanotechnology and machine intelligence, to name a few, could improve our lives, or have unintended catastrophic consequences.
So what does all this have to do with exoplanets and SETI? Everything. And vice-versa. Our broadening perspective is revealing unanticipated connections between what we see out there and what's going on down here.
Decades before we knew of any exoplanets at all, scientist Enrico Fermi calculated in 1950 that if even a very few technological civilizations appeared in our galaxy since it formed — possibly before the sun and Earth even existed — they should have spread throughout the galaxy in the tens of millions or even billions of years since.
Evidence of their existence should be widespread, he postulated. But instead of detecting extraterrestrial signals and grand engineering projects, we have "The Great Silence." This is the "Fermi Paradox" in a nutshell.
So where are they? Simple life outside the Earth might be found in our solar system, like on nearby Mars, or at the more distant water-ice moons of Europa or Enceladus — but not alien civilizations. For those, we are looking farther, while building a substantial statistical database.
Current extrapolations suggest that as many as 40 billion of the at least 100 billion total planets in our galaxy (let's forget about the 100 billion other galaxies out there for now) are Earth-sized — a number much, much higher than most scientists dared guess when Fermi posed his question. So the "Fermi Paradox" has become more paradoxical than Fermi ever imagined.
Emerging civilizations would have to be exceedingly rare to explain the paradox. Natural events like supernovae can sterilize entire star systems, and more devastating gamma ray bursts even larger chunks of space, so these could affect the number of surviving civilizations. A more common idea is that self-destructive technologies like nuclear weapons play a role. Some think that may be the rule.
Civilizations may go radio-dark when they find some technology unknown to us, or when they transform from biologic to artificial intelligence, and their signals become undecipherable. Once the development of AI gets rolling, the thinking goes, some form of transcendence becomes inevitable. It's not hard to imagine that we're on that kind of track.
SETI operates on the hope that either some societies last a long time, or enough civilizations are at the right stage of their development for us to chance upon their signals. As SETI researcher Jill Tarter points out, if the galaxy were an ocean, we've only scooped up a cup-full of water to examine so far. Try drawing conclusions about life in the sea from that.
The point is that if we find evidence of any aliens at all, that would give us hope for a long-term, sustainable future. On the other hand, the more habitable planets we find without detecting alien signals, the more we must call into question the long-term survival of technological civilizations — including ours. That could mean there's a roadblock ahead. We can't know what it is, or when it might stop us, but the stats would be stacked against us.
If all or most technological civilizations develop synthetic life forms that ultimately replace their creators, or their biologic creators merge with AI, the resulting entities, lost in their virtual worlds, may lose interest in mere physicality. Radio emissions may go silent, replaced by the uninterpretable communications of silicon minds.
People tend to have strong personal opinions about when, or if, computers will surpass human intelligence, however it is measured. But even among the more skeptical, there seems to be shift away from outright denial; it just will probably be a very long time before we get there, they say.
These evenings, Mars, with its beautifully bright orange glow, crosses from the southeast early-on, to the southwest in the wee hours. It is possible that that's where we could find our first extraterrestrial life … probably microbes. Or it could be near bright Jupiter high in the west right after sunset. That's where Europa is, the moon with a deep ocean under the ice. The prospect for more complex life seems even better there.
Saturn is at opposition this month, and climbing into the southeast during the evening. It is dimmer than Jupiter and Mars, but that is where the icy Enceladus is. That moon's water geysers may be spewing microbial life right out into space from its subsurface reservoirs.
Now spread your gaze out among the myriad stars stretching into the distance, and try to imagine what possible aliens might be like … how they may think. At this point, your guess is probably as good as anyone's.
Find rise and set times for the sun and moon, and follow ever-changing celestial highlights in the Skywatch section of the Weather Almanac in the Daily Republican and Sunday Republican.
Patrick Rowan has written Skywatch for The Republican since 1987 and has been a Weather Almanac contributor since the mid 1990s. A native of Long Island, Rowan graduated from Northampton High School, studied astronomy at the University of Massachusetts-Amherst in the ’70s and was a research assistant for the Five College Radio Astronomy Observatory. From 1981 to 1994, Rowan worked at the Springfield Science Museum’s Seymour Planetarium, most of that time as planetarium manager. Rowan lives in the Florence section of Northampton with his wife, Clara, and cat, Luna.