SETI has been a lengthy experiment in trying to detect our extraterrestrial equals or better somewhere out there by detecting their electromagnetic radio (sometimes optical or infrared) transmissions. Five decades on, the quarry remains elusive. My advice to SETI scientists is not to put all your SETI eggs in the electromagnetic (EM) basket.
SETI stands for the Search for Extra-Terrestrial Intelligence. Kindly note that the word ‘radio’ appears nowhere in that phrase, yet searching for artificial radio transmissions from extraterrestrial civilizations seems to be near synonymous with SETI, as reinforced via the popular movie “Contact” (based on Carl Sagan’s novel). Now there is nothing wrong with radio SETI. The search for radio waves has been well thought out and would appear to offer up the maximum chance for success. But, there are more ways to skin the SETI cat (as it were), and after 49 years of searching primarily via radio, I suggest that some more ways be adopted and explored. Any part of the electromagnetic (EM) spectrum is suitable and up for investigation, such as optical SETI (looking for laser beams) or infrared SETI (searching for Dyson Spheres) or just looking for alien artefacts (as in the novel/movie “2001: A Space Odyssey”). From that, we note that one can approach the study of UFOs and/or ancient astronauts as representing a form of SETI. Whatever investigation tells you that extraterrestrial intelligence (ETI) exists, or once existed, or doesn’t exist at all (and a negative result is as important as a positive one) is SETI.
Why do SETI at all? That is an obvious first question. Fortunately, there are lots of good answers to that question. There’s pure scientific curiosity for starters - exploring just for the sake of exploring. Then there’s the more philosophical approach in that SETI helps to better determine our place in the cosmos. A negative answer is just as important as a positive answer in determining whether humanity is unique, top of the heap, one of the great unwashed cosmic crowd, or the new boy on the block. SETI has a practical side too in determining the existence of potential neighbours which could be sources of benefit and/or threats to us. Obviously, a select few scientists, SETI enthusiasts, have long felt that SETI was, and is, worth doing. Radio SETI is (as of this writing), a quite mature science now 49 years old.
Now if seven is a lucky number, then seven times seven should be even luckier, yet, some 49 years after the first radio SETI experiment (Project Ozma) was conducted by Dr. Frank D. Drake in 1960, there’s be no luck in detecting any sign of any other technological extraterrestrial civilization (49 years as I write this – it’s even longer now). What does this suggest to us as a life form with an evolved technological civilization? Where are our ‘kin’ out there among the stars?
Firstly, it suggests that radio SETI isn’t going to be quite as easy as first envisioned. The number-crunching back in those early days suggested that ETI with a suitable detectable technology (radio emissions or rather transmissions) would be pretty common. Even though only a relative few of those haystack stalks have been sifted for that needle, it’s becoming clearer that form of SETI isn’t going to be easy; N (the number of technologically radio communicating ETI in the cosmos) isn’t going to be an extremely large number. So, some constraints on the SETI concept and logic have come home to roost.
In terms of the search to date, it’s clear (to me anyway) that there are no Type III civilizations (able to harness the energy output of an entire galaxy) in any galaxy even remotely ‘close’ (in cosmic terms) to us. If there were any Type II civilizations (ability to command the energy output of an entire star) nearly in our own galaxy it should have proved pretty obvious by now. There have been of course many false alarms, but also a few cases that looked like a positive signal was received. Alas, all have been one-offs and have never been picked up again. Without verification, those ‘wow’ signals remain enigmas, but not proof positive of extraterrestrial intelligence (ETI).
Firstly, my explanation as to why we haven’t detected ETI via radio-SETI 49 years on. I consider it unlikely in the extreme that any ETI would deliberately target our parent star and solar system. We’re just too average. There’s no compelling reason to target Sol as opposed to hundreds of thousands of other stars. Even if they did, what are the odds that their targeting us would just happen to coincide with our evolving the requited technology to detect same? What if we were targeted, but thousands, maybe millions of years ago? ETI gave up the ghost and targeted elsewhere!
The alternative is that we could detect ETI electromagnetic (EM) leakage. Alas, if we’re typical, EM leakage (radar, radio, television, etc.) will probably be something fairly short-lived in the history of a technological civilization. Our serious EM leakage is less than 100 years on, yet already the writing is on the wall that our own leakage is rapidly diminishing. Consider that one can get cable TV, radio over the Internet, etc. Earth is rapidly becoming an electromagnetic quiet location. Within another century we’ll probably be leakage free, or as near to it as makes no odds. So, what’s the probably one civilization will detect another civilization’s leakage, if said leakage only exists for a small fraction of that civilization’s existence? Also, relative to deliberate targeting, leaking isn’t very intense and thus ever less detectable at ever increasing interstellar distances. Increasing distances increase the odds that there will be a receptive ETI within the increasing spatial volume, yet by the time the odds are good for finding such an ETI, the intensity of leakage has faded too much to be detected. But still the search goes on.
It is said that the optimist is frequently, in fact usually disappointed while the pessimist frequently or usually isn’t. So is SETI a suitable research venue or course of inquiry for the optimist or the pessimist? I suggest here that to do SETI you need to be the eternal optimist, while realistically, SETI is for pessimists! Traditional SETI searches for photons, traditionally radio, increasingly optical and intra-red (IR), emitted by an ET technology, to date, going on five decades, has resulted in, well, no dice. Maybe there is no ETI, or maybe there’s ETI but little in the way of their manufactured photons.
There are two ways we can uncover, discover, or detect photons from an ETI. Firstly, there’s detection via the leakage of their microwaves emanating from their radio, TV, radar, etc. technologies. Such leakage escapes into space and ultimately finds there way to Earth, landing unto photon detectors at the business end of our telescopes. There are two difficulties with that scenario. Leakage, the tiny leftover residue of what was meant for local consumption, is going to be weak for starters, growing rapidly weaker as it dilutes quick-smart as it spreads throughout the vastness of three dimensional space. That makes it relatively hard t detect and recognize it for what it is. The other reason is that the timeframe of a civilization’s leakage could be very short lived, relative to the duration of that civilization, if we are anything to be judged by. Increasingly information is being transmitted by cable (no leakage), not broadcast. So, if you want to detect leakage photons from a civilization that exists for, say one million years, wherein that leakage lasts for only several hundred years, well, the odds are very much against you existing at the very time span when the leakage is happening.
While radio leakage is ‘bright’ relative to the environmental stellar surroundings of an ETI, optical and IR leakage will be dwarfed and drowned out by the ETI’s parent star. The traditional analogy is looking for and detecting the light of a firefly whose is within an inch of a brilliant searchlight. So, little hope in that respect.
The other way of detecting ETI photons is if they deliberately scream their photon lungs out via a targeted radio/optical/IR beacon that says, in one hell of a loud ‘voice’, “Here we are, now where are you?” Is that likely for the vast majority of ETI? Probably not, although there will always be a exceptions to how the majority rules; perhaps so small that it’s of relatively little SETI consequence.
There’s reasons why we (taking ourselves as an average ETI) are afraid of the dark and mark on unexplored maps ‘here they be dragons’. It’s fear of the unknown. Any ETI civilization, with emerging photon technology, hasn’t a clue what’s out there and what the potential dangers might be from other ETI’s. Discretion is the better part of valor; it’s better to be an alive coward than a dead hero. Maybe you can’t hide, but that doesn’t mean you need to draw unnecessary attention to and self-advertise yourself. I mean if you’re walking down a dark alleyway and see a gang of hoods in the distance you don’t exactly draw attention to your situation. Maybe they won’t notice you if you act in an inconspicuous manner. When faced with the unknown and potentially unknown adversaries, you err on the side of caution, self-interest, and survival. “Be afraid, be very afraid” is a good strategy, and live to be scared another day.
You can’t assume that the Universe is full of cuddly and friendly ET teddy bears – here they be Klingons in the uncharted maps of deep space is a better, safer assumption. OK, so we ourselves transmitted a beacon, a signal, to M13 many years ago. This aroused a storm of protest at the time. It was an elite, incredibly tiny minority of scientists who took it upon themselves and made a decision on behalf on the entire human race, to signal our existence to the Universe – well M13 anyway. Nobody asked for your okay, did they? Of course the counter argument was that we were already leaking, so no harm done, but then leakage is to a beacon what a candle is to a powerful electrical searchlight! [By the way, I never lost a wink of sleep over the M13 message at any time. Truth be told, it was really more a PR stunt than a serious attempt at shouting to the Universe our existence.]
The ultimate SETI upshot is, what if nearly everyone, every ETI civilization, is running scared and is in passive SETI receiving mode relative to taking the initiative, grasping the SETI bull by the horns, and doing a ‘hello, here I am’ thing? So there’s lots of ETI out there, but SETI won’t discover, or is very unlikely, to discover them.
The search goes on, and the onus, the SETI strategy, is on the searcher. One can’t assume anything about ETI advertising their existence and giving us a helping hand in detecting them.
To be continued...
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