SETI, the Search for Extra Terrestrial Intelligence, is in the main the scanning of the heavens by radio telescopes for artificial radio signals emitted either deliberately or via leakage from technologically advanced extraterrestrial civilizations. The search has been on again, off again, but mainly on again for over 50 years, without, to date, any positive resolution (you can't prove a negative, so the hunt continues, in case). Unfortunately, despite their ongoing failure to detect ETI, they rubbish those involved in other types of SETI - like UFOs and 'ancient astronauts'.
Now some SETI scientists have spend a goodly proportion of their careers, maybe even their entire careers doing their search thing. What that tells me is that way down deep inside, at a scientific gut-feeling even philosophical level, they are convinced that one or more (probably more) advanced extraterrestrial civilizations, our equals or better (probably better) exist. That's really great!
However, those same SETI scientists, when asked if that advanced extraterrestrial civilization(s) might have not only radio technology, but subluminal interstellar spaceflight abilities, well the eyebrows start heading north. To further ask them whether those advanced ET civilizations might have been, and might currently be now, on-site (i.e. - here around Planet Earth), well the eyebrows head up to the North Pole!
So, ET radio transmissions good; but ET visitations bad!
The nasty bit is that subluminal interstellar spaceflight violates no laws of physics; no laws of engineering. The time it takes to boldly go, seek out and explore, even colonize the galaxy our solar system is home to, is but a fraction of the age of our home galaxy. So, if radio ET exists, as SETI scientists must have faith in regarding that premise, then ET interstellar travel, exploration and colonization is equally plausible. SETI scientists can not logically dismiss that plausibility, especially if there's a reasonable few advanced ET civilizations out there, and keeping in mind it only takes one such bolding going ET civilization to saturate our galaxy with their presence.
Now it needs to be pointed out and re-enforced again, and again, that a visitation to Planet Earth has bugger-all, zip, zilch to do with humans beings currently residing here or ET responding to our own radio leakage. You see that's the SETI scientist's argument why ET's UFOs cannot be here. The signature of our existence here travels into the cosmos via EM radiation at light speed. Translated, our only plausible detectable EM signature is our radio/radar waves, which have only been outward bound for a century of so. So, the maximum radius our ET has to be, in order to know about us is 100 or so light years. But they then have to hop in their UFOs and travel through interstellar space to visit us, so the practical radius shrinks. The two constraints mean that ET would have to be close by, something probably against all the cosmic odds. But that argument is so flawed as to be laughable. This is an egocentric trip personified! ET can only be here because humans are here! Crap!
Humans here are irrelevant to ET being here. The reason Planet Earth gets a visit is that ET was roaming around the stellar neighbourhood doing their Captain Cook or Captain Kirk sticky-beak exploring thing, and our star, our Sun, Sol is one of the better candidates as a bio-friendly mainstream star and one having a home to a planetary system, ably detected by ET before-the-fact in the same manner as we in turn detect extra-solar planetary systems today. So Mr. Spock says to Captain ET, "Sir, Sol isn't very far out of our way to take a look at the planetary regime, especially as how I've spectroscopically detected potential biological signatures of oxygen and methane in the atmosphere of one of the planets." And so ET's starship zeros in for a closer look, and our Mr. Spock exclaims, "Sir, hey wow, that third rock from Sol has a biosphere. Fascinating! Let's catalogue that!"
Okay, so that conversation took place 300 million years ago. That interesting data point now pointed the way and reason for numerous follow-up visits, visits that might be continuing right through to the present day. The critical thing (apart from humans having nothing to do with ET's initial visit) is that once that data-point was noted and logged it could in turn be communicated to other advanced ET's out there. By now, over 300 million years or so, maybe more, maybe less, since first visit (hardly first contact) the whole bloody galaxy knows about Sol, her third rock outwards, and that biosphere!
Okay, having dismissed the improbable humans-are-responsible for ET being here non-argument, one need ask, without human influences, how often can we expect, on average, Captain ET and crew to show up?
The physicist Edward U. Condon, in his very own summary to the report of the team of investigators who looked into the UFO issue under a government (USAF) contract, never ruled out the possibility of extraterrestrial visitors, only that 10,000 years between visits was a minimum figure. That's in the report that he gave the thumbs down to regarding the UFO ETH (extraterrestrial hypothesis). UFOs today - no; visits by ETI every 10,000 years was okay, enough time for them to get from there to here. On the other hand, noted astronomer and exobiologist (now termed an astrobiologist) Carl Sagan thought 100,000 years between visitations was a reasonable ballpark figure.
Now, depending on who's calculations you accept, whether you're an optimist or a pessimist, an interstellar boldly going ET civilization should have come across Planet Earth, on average, every 10,000 according to Condon [2], which is an order of magnitude more frequent that the 100,000 years given by Sagan [1]. It has been pointed out, and it's certainly true, that given the age of our Planet Earth, it would be Royal Flush times 1000 odds if a first visit just happened to have, well happened, in our lifetime. But, and here's where the SETI scientist's position becomes untenable, our planet, at 4.5 billions years of age (far younger than the age of our galaxy) should have received somewhere between 45,000 (Sagan) visits overall and 450,000 (Condon) visits overall by ET. Our SETI scientist would say that our "now" falls between the visitations -those gaps when ET is doing his interstellar boldly going thing somewhere else.
What the SETI scientist fails to come to terms with, fails to grasp, doesn't quite have the smarts to understand and accept, is the once Planet Earth has been found, the first of those 45,000 or 450,000 expected visits, while certainly isn't going to be in our "now", the second, third, fourth, etc. visit will no longer reflect 'on average', something hinted at earlier.
I would have to assume, that ET, from the first visit, all those years ago (thousands, millions, even billions of years ago) wouldn't have tagged Planet Earth as just another hunk of planetary debris, unworthy of any ongoing interest. From the get-go, Planet Earth would have showed unusual traits - an atmosphere, not so much; a lithosphere, not so much; a hydrosphere, yes indeed, very much; but especially a biosphere, very, very, very much.
If ET has any scientific curiosity worthy of the name, same as our SETI scientists are curious about ET, then Planet Earth would not only be routinely tagged and entered into the alien's database, but uniquely tagged as an abode worthy of an advanced rate of follow-up visitations. We would be monitored, maybe not 24/7, but more frequently than once every 450,000 to 45,000 years.
But even if that interval had been maintained, well that puts visitations well within the range of the time when modern humans were already established as the future if not already the dominant lords and masters of Planet Earth. By Jove our ET neighbours would be certainly stepping up surveillance of this development. They'd obviously want to keep tabs on whether or not our intelligence might ever prove to be a threat to their intelligence, for just as Planet Earth can not hide from the scrutiny and surveillance of ET, so to ET can not hide from ours, once we start to boldly go.
So, ET radio transmissions good; but ET visitations bad! I don't think so, and any SETI scientist who suspects otherwise is akin to the proverbial ostrich's head surveying that sand dune.
Translated, any ET with smarts who knows about us from visitations millennia ago; millions of years ago, would be here now keeping a watchful eye on us. Sorry SETI scientists, UFOs are a logical outcome of this scenario, and if you fail to se this, well, you're in a Catch-22 situation; you're between a rock and a hard place!
SETI is in a Catch-22 because on the one hand SETI scientists cannot reject ETI here at the same time searching for and accepting the presence of ETI out there when both possibilities are equally plausible. SETI scientists cannot search for ETI out there, yet refuse to search for ETI locally when the evidence for both is technically the same. SETI scientists say there's no evidence (or poor evidence) for ETI here - yet there's (to date) no evidence (or poor evidence) for ETI out there, yet they stake their professional careers on ETI out there and rubbish ETI here. How so the rubbishing?
Of course the SETI scientists counter that each of the threads of ETI having been then or now on Earth are weak-in-the-knees when it comes to solid evidence. Roswell is weak; UFO abduction cases are weak; the UFO conspiracy or cover-up case is weak; UFO photographs and videos are weak; UFO radar cases are weak; the case for von Daniken's ancient astronauts is weak; the ghost rocket sightings (1946) are weak; contactee claims are especially weak; UFO eye-witness reports are unreliable, etc. But, put them (and much more besides) all together and like all good detective stories combine/integrate all the clues into one composite whole (after separating out the wheat from the chaff and eliminating the red herrings) then the whole is more than the sum of the parts. You get a consistent pattern that emerges; not the radio signal patter-of-little-dots-and-dashes the SETI scientist wants but a nuts-and-bolts and a here-and-now pattern.
Now admittedly any one of a hundred different and independent threads might in itself be not all that convincing, but then all 100 are woven together - that's a different duck of another colour. It's like if it looks like a duck - it may not be a duck. If it walks like a duck - it may not be a duck. If it swims like a duck - it may not be a duck. If it quacks like a duck - it may not be a duck. But if it looks, walks, swims and quacks like a duck - then it's a duck!
But there's another quirk on the part of SETI scientists; the ultimate Catch-22: As already noted, SETI scientists in general are on record as stating that there's "poor" or "crummy" evidence overall for the rival UFO ETH or 'ancient astronauts' and as such, are topics not worthy of a SETI scientist's time and presumably that of any physical scientist or indeed any scientist full stop. Yet the evidence collected for ETI out there in the depths of interstellar space in traditional SETI-land, 50 years plus on, is equally as poor whether there is one SETI "WOW" signal (as usually highlighted in SETI books) or a 1000 SETI mini-wow signals of unknown origin, but strongly suspected to have ultimate terrestrial origins. SETI scientists have come no closer to providing the ETI 'smoking gun' as has Erich Von Daniken ('ancient astronauts') or Stanton Friedman (UFO ETH).
At best that's an attitude or a philosophy that is inconsistent at best and perhaps a contradiction at worst within the SETI community. In fact, it's a downright double standard. If I were a young scientist just starting out, would I consider SETI? Probably not because there's so little evidence of such poor quality that's emerged over five long decades that I'd think I'd probably be wasting my time and throwing my career away. So, whether it's SETI or UFOs or 'ancient astronauts' it's all equally piss-poor evidence, but at least it's a level, playing field. It's still quite plausible that an amateur UFO buff or an archaeologist may yet scoop SETI to the ETI punch.
My ultimate conclusion and recommendation to those between the irresistible force and the immoveable object is to not put all your SETI eggs in the EM basket.
[1] Sagan, Carl & Shklovskii, I.S.; Intelligent Life in the Universe; Holden-Day, San Francisco; 1966; pages 450-452:
[2] University of Colorado & Gillmor, Daniel S. (Editor); Final Report of the Scientific Study of Unidentified Flying Objects Conducted by the University of Colorado Under Contract to the United States Air Force; Bantam Books, N.Y.; 1969; page 28: [The Condon Committee Report.]
Science librarian; retired.
