Some Ponderings on SETI, the Search for Extraterrestrial Intelligence.

SETI stands for the Search for ExtraTerrestrial Intelligences out there, somewhere. Sporadic searches for alien radio signals, whether deliberately beamed out by ET and/or just plain leakage, have, to date failed to find the smoking gun, albeit they have now and a rare again found some wisps of radio smoke. Here I just ramble and ponder a bit over some of the aspects central to that search for signs of other intelligences among the stars.

Lack of Progress: As to SETI, well the traditional reason given for lack of success to date is that they are looking for a needle-in-a-haystack and only a tiny fraction of that haystack has been examined. Actually I think that argument is wearing a bit thin by now. I think a reasonable alternative answer in that the window of opportunity to detect EM (electromagnetic) leakage - radar, TV, radio - is going to be very small. The era of EM 'noise' is not going to be very long relative to the duration of the technological civilization. As to ET deliberating sending out high-powered signals in hopes of attracting attention, well that's a pretty scatter-gun approach. The motive is iffy and the odds of success given the vastness of empty space (space is big; targets are tiny) and the number of dead abodes and the biospheres that don't have the technology to detect your signals and even those that do might be pointing their antennas in the wrong direction at the wrong moment adds up to a lot of wasted energy for probably small odds of success.

So if I were a SETI scientist, I wouldn't be putting all my eggs in the EM basket. After all, the phrase "Search for ExtraTerrestrial Intelligence" says absolutely nothing about how to search or what to search for. That, in my opinion, makes looking at the 'ancient astronaut' and the UFO phenomena equally valid approaches - but try telling that to a SETI scientist!

Our EM Leakage: Our radio and TV signals would probably be so diluted via that inverse square relationship that aliens, despite all the SETI texts to the contrary, have never seen "I Love Lucy". However, I do seem to recall that our powerful military radars could be, at least out to some certain amount of light-years, detectable. Of course there's not much of a message to be gained from that apart from perhaps ascertaining that there was a technology on Planet Earth and what the distance Earth was from the Sun and what our rotation rate was and how long our orbital period was.

Their EM Leakage & Alternatives: Of course Earth-like leakage might not be in the same ballpark as an extraterrestrial's. Perhaps a really advanced alien civilization has EM leakage a couple of orders of magnitude greater than our own. I imagine that's what SETI scientists are hoping for, otherwise SETI scientists, like Seth Shostak, might as well give up the ghost (or the hunt), close up shop, shut down the radio telescopes, retire, and go home and smell the roses.

Unless of course SETI scientists try some of the other suggested search approaches or strategies. There's those theoretical Dyson Spheres, a theoretical astro-engineering project on an immense scale designed to capture most of a star’s energy output, but I understand no infrared signatures have yet been deemed anomalous - at least to date.

I've also read a suggestion that ionization trails left behind by interstellar star-ships might be viable candidates as a means of detection. It's like seeing a contrail here on Earth and therefore inferring an aircraft.

The search for extra-solar planets is now apparently sensitive enough to detect the major atmospheric components of same, once detected. One suggestion is that as sensitivity ever increases, it might be possible to detect or infer industrial pollutants in said atmospheres, giving the game away that there's a technology present.

Of course that one "WOW" signal, that one-off ‘hit’ that could never be verified a second time, still needs explanation. Pity it was never detected again. No doubt such flirting with evidence gives SETI scientists like Seth Shostak, Frank Drake, Jill Tarter and company incentive to keep looking at the skies.

Some SETI Difficulties: I did suggest above that SETI via EM leakage was probably going to be a relatively narrow window of opportunity for the reason you suggest that ideally advanced technology is more efficient - less wasteful - technology. If SETI scientists are pinning hopes on direct beaming, deliberate beaming, I suspect that the grand-kids of Seth Shostak, Frank Drake, Jill Tarter and others will be following in their grandparents footsteps, continuing the search. I mean if you have even several beaming radio telescopes on a rotating, orbiting planet with a multitude of possible axis orientations, around a star that is also in an independent orbit around the galaxy aiming at another rotating, orbiting planet with a multitude of possible axis orientations, around a star light-years away that is also in an independent orbit around the galaxy, even if the planet on the receiving end has several radio telescopes pointing at the heavens, the odds the two would mesh seem rather small, IMHO. That can of worms aside, there's also the issue of observing at the right wavelength, and that's another multiple-choice question. It all seems a bit in the too hard basket. Still, the world is full of tales of success against all the odds, so hats off to their eternal optimism.

Are All-Sky Surveys A Wasted Effort? The question remains, if EM leakage is going to be relatively weak in the extreme by the time it reaches us, then why has SETI done and continues to do all-sky surveys letting the Earth's rotation sweep the sky a strip at a time while you just point your radio telescope straight up? In fact that's the only option if you can't steer your radio telescope. That's an efficient way of finding leakage; not so efficient if you are looking for specific stars or stellar systems that look likely as candidates for maybe having alien civilizations that just might be beaming a big "Hi There" to you or in your direction.

Search Strategies: I am very much aware that SETI can and has done targeted searches, tracking likely stellar candidates over many hours, days, weeks until at least it appears likely that that candidate system isn't targeting us with a "Hi There". The very first SETI search in 1960 by Frank Drake was a targeted search. That's fine, but it is only one of two radio wavelength search strategies that SETI has employed over the decades between 1960 and now. The other strategy, a complementary strategy, as I said before, is the all-sky survey. All-sky surveys are particularly appropriate for radio telescopes with very limited steerage (like Arecibo) or no steerage at all, like the Big Ear Radio Telescope associated with Ohio State University (unfortunately now demolished to make way for a golf course). It was the Big Ear that detected that one-off "WOW" signal. Actually there is a third SETI strategy called Piggyback SETI. Basically it just examines the data routinely obtained by radio telescopes being used for more traditional astronomical purposes, which could be a targeted or a general survey operation - just in case there was an artificial signal contained within the data collected that would otherwise have been ignored by astronomers not looking deliberately for artificial signals. Of course in an ideal world SETI scientists would love to be on the receiving end of a targeted "Hi There", but we, and they, don't live in an ideal world. Therefore, the need to employ as many search strategies as possible, including all-sky surveys that just might detect radio leakage.

SETI Economics: Perhaps SETI is just constrained by economic factors – funds available. If SETI had 100 times the funds and equipment, well maybe SETI wouldn’t still be in search of its subject matter. But just about every endeavor or potential endeavor is ultimately constrained by costs. That's hardly a revelation! And yes, SETI hasn't exactly been flooded with funding. Actually, as a brief aside, I find it interesting that while the American Congress axed tax dollars for funding SETI (several times over), tax dollars to fund UFO investigation by the USAF and other government agencies was never questioned!

What If? Anyway, there's always been that Big Question, what if everybody is listening and nobody is sending (as in deliberately sending); or the reverse, what if everybody is sending but nobody is listening? Well of course we know the former isn't correct since we've deliberately sent a few half-hearted messages into the cosmos; the latter isn't correct either since we're listening.

To Send: However, I need an answer to the question, what's in it for the sender to deliberately broadcast loud-and-clear messages into the cosmos? I mean this is hardly a job application where you need to promote yourself; nor is this some sort of romance match-making endeavor where again, you need to advertise your availability. So, what is the motive to shout into the cosmos "Hi There"? I mean our half-hearted cosmic messages have been roundly criticized by a whole host of rather intelligent people. If there is no clear-cut reason to deliberately advertise your existence; no advantage to be gained, then why do it? Why would you, the reader, as the power-that-be, tell the cosmos in no uncertain terms that Planet Earth exists?

Or Not To Send: If you were the power-that-be here on Planet Earth, if you and you alone were to speak for Planet Earth and Earthlings, you might adopt a totally isolationist policy. Planet Earth would maintain radio silence. Earthlings would not boldly go into the cosmos. However, if everyone had a turn at speaking for Planet Earth, no doubt there would be people who would broadcast "Hi There" and there would be people who would boldly go out into the cosmos. Now, the question arises, if there would be such diversity here on Planet Earth, not everyone would adopt your point of view, then it stands to reason that not every extraterrestrial civilization would maintain radio silence and not every extraterrestrial civilization would refrain from boldly going, seeking out new worlds and new life forms and new civilizations. That being the case, I need only point out that it would take just one boldly going extraterrestrial civilization to explore every nook and cranny in our galaxy in roughly ten million years at an expansion rate of just 1% the speed of light. Contrast that tiny ten million year time frame with the galaxy's ten billion year existence. Every nook and cranny includes Planet Earth of course. Conclusion: Planet Earth's existence is known about in the cosmic database or "Encyclopedia Galactica" if you will.