The Search for Extraterrestrial Intelligence: SETI

SETI stands for the Search for Extra-Terrestrial Intelligence. Now there is nothing wrong with radio 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? Then there's the more philosophical approach in that SETI helps to better determine our place in the cosmos. 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.

Firstly, it suggests that radio SETI isn't going to be quite as easy as first envisioned. 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. 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. 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. 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. 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. 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. Is that likely for the vast majority of ETI? 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. 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 f 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. What SETI is the best SETI? Since then, lots of astrobiology/SETI scientists have proposed lots of other possible radio frequencies, such that today, SETI searches tend to be broad spectrum ones rather than focusing on just one or two frequencies.

So, what SETI is the best SETI? Well, SETI has to be affordable and practicable. To make that economic long story somewhat shorter, it got me to thinking that there's a cheaper SETI option than current radio SETI. For example, as noted above, I doubt if ETI would try to draw attention to themselves via targeting solar systems with optical or radio beacons. Anyway, the real point is that there are lots of possibilities of examining existing astronomical data for evidence of ETI.

One doesn't want to have all one's SETI eggs in the radio SETI basket. ETI will (at least initially) explore their cosmic environment via interstellar unmanned probes, not unlike our Pioneer 10 and 11, or Voyager 1 & 2 probes, albeit ours were local explorers not designed to explore other solar systems. In summary, here are a few fairly low cost SETI strategies. 2) Surveying nearby sun-like stars for electromagnetic leakage (like radar, radio, TV, etc.). 4) Examine with a fine tooth comb any existing astronomical data for anomalies suggestive of intelligence. I wish to make it clear that I totally support radio SETI to the hilt. The sole exception is that if one wants to look for signs of ETI in other galaxies than our own, then radio SETI is just about the only game in town.