SETI stands for the Seek for Extra-Terrestrial Intelligence. Kindly note that the word 'radio' appears nowhere in that phrase, but searching for synthetic radio transmissions from extraterrestrial civilizations seems to be close to synonymous with SETI, as bolstered via the favored film "Contact" (based on Carl Sagan's novel). Now there's nothing flawed with radio SETI. The search for radio waves has been well thought out and would seem to supply up the utmost chance for success. However, there are more ways to skin the SETI cat (as it were), and after forty nine years of searching primarily through radio, I recommend that some more methods be adopted and explored. Any a part of the electromagnetic (EM) spectrum is suitable and up for investigation, such as optical SETI (searching for laser beams) or infrared SETI (searching for Dyson Spheres) or just on the lookout for alien artifacts (as within the novel/film "2001: A House Odyssey"). From that, we note that one can strategy the study of UFOs and/or historic astronauts as representing a form of SETI. No matter investigation tells you that extraterrestrial intelligence (ETI) exists, or once existed, or doesn't exist in any respect (and a negative result is as essential as a constructive one) is SETI.
Why do SETI in any respect? That's an obvious first question. Fortunately, there are many good solutions to that question. There's pure scientific curiosity for starters - exploring just for the sake of exploring. Then there's the more philosophical method in that SETI helps to raised determine our place in the cosmos. A negative reply is just as important as a constructive reply in determining whether humanity is exclusive, prime of the heap, one of many great unwashed cosmic crowd, or the new boy on the block. SETI has a sensible side too in determining the existence of potential neighbors which could be sources of profit and/or threats to us. Obviously, a select few scientists, SETI fanatics, have lengthy felt that SETI was, and is, price doing. Radio SETI is (as of this writing), a quite mature science now forty nine years old.
Now if seven is a lucky number, then seven times seven should be even luckier, but, some forty nine years after the first radio SETI experiment (Project Ozma) was performed by Dr. Frank D. Drake, there's be no luck in detecting any sign of another technological extraterrestrial civilization (49 years as I write this - it is even longer now). What does this recommend to us as a life kind with an developed technological civilization? The place are our 'kin' out there among the many stars?
Firstly, it means that radio SETI isn't going to be quite as straightforward as first envisioned. The number-crunching back in those early days suggested that ETI with a suitable detectable expertise (radio emissions or rather transmissions) would be pretty common. Regardless that solely a relative few of those haystack stalks have been sifted for that needle, it's changing into clearer that type of SETI is not going to be easy; N (the number of technologically radio communicating ETI within the cosmos) isn't going to be an especially massive number. So, some constraints on the SETI idea and logic have come dwelling to roost.
By way of the search so far, it is clear (to me anyway) that there are no Type III civilizations (able to harness the energy output of a complete galaxy) in any galaxy even remotely 'shut' (in cosmic phrases) to us. If there were any Type 2 civilizations (capability to command the energy output of a whole star) practically in our personal galaxy it should have proved pretty obvious by now. There have been after all many false alarms, but in addition a couple of cases that looked like a constructive signal was received. Alas, all have been one-offs and have never been picked up again. Bloggind with Carl Kruse
out verification, those 'wow' signals stay enigmas, however not proof constructive of extraterrestrial intelligence (ETI).