Life, the universe and everything is full of paradoxes, puzzles, anomalies, and just a host of other weirdness often seemingly deliberately designed to toss wicked curve and knuckleballs at us ever scratching-our-heads humans. SETI doesn’t seem to be immune from this mischievous wickedness. Is the cosmos, Mother Nature, just a real bitch, just naturally perverse, or is there some sort of intelligence at work here tossing us those wicked curve and knuckleballs?
SETI stands for the Search for ExtraTerrestrial Intelligence, and the usual ways and means of doing that is to scan the heavens with radio telescopes looking for an intelligent radio signal from ET. Some of the nasty flies in the SETI ointment are deciding the direction to look at and the frequency to scan for. Fortunately, modern technology can focus in on those specific stellar candidates highly likely to be homes to ET (at high sensitivity), or sweep broad areas of the sky (at less sensitivity) and search multiple frequencies at a go. The nasty fly in that ointment is that any individual or team of individuals would quickly be overwhelmed with data such that separating the signal(s) from the noise would be so time consuming as to prohibit scientists from searching at all.
SETI scientists, fortunately, do not spend their time looking at the raw data on their monitoring screens that are linked to their radio telescopes, 24/7/52. Fortunately, modern technology has produced the computer. Computers do most of the hard yakka – the tedious bit of sifting through the massive amount of radio chaos for the potential tiny bit of radio pattern.
Computer software algorithms scan the raw data quick-smart and can immediately weed out 99.9% of all the radio junk, the hiss, static, cosmic microwave radiation left over from the Big Bang, lightning discharges, and other background natural radio noise. The remaining potentially interesting 0.1% will then be looked at by another computer, this one with wetware software – the human brain that resides inside the SETI scientist. Now 99.9% of the interesting 0.1% that remains after the initial computer software algorithms have done their thing will no doubt be shown the WPB (garbage bin) after the SETI scientist has done his or her wetware analysis. Most post-computer residue is eliminated as having a terrestrial and human origin – this radio station; that orbiting satellite’s transmission, etc. The types and ranges of artificial radio signals generated by humans are well catalogued and understood. It’s unlikely an artificial terrestrial signal will be mistaken for ET – at least not for long.
The 0.1% of the 0.1% that remains after 1) rejections by the computers and after 2) initial investigations by the SETI scientist is now getting really interesting, but again most of that can eventually be traced to various unexpected or unsuspected terrestrial emissions (say from top secret installations or satellites) and/or more likely as not various natural extraterrestrial ‘signals’ like those given off by pulsars that upon initial detection seemingly mimic ET. Anything left after that, to the SETI scientist, is in the category of ‘WOW’. SETI has indeed found a ‘WOW’ signal, but it was a quickie one-off, never to be ‘heard’ again.
Now SETI scientists (like all good scientists) have a protocol that requires data to be verified. In the case of SETI, an interesting ‘WOW’ signal needs to be verified, first by the home telescope by turning the telescope away then back to the original position. If the signal continues when the telescope is moved away, the source is local. If the signal cuts out but returns when the telescope in put back into it’s original configuration, the source is probably far away – like somewhere out there. Hopefully, after some elapsed interval of time, when the telescope returns to the same celestial coordinates, the signal will be there. The signal also has to be verified by one or more other telescopes. The upshot of all of this checking and double-checking is that the ‘WOW’ signal can’t be just a quickie one-off with no message content or intelligent pattern in the background noise. One very long burst would do it, or even an on-again, off-again, on-again pattern over lengthy durations, but it can’t be a one-off quickie that leaves no chance for verification – that’s the key; verification and especially independent verification. Alas, to date, one unverified ‘WOW’ signal, or so I thought.
Based on the emphasis given to it in most books dealing with SETI, the Search for ExtraTerrestrial Intelligence, as practiced by scanning the heavens with radio telescopes for ET’s radio (electromagnetic – EM) communication beacons or general EM leakage, the SETI community has experienced many initially anomalous radio signals, but only one that had remained unsolved and unresolved – the ‘WOW’ signal. The ‘WOW’ signal was detected at the “Big Ear” radio telescope at the Ohio State Radio Observatory (since demolished to make way for a golf course) in August of 1977. To this day it 1) remains unexplained and 2) remains unverified. I thought that had been the be-all-and-end-all of anomalous signals. However, I’ve been corrected by a senior astronomer at America
“Also, the WOW signal is only one of nearly a thousand signals that were detected, and whose origin remains unknown. It has the benefit of a catchy name.”
So what’s our SETI scientist telling us here? Well, that on at least 1000 occasions radio telescopes have detected short-duration, non-repeated, non-verifiable signals that have all the hallmarks be being artificial in origin and thus worthy of a SETI scientist’s attention.
Now I didn’t realize that traditional SETI had so many, if not unknown ‘WOW’ ‘signals’, at least unknown ‘mini-wow’ ‘signals’ (my phrase). But doesn’t that strike you, the reader, as decidedly odd? I mean, it’s pretty straight-forward to double-check and reacquire terrestrial ‘signals’, even if they originate from our space probes somewhere out there. It would be rare indeed for there to be a one-off terrestrial ‘signal’ that was picked up but a ‘signal’ that never existed before or after that detection event.
Now terrestrial satellites move quickly across the sky, and disappear from the antenna beam in a matter of seconds. However, satellites orbit the Earth and will reappear again over the horizon, so signals from same can’t be a one-off.
Assuming therefore that these thousand mini-wows aren’t terrestrial, they must have an extraterrestrial origin. So, if the thousand ‘mini-wow’ unknowns are extraterrestrial in origin isn’t it odd each and every time the SETI community goes back to reacquire the ‘signal’ in order to verify the bona-fides as to the precise nature of that ‘signal’, it proves to be quickie one-off? I mean a few times is understandable, but a thousand times? I’m reminded of that James Bond quote from “Goldfinger” – ‘Once is happenstance, twice is coincidence, but three times is enemy action’. I assume that the distribution of these ‘mini-wows’ must be pretty random, for if they all came from the same area in the heavens that itself would be in itself telling. This is fascinating – it almost seems if some sort of cosmic joker is playing endless April Fool’s pranks on the SETI community. It must be quite frustrating.
Now IMHO a real ETI radio signal wouldn’t just last all of two seconds, never to reappear again. Even if the point-of-origin were on the surface of an extra-solar planet such that the beacon swept across us very quickly, it would still reappear to one or more of our terrestrial radio telescopes the next time the extra-solar planet rotated that point-of-origin into view again. Earth’s rotation doesn’t really count – if a radio telescope picks up an anomalous ‘mini-wow’ signal from a target that’s just sinking beneath the western horizon then it’s easy of those astronomers to alert in real time another radio telescope facility further to the west where the target is still visible, and thus continue the monitoring.
The only quasi-quickie one-off natural extraterrestrial phenomena I can think of are gamma ray bursts, but SETI scientists know about them and I doubt they would be detected by radio telescopes anyway since gamma rays are high energy (short wavelength) relative to radio waves (long wavelength).
Is there an answer? Well, yes, there is, but it’s so out in left field that it is in left field’s left field. However, if the SETI community can’t suggest anything better, here goes nothing!
To be continued...
No comments:
Post a Comment