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- Subject: OPTICAL SETI REVISITED
- Date: 8 Aug 91 22:05:08 GMT
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- The Search For Extraterrestrial Intelligence (SETI) In The Optical Spectrum
-
- or
-
- Optical SETI Revisited
-
-
- Now I know that quite a few subscribers to rec.video.satellite are
- interested in "long-distance TV reception". How about detecting really far-
- out signals, i.e., from hundreds of light years away? These signals are
- unlikely to be NTSC, PAL or SECAM but they would be of the extraterrestrial
- kind. In early May I went back home to England for an extended stay.
- Shortly before that trip, I gave an invited talk about "Professional Optical
- SETI" to the SETI Institute (NASA - Ames Research Center, Moffett Field).
- How many subscribers of this bulletin board are amateur astronomers and
- might be interested in Amateur Optical SETI?
-
- Up to now, the general consensus has been that the "magic frequencies" for
- such interstellar beacons would lie in the 1 to 10 GHz region, preferably in
- the vicinity of the magic wavelength "water-hole" around 1.4 to 1.7 GHz.
- For 30 years, radio telescopes have concentrated on this narrow regime,
- almost completely excluding the major part of the electromagnetic spectrum.
- The popular literature about SETI usually says nothing about the optical
- approach, or if it does, dismisses it in a paragraph or two as being
- useless. Over the years, several noted scientists, starting with Professor
- Charles Townes (of laser fame) in 1961, have raised this matter (in the
- literature), only to be shot down by their colleagues. It is my intention
- to change how the SETI community views the efficacy of the optical approach.
-
- For the past year I have been working (as a volunteer) through Dr. Robert
- Dixon's SETI Group at the Radio Observatory, Ohio State. I have been making
- a very detailed case to NASA, mainly via the electronic mail, that much of
- the 30 year old Microwave SETI rationale is suspect. No sensible
- Extraterrestrial Intelligence (ETI) would be caught dead signalling with
- old-fashioned microwaves (microwave photons), but instead would be using the
- superior optical technology, either in the visible or near-infrared
- spectrum, or in the far-infrared. The Carbon Dioxide laser transition at
- 10,600 nm could be called a "magic optical wavelength".
-
- For some strange illogical reason, one branch of NASA is directing
- substantial R&D in free-space optical communications for the next generation
- of deep-space probes, GEO to GEO, and GEO to LEO links, while another branch
- of NASA insists that ETIs would not be using this technology to contact
- emerging technical civilizations (us). Early next century, when men (and
- women) first walk on Mars, the HDTV pictures of that historical event will
- come back to Earth most of the way via laser beam, will bounce between
- geostationary satellites via laser, and will arrive in people's homes via
- fiber-optics. Truly, the mass communications means of the future is
- photonic. When, later next century, NASA sends non-relativistic probes to
- the nearest star systems, the data and pictures of the encounter with those
- solar-systems (hopefully) will come back via laser. So why shouldn't lasers
- be the principal means of "electromagnetic" communications in the Milky Way
- Galaxy?
-
- Unfortunately, despite protests to the contrary, the SETI community appears
- guilty of a severe lack of imagination and contamination with anthro-
- pocentric views associated with mid-20th century technology. There has been
- as "Assumption of Ineptitude" applied to ETI technical prowess. This term
- should not be confused with the "Assumption of Mediocrity" applied to our
- own technical civilization. By definition, because we are an emerging
- technical civilization, ETI technology to us will appear to be like "magic".
-
- It is humbling to remind ourselves, that a century ago, very few people on
- this planet used electricity - we have come a long way in a short time (on
- the cosmic timescale)!
-
- Although to date most of my theoretical analysis has concentrated on
- Professional Optical SETI, I have more recently started making the case that
- amateur optical astronomers could make a useful contribution to the low-
- level targeted search of the entire celestial sphere. Such a program would
- concentrate on the 800 stars that are presently the subject of NASA's ten-
- year Microwave Observation Project (MOP) which is just getting started.
-
- If I find there is sufficient interest out there in Optical SETI, I will
- upload some documentation that will further explain my approach, and how I
- think that the SETI community is "tuned to the wrong frequencies". This
- week, there is a major US-USSR SETI Conference being held at UCSC-Santa
- Cruz. I am hoping that the SETI community will find the time to discuss my
- revisiting of the optical approach. In time, you will probably get to read
- more details about what I have to say in the scientific literature and
- glossy scientific magazines.
-
- I believe that amateur optical astronomy clubs and societies could well-
- afford the cost of the instrumentation to attach to conventional telescopes,
- and thus participate in the greatest hunt ever - the hunt for ETI. It
- should be possible to modify an 8" to 12" telescope for about $8,000. If
- you are interested in participating let me know. This unofficial poll will
- help me judge just how appealing (and exciting) this scientific endeavor
- could be to the average citizen. I would like to hear from anyone in
- Columbus, particularly those connect with OSU who are not presently
- associated with Dr. Robert Dixon's activities and the "Big Ear" radio
- telescope in Delaware, to also contact me if they are interested. Since
- this message will be read around the world, I would also like to gauge the
- international interest in this subject, particularly in the United Kingdom.
-
- Despite my Trekki logo below, the essence of my approach is that ETI optical
- photons have been coming in our direction for a long time, except that we
- have been too blind (and dumb) to notice. Some might ask "Why bother to
- look for extraterrestrial intelligence before we have discovered terrestrial
- intelligence"!
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-