Posted on 01/27/2005 8:03:58 PM PST by KevinDavis
Will we ever find a primer for decoding messages from extraterrestrials? Last month, anthropologists who gathered for a major conference in Atlanta, Georgia heard some news that will be sobering for SETI enthusiasts: it may be much more difficult to understand extraterrestrials than many scientists have thought before.
Among the sessions held during December’s annual meeting of the American Anthropological Association was one called "Anthropology, Archaeology, and Interstellar Communication: Science and the Knowledge of Distant Worlds." The session included papers by scholars from such diverse fields as astronomy, archaeology, anthropology, and psychology. Is there a Cosmic Rosetta Stone, they asked, drawing parallels to Earth’s own Rosetta Stone, which provided the key to decoding Egyptian hieroglyphics? Will we ever find a comparable primer for decrypting any messages we might receive some day from extraterrestrials?
(Excerpt) Read more at space.com ...
No way! I didn't claw my way to the top of the food chain to eat nothing but freaking vegetables!
Beep beep beep ... Squark ... Beep ... Beep beep beep beep ... Beep ... Boop ... Boop beep beep beep beep ... Beep beep ... Boop beep ... Boop ...
Beep Beep Beep Beep Beep Beep Beep Beep Beep Beep Beep Beep Beep, right back atcha.
-ccm
(From: http://www.seds.org/~rme/seti.html)
"Given an effective radiated power of the transmitter (in watts), the effective area of the receiving antenna (in square meters), the excess receiver noise temperature of the receiver used (in K), the averaging time of the receiver (in seconds), and the accepted band-width of the signal (in Hz), the range at which we can detect a signal transmitted by an intelligent civilization, is:
R=8x10-6(PeA/T)1/2(t/B)1/4 light years.
Where the constant is calculated from 1/[9.4608x10 15(4pik) ½]. Here the constant is the number of meters per one light year, and k is the Boltzmann constant.
So to offset the distance limitation (and others), SETI searches usually look for an extremely narrow band CW carrier that have been Doppler shifted at planetary motions. Another problem is what frequencies do we look for? This is not unlike searching for an AM station on your radio in an unfamiliar part of the U.S. However, what if there were billions of frequencies, only one station, and you had an extremely directional antenna? This is one of the main problems of SETI. So to offset this just a bit, most searches look for many frequencies at the same time (in the billions now) and they look in a band that we may be able to detect something. Unfortunately we are limited in the bands we can use for such an endeavor.
There are two real sources of noise that limits the radio astronomer's ability to search for very weak signals. 1) The Galactic noise halo (which interferes with us below 1GHz) and 2) noise due to earth's atmosphere (interferes with us above 10GHz). This pretty much keeps all SETI searches (at least radio ones) between 1 and 10Ghz. Further inside this range are the frequencies that the OH (hydroxyl) 1.64GHz and H (hydrogen) 1.42GHz [also known as the 21cm band] molecular masers emit. This is the so-called water hole. OH H. These two bracket the coveted frequency bands most used by both radio astronomers and SETI searches.
However, IMHO, we just might be going about this wrong.
Here is what I am driving at:
The main frequency ranges that most SETI searches use are the ones coveted by radio astronomers, the "water hole" we discussed earlier. We already have international treaties to not broadcast at this frequency at all. So here we are looking for signs of a narrowband signal heralding the fact that there is other intelligent life out there. Here is my idea. Should any intelligent race develop radio and radio astronomy, they too may recognize the importance of this 21cm band. And they also may instigate a SETI search using this frequency not unlike what we are doing. So here is the question. Would they hear us at that frequency band? It is the very one that we are not transmitting on at all. I could just see 500 races all looking for each other at the very frequency band none of them are transmitting on due to the very nature of the importance of that frequency to the exploration of the universe.
Now back to the question at hand.
Should we ever “see” a signal that could be decoded, what in the heck could we use as a “Rosetta Stone”? Often, mathematics is cited since a number such as Pi or e would be the same everywhere. Another idea I really liked (just supposing we actually got our hands on an artifact with some sort of text) is that another thing that would be universal is the periodic table. That would make a fabulous “Rosetta Stone”. Note: This is not my idea. I actually got it from a SiFi short story.
"Hydrogen times pi! I told you!"
LOL! :-)
I liked the first part of the movie. About half way thru, it got silly IMHO.
Maybe transmitting on the Carbon frequency would be a good idea. Might keep us from trying to converse with something TOTALLY weird.
You have some rough posts to get a grip on before coffee.
ROTFLMAO! I am going to steal that! :-)
You have some rough posts to get a grip on before coffee.
hehehe
Isaac Asimov.
So tell me: In the movie, they talk about signal strength as being "over 100 Jannskies" (sp?). Is that an actual scientific unit of measure?
Nope. "Omnilingual" by H. Beam Piper
My mistake. I suspect I saw it in an anthology edited by AA.
Yup!
From here:
http://www.gb.nrao.edu/~glangsto/lessons/lessonCalibration.html
"One Jansky is 0.000000000000000000000000001 Watts/meter^2/Hz which is a very small value."
I think that is where I first read it as well. I would have to go look thru my anthologies though. :-)
This thread is now officially ejumakashunal. In fact, it's better than that. This thread "advances the search for truth, which is exactly what science is."*
*Palmer Joss told me so.
Thank you. :-)
Somehow I just hear the voices in my head, I don't need a translator.
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