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SETI and the hydrogen frequency?
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Bjørn E. Pedersen Send message Joined: 22 Aug 09 Posts: 4 Credit: 9,381 RAC: 0 |
Hi all you happy people. I'm quite new in the seti@home. And i hoped you could give me some information. I have installed the boinc screensaver, and it just keep running :) But my question is: Is SETI only scanning at the frequens of hydrogen and why? I have found the following link that explains some of it. http://www.setileague.org/askdr/hydrogen.htm But Does SETI only scan, at the hydrogen frequency and why? Has it something to do with, that the background noise from suns and neutronstars are at this frequency? Sorry if this already have been debated in other topics, but I couldn't find any such topics. Thanks Bjørn E. Pedersen |
John McCallum Send message Joined: 5 Dec 04 Posts: 877 Credit: 599,458 RAC: 8 |
"Has it something to do with, that the background noise from suns and neutron stars are at this frequency?" You hit the nail on the head my son.The hydrogen frequencies are the least noisy and so it is assumed that any Extraterrestrial will know this also and IF they are trying to communicate with the rest of the galaxy/universe or simply the nearest star to them this is the frequency that they might use.Of course I could be wrong and making all this up.Welcome to the Home for Bewildered Gentlefolk.(AKA s@h forums). Old enough to know better(but)still young enough not to care |
Bjørn E. Pedersen Send message Joined: 22 Aug 09 Posts: 4 Credit: 9,381 RAC: 0 |
Thanks for the Answer John. |
John McCallum Send message Joined: 5 Dec 04 Posts: 877 Credit: 599,458 RAC: 8 |
Look in the staff blogs area for more info from Kevin Douglas PHD on the hydrogen subject he did some research on it if I remember correctly. Old enough to know better(but)still young enough not to care |
Johnney Guinness Send message Joined: 11 Sep 06 Posts: 3093 Credit: 2,652,287 RAC: 0 |
Bjørn, You could also read this; How SETI@home works. Its a 6 page article but it explains about why SETI@home searches the hydrogen line. You could also read; Wikipedia - Hydrogen line Hydrogen is the simplest and most abundant element in nature and a spectral line is created by changing the energy state of neutral hydrogen. This occurs at about 21 cm or 1420 MHz. Other intelligent civilisations would find this out quite easily and would know its an obvious marker point in the electromagnetic spectrum. Good for telling everybody your here! John. |
Bjørn E. Pedersen Send message Joined: 22 Aug 09 Posts: 4 Credit: 9,381 RAC: 0 |
Thanks for all the answers and links. I will get right on with styding them :-) |
William Rothamel Send message Joined: 25 Oct 06 Posts: 3756 Credit: 1,999,735 RAC: 4 |
The SETI frequency that is scanned is one of the absorption lines of Hydrogen. one of the the LYMAN series --I think. It is the most profoundly emissionless region in the spectrum. Makes you wonder though why a signal wouldn't be absorbed as well by all of the Hydrogen in the path from sender to receiver. |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
The SETI frequency that is scanned is one of the absorption lines of Hydrogen. one of the the LYMAN series --I think. It is the most profoundly emissionless region in the spectrum. Probably because it is very sparse, unless you meet a cloud like the one described in Fred Hoyle's "The black cloud". Tullio |
Johnney Guinness Send message Joined: 11 Sep 06 Posts: 3093 Credit: 2,652,287 RAC: 0 |
Guys, I have a lot of doubts in my mind about only searching the Hydrogen line, which is what SETI@home does. If ET is sitting on his planet shouting on the top of his voice through a star sized telescope, we will still miss it! ET could be sitting there right now saying; "Why won't those dam Earthlings transmit back?. I have been signalling them for the last 100,000 years!" I'm really not convinced by the argument about searching the Hydrogen line. I still think the search should be much broader, even if its more difficult to remove the RFI. John. |
William Rothamel Send message Joined: 25 Oct 06 Posts: 3756 Credit: 1,999,735 RAC: 4 |
John, So good to hear from you and Tullio again. Perhaps someone out there who is an Astro-Physicist could comment. I suspect that this is the most logical band to peruse at the microwave spectrum. I don't know if other frequencies or multiples of this frequency makes sense. What I do know is that spread spectrum communication is extremely effective. Perhaps there is a logical progression of spread spectum sets of frequencies that might be deducible to the cognoscenti--terestrial or alien. Anyone know ??. What is the Allen Array doing for frequency monitoring? To me--it's more valuable to go back to a hot spot and run it to the ground to see if there might be a true alien signal that might contain unmistakeable intelligence. Such as counting out the prime numbers or cycling through the first 50 digits of pi. Regards, Bill |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
AFAIK SETI is looking for a narrow line emission, Astropulse (which I don't get anymore on my Linux box) is searching a wider spectrum. Also Einstein has a search called astrobinarypulsar which searches for binary pulsars in Arecibo data and that is also a wide spectrum search. That one I can crunch. Cheers. Tullio |
Bjørn E. Pedersen Send message Joined: 22 Aug 09 Posts: 4 Credit: 9,381 RAC: 0 |
I just found a link where theoretical physicist, Michio Kaku talks about SETI and the hydrogen Frequency. As Michio Says maybe aliens use another frequency or maybe laser technology. http://www.youtube.com/watch?v=Kw8dcb8iKSM Much of his argumentation makes sense to me. |
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