SETI - The science behind the search


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Profile Martin
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Message 987353 - Posted: 7 Apr 2010, 21:08:34 UTC

Posted not to offend! Opinions?

http://www.youtube.com/watch?v=kgqfQ-a8OqE

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Message 987364 - Posted: 7 Apr 2010, 22:48:45 UTC - in response to Message 987353.

According to the video author, "SETI is little more then a fraud" and a method for funding the researchers' retirement.

Naive and typical of what passes for pseudo-intelligent commentary on Youtube / "I fancy myself a scientist".

It's disappointing to see the simplistic way limited knowledge coupled with conjecture is presented as fact and not in need of peer reviewed, irrefutable, independently reproduced results.

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Message 987377 - Posted: 8 Apr 2010, 0:14:54 UTC - in response to Message 987364.

What ^^^ said.
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Message 987653 - Posted: 9 Apr 2010, 9:27:53 UTC

So many holes in his argument that I don't know where to begin.

There are frequencies that are amazingly noise free. If you transmit in tight beams, instead of radiating out in all directions, you don't need anywhere near gigawatts of power. Voyager spacecraft sent signals from the edge of the solar-system back to Earth that were easily picked up by fairly small dish antennas. They broadcast with something like 23 watts, only a little more than a cell phone uses.

And the most telling argument: people involved with SETI research are generally quite intelligent. I am sure that they could find far more lucrative ways of funding their retirement than having to deal with people like us on a daily basis. ;o)

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Message 988213 - Posted: 10 Apr 2010, 23:38:29 UTC

I am sure that they could find far more lucrative ways of funding their retirement than having to deal with people like us on a daily basis. ;o)


Well said!!!

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Message 998148 - Posted: 23 May 2010, 4:35:41 UTC

He actually does seem like a fairly intelligent fellow, and the points he hits on are valid and known issues. However he overlooks the possibility mentioned earlier in this thread by kenzieB. A narrow band, focused transmission strong enough to be picked up would require far less power output than an omnidirectional transmitter, although it would still have to be tremendously powerful at interstellar distances. The chance of picking one up is fairly small, but it exists. In my mind, that is enough reason for this project to continue.
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Message 998331 - Posted: 24 May 2010, 0:00:34 UTC

I think the guy in the video looks like an idiot. This point is proven by the fact that he has done no research at all into the topic.

I left this comment on the video;

Johnney Guinness comment;

Radio telescope dishes are a parabola. This means if you use one as a transmitter, you are only transmitting in the direction you point the dish. Yes, the signal will still diminish over large distances, but the more precise you build the dish and transmitter, the greater the distance the signal will travel. You can think of it like a laser beam instead of a light bulb. Its basic space science, which just goes to show your own level of intelligence, or lack of it.


There is a good change he will delete the comment to defend his credibility.

John.
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Message 998370 - Posted: 24 May 2010, 2:51:51 UTC

Meh I don't think he's an idiot, I just think he's drawing misguided conclusions based on incomplete information. Given the proper knowledge he would probably comprehend it and change his view on the matter.

For some reason our comments aren't showing up on the main video page, you have to click "view all comments" in order to see them.
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Profile Johnney Guinness
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Message 998679 - Posted: 25 May 2010, 3:08:13 UTC - in response to Message 998370.

Meh I don't think he's an idiot, I just think he's drawing misguided conclusions based on incomplete information. Given the proper knowledge he would probably comprehend it and change his view on the matter.

For some reason our comments aren't showing up on the main video page, you have to click "view all comments" in order to see them.

Yea, he replied to me and i answered some of his questions. But i think your right James, with some of his questions answered, he might well change his mind.

John.
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Message 1011461 - Posted: 4 Jul 2010, 1:51:03 UTC

..."We hold these Truths to be self-evident, that all Men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty, and the Search for Extraterrestrial Intelligence because the pommies have been found wanting"...

Enjoy July 4 all you Yanky Doodle Dandies.
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Message 1011478 - Posted: 4 Jul 2010, 3:02:21 UTC
Last modified: 4 Jul 2010, 3:11:40 UTC

Well it's good to have some criticism to reflect on what's going on in SETI. It would be useful to dig out the math and engineering to Nail down if we had an antenna of a certain size and gain and a receiver of a certain sensitivity using the best signal processing techniques how far out could we detect spurious transmissions of, say, a few million watts at our LYMAN frequency. I'll wager that at 1000 light years we might not be able to detect such a signal. Best I can recall there are maybe only a thousand stars out to this distance from Earth to begin with.

Now what about a focused beam at the same frequency and at say a burst of a 100 megawatts ? How far out then with likely beam divergence numbers?

There used to be a web site that would calculate these things for you if I do recall correctly.

What if a laser were used, the detector were in space and cooled to close to absolute zero . How far out now?

We can see things across the universe with our greatest telescopes. Maybe the answer would be a visual indication of a sign saying "we are here". This could be couched in an anomaly that we can detect such as a planet causing wobble in a star or the like. This might be the way to justify looking at vast distances and expecting to see such a sign of intelligent life..

To me SETI is still like playing the lottery--a fools game to be sure but I usually buy one ticket now and then. There could be somebody out there. I think maybe not in our galaxy and I think that if there were; we would probably never know. Communicating is out of the question, but knowing affirmatively would be sublime--It's the stuff of what dreams are made of.

Regards,

Daddio

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Message 1014492 - Posted: 10 Jul 2010, 23:00:28 UTC - in response to Message 1011478.



To me SETI is still like playing the lottery--a fools game to be sure but I usually buy one ticket now and then. There could be somebody out there. I think maybe not in our galaxy and I think that if there were; we would probably never know. Communicating is out of the question, but knowing affirmatively would be sublime--It's the stuff of what dreams are made of.

Regards,

Daddio

Bill Daddio,
This is my lottery too....LOL. Except this lottery only costs the price of leaving your PC switched on and running SETI@home. But the prize for winning the SETI lottery is worth more than any money can buy. Its the key to unlocking other worlds, other mystery's, other scientific knowledge and other civilisations. What a prize!!

John.
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Message 1015297 - Posted: 13 Jul 2010, 7:55:19 UTC

This has just come on our national broadcaster's website:

http://www.abc.net.au/news/stories/2010/07/13/2952506.htm?section=justin

I'm not exactly sure which forum I should place it in for anybody interested but this one seems to be the most appropriate. All the best.
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Message 1015303 - Posted: 13 Jul 2010, 10:05:39 UTC - in response to Message 1015297.
Last modified: 13 Jul 2010, 10:11:54 UTC

Nice reference but very clumsy logic. Radars are not quiet and are several million watts in bursts. i am talking about airport ground radar. Tv stations still exist and are also in the 100,000 to 1 million watt range. AM radio also 50,000 watts in the US. Just because satellites are offering communications at lower power doesn't mean that these other sources are going to go away.

Also good to note that there are very few stars out to 300 light years. Hopefully the searching for planets activity will look at these first. My approach also suggests that habitable planets in the sense of having all of the delicate balances necessary for intelligent life that might be able to communicate amongst themselves electronically are exceedingly rare. Best we hope for a beacon of high, focused power.

I love Monte Carlo simulations but the uncertainties in this type of model when applied to exo-planets are almost infinite.

lately i am worrying more and more about the contemporaneousness problem in that our timelines would have to match up and allow for perhaps 100,000 years for the signal to wander here to Earth. It would have to be a focused beam of high power and that suggests that they would have to know where to send it and know essentially 200,000 years ahead of time that oh yes there will be somebody listening 100,000 years hence from this planet that we see was like 100,000 years ago if we send a message.

Like I say, "a fool's game" but fun to play the lottery none the less.

Ironically, the search for planets suitable for habitation will probably put an end to SETI once we conclude that there are none out to where we could hear them. Perhaps we could see a blue atmosphere with a ring of space junk around a planet. Seti may soon take this form of looking as well.

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Message 1015659 - Posted: 14 Jul 2010, 21:29:58 UTC - in response to Message 1015297.

This has just come on our national broadcaster's website:

http://www.abc.net.au/news/stories/2010/07/13/2952506.htm?section=justin

I'm not exactly sure which forum I should place it in for anybody interested but this one seems to be the most appropriate. All the best.

Kadaitcha_Man,
I read that article, its pure pessimistic rubbish. Its far more likely that we are not detecting aliens because they are staying "radio quiet", they just don't want to be heard.

Daddio,
You make some interesting points. Sending a signal over a colossal distance or time span would mean preempting exactly where the planet and star would be. This does not seem practical. However broadcasting your DNA code randomly around the galaxy does seem like a good idea. If some alien detects it, he could clone you. To me, this seems like a good idea.

John.
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Message 1018523 - Posted: 22 Jul 2010, 22:53:18 UTC - in response to Message 1015303.

Also good to note that there are very few stars out to 300 light years. […]

I don’t know what “very few” means to you here—but it’s certainly not applicable to my perception: the number of stars known to lie within 300 LY of here is in the tens of thousands.

Even to about one-tenth that distance—10 parsecs or 32.7 LY—nearly 400 stars have been identified, at least a dozen of them having planets, with more being discovered every year. According to the Atlas of the Universe’s Stars within 50 light years page, there are some two thousand stars out to that range, 133 of the systems even being bright enough to see without optical aid! Extrapolating from either of these samples will yield figures in the hundreds of thousands for a 300-LY radius.
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Message 1018635 - Posted: 23 Jul 2010, 10:45:12 UTC - in response to Message 1018523.

Probably less than 1000 sun-like, main sequence stars out to 100 light years. Don't want to count red dwarfs etc. Others have stated 586 stars.

Very few means a small, small percentage of the 100-200 Billion Stars in the Milky way.

My point being that there is not an infinity of stars within eavesdropping distance of the Earth.

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Message 1020043 - Posted: 27 Jul 2010, 10:07:29 UTC

Its not important what he says, but gets you thinking that the project have major flaws.

1) Searches in a specific band.
2) Not enough resources to analyze the already analyzed data.

And this is just at the concept. I know im releativly new, but i feel stupid just crunching numbers for something that is doomed to fail.

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Message 1020049 - Posted: 27 Jul 2010, 11:00:58 UTC - in response to Message 1020043.

And yet there are people trying to duplicate SETI@home.Look at www.setiquest.org.
Tullio
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Message 1020235 - Posted: 28 Jul 2010, 1:57:26 UTC - in response to Message 1020043.

... I know im releativly new, but i feel stupid just crunching numbers for something that is doomed to fail.


Even if we don't find anything, that in itself is interesting in many ways.

Also, we are likely to find many other unexpected things along the way...


Happy crunchin',
Martin


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