This thread seems to be evolving into the underlying question of why we crunch for SAH. My reasons I have already stated.

What are yours?

... because the odds of finding something may be vanishingly small, but just think how mind-blowing it is going to be if we actually do find something.

Oh, I am right with you on that Ned. Except that the existing rules assure failure:

As I understand them, the rules of SAH are to find 2 roughly identical “messages” sent our way at different times from the same point in space.

So far as I know, we sent out one message from Arecibo several decades ago. So, my point was, that Earth wouldn’t meet the minimum requirements for intelligent life according to the requirements of SAH.

Even were we to pick up the alien equivalent local AM radio broadcasts (theoretically possible to detect from several tens of light years away) SAH wouldn’t recognize them as being intelligent.

Presumably any “interesting” signals like this would be saved for future analysis but would not be considered a success from SETI’s POV.

And of course, a whole separate issue is that even if a broadcast of the alien equivalent of Bach had been recorded, we’d never know because nothing is being done with the results we send in anyway.

We are not actually looking for the messages, we are only looking to see if we can find signals that look like they have come from radio transmitters. The signature of a transmitter can be regarded as un-natural.
It is improbable that we can detect "broadcast" transmissions because these signals by definition are sent in every possible direction.
Therefore any signal we do find find will have probably come from a high power transmitter connected to a directional antenna.
UN-modified AM transmitters send out the carrier frequency and two sidebands that contain the message(s). The sidebands are equally spaced above and below the carrier frequency. That would be one possible source of a triple. The maximum power in each sideband is one third of the total power.
As the carrier does not contain any messages, on high power systems the carrier is often surpressed, one way of saving bundles of cash. This could be source of pulses.
A transmitter not transmitting any data would just produce a spike at the carrier frequency.

The problem if ET is using a directional antenna is that it probably will not be pointing in our direction every time Aricebo looks at ET location, therefore we have to look at that location many times.

And one of my points was that since we only once sent out such a concentrated message, applying SAH rules, we would bypass Earth as a sourse of intelligent life. (Which may well be true, of course. LOL)

[edit] Which bypasses the other issue that the results we send back are not being analyzed anyway, so. . . [/edit]

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Pure mathematics is, in its way, the poetry of logical ideas.

Albert Einstein

[edit] sorry, I mis-read your post. So what then, precisely, is SAH looking for? And since there is no apparent post analysis on our results done, how do we know if we know success from failure? [/edit]

This is a relatively poor analogy, but we'll talk about Analog, NTSC Television signals as a place to start.

TV has a frame rate of 30 frames per second -- it has it's own rhythm. There is another "beat" at 15 khz to start each scan line.

This is the same for "I Love Lucy" and "Sesame Street" and the nightly news.

... and it is very unlikely that this kind of regular signal would ever exist in nature.

DTV is similar in that it is a 19.39 MHz data stream, and that kind of regularity is going to stand out against a truly random background. There is a recurring bit pattern for synchronization.

In both examples, we're talking about images, but for a hypothetical extraterrestrial "short-wave listener" they may not be able to tell if this is data, video, audio, or whatever -- let alone be able to tell "I Love Lucy" from the Boston Pops.

... but it'd be a clear sign that the signal wasn't random -- that there was some intelligence behind it.

Edit: we're looking for something like that. Something regular, something that doesn't look like noise.

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[edit] sorry, I mis-read your post. So what then, precisely, is SAH looking for? And since there is no apparent post analysis on our results done, how do we know if we know success from failure? [/edit]

This is a relatively poor analogy, but we'll talk about Analog, NTSC Television signals as a place to start.

TV has a frame rate of 30 frames per second -- it has it's own rhythm. There is another "beat" at 15 khz to start each scan line.

This is the same for "I Love Lucy" and "Sesame Street" and the nightly news.

... and it is very unlikely that this kind of regular signal would ever exist in nature.

DTV is similar in that it is a 19.39 MHz data stream, and that kind of regularity is going to stand out against a truly random background. There is a recurring bit pattern for synchronization.

In both examples, we're talking about images, but for a hypothetical extraterrestrial "short-wave listener" they may not be able to tell if this is data, video, audio, or whatever -- let alone be able to tell "I Love Lucy" from the Boston Pops.

... but it'd be a clear sign that the signal wasn't random -- that there was some intelligence behind it.

Edit: we're looking for something like that. Something regular, something that doesn't look like noise.

I freely admit that you have moved outside my knowledge zone, so I propose a couple of simple, yes/no questions based on your knowledge of RF engineering as propagated through an Oxy/Nitrogen atmosphere and into interstellar space.

Let’s take a reasonably close to us distance (Say 50 l-y.) alien civilization. Very close considering the 15 billion light year radius of the observable universe. Let us say that, 50 years ago, ET broadcast the local version of Boston Pops to the local citizenry on it’s local TV station. Let’s say that, a couple years later (as we did here) they switched to cable (no emissions.)

So “yes/no” question number one: would Arecibo pick up the original broadcast (assuming standard modern earth television telecast standards.) Yes or no.

Second yes/no question. Since there is no analysis of the results we return, should one of our computers pick up in this signal, it might be years before anyone knows that it is interesting and deserves a second look. By then, our alien friends have gone cable, so no more signals. Would then the conclusion be that this was a false positive and that there was no intelligence at this particular location. Again, yes or no.

Don’t get me wrong. When I first joined SAH two years ago I believed as strongly as the most devout. But to my mind it has become much like a religion: an article of faith not to question. But simple rational thought leads me to conclude that, while there is almost certainly intelligent life in the universe, as presently constructed, SAH as virtually no chance of ever detecting it.

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Pure mathematics is, in its way, the poetry of logical ideas.

Albert Einstein

[edit] sorry, I mis-read your post. So what then, precisely, is SAH looking for? And since there is no apparent post analysis on our results done, how do we know if we know success from failure? [/edit]

This is a relatively poor analogy, but we'll talk about Analog, NTSC Television signals as a place to start.

TV has a frame rate of 30 frames per second -- it has it's own rhythm. There is another "beat" at 15 khz to start each scan line.

This is the same for "I Love Lucy" and "Sesame Street" and the nightly news.

... and it is very unlikely that this kind of regular signal would ever exist in nature.

DTV is similar in that it is a 19.39 MHz data stream, and that kind of regularity is going to stand out against a truly random background. There is a recurring bit pattern for synchronization.

In both examples, we're talking about images, but for a hypothetical extraterrestrial "short-wave listener" they may not be able to tell if this is data, video, audio, or whatever -- let alone be able to tell "I Love Lucy" from the Boston Pops.

... but it'd be a clear sign that the signal wasn't random -- that there was some intelligence behind it.

Edit: we're looking for something like that. Something regular, something that doesn't look like noise.

I freely admit that you have moved outside my knowledge zone, so I propose a couple of simple, yes/no questions based on your knowledge of RF engineering as propagated through an Oxy/Nitrogen atmosphere and into interstellar space.

Let’s take a reasonably close to us distance (Say 50 l-y.) alien civilization. Very close considering the 15 billion light year radius of the observable universe. Let us say that, 50 years ago, ET broadcast the local version of Boston Pops to the local citizenry on it’s local TV station. Let’s say that, a couple years later (as we did here) they switched to cable (no emissions.)

So “yes/no” question number one: would Arecibo pick up the original broadcast (assuming standard modern earth television telecast standards.) Yes or no.

Second yes/no question. Since there is no analysis of the results we return, should one of our computers pick up in this signal, it might be years before anyone knows that it is interesting and deserves a second look. By then, our alien friends have gone cable, so no more signals. Would then the conclusion be that this was a false positive and that there was no intelligence at this particular location. Again, yes or no.

Don’t get me wrong. When I first joined SAH two years ago I believed as strongly as the most devout. But to my mind it has become much like a religion: an article of faith not to question. But simple rational thought leads me to conclude that, while there is almost certainly intelligent life in the universe, as presently constructed, SAH as virtually no chance of ever detecting it.

First question: yes.

Depends a little on their technological evolution, and if their use of radio evolves as ours has, they're running some serious power to make their primitive receivers hear the signal. We aren't blasting as much RF "trash" into space as we used to.

Second question: no.

Remember, we're looking for a pattern and that pattern is some sort of regularity that would be difficult to explain by anything other than intelligence.

The "second look" would likely be in the database before ET gets cable (ignoring cell phones, wireless LANs, satellite phones, etc. of course)

I know there has been lots of talk about the NTPCKR and some grumbling about progress. If the NTPCKR had been available when the first work unit was returned, it would have checked the database and found that no signal had been found at that spot in the past.

For the NTPCKR to work, there has to be history. We've been building that history.

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I freely admit that you have moved outside my knowledge zone, so I propose a couple of simple, yes/no questions based on your knowledge of RF engineering as propagated through an Oxy/Nitrogen atmosphere and into interstellar space.

P.S. don't look too deeply into this. We're not looking for "I Love Lucy" as much as we're looking for some small sign of, well, "something" -- anything.

We might recognize an Extraterrestrial TV signal, but we'd have some idea that it wasn't random.

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kenzieB wrote:

...
Let’s take a reasonably close to us distance (Say 50 l-y.) alien civilization. Very close considering the 15 billion light year radius of the observable universe. Let us say that, 50 years ago, ET broadcast the local version of Boston Pops to the local citizenry on it’s local TV station. Let’s say that, a couple years later (as we did here) they switched to cable (no emissions.)

Broadcast Television has not stopped, it simply serves a smaller fraction of the population than it did once. Not everybody resides where cable is available, not everybody can afford it or the competing satellite services.

kenzieB wrote:

So “yes/no” question number one: would Arecibo pick up the original broadcast (assuming standard modern earth television telecast standards.) Yes or no.

No.

But it could. The project chose the waterhole frequency band on the basis that a civilization doing interstellar communication would most likely take advantage of the reduced noise there. Had we been looking for leaked terrestrial communications, a lower frequency band might have been chosen. OTOH, the Arecibo receivers and their feeds aren't designed for TV frequencies which probably made it impractical anyhow.

kenzieB wrote:

Second yes/no question. Since there is no analysis of the results we return, should one of our computers pick up in this signal, it might be years before anyone knows that it is interesting and deserves a second look. By then, our alien friends have gone cable, so no more signals. Would then the conclusion be that this was a false positive and that there was no intelligence at this particular location. Again, yes or no.
...

No.

We're doing the second phase of the project, so far reducing petabytes of raw data to more than 2 billion possible signals gathered over about ten years. Analysis for persistent signals is the third phase and can be done at any time, an interstellar communication system is likely to have an extended lifetime. The NTPCKR coding effort is getting some time, perhaps hardware which can run it fast enough will follow. It is possible, though unlikely, that a persistent signal will be good enough that confirming with reobservation is not necessary. Reobservation would obviously be tried, probably using various radio telescopes, and if the signal were no longer present there would be a lot of discussion.

                                                             Joe

Let’s take a reasonably close to us distance (Say 50 l-y.) alien civilization. Very close considering the 15 billion light year radius of the observable universe. Let us say that, 50 years ago, ET broadcast the local version of Boston Pops to the local citizenry on it’s local TV station. Let’s say that, a couple years later (as we did here) they switched to cable (no emissions.)

Not to nitpick, but keep in mind that cable companies use satellites to receive the broadcasts from the studios and broadcast centers. They only actually use cable to pipe the shows to the viewers. So switching to cable still means they have to beam high-powered transmissions up into orbit to reach the satellites...and that signal will continue right pass the satellite and continue into interstellar space. :)

In addition to entertainment, it's reasonable to assume that most civilizations will still use satellites for many other reasons such as weather monitoring, scientific research, and military uses. So I find it unlikely that anybody would switch every single form of communication over to a hard-wired or cable solution. :)

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You will be assimilated...bunghole!

Also cable is actually a retrograde step, in that it requires more physical infrastructure - cables, poles, holes in the ground, physical installation meaning that you can't just buy the set, take it home and start watching. I can imagine that at least some civilisations would look at that and say 'no way.'

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Also cable is actually a retrograde step, in that it requires more physical infrastructure - cables, poles, holes in the ground, physical installation meaning that you can't just buy the set, take it home and start watching. I can imagine that at least some civilisations would look at that and say 'no way.'

At the current stage of this little planet's development, "take it home and start watching" probably implies "cables, poles, holes in the ground, physical installation" - for the power supply. Not true for much of rural North America when radio broadcasts first became available, of course, or much of the rural third world today - wasn't there a network of battery recharging stations before dry cells became ubiquitous?

We often forget how quickly electrical technology has developed, and how much of a transitional state we are still in. I suspect the hardest part of SETI is finding a planet which is just at the stage of using technology "we" can listen out for, before "they" move on to something else.

At the current stage of this little planet's development, "take it home and start watching" probably implies "cables, poles, holes in the ground, physical installation" - for the power supply. Not true for much of rural North America when radio broadcasts first became available, of course, or much of the rural third world today - wasn't there a network of battery recharging stations before dry cells became ubiquitous?

We often forget how quickly electrical technology has developed, and how much of a transitional state we are still in. I suspect the hardest part of SETI is finding a planet which is just at the stage of using technology "we" can listen out for, before "they" move on to something else.

Good point. Make that "MORE cables, poles, holes in the ground, physical installation" etc. I seem to remember something about someone experimenting with beamed or radiated power too, but only hazily - it may have been an S-F novel rather than real.

I agree. Basically, we're playing with averages; SOME civilisations, at SOME time are likely to use radio communication for SOME length of time (we hope).

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Although moving away from wireless/radio and back to cables is kind of a backwards step, to be honest, I prefer having a physical medium for communications. A lot of people like the freedom of not being bound by wires (laptops, for example), but I like knowing that the connection is there and will be running at it's maximum speed the entire time. Wifi can't do that.

I like being able to go 300 feet and still have 100mbit/gigabit. 300 feet for even wifi-b is kind of a stretch, but it will connect, but don't expect any decent speed out of it.

That's just my opinion though. I'm guessing that for a lot of people, they don't need or want high speeds with wireless if they're just checking their email and doing a few google searches, but I know I do, so wires are great for me.

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Linux laptop:
record uptime: 1511d 20h 19m (ended due to the power brick giving-up)

Although moving away from wireless/radio and back to cables is kind of a backwards step, to be honest, I prefer having a physical medium for communications. A lot of people like the freedom of not being bound by wires (laptops, for example), but I like knowing that the connection is there and will be running at it's maximum speed the entire time. Wifi can't do that.

I like being able to go 300 feet and still have 100mbit/gigabit.

And you LIKE dragging an ethernet cable 300 feet? ;^)

Although moving away from wireless/radio and back to cables is kind of a backwards step, to be honest, I prefer having a physical medium for communications. A lot of people like the freedom of not being bound by wires (laptops, for example), but I like knowing that the connection is there and will be running at it's maximum speed the entire time. Wifi can't do that.

I like being able to go 300 feet and still have 100mbit/gigabit.

And you LIKE dragging an ethernet cable 300 feet? ;^)

Like I said, it doesn't bother me...and besides, who actually goes 300 feet?

Not only that, but I wired my house up. Using a 24-port gigabit switch as a patch panel.. I've got drops all over the place, so I don't need anything longer than 20 feet from the outlet to the laptop. :p

Besides, wires have a third advantage over wireless (distance and throughput are already stated).. security. I don't have to worry about doing MAC filtering or WEP security on my network. the only access to my network is from inside the house. Not paranoia or anything, but MAC filtering is easy to spoof, WEP can be cracked, and WPA can be as well, it just takes longer and needs much more packets..and there's the problem of not every device supports WPA, and you can't run WPA and WEP at the same time.

Not saying wireless is useless..it does have it's merits, but I just prefer not to deal with it. All the experiences I've have with it, I haven't been "blown away" impressed. I was able to check email and browse the web and anything that normal people would do, but I transfer data a lot, and wireless doesn't like doing that very much. The only issue I run into unless I'm within 30 feet of the AP is the random "disconnected..connected" issue that always seems to happen when i'm doing something important. I've tried different laptops with different makes/models of NICs, I've tried USB NICs from different brands, tried different drivers. Most people don't ever have that issue, but I seem to be a magnet for it.

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Linux laptop:
record uptime: 1511d 20h 19m (ended due to the power brick giving-up)

Not to nitpick, but keep in mind that cable companies use satellites to receive the broadcasts from the studios and broadcast centers. They only actually use cable to pipe the shows to the viewers. So switching to cable still means they have to beam high-powered transmissions up into orbit to reach the satellites...and that signal will continue right pass the satellite and continue into interstellar space. :)

Not to nitpick the nitpicker, but. . .

As I understand it, Earth-To-Satellite transmissions are focused, not widely broadcast. Not much leakage. And what leakage there is would be not be a broadcast signal. Long odds on randomly grabbing that out of the ether. Plus, since Earth and satellites rotate, even if an alien civilization happened on it once it would be unlikely to be there when looked at again months or years later since transmitter/alien receiver would no longer be aligned. Thus, by the rules of SAH, no intelligence in earth.

:)

In addition to entertainment, it's reasonable to assume that most civilizations will still use satellites for many other reasons such as weather monitoring, scientific research, and military uses. So I find it unlikely that anybody would switch every single form of communication over to a hard-wired or cable solution. :)

Again, all examples of focused or directed light (laser) transmissions. Extremely unlikely to be picked up except by hugely unlikely serendipity. And not likely to be seen again because of the constant motion between transmitter and receiver.

And before you bring it up, satellite-to-planet signals have a whole planet blocking the signal. For all intents and purpose, the planet goes dark.

:)

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Pure mathematics is, in its way, the poetry of logical ideas.

Albert Einstein

Also cable is actually a retrograde step, in that it requires more physical infrastructure - cables, poles, holes in the ground, physical installation meaning that you can't just buy the set, take it home and start watching. I can imagine that at least some civilisations would look at that and say 'no way.'

At the current stage of this little planet's development, "take it home and start watching" probably implies "cables, poles, holes in the ground, physical installation" - for the power supply. Not true for much of rural North America when radio broadcasts first became available, of course, or much of the rural third world today - wasn't there a network of battery recharging stations before dry cells became ubiquitous?

We often forget how quickly electrical technology has developed, and how much of a transitional state we are still in. I suspect the hardest part of SETI is finding a planet which is just at the stage of using technology "we" can listen out for, before "they" move on to something else.

Thank you Richard, that was more or less my point.

As SAH is presently structured, it could be years or decades before we look at any interesting signals, and ET will have long since moved onto something else. So, no second signal, no intellignece.

[edit] it seems to me that, by the nature of it's rules, SAH, assures its own failure. This project would probably not detect intelligent life on Earth at a 50 L-Y range.[/edit]

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Pure mathematics is, in its way, the poetry of logical ideas.

Albert Einstein

Not to nitpick the nitpicker, but. . .

As I understand it, Earth-To-Satellite transmissions are focused, not widely broadcast. Not much leakage. And what leakage there is would be not be a broadcast signal. Long odds on randomly grabbing that out of the ether. Plus, since Earth and satellites rotate, even if an alien civilization happened on it once it would be unlikely to be there when looked at again months or years later since transmitter/alien receiver would no longer be aligned. Thus, by the rules of SAH, no intelligence in earth.

:)

Well a satellite isn't going to actually block the radio signal right? So even though it's fairly well focused, the beam is going to sweep over most of the galaxy as the Earth rotates. :)

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You will be assimilated...bunghole!

Not to nitpick the nitpicker, but. . .

As I understand it, Earth-To-Satellite transmissions are focused, not widely broadcast. Not much leakage. And what leakage there is would be not be a broadcast signal. Long odds on randomly grabbing that out of the ether. Plus, since Earth and satellites rotate, even if an alien civilization happened on it once it would be unlikely to be there when looked at again months or years later since transmitter/alien receiver would no longer be aligned. Thus, by the rules of SAH, no intelligence in earth.

:)

Well a satellite isn't going to actually block the radio signal right? So even though it's fairly well focused, the beam is going to sweep over most of the galaxy as the Earth rotates. :)

Once, yes. But because our planet is not that stable (it oscilates on it's axis, it bumps around in it's orbit because of pertubations from the moon and other sources), and lots of other weird little motions, the chances of an alien civilization picking up that signal a second time are pretty much 0. So, as I said before, according the the requirements of SAH, there would be a negative finding for Earth.
:)

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Pure mathematics is, in its way, the poetry of logical ideas.

Albert Einstein

Not to nitpick the nitpicker, but. . .

As I understand it, Earth-To-Satellite transmissions are focused, not widely broadcast. Not much leakage. And what leakage there is would be not be a broadcast signal. Long odds on randomly grabbing that out of the ether. Plus, since Earth and satellites rotate, even if an alien civilization happened on it once it would be unlikely to be there when looked at again months or years later since transmitter/alien receiver would no longer be aligned. Thus, by the rules of SAH, no intelligence in earth.

:)

Well a satellite isn't going to actually block the radio signal right? So even though it's fairly well focused, the beam is going to sweep over most of the galaxy as the Earth rotates. :)

In real terms earth to satellite transmissions are fairly low power. The transmitters are in 10's of watts and the parabolic antenna are usually less than 10 ft (3m) diameter.

High power transmissions are in 10's of kW or more using 60ft (18m) dia. As once used on DEW line, ACE-High and off shore oil rigs.

Daniel,

stay cool. There is no need for you to leave the project. When you have got a problem with it, post it here or on your team web-side. I have seen, that you are a member of PD3Now. This is a very strong team with a great bandwidth of knowledge.
As Sutaru posted before, put more WU´s in stock. This would solve your problem. It is a very simple solution and the best.

It would be great of you, when you will change your mind and stay.

Those settings are already on maximum (10 Days) what i still wonder is that this work is usually then gone within a day or 2, then my cache is empty and i go nuts because i dont like to babysit seti all the time, since i also got some real life to deal with.

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Hello to everybody here. I just wanted to add my thoughts about this topic. You won't find to many posts from me here and the reason for that is that I don't take boinc too seriously. It is a project that uses your computer mainly when not being used to do what computers were designed to do eg. home use or business use. So I don't get all upset when there is no work for my computers to crunch. It is a hobby of mine. I learned a lot because of seti. It has pushed me to build my computers from scratch because I wanted to be able to crunch more w.u. Seti made me aware of many other things in the computer world. It is fun for me to learn about the crunching of radio signals. I have been doing this since May of 1999 and through the years there has been multiple setbacks and problems. One thing has to be remembered there will always be someone with better computer than yours, someone with more credit than you and more important than anything else THERE IS LIFE BEYOND SETI. We here in the US are in deep dodo economically, jobs are being lost, we are bombarded with scare tactics on every day bases. The sky is falling. Ohhhhh.... I can't take this any more. Well there you go , relax and if you don't like doing seti it's okay to leave. You'll come back I know I did. by the way English is my second language as well and spell checker has been used extensively to write this post. I hope I did not offend anybody and if I did it was unintentional and I apologize in advance. MrJeep

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