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SETI@home Explained, From Inside 121

Posted by timothy from the how-much-is-the-grey-one-mommy? dept.
eheien writes: "The IEEE currently has an article detailing SETI@home, written by the project founders. The article goes into a great deal of detail on how SETI@home works, how sensitive the search is to signals (it can detect a cell phone on Saturn's moons), how successful it has been, and so on." It's a good read, and has some impressive numbers about the project that most SETI@home participants may not have realized.
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SETI@home Explained, From Inside More

SETI@home Explained, From Inside

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  • for awhile, i had 5 linux machines running packets 24/7.

    about the time i hit 1000 data packets processed, i learned that they were accepting money from the co founder of microsoft.

    that's a little like taking maney from organized crime...so i pulled the plug/couldn't care less now.

    but it was interesting to learn how to set up all the boxes, diald, etc., plus there was always the hope of something significant happening.

    i checked over at distributed.net but it was looking pretty yawnish, and california was getting hit with a heat wave and was dipping low into the barrel, so i just packed it up.

    if something interesting for distributed stuff comes up again, and energy sanity has returned to california, i might be interested in bringing everything back up.



  • FIRST POST!
  • "on how succesful it has been"

    No offense to the guys at Seti@Home, but wouldn't success mean the detection of a extra terestrial signal?

    ---
  • Maybe it's just me but I'd love to have actual proof that there is someone else out there. It would be a big deal. It would change the way many people think for example.

    And on top of that, what can we learn from the signal we may detect? What does the signal contain? It's exciting!

  • It seems to me that the point of SETI@home is that even this (relatively) basic search is consuming enormous amounts of CPU cycles. Searching for signals more complicated than this is just not technologically feasible yet.
  • [Brittish] slang for 'guy' is bloke, not bloak.

    If you meant something else..."never mind"


    ---- Sigs are bad for your health ----

  • I don't think gravity waves move faster then light.
  • umm, unfortuantly, I don't run distributed software for the sheer thrill. I run it to win the damn money. Who says I am going to, but I compare it a lot to the lottery. I don't have to pay w/this and I have a lot better odds of winning (like 1 in 1800). SETI I don't win anything and it may even cost us our lives (key word is MAY) in the future when we start fucking up the lives of other worlds not just our own...

    I will stick to what is harmless and could give me money :)

    No dorky clubs for me where I compare how much CPU time I wasted going to a program :)
  • You would think that if some intelligent lifeform out there wants to send a signal that someone can easily decode they send it as simple and plain as possible! Simplest known method (to us) is modulating an electromagnetic carrier wave either with amplitude or frequency and it is a good guess that any other intelligent lifeform would be governed by the same laws of physics(electromagnetic radiation is pretty universal).

    As to composite signals from several stars: yeah, right. Composite signals from two or more places converge into intelligent signals in at the most one place. It is a fair bet that lifeform capable of sending interstellar signals know some basic geometry. Setting that place to be earth would make no sense unless they knew that we are here and were only trying to reach us.

    Even if we could only detect one part of this "composite" signal it would still definetly be irregular enough to qualify it as an alien communication. This is essentially what seti@home is looking for. It is not trying to decode anything, just detecting irregularities that might implicate intelligence..

    Non-consecutive frequencies? What does that have to do with anything. Seti@home picks frequency bands and distributes those as chunks to work on. If someone should happen to send a signal modulated at a frequency higher than half of the bandwidth of those chunks it would not really matter! It would create a sideband and only this sideband would show at some other chunk. This would definetly be an irregularity that sets off all kinds of alarms and people would start to investigate more.

    How the hypothetical aliens encode their message is totally irrelevant to seti@home. If there is a transmission method besides modulation of electromagnetic radiation it is also irrelevant to seti@home. If, however, this transmission can be received with a radio telescope it is more than likely that seti@home will catch it. Even if it catches only a part of some wierd pattern it is enough. We don't need to know more than a fraction of the message to know that something is being sent and for this seti@home is more than well equipped!

  • SETI@Home is impractical. There is very little chance in finding anything, and even if there was, it would most likely be given to someone who runs it for 2 seconds, then decides that it isnt cool enough, and goes back to the "OpenGL Windows Logo".
    I quit running data processing stuff as soon as I began to overclock heavily. My machine needs its rest!
  • The SETI@home system records a 2.5-MHz-wide band centered at the 1,420 MHz hydrogen line. Because this line would be of interest to astronomers of any species who were studying the galaxy, this frequency is one of the most likely locations for deliberate extraterrestrial transmissions.

    The SETI project makes an assumption that because Hydrogen is the most abundant element in the Universe it follows that a transmission from another species would necessarily be at that frequency. The other species would choose to transmit on the frequency that is most likely to be listened to. Although this assumption may make sense to us, it does not necessarily follow that it will make sense to another sentient life form on another planet. It is essentially attempting to predict the behavior of a species about which we know nothing other than they are sentient and have developed technology.

    We must consider the possibility that another species would choose to broadcast on another frequency. The reasons for choosing another frequency may be cosmologically or mathematically significant. That is, since we do not have a complete theory of the everything (unified theory), we may not yet recognize that there would be a better frequency for broadcasting. One that would be the most obvious choice to a species that had already developed a unified theory. Therefore SETI may be looking at the wrong frequency.

    Another siginificant issue is the power required to send the transmission any significant distance in Galactic terms. I won't get into that (because I can't remember the stats of the top of my head) but suffice it to say, that it would require many more times the power generated on earth every day.

  • rrr (Score:1)

    by delmoi ( 26744 )
    um...
    s/intercity/intensity

    Damn spellchecker...
  • Even though, it kills my CPU heavily, it's still need to watch when your extremely bored, and no new slashdot articles have been added in the past 15 minutes. Don't you hate that? I know schools that run seti@home on all there machines, hoping to find something. I know for a fact, they won't.
  • Ah finally someone who relates to me... Hey, why did I get modded down for being a troll?? It's not MY fault is some coward posts shit in response to my post... Dang. That's irritating.
  • Well, there are charitable people and then there are Microsoft execs. Microsoft execs are more akin to Satin giving away money or The Godfather giving out favors. All they ask in return is that one day they may approach you with a favor needing to be fulfilled. A body cleaned up for display, your everlasting soul, to sign an exclusive agreement forcing all your students to use Windows based products for all their classwork in exchange for the money granted to the university, etc. Simple stuff like that.
  • Well, no, but I had read a paper somewhere (I think Discover magazine) that disturbances in space-time caused by gravity are felt instantaneously throughout the universe, and that one of the potential uses for this tidbit was a faster method of communication for extrasolar space probes. Right now it's like an 18 minute trip for a message to a satellite around mars.

    Of course, "gravity waves" is an arguable concept in and of itself.

  • I doubt that i am smarter then most of the people who run seti. However, It doesn't mean that they are not wasting their time. Just because "hundreds of people" believe something, does not mean that it is correct. "Lots of people" have done lots of stupid things. Give me valid mathematical reasons why I'm wrong, or shut the hell up. I won't submit to the "They're smart, they must be right!" line
  • You know, just semi-offtopic, but that Windows screen saver app SUCKS. My PIII-733 linux box with the text client completely blew the doors off my Win2k PC running the stupid graphical screensaver client even though they were both running 24/7. I don't remember offhand but I believe my linux box could do 4+ blocks in the time my Win2k PC did 1 (24 hours!!) WTF. That 3d display must be really inefficient.
  • Really *knowing* that We Are Not Alone would have a major impact on the collective human psyche (as well as drive a huge increase in the sales of weaponry to mid-West USA survivalists *grin*). We don't have to be able to travel a couple of hundred light years to meet them.

    One big problem is that we've only been emitting radio signals ourselves for the past 100 years. An alien civilisation would have to be at a *very* similar stage to ours to pick us up (or vice versa). How many are we missing because they don't use those old-fashioned radio waves, or haven't invented them yet?
  • it can detect a cell phone on Saturns moons

    Dammit, I knew I shouldn't have made that call.
    They're sure to find us now...

  • That's it then! (Score:3)

    by DrWiggy ( 143807 ) on Tuesday January 16, 2001 @01:47AM (#505570)
    it can detect a cell phone on Saturns moons

    Hang on, the only way to be sure of this is to have tested the hypothesis. That means they're picking up cell calls on Saturn's moons. Doesn't this strike anybody else as being perhaps odd? I know Vodafone are on a campagin of world domination, but I didn't know they had bought out telcos out there! :-)
  • A cell phone is a horrible design for sending long range signals. It's omnidirectional, pratically powerless, and not at an ideal frequency. If you wanted to send a signal to other worlds, you'd have no problems if you knew what to do. The single problem is the huge ammount of time it takes for a signal to get from one place to another.

    Mind you I am speaking on technical merits only, ET is merely a human manifestation of the need for hope that there is something better out there. The new religion if you will.
  • So, I wonder, are WE transmitting a repeating signal at 1450 Mhz or near it?
    Yes, there have been signals sent out on the hydrogen bands from various radio telescopes, mostly as part of a PR campaign for SETI research. Some of the signals have been sent to stars that are close (as stars go) and some to other galaxies.

    There is some concern as to who might answer such a transmission. Would the Vulcans come by for a drink as in Star Trek, would the Babylon 5 Vorlons stop by for some new DNA samples, or would Damon Knight's Kanamits show up?

    I'm not an actor, but I play one on TV. - Me
  • You know, with all these Seti@Home clients churning away, could the bulk EMF from the computers be interpreted as a sign of intelligent life from Earth to the Aliens?
  • Yes, there have been signals sent out on the hydrogen bands from various radio telescopes, mostly as part of a PR campaign for SETI research.

    Except possibly for some, low power, illicit, transmissions, we've never transmitted on the hydrogen line.

    I think you may be thinking of the Encounter 2001 transmissions [cmu.edu] (science URL given, not the commercial one [encounter2001.com]). These used 5,010.024 Mhz.

    The much earlier one, from Arecibo, was somewhere around 2,250 MHz, although I cannot find a reference to positively confirm that just now.

    These frequencies are chosen because they are the frequencies of existing planetary radar transmitters, and, in turn, might represent frequencies near military radar frequencies; they were not chosen because of any likely significance to ET.

    Some of the signals have been sent to stars that are close (as stars go) and some to other galaxies.

    The Arecibo message was sent to the (historic) position of a globular cluster (M13) in our own galaxy. The Encounter 2001 messges were sent to the (proper motion and light time corrected) locations of relatively close stars.

  • ...and the first response?

    "ME TOO!" (likely posted by a Sirius On-Line customer)

    -LjM
  • Check this quote:
    Figure 1. SETI@home uses the National Astronomy and Ionospheric Center's 305 meter telescope at Arecibo, Puerto Rico.

    Now wouldn't HAARP's efforts directly effect this type of technology??
  • If they're capable of traveling faster than the speed of light (for all you UFO buffs out there), they must ALSO be capable of communicating faster than the speed of light.

    That's a pretty big "if". Gigantic in fact.

    That means they definitely are NOT communicating via radio waves.

    Well, it depends. If you are *deliberately* trying to communicate with a civilization on a lower rung of the technology ladder, you don't send your message by subspace parcel post; you send it in some way that the receiver can, well, receive.

  • The vast majority of the database's signals are evidence only of terrestrial intelligence.

    And here I was, thinking there was no such thing as terrestrial intelligence...

  • Future headline (Score:4)

    by joshv ( 13017 ) on Monday January 15, 2001 @07:42PM (#505579)
    Los Angeles - Jan 12, 2347

    After burning through approximately 2.12E678 CPU hours of computer time in over three centuries of existence, SETI@Home is finally calling it quits.

    Their search for extraterrestrials has foundered, producing only a few candidate signals per year, none of which has ever been proven to be of extraterrestrial origin. Says Lars Pendelson, current project president: "Yeah, we just can't see going on when they are more practical applications of the technology".

    Those more practical applications were discovered recently when the SETI@Home team discovered a promising possible alien signal was actually a cell phone call placed by an astronaut on the Saturn space station. Lars comments, "Yeah, we were really pissed about that one - we had the code geeks working overtime decoding that one, only to discover it was some bloak talking dirty to his girl on the Saturn space station. But at least we found a practical application for the technology".

    Beginning next month, the SETI@Home space array and orbital server farm will be redeployed routing cell phone traffic for Mars, Saturn, Jupiter and the asteroid belt.

    Users of the SETI community were understandbly dissappointed that their pet project was going away. The slashdot community in particular was in an uproar, having just recently narrowly edged out Team Microsoft in a heated, centuries long stats battle.

    Lars knows that the user community will be let down, but hopes that they realize that finding ET is an "utterly hopeless and wasteful quest." He continues, "It's just plain stupid to waste all this equipment, when cell phone service in the outlying solar system is so poor."

  • off topic as well, same thing happened to me on Christmas Day. Ruined my DII play disc...luckily, I'm still alive....thought I was gonna die for a sec....scared the crap outta me!
  • Roaming Charges for Saturn's Moons can be as much as $100 for each minute; but You can step up your service contract to include all of the Moon's and half of the Jupiter moon's for only $39.95.

  • Re:seti was fun. (Score:1)

    by Anonymous Coward
    Get off your soapbox. The microsoft execs are GOOD PEOPLE. i may not like there business, but bill gates etc giving away that much money too good causes Would it be better if they kept it all to themselves. And remember, a individual giving away money is different than their respective business. Hell if MS just gave them money, i still wouldnt care. Its not like there are strings attached I guess your opinion is that since they work for MS they cant do anything good.
  • It also assumes that an advanced alien civilization would still use conventional radio for communication. I think if we would check in other areas of the electromagnetic spectrum, we'd be more likely to find activity in ELF bands. Theoretically, you could modulate gravity, and it would echo throughout the universe instantaneously. Now if I had to fax something to Alpha Centauri by 3:00 pm, that's the way to go.

    Oh, and just following the link at the end of your post:

    Moreover, mounting evidence that the GOP stole the presidential election by denying African-Americans their right to vote has created public outrage


    COUGHCOUGHBULLSHITCOUGH...*ahem*

  • I got 6856 hours and counting...

  • There is a lot of activity occuring in distributed computing. This [nyx.net] page has a lot of good info.

    Or use Google [google.com]

  • True... If somebody cared to donate a 5,000 processsor supercomputer to Seti@Home then maybe we could take a more wholistic approach to looking for ET. Of course that'll never happen, but it should be noted that the popularity of Seti@Home far outstripped what the organizers expected. Plus, computers are going to keep getting faster for a good number of years, so maybe a few years down the road, a lot more indepth analysis of the signals could be done.

  • The article says:

    Our search for extraterrestrial intelligence assumes that an alien civilization wishing to make contact with other races would broadcast a signal that is easily detectable and easily distinguishable from natural sources of radio emission. One way to achieve these goals is to send a narrowband signal. By concentrating the signal power in a very narrow frequency band, the signal will stand out among the natural broadband sources of noise.

    Ok, now, if the little green men have a headstart on us, and they are smart enough, why don't WE SMART EARTHLINGS not broadcast to THEM a powerful narrow frequency signal? If our guesses here are right about their higher intelligence, they probably have better resources for computing and will be able to process whatever it is we're sending... And all that, given that some gov body on earth is willing to invest in a project where a signal is being transmitted for over 50 years from earth towards space, and is willing to understand that IF the signal is being received and translated, a response will come in YET ANOTHER 50 years (And notice my optimism about the distance in light years, and in cycles of response!)... well, if such a goverment existed, it would be in Amsterdam, where pot is legal :-)

    My two buckazoids :-)

    Skaag.

  • Re:is this really worth it? (Score:3)

    by bcrowell ( 177657 ) on Monday January 15, 2001 @08:48PM (#505588) Homepage
    how are we going to respond or communicate if they are 150 light-years away
    If "communicate" means a dialog, then obviously we aren't -- it's forbidden by the laws of physics. But even if we lucked out and found aliens 5 or 10 light-years away, the speed of light wouldn't be the important thing. The important thing is that we'd have nothing in common. The galaxy has existed for billions of years, so there's no reason to think we'd both happen to discover radio technology at almost the same time. A randomly chosen intelligen species is likely to be either millions of years ahead of us or millions of years behind us in development. If we were a million years ahead of them, they wouldn't be doing radio. So most likely they'd be so far ahead of us in terms of development that it wouldn't be a two-way dialog where we both have profound thoughts to offer each other.

    Is there any point? Don't be silly. Discovering intelligent life elsewhere in the universe would be the most important intellectual event of the last thousand years.

    maybe we should work on traveling these kinds of distances in space first.
    What's your logic? Radio is fairly easy. Physical travel across interstellar distances is ridiculously hard. The energy required to accelerate a 100-ton space ship to 10% of the speed of light would be about 10^20 joules, which is hundreds of times greater than the entire world's annual energy budget. Sending people to Mars isn't even likely to happen within the next 100 years.


    The Assayer [theassayer.org] - free-information book reviews

  • "....This threshold corresponds to 7.2 × 10^25 W/m2 at our finest frequency resolutions, or the equivalent of detecting a cell phone on one of the moons of Saturn...."

    Holy $hit! thats one powerful cell phone! Nokia's new feature: instant user incineration upon pressing the "send" button. :o]

    musta meant 7.2 × 10^-25 W/m2.

  • INCOMPLETE DRAFT
    NORAD's multiple radar installations give out enough narrow beam radio to be picked up as far as 50 light years away.

    Military radars tend to be wideband. If they actually pointed in one direction in space, the range would go off as the fourth root of the bandwidth. They don't point in a constant direction, so the observation time will be limited. Once you exceed a time of about 1/(bandwidth) the range is proportional to the fourth root of the observation time if you tune the observation time to the in beam time, and the square root if you use a fixed observation time.

    SETI@Home has a bandwidth that is 100s to 1000s of times too narrow to be optimum for such radar (square root penalty, I think) and uses a fixed observation time for the purposes of the above range formulae.

    The power that one has to consider for such calculations is not the peak power, but the average power.

    The one sort of radar that definitely does have the necessary characteristics for detection at well over 50 light years is CW Doppler radar used by Arecibo, Goldstone and others for measuring asteroid orbital paremeters. This has a relatively constant direction (they know where to point from optical observations). It's disadvantage, which it tends to share with other radars, is that it unlikely to produce more than one detection, which means that it can't be confirmed; I think some people suspect that we may already have detected such signals, but have to discount them as one off events.

    All our attempts to send our own messges have used this sort of planetary radar transmitter.

    Listening on 1.42GHz tends to favour intentional contact signals over leakage. Although the SETI@Home configuration can't achieve this, Arecibo ought to be able to detect its own radar transmissions across the galaxy.

  • > The assumption is that ETI would use radio
    > because the laws of physics prohibit anything
    > faster, but if that's true, why would they even
    > bother?

    Well, we have been sending RF garbage into space since Der Fuhrer hosted the Olympics in 193X, regardless whether or not it was feasible to be sending people to Alpha Centauri or it was too far away to really talk to Little Green Men. Bets are that ETI has been doing the same thing as well.

  • I should add, that whilst fourth root for range may not seem that bad, the number of candidates stars depends on the cube of the range, out to a few hundred light years, so the 100 million, or so, bandwidth discrepancy will result in about a million times less chance of detection for the same total signal duration and mean transmit power, compared with a CW beacon at the minimum useful bandwidth.

    The limited in beam time may well further reduce the candidates by a factor of over a thousand.

  • I was modified down to Offtopic for my post? Considering it was "on-topic". Some moderators at /. should get a brain transplant!

    Poof!
  • If our guesses here are right about their higher intelligence

    I don't think that it's valid to assume anything at this point about intelligence of aliens, particularly since if they evolved in an environment very different than our own, their thought processes are also likely to be very different, and may not correspond to our ideas about what intelligence is. Even amongst different cultures on Earth, it's difficult to administer an objective IQ test.

    It would be safe to assume that any aliens that are able to initiate contact with us are more technologically advanced, but that's all. For example, it's entirely possible that even if they possess that technology, they took much longer to develop it that we would have.

  • As long as they don't bounce the signals off our own satellites, everything is okay.

    As long as they don't bounce the signals off our own satellites, everything is okay.

  • So what you're saying is: ET can't phone home?

  • Serious Inter-LATA (Score:4)

    by ewhac ( 5844 ) on Monday January 15, 2001 @07:01PM (#505597) Homepage Journal

    So what are the roaming charges for Saturn's moons?

    Schwab

  • One of these days... (Score:5)

    by eric2hill ( 33085 ) <eric AT ijack DOT net> on Monday January 15, 2001 @07:07PM (#505598) Homepage
    ...there will be a SETI@Home story posted on /. and ET will finally make him/her-self known to the masses:

    ET (ET@QUADRA-5.EAM3002.GALAXY.NET)
    FIRST POST!
    Sorry. Humor for the evening :)

  • Yep the graphical client does sucks. I have a Dual Pentium III 800. When I run the graphical client maximized the things takes 100% CPU - this means it uses both CPUs. When I minimize it, it takes only 50% of CPU. So obviously there are two threads in the thing, one for the calculation engine and the other for display - and each is equally CPU hungry.

    -josh

  • Social experimentation. (Score:5)

    by re-Verse ( 121709 ) on Monday January 15, 2001 @07:09PM (#505600) Homepage Journal
    I think the more interesting thing than the technology behind seti, is the sociology.

    Thousands of people are using it, religiously. I've been running it since it came out, i've overclocked my computer father, upgraded my processor, and even went so far as to install it quietly on the server farm at work :)
    I'm not sure if people are in to it because they Dig feeling like part of the worlds largest computation (information age mob mentality?) or simply because we're incredibly lonely and, more often than not, thourougly dissapointed in the human race. The fact that you have seti at home clubs and organizations, people hold personal meetings to discuss how many work units they've burned in the last month (I guess thats the other factor... what better way to flex your hardcore box), Almost outweighs the fact that you can hear cell phones on saturn... besides, from what i hear, the long distance rates from there are deadly.
  • It's a base station!

    Chris Mattern
  • Fortunately, searching for signals in a data stream from a radio telescope is an easily distributed task. We can break up data from an observation into frequency bands that are essentially independent of one another. In addition, an observation of one portion of the sky is essentially independent of an observation of another part. This lets us divide a large dataset into small chunks that a personal computer can analyze comparatively quickly. In this way, we can distribute the work to people willing to donate their spare CPU cycles.

    Yes, this will catch most signals directed at us. But, what if aliens are sending a composite signal from several stars? Also, what if the aliens are sending a signal whose principle is as yet unknown here, and it occupies nonconsecutive frequencies?

    The point being the data should be examined for more than one kind of pattern, and patterns introduced and/or obliterated by the distribution network should be accounted for.

  • Nothing new (Score:4)

    by perrin5 ( 38802 ) on Monday January 15, 2001 @07:10PM (#505603) Homepage
    This article doesn't seem to go into any real new detail. The only interesting data is that they seem to be trying to expand their search by adding a new telescope. While this is a great idea, the SETI@home project can only do so much crunching.

    The problem to date, to my mind has been that the processing is too front end intensive. This project should do rough curve fitting first (ie do quick calculations on client computers, to find a general idea of the curve) and then select areas of interest to farm out more signifigant data to client computers. But that's just my opinion.

    who knows, with 10 gHz possibly on the way, this discussion may be a moot point as I send it.
  • This project should do rough curve fitting first (ie do quick calculations on client computers, to find a general idea of the curve) and then select areas of interest to farm out more signifigant data to client computers.

    I think you miss the point of the clients in SETI@Home. The purpose of the clients is to do the pre-filtering, so that Berkeley has a manageable number of candidates for subsequent processing.

    The only real curves they have to work with are the curves of event rate against detection threshold, and they had good ideas of those already; these are used to set the reporting thresholds for the clients. They will consider themselves very lucky if they find even one confirmed ET, so they are not trying to construct maps of ET density.

    The original concept [berkeley.edu] did assume restricting the work units to ones from the plane of our galaxy, as those would give the highest proportion of Sun-like stars, but that was when they didn't think they would have enough clients to process all the data.

    Unless and until we have detected several ETs (who may then tell us where to look for the others!) we have no means of calibrating any rules we use to select good candidates.

  • Um, actually you will have a higher power bill when running distributed processing apps (assuming you are running a modern OS) than when you are just leaving your computer idle. This goes doubly true if you would shutdown your computer at night if you weren't running some distributed application. In the long run, from a purely monetary standpoint, those lottery tickets are probabaly a better buy.

  • There is a shared memory interface to a separate graphical display on the Unix version. I have a feeling that the specification for that interface has been published, but I can't find it at the moment.

    Many of the graphical features are available using third party tools, using data in the state.sah file; it's basically only the real time spectrum and the real time amplitude profiles that require a special interface.

  • It doesn't seem like we would get much out of it and it could court disaster. If alien races intercept our signal, then THEY are the ones that receive the knowledge that they are not alone in the universe. They might be afraid to respond. On the other hand, they might be aggressive or deparate for a change of scenery and we just alerted them to our presence. The safer method of searching for extra-terrestrial life is to receive signals instead of broadcasting them. But that leaves the question: If we ever were to receive a signal, would we attempt a response?
  • is there really any point to have this project. even if we find intelligent life (and i am willing to bet that the odds are a LITTLE against us) how are we going to respond or communicate if they are 150 light-years away. by now they probably have forgotten that they have sent the message. maybe we should work on traveling these kinds of distances in space first.
  • Actually...I just run it because I am immensely interested in the possiblity of contact from other worlds. Especially given the sorry state of the various Space Programs of the world today, anything that I can do to aid in the possibility of finding other life in the universe is worth my effort. Besides, what more attraction do you need than the fact that it is free, easy to install, important, and rarely messes with your other stuff. I'd love to see some large corporations and government entities officially adopt SETI as software that is used in their computing environments. Can you image "every new computer deployed to a GE employee will have SETI@home installed"...you could even spin off a SETI@work client :)

    Final Analysis: (Free)+(Doesn't impact my system)+(Important)=(something that I will do).

    But that's just my $.02...
  • So that's what has been happening for 1485 hr 26 min 30.3 seconds on my computer! I was wondering what was going on with that thing...
  • Good question.. this is what the SETI program is trying to find out. That question is like asking "can we go to the moon" around 1930. Many people seem to think it's possible, and have theories to support them. Many don't, and have theories to support their positions as well. Obviously in the 1950's it was pretty clear that we could, even without actually accomplishing the feat, changing the problem from one of theory, to one of engineering.

    I really don't think that SETI will find any signals (note, this is a nearly completely groundless position, based solely on gut feeling). I also think that it would be criminal to miss a chance to communicate with another intelligent civilization, simply by not listening.

    Doug
  • There is a nifty little utility that does just that and more...

    It is called SETI Monitor and is listed on the main SETI@Home site under Related web sites - Add-ons for Windows clients.

    You can get it at http://users.surfree.net.il/l.fainshil/

    I am sure there are tons of other utilities that do the same thing but I like this one.

    SETI Monitor displays a graph of the the spikes and gaussians found on the work unit currently being processed along with the estimated time left, estimated total time for the WU and other technical information taken from the state.sah file.

    It also remembers all your past work units with all the above stats for each and can display a summary page of all the spikes and gaussians you found since it has been running.

    I've been using SETI Monitor for a few months now and although the information it displays is interesting in the beginning, it slowly becomes almost as boring as the screensaver graphics. But I still like the feature where it keeps track of all the WUs that I have processed (and you can GREP through its list of old result files to do your own stats).

    Happy crunching.

  • Might this not be due to the fact that the telescope is a passive instrument, and does not put out any sigificant signal of its own?
  • am i the only one who thinks that seti@home is the biggest waste of cpu cycles ever?

    it's immensely popular because:
    1. it was the first popular distributed project that was more easily understood by the public than breaking some 64-bit code.
    2. communicating with aliens has been a primary theme in science fiction in the last 100 years
    3. many so called spiritual people have turned from believing in the Supreme Being to superior beings.
    4. X-Files

    there's no doubt there is/was/will be intelligent life out there. but i think it's much rarer than most people think. the incredible series of events that created intelligence on earth is staggering in complexity and randomness. granted, there are probably many other random even paths that lead to intelligence, keep in mind that intelligence itself is not evolutionarily stable. it's a strategy a small part of the animal kingdom happened to stumble across here on earth but it was all luck that allowed intelligence to survive. if it wasn't for a couple of well timed asteroids, the proper amount of radiation, etc. the world would now be owned by insects (and maybe one day it will) as they are the most efficient form of life on the planet.

    so lets assume that intelligence is needed in sending a coherent message that we can detect. how long have we, as the human race have had the capability of generating radio waves. a century perhaps?

    if the universe has a finite age, we can assume that the development of intelligent life took some window of time and it's not an unreasonable assumption that any intelligent life in the universe had only evolved to the point of sending radio waves in say the last million years.

    and here's the kicker. how long will an intelligent lifeform survive? we have come close to wiping ourselves out several times already. every year more ways of wiping out the intelligent population on our planet are developed. if anything, we're more at risk because most of us have relaxed since the end of the Cold War. how long do we have? lets say 400 more years before something catastrophic happens (i think further out and that and we may have settled enough extra terrestial worlds that we'll make it, but that's a big if).

    we have to assume that other intelligent races will face similar problems as we do, intelligence came out of competition, after all, so do wars and tribal/religious persecution...

    So lets say the average window during which an intelligent species can broadcast a meaningful radio message is 500 years.

    combine this with the time to intelligence mentioned earlier and we have a very tiny portion of space that SETI can cover considering the limitations of light speed.

    and this is assuming that the intelligent species that happens to be in the perfect region actually bothered to develop radio waves in the first place (or equipment that sends radio off as a side effect). not every atmosphere will bounce radio waves the way it does on earth, maybe our otherwise perfectly located race never needed radio, they developed a different communication system (light based) or have ESP or something.

    my point is that yes there is life out there, but this seti@home project is a pipe dream. we are using billions of cpu cycles for something it may be impossible to find. ever. and think of another thing, 99.9999999999999999999999999% of your these precious cpu cycles are used to analyze completely random noise. at least if the seti@home shared their cpus with other radio astronomy projects, that would be cool.

    use your cycles at folding@home or similar projects instead. every work unit is meaningful and the possible results of f@h have the potential to be immediately useful to humans now.

    i don't expect seti@home to go away, but i do wish people would stop caring less about the stats and get off the et kicks and realize that crunching useless data is still the same as not using your cpu idle time at all.

    there are other distributed projects that are much more meaningful but can hardly get started because of seti@home's success which is mainly driven by media and the recent infatutation with the super natural into which et's fall for some bizarre reason...

    --
    j u l e s @ p o p m o n k e y . c o m
  • It makes me wonder, and i'm sure i'm not the only one, is Seti@Home real, or is it running cpu cyles on my machine to bog me down, and to give me a really neat screen saver? I have about 500 units now, running it for more then a year, I've never seen anything cool about it. The only reason I still run is to complete against my friend, for units.

  • it just dawned on me. (Score:4)

    by fudboy ( 199618 ) on Monday January 15, 2001 @09:01PM (#505616) Homepage Journal
    I know seti@home has been rather popular, but I see from some of the posts here, as well as many friends & co-workers, that people are growig bored with the client. there may have been 2.1M volunteers, but I'm sure a fair percentage, if not a majority, have dropped off the seti wagon in favor of other screensavers.

    that's not to say SETI@home isn't doing great, I hear they've even been in the situation of not having enough work units to send out, but this whole project could be made into something much bigger, much grander.

    I sure S@H could be looking at this data with more precision than they are currently, through numerous refinements to the search criteria and formulae. The limit is only in how many cpu cycles they can reliably expect. I believe the volunteer membership base could be doubled with one very minor refinement to the graphical client: by briefly blink-highlighting canditate signals in the 3axis bar graph gizmo. The article mentions that they've accumulated 1.1 billion candidate signals to date. You can be relatively certain that if you've completed even 1 data unit, you found one of these signals.

    It seems to me that the eventual boredom with the SETI@home client is due to the almost complete dearth of feedback or accomplishment. the information displayed on the client is interesting, but it changes very slowly and in a completely predictable way. The simple psychological reward of blinking a triplet or a phased pulse when a canditate signal is hit would go a long way towards providing the rewarding sense of accomplishment people seems to be hoping for out of this project. This simple new feature would not interfere with the science and hardly slow down the typical cliet computer, so I say please!~ add this feature!

    :)Fudboy
  • Good !
    Now everyone get out of this SETI sh** and run the www.distributed.net client !

    Yours,

    Matador
  • Argh,,, do you know anything about the way overclocking and the whole chip manufacturing process goes? Overclocking doens't break data, it Can lead to system instability, through heat buildup, but a heatsink and a nice fan will fix that. But geez.. it doens't bloody scramble your data. I hate computer wives tales.

    As far as my employment. I'm system administrator... and the guy with the money (I hate the word boss) has seen my little seti farm, and told me "let me know when you catch any ETs"

    So feh to the first part and feh to the second part.
  • Well, success could either be measured by successful detection of an ET signal or by the sheer amount of computing that has been done. In this case it's the latter. In the article they note that roughly 4.3 x 10^20 flops have been performed in the name of S@H using more than 500,000 years of CPU time, which is a major computing landmark in and of itself.

    As for successfully finding a signal, they do mention that postprocessing has yet to move into full gear. Even when it does start, it usually takes several years to complete (at least based on the timeframes for other SETI projects).

    One interesting idea I've contemplated is that S@H and other similar distributed computing projects have actually had a positive effect on the technology sector of the economy. Without a doubt, there are people that care only about their stats, and are willing to purchase faster machines in order to boost their stats (and hence create a bit more demand for hardware). Given that there are over 2 million participants, this effect adds up. I'd be curious to see estimates or a study on this matter if anyone knows of some.

  • You know, that's pretty damn petty.

    Do you think a SETI project would turn down anyone who wanted to give to them? Considering the difficulty SETI projects have getting funding, I'm sure they're happy to take the money.

    If you really think that giving money to SETI@home is part of Paul Allen's/Microsoft's plans of world domination, then you are a sad, sad, person.
  • Being able to detect a cell phone as far away as one of Saturn's moons is actually pretty lame. Remember, the intercity of a wave in space is relative to the square of the distance. So, if you tried to find something a thousand times the distance of Saturn to earth, it would be a million times weaker. Saturn is only about 1/14,000th of a light year away. IIRC the nearest star is about 10 light-years away. So, in order to year a signal from there, you would need a transmitter about 140,000^2, or 19 billion times as powerful as a cell phone. Take that out from 10 light-years to 100 and you'll need 190 billion times more power then is used in a cell phone.

    I don't know how many objects exist that close to earth, but I don't think its that many. While there very well may be something out there, sending signals, I seriously doubt that it will ever be picked up by seti at home.

  • Re:seti was fun. (Score:1)

    by Anonymous Coward
    better format all those machines then. Paul Allen not only contributes to the SETI institute, he also pays Linus's salary. Yep, he is one of the major investors in Transmeta, every slashdork's favorite soon-to-be failed startup.
  • That's a good idea, but there are a ton of dreamers (such as myself) that will continue to plod away and use SETI regardless of the feedback I receive. Bluntly, I use SETI completely in the background (no screensaver), and run it all the time. To me, it's more important the feeling knowing that I am a part of a larger whole, and working on something that I would really like to see happen within my life. Just the proof that intelligent life exists, just the little part that I play in the search, is meaningful to me. And besides, it's not like I am using those cycles for anything useful, now.

    As the song goes:

    "So remember, when you're feeling very small and insecure
    How amazingly unlikely is your birth
    And pray that there's intelligent life somewhere up in space
    Because there's bugger all down here on Earth"
    --"The Galaxy Song", Monty Python's Flying Circus
  • If they could, then we could hack it and add cool things like the very neat idea you mentioned, and probably some other goodies as well.

    TomatoMan
  • Wonder how they got up there, maybe an agressively telco looking for new markets ?
  • I doubt an alien civilization is going to broadcast the most complex way possible if it wants to find people. Chances are if they're using complex algorithmic frequency hopping or encryption, they aren't broadcasting "Hi, here's our basic math system" anyway.

    Daniel

  • Assumptions (Score:3)

    by jaysones ( 138378 ) on Monday January 15, 2001 @09:26PM (#505627)
    You know what's funny- I've been running the client for a long time and it never really struck me to learn how SETI works. I only understood about 50% of that article, tops. However, it made me think of a really cool aspect of the Internet that hasn't struck me before: SETI is a great example of how the Internet can put really smart specialists (them) in touch with interested, but uninformed resources (me), and work that relationship towards a really cool goal.

    Conversely, I realized that I could have been easily hoodwinked by a great sounding operation that I understood (basically) only on faith! I guess the lesson here is caveat downloader!

  • "Without a doubt, there are people that care only about their stats, and are willing to purchase faster machines in order to boost their stats (and hence create a bit more demand for hardware)."

    Nah we wouldn't do that would we. ;-) And if the computer isn't fast enough we overclock. 5799 units, 4111th place, more than 99.847% of the users
  • Any plan to get aliens to give us hyperspace technology , so i can become a star fighter piolet for real in my spare time , is a good idea, but if we contact a race like the borg , then i would like to take this time before i join the collective to say " SETI sucks , you pasty face troll nerd wankers , you owe me a private conscience "

  • I do the same thing. I've even set my ol' celeron 400, and my machine at work too- but I am a sad-sack sci/sci-fi buff.
    These things are expected of me.

    I was thinking more of my co-worker dullards, always fickle and finicky for the latest eye candy. those bastards.

    :)Fudboy
  • And by keeping the computers active it cuts down on the heating bill. 8 computers X 200 watts = a lot of heat when their overclocked.
  • Err, I think it should be date line, "Los Antis", depth 20 fathoms.

    Rather than improve the efficiency of the client program, the "SETI@home", the authors decided to waste more and more CPU cycles performing useless math operations. The net result, is that the ice caps melted back in 2089. The cause of the melting was traced too an effort to supply domestic energy for billions of consumers computers running the version 38.5 "SETI@home" screen saver.
  • I fully support SETI@Home, however I don't think SETI@Home (or any of our current search techniques) are going to be successful.

    A few quick assumptions:

    1. We do not understand everything there is to understand about physics.
    2. Any alien civilization out there capable of communicating beyond their planet is most likely far more advanced than us.
    3. Any alien civilization far more advanced than us will have a better understanding of the laws of nature than us.

    Leads me to believe that they would have developed a means of communication by now that we haven't even thought of. If they're capable of traveling faster than the speed of light (for all you UFO buffs out there), they must ALSO be capable of communicating faster than the speed of light.

    That means they definitely are NOT communicating via radio waves.

    So what could they be communicating with? Perhaps they open up mini wormholes and send signals through those. Perhaps there's yet some force of nature (specifically type of signal) we have not yet detected [insert Star Trek signal name here]. Or maybe they're using something like quantom entanglement (http://www.qubit.org/intros/entang/).

    I imagine that IF these aliens exist, one day we might just suddenly open a floodgate by tapping into their version of the internet. We just haven't figured out how to do that yet. Or they don't exist, or they do exist and they're so far away and physics is so limiting we'll never find out they do.

    Whatever it may be, I doubt radio is the source, but as someone said above, it'd be almost criminal to not look.
  • IIRC the nearest star is about 10 light-years away

    Actually, it's a bit closer than that - about eight light minutes. But perhaps you're thinking of Proxima Centauri, which is about 4.6 light years distant.


    ---
  • I'm thinking that some of this may be competition based- "My box completed 300 units, how many has yours?"

    This coming from a seti user with 35 units....

    ... the psychological analysis is staggering! :)
  • That was pretty early on in the project, and I think some redundant error detection was warranted.
  • "Our search for extraterrestrial intelligence assumes that an alien civilization wishing to make contact with other races would broadcast a signal that is easily detectable and easily distinguishable from natural sources of radio emission."


    Does anyone have any idea if there are any projects in which we are transmitting this kind of signal?
  • Don't be fooled by the article. Those guys aren't really the founders. Here's the real scoop from the REAL seti founders:

    QIn'latDaq jevwI'

    QIn'lat veng jaHtaH jevwI'
    veHnaghmeyDaq QanmeH nejta' ghotpu'
    'ach Hur ratlhta' wa' loD
    ghaHDaq jaHta' qeylIS' 'ej jatlh nuq bIvangtaH
    mughIjbe' SuS jatlh nagh ruSwI' je vISo'be' qabwIj
    SuSDaq vIQam 'ej muvuvmoH 'oH
    batlh Qochbe'ta' qeylIS 'ej vengDaq jaHta'
    jajchu' ghoSpu' jevwI' 'ej loD HoHpu' 'oH
    ghotpu' jatlh qeylIS qoH vuvbe' SuS

    --Shoeboy
  • Assuming the money thing is true, how is that any fucking different from having a Win32 port of the client?
  • The real importance of detecting a single alien signal is to start a new global war economy, we must be prepared to fight back the bad aliens, right? imagine how much cash NASA would receive for the space program, imagine how much cash would be available for the nations so they can do they own research. I don't think answering the real question "Are we alone" is the point.

  • good description, but... (Score:3)

    by neuroslime ( 304931 ) on Monday January 15, 2001 @07:15PM (#505643)
    This article is a very nice description about what seti@home does, but the question is: Does it even have a chance of working? The assumption is that ETI would use radio because the laws of physics prohibit anything faster, but if that's true, why would they even bother? Most likely they would be too far away to really talk with wouldn't they?
  • Their damned cell phone wouldn't work a block from the store I bought it in. (I know the store location has nothing to do with tower positions, but still, it's the principle of the thing).

    -josh
  • >about the time i hit 1000 data packets processed, i learned that they were accepting money from the co founder of microsoft.
    >
    >that's a little like taking maney from organized crime...so i pulled the plug/couldn't care less now.

    Just a nitpick, that's the SETI Institute (Project Phoenix) which received the money from Allen. For a complete list of all of the *SETI@home* corporate/individual sponsors, check their front page and donor list. Project Phoenix and SETI@home are not the same.
  • Let's crack useless encryption keys instead!
  • It seems to me that the eventual boredom with the SETI@home client is due to the almost complete dearth of feedback or accomplishment. the information displayed on the client is interesting, but it changes very slowly and in a completely predictable way.

    Yeah, I always thought they should add an "ET Counter" that displays the total number of aliens your computer has found so far!

  • are WE transmitting at 1450 Mhz? (Score:3)

    by Barbarian ( 9467 ) on Monday January 15, 2001 @11:57PM (#505657)
    So, I wonder, are WE transmitting a repeating signal at 1450 Mhz or near it? If WE are not transmitting a distinguishable repeating signal near 1450 Mhz, why would we expect anyone else to?
  • "Wait! There's something coming through in the harmonics!"
    "What is it?"
    "It's hard to say, I can only decode one letter at a time. I'll send them to the screen."
    YHBT, YHL, HAND.
    "But what does it mean?"

    dave
  • One of the interesting things I read on the SETI FAQ page was the fact that the current SETI project would not be able to dectect the Radio Telescopes that it uses to pick up the foreign signals!
  • 'm not sure if people are in to it because they Dig feeling like part of the worlds largest computation (information age mob mentality?) or simply because we're incredibly lonely and, more often than not, thourougly dissapointed in the human race.

    Despite us living in a very individualistic era, the human instinct generally is to band together into packs. How this manifests itself in an intelligent species is an unquenchable desire to "be a part of something larger than yourself" - such as taking a small piece of an incredibly large computational puzzle. The rewards, when they come, will be enormous, and shared by us all. Until then, we can band together and dream...

    Darnit, it looks like the Internet might be good for something after all.

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