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SETI@Home Adds New Search Method
Adam Korbitz writes to point out that SETI@Home has added a new algorithm for use in evaluating signals from outer space. It's called "Astropulse," and they've made the scientific details available. Quoting:
"The original SETI@home is narrowband, meaning that it is listening for a particular radio frequency. That's like listening to an orchestra playing, and trying to hear when anyone plays the note "A sharp." Astropulse listens for short-time pulses. In the orchestra analogy, it's like listening for a quick drum beat, or a series of drumbeats. Since no one knows what extraterrestrial communications will 'sound like,' it seems like a good idea to search for several types of signals. In scientific terms, Astropulse is a sky survey that searches for microsecond transient radio pulses."
I find it slightly surprising it has taken the SETI project how many years to start checking broadband as well as narrowband signals. All those years spending a fortune in resources but only checking narrowband seems rather a waste of time. I would have been checking all sorts of broadband signal types from the very beginning.
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Haven't we already covered this? The cost in electricity for them to use my "unused" resources is not worth it for SETI which offers and most likely will never offer any tangible benefit to our society.
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As the information in a radio signal approaches the Shannon limit, it becomes indistinguishable from noise to an outside observer. Any sufficiently advanced civilization will have the technology to maximize the information sent in a radio signal. Therefore we will not be able to detect radio signals from other civilizations (except for perhaps a 100-200 year period in their evolution where they use inefficient radio signals)
Strange that they are only doing that now - haven't they seen Contact?
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Except for a huge assumption you're making: that an advanced civilization wouldn't want to broadcast a distinctive, easily decoded, narrowband signal. Perhaps they might want to do it to announce their existence to the rest of the universe, even though they would have the know-how to sendmuch more efficient broadband signals.
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If the alien really IS Jodie Foster's father.
No mod points, no meta-moderating/Firehose/all the other free work Slashdot wants me to do.
You now have the option to filter out aliens who might want to probe you.
If I wanted to send a signal across the universe, I'd use light, not radio waves.
So, why is SETI still limiting itself to searching for signals in the radio spectrum?
If the point is to find radio beacons from alien civs looking to be found the odds of that are near zero. Darwin is everywhere. Only the paranoid survive.
As a musician and a recording engineer, I feel I must comment on the analogy used.
For someone with a trained ear picking out an A#, or any particular note, shouldn't be all that difficult, especially if that note is tonic, 3rd, 4th, 5th, or other similar high recognizable interval from the tonic. It would be trivially easy for someone with perfect pitch to pick out a particular note.
I suppose the analogy might hold if we compared the prior SETI searching signals to be like a man who is deaf in his right ear turning his left ear away the orchestra to try and determine if the 2nd piccolo is playing sharp on A#, and now, SETI is that same man, facing forward with a brand new hearing aid, merely trying to pick out staccato notes.
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... same results? Given their vast historical success in their endeavors (/sarcasm)... I'd bet on it.
Thump...Thump..Thump..
I wonder if they should look for styles of rythms. Dance, hip-hop, etc.
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I wonder if similar detection rates have been calculated for SETI (e.g., assume ET having a transmitter of 1 MW, at what distance would you still detect anything? And how many life supporting planets are in that range? ) This will depend a lot on the parameters in your Drake's equations, but they should at least give some order of magnitudes. I remember reading some skeptic article several years ago, which claimed that even with optimistic estimates, the chance of detecting anything would be absolutely zero.
Until that time, I rather waste my computer cycles on the LIGO data (Einstein at home) or one of the various medical applications (e.g. Folding at home), which produce scientific results today.
karma police: arrest this man, he talks in maths; he buzzes like a fridge, he's like a detuned radio. [radiohead]
Guys and Dolls, aliens are certainly interesting, but I want to remind everybody that there actually exist projects you may donate machine time to, projects whose results might be more immediately useful, such as folding@home (folding.stanford.edu). Cheers, PB
Do they still gots that 'leet screen saver that looks like it's doing important stuff, so that when the babes come by your cube, you can impress her by saying you are searching for extraterrestrial life, instead of living a pathetic life of sheer misery?
As a moral Atheist, I take particular offense to this. Believing in a personified God figure who watches and judges may be really useful for the sort of people who need it, but some of us happen to feel a natural impulse to do good, which I feel is instilled in our nature.
The key is to see people as your brothers, sisters, children, parents... everyone part of your family, and to learn to love them despite differences.
You don't have to feel imposed upon by a Daddy God to be a good person, and in fact I would argue that a person who requires Daddy God to keep them in line is probably not very in touch with themselves.
You may have noticed that most species are wholly moral, they don't live hedonistic lives, and they love and care for their young and other members of their social group without need of intellection about imaginary Daddies. This should convince you that there is something innate in all animals, including Humans, that makes it possible - perhaps even imperative - to be moral beings.
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Does anybody else find it ironic that we are looking for intelligent extra-terrestrial communications on the very same frequency that we (an intelligent species) are prohibited from transmitting on? The 1.420 gigahertz frequency was chose (I believe) because of the hydrogen line. It would seem to me that a more effective methodology would be to do a spectrum sweeping search. The odds of any intelligent species transmitting on just one frequency are unlikely enough. Combine that with the fact that we are only listening on one frequency. Now we can compare finding a needle in a haystack as trivial in comparison.
...In Soviet Russia!
-- thinkyhead software and media
The problem with a tight beam is that although you may get further, you only get one narrow beam that's unlikely to be crossed. A radiant energy is far more likely to be detected if it emanates in all directions.
So, combine your tight beam with continuous oscillation in all directions, and then you've got something.
-- thinkyhead software and media
If SETI ever detects a real, verified alien signal, as soon as I hear the news, I'm going to drop whatever I'm doing, and rush to see the comments on Slashdot. I can't imagine what the response would be if a project so (apparently) universally hated here actually turned up a positive result.
Not that I run SETI@home, plan to, or expect an actual SETI discovery to happen in my lifetime, if ever. It's just something on my "wouldn't it be funny to watch if..." list.
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Yes, but is there any alien life? Certainly there's been no evidence of any, though you talk as though it certainly, and inevitably, exists. It sure sounds like you are the one making assumptions and promoting a faith based argument!
And as for this changing anyone's beliefs, that's highly debatable. Christian author CS Lewis wrote a trilogy in the late '40s that imagined intelligent life to be on both Mars and Venus. He was a noted apologist and theologian for the Christian faith, and he had no problem with considering the existence of extraterrestrials. (Note: The starting book of the trilogy was called Out of the Silent Planet).
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SETI is a gov't dis-information campaign. http://www.v-j-enterprises.com/sfufovsseti.html
SETI is "listening for aliens," yeah, right! Like Howard Hughes' old Glomar Explorer was mining manganese nodules? The SETI paradigm is so implausible, given the rate at which noise to signal ratios approach infinity as distance from Earth approaches two or three lightyears, that it seems far more likely that all those SETI@Home screensavers are doing something else.
If Ed Mitchell is right, they're listening for the return of the Mother Ship coming back to Roswell to pick up the survivors, and we'll be lucky if we notice it coming through the Oort Cloud.
My personal guess is more mundane. All that distributed processing power has been harnessed to help Echelon listen for Al Qaeda.
SETI is absurd on the merits, though. If aliens are out there, if aliens are advanced, if Einstein was right and quantum mechanics is righter, why would aliens use something as feeble as the electromagnetic spectrum? They're probably doing something we can't even imagine, like knocking on the walls between universes.
``Tension, apprehension & dissension have begun!'' - Duffy Wyg&, in Alfred Bester's _The Demolished Man_
SETI, as primarily currently pursued, is unlikely to find anything. I sum up my perspective, "We don't talk to nematodes and *they* don't talk to us." It is useful to consider the difference in intellectual capacity between humans and nematodes is far less than that between Matrioshka Brains and us.
Most advanced extraterrestrial civilizations are going to be far far ahead of us. At the point where they have constructed Matrioshka Brains. The intellectual capacity of an MBrain is roughly a trillion trillion times that of a human brain. They can simulate the history of entire humanities in seconds. We are simply not of interest to them.
There are 3 ways to detect MBrains.
1. Stellar occultations (similar to some of the exoplanet searches now being done).
2. Gravitational microlensing studies (also being done).
3. Large scale mid-to-far IR surveys looking for bright IR objects that do not appear to be visible (not being done because our far IR detectors are extremely poor and not particularly sensitive; and they must be operated from space so they are $$$).
The observant will note that none of these involve using computer cycles for the analysis of radio wave noise. The astronomer geeks will notice that long term backyard surveys searching for exoplanets using variations in stellar brightness might either capture candidate stars with exoplanets or perhaps an occasional gravitational microlensing event or maybe an MBrain traveling through the galaxy on its way to the nearest carbon white dwarf star (because they need more carbon for extreme nanotech) or a stellar gas nebula for a fueling pit stop. The extremely astute might notice that should sufficient numbers of these be discovered then there might be another explanation for all of the "dark matter" which doesn't result from the physics of the universe but from the natural activities of intelligent life. (Perhaps making the theoretical physicists extremely unhappy.)
It is also the case that to scan large fields of stars for variations in brightness and separating the normal variable stars from those which are "unusual" would not be a small use of ones spare computer time.
Some product manager at Astroglide is seriously pissed off that the name of the new line of Astropulse vibrators just got ripped off by SETI.
I would guess, based on human usage, that if SETI intercepted an alien signal it would have a 50% chance of being alien porno.
Everyone knows extraterrestrials communicate the cosmos with neutrinos. Why waste time with RF?
...must we sift through all those old tapes?
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Ants; wars.
Pigs; cannibalism.
Apes; deceit.
I know it sounds like I'm trying to refute your example but these exceptions prove even animals can be immoral.
So it's imperative WE be moral. It's what separates us from animals, after all...
No matter what SETI uncovers, beliefs will adapt.
I just hope we find the way before something ends us as a species.
If it is all to have meant anything, we must get out of here and spread across the cosmos.
Precisely for the reason that if we ARE alone, it is our destiny.
And if we are NOT alone, we must take our place and preserve (and spread) our culture.
I don't believe we can acheive this unless our cause is just, and even then, it's going to be tough.
I don't know the meaning of the word 'don't' - J
Well, that's progress. I've criticized SETI@Home for looking for "carriers" signals with a large fixed-frequency component. They need to get beyond that. AM and FM signals have carriers (Analog TV is AM video with an FM audio subcarrier), and as a result, 80% of the signal energy is wasted. None of the more modern digital transmission systems have strong carriers.
The more efficient a transmission system, the more it looks like white noise if you don't know how to decode it. If there's some big repetitive component like a carrier, or the horizontal and vertical retrace intervals in analog TV, it's inefficient. The FCC wouldn't approve any new transmission system which wasted bandwidth like that, and the old ones that do are being phased out.
So SETI systems that look for carriers are looking for civilizations advanced enough to generate high-power RF signals, but not advanced enough to use more efficient digital modes. Our civilization went through that period in under a century. It's also fairly clear that nobody in our stellar neighborhood is continuously sending a strong RF carrier in our direction; that's been looked for.
Question: can the new SETI algorithm pick up an HDTV broadcast station?
Quite the opposite, it will fuel existing movements, and as well as start new ones, such as: Raelians, Heaven's Gate and many other alien based religions.
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if you want to do something useful with you wasted cycles (IMO)
SETI is not looking for 'leakage' transmission.
At this point in our own development it's unlikely that a civilization substantially more advanced than ours could detect our *own* leakage signals from interstellar distances. A strong obvious leakage signal is wasted energy.
Instead SETI is looking for intentional beacon signals, presumably ones designed to be easily detected and made by civilizations where energy is a few orders of magnitude less costly than it is for us.
Mostly SETI has looked for continuous signals on the microwave hydrogen line with the rationale that it would be a good frequency to put a beacon on because any one performing radio astronomy will be looking there. They've also been mostly looking for continuous carriers with the assumption that continuous carriers can be averaged for long spans of time and picked up out of the noise floor.
Now they are also looking for pulse like signals, the rationale being that with a given energy budget you can get higher above the noise floor using a pulsed signal... and that few natural phenomena have pulsed output.
So yes... what SETI has done in the past isn't optimal for the hopeless task of catching leakage current.
As to why we haven't found anything yet, we only need to consider ourselves: It would be completely reasonable to spend equal amounts of money on both SETI transmission (running our own beacons) as reception, yet we only do reception. Only for a few brief moments in the history of man have we produced beacon signals that we would have had any hope of picking up ourselves from another solar system. It may well be that the universe is chock full of intelligent life which are all listening but none speaking up.
For a long time I have looked at SETI as doomed to failure... and not because there isn't any intelligent life out there. Here's my reasoning. In the history of the human race, how long have we had radio? Slightly over 100 years.. that's a tiny portion of our over all development. And we can not say that we will still be using the technology 100 years from now. Just as the horse and buggy was the height of technology, the automobile came along and replaced it... and this would not have been anticipated by people in 1800. So we may be looking at a relatively narrow window for use of this technology. So to go along with this you would have to have intelligent aliens who are at a similar stage in development to us.. not too early as to not use radio waves and not beyond the technology. Consider that there are planets and stars much older and younger than our own, and even on our planet how many waves of life there have been, the odds of finding alien life at just the right level of technology would seem to be unlikely.
Am I the only one that thought the last line, "In scientific terms, Astropulse is a sky survey that searches for microsecond transient radio pulses." was easier to understand, in its brevity, than the supposedly layman explanation preceding it?
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probably a "black" project anyway. I doubt at the core if it really has anything to do with aliens.
So they'll be able to find nothing even faster...
someday I will discover aliens with SETI@home while I play world of warcraft. then the beautiful alien women will come down to earth and take me away from my evil manager at Arby's