Im pretty sure they send the original work package to several users, just in case that happens.
-Fox
The big SETI@home database keeps track of all the work units that it has sent out. It doesn’t delete the work units from its local hard drives after sending them out so it’s not as if the work units are lost to SETI@Home once they go out the TCP/IP pipeline. I’m not sure what they have set the “time to live” for exactly but I’m sure that’s how they do it. If you don’t send back the work unit within X days (30 days would probably be a pretty safe number to pick) the work unit is sent out again to another user. This is a pretty basic consideration for distributed computer projects like SETI@Home.
bernse - SETI has a copy of what they sent you. So it’s not lost. In fact, when you send your results back, they compare it to what they sent you to make sure you didn’t hack the program and create a false signal or something. I can only assume that they would resend it if there was no reply from you after a certain amount of time.
Foxfyre - IIRC, SETI looks for signals that are obviously from an intelligent source through pattern recognition. An ET signal would be something that is repeatable & cannot be created through any known natural phenomena. There are other criteria SETI uses which I don’t recall right now. Try checking their website. As far as the meaning goes, it would be amazing enough just to know that they’re out there. That is the first question and primary goal of SETI (“do ETIs exist?”). After that, we can worry about translation.
MEBuckner - good question. Not sure. It seems like spectrography is better suited to elements or simple molecules rathar than complex stuff like CFCs. Not to mention that, if like our atmosphere, the concentration of CFC would be lower than oxygen and harder to detect. But maybe it can…anyone else know?
Chronos - True. Especially for gases that are out of thermodynamic equilibrium like oxygen & methane in our atmosphere.
BTW, (sorry if this was already mentioned) SETI is also looking for optical signals (directed lasers) in addition to radio signals. An optical signal would probably be one that was intended to be a signal for other intelligences (it is a directed source) whereas a radio signal could be directed or incidental (like our tv & global communication signals that also happen to be emitted to space).
They also send the same work unit to multiple users for purposes of validation. They were worried about people cooking the results or using suspicious floating point optimizations on their machines, so the easiest thing to do is send the same thing to unrelated users and check that they got the same answers.
I have not heard of this, very interesting. Do you have a link?
IMHO we will not find any ETI signals until we discover a faster way to transmit/recieve signals, if any way is even possible. For all we know we could have ETI messages slicing through our bodies right now, with no way to know it.
An Astronomer Physicist predicted we will find a faster way to transmit data within 50 years (this was around 10 years ago so its down to 40, and it was more of a bet with a colleague than a prediction, but close enough). He even had a theoretical way we would do this. I wish I had a cite, but I saw it on a NOVA program many years ago. If anyone has a link, please provide it. (BTW, the same guy had several other predictions that came true)
-Fox
Does anyone know if that ‘data’ they show is the actual data its processing or if its just there for show? It seems to me like its the same graphs, etc over and over and over again.
Also ddoes anyone know a link to an explanation of what those graphs mean?
-Fox
My question: many years ago I read a book by the late physicist Dr. Dan Q. Posin. I believe that he was a professor at the U of Chicago, and was a popularizer of science in the 1960’s and 70’s. Anyway, his book speculated on the chances of finding alien life, and he made reference to the natural oscillation frequency of the hydrogen molecule (forget what that frequency is). He reasoned that an alien civilization wishing to make contact with its neighbors would use an easily recognized carrier frequency for its message. My question: the current SETI project-is it searching all RF frequencies, or his the hydrogen frequncy still the main one being searched?
I actually
wrote Dr. posin (while in grade school) and received a very nice letter from him! Unhappily, i no longer have it.
I dont know, but my SETI @ Home client lists a base freq. of 1.421103516 GHz This could be just the base freq of my work package, or the base freq of all of them. Im guessing its just mine.
-Fox
It’s supposed to be real data, and it does look different sometimes. The seti project page has a full description in the links underneath the “Science” section of the home page:
http://setiathome.ssl.berkeley.edu/learnmore.html
Look under “Screensaver Graphics Explained”.
Sorry for the hijack, but I work at a distributed computing company called Entropia, and we run a non-profit charity program called FightAIDS@Home that does molecular binding studies of 3-D molecular structures against HIV protease to find new drug leads for the Scripps Research Institute.
It’s pretty damn cool, but of course, I’m a little biased. I really liked SETI@Home when I first found it, but decided I’d rather donate my spare cycles to a problem on THIS planet rather than somewhere else in the universe.
And as for all the scheduling complaints about SETI, ours works only when you set it to, and can work ALL the time during those house by checking for spare cycles every 1/100th of a second (not just in screen saver mode) and backs off when you need more power so it is totally transparent. In short, you donate a lot more time to an awesome cause. I’m actually surprised SETI hasn’t moved to this dynamic processor use and scheduling model. Like SETI, we also redundantly send out work if a task times out. If anyone’s interested, I’d recommend checking out:
http://www.entropia.com/join.asp
Again, sorry for the hijack but I love working here, and the more people that join this network, the better the job sceurity for me!