Questions about running the SETI@home software
Questions about SETI@home science
Questions about SETI in general
General questions about SETI@home and getting started
You'll need a computer with at least 32 MB of RAM, 10 MB of disk space, and an Internet connection (dialup is OK). You can use SETI@home on a laptop that is connected sporadically. We plan to support Win95, Win98, WinNT, Mac, and many versions of UNIX, including Linux on various CPUs. We hope to eventually support other systems such as OS/2 and BeOS. We won't support WebTV. There are no CPU speed or modem speed requirements. It doesn't matter where in the world you live.
No. All you need to do is download and install the client software.
About 5 minutes over a 28.8Kbps modem.
SETI@home connects only when transferring data. This occurs once every few days and lasts for about 5 minutes.
SETI@home uses a lot of memory while it's running, and it would cause swapping on some computers. We want to make sure it has zero impact on your normal computer work. So, for PC and Mac, the default mode is screensaver.
However, if you already have a favorite screensaver, or prefer not to run a screensaver, SETI@home can also be run as a background program that computes all the time and has no graphics. The UNIX version works like this.
It's not currently fast enough, and there are lots of system-dependent details that we need to handle in C.
The screensaver will be available for download only from our web server, and it will upload and download data only from our data server. The data server doesn't download any executable code. All in all, the screensaver will be much safer than the browser you're running right now!
Not the initial version. Maybe a subsequent one.
We decided not to make source code available for security reasons and for science reasons as well. We have to have everyone do the exact same analysis, or we can't have any control over our research and be confident in our results. We were also worried that there may be a few people that want to deliberately try to screw up our database and server.
Users will not have to do anything if they don't want. The results can be sent automatically, next time the users are on the internet (checking their mail, surfing, etc), or it can be set to ask permission before logging on to the internet.
SETI@home uses the HTTP protocol, and should work through any semi-transparent firewall that allows outgoing Web traffic. We are currently working on making SETI@home work through more restrictive firewalls and proxies.
Windows software is packaged in files ending with .exe, Mac software with .sit, and UNIX with .tar - chances are you have downloaded software for a system other than yours.
Yes, you can - and as long as you use the same login on each machine, you'll get credit for them all.
Please note that you can (currently) only run one SETI@home process on a Windows or Mac machine, and if you are running multiple SETI@home UNIX processes, they must be running out of different directories.
We keep track of every work unit that goes out - if it is taking too long getting the results back, we'll send it out to somebody else. Only after we get results back and confirm them we will remove the work unit from disk.
Questions about running the SETI@home software
Not to worry. This is completely normal as the newer clients have updated science code which looks at the data in more detail that previous clients. This increase in the actual science done by the clients requires more CPU time.
By the way, different operating systems and different CPU types can run at vastly different speeds. Some may process work units in a matter of hours while some may take days.
See 2.1. above - newer versions are running slower, yet people are still running older versions to "up their stats." This is a moot point since we'll be zero-ing out the database come the official launch date.
The clients are still looking for Gaussions, however rather than display information about gaussions all the time, in newer clients the information only appears if the client has found something interesting to report.
The SETI@home client may be being interrupted by another screen saver or screen saver-like program. As SETI@home is designed to be as noninvasive as possible by only using your computer while it is idle, if the client detects another program that wants to run, SETI@home will quit and step out of the way. If this other program is another screen saver or some other application that waits until your computer is idle before running, both SETI@home and the other program will try to run when the computer is idle causing SETI@home to quit. One common application which shows this behavior is McAfee VirusScan. If you have VirusScan installed, make sure that you have turned off the ScreenScan portion of the application as this will interfere with SETI@home.
Currently there is no way to do this. Eventually there will be an automated web-based mechanism for which you can submit a "change request", get a temporary password, and then you can change your info. We need this added level of security to make sure people don't haphazardly change other users' information.
Our screensaver works just like any other screensaver, which includes the ability for the operating system to enforce password protection. This is done through the normal password protection channels.
This is a known bug within the 1.0 release of the software. We are currently working on a fix which should be out by May the 21st.
Due to overwhelming interest in the SETI@home project, the server may intermittently be unreachable as too many clients are trying to connect. The server may also be occasionally down for maintainance. If you are unable to connect, please wait an hour and try again.
Questions about SETI@home science
A procedure has been agreed upon by SETI researchers around the world. First, other SETI researchers will independently verify the signal. If the signal is real and can't be explained by man-made sources (satellites, reflections etc.) then press agencies and governments will be notified in a systematic way.
Yes. Our software keeps track of where each piece work is done. If your computer is involved in the detection, you will, if you wish, be listed as a co-discoverer.
In 2 years the Arecibo radio telescope will have scanned the part of the sky visible to it three times, and SETI@home will have analyzed this data. That's enough for our purposes. And by then there will be new telescopes, new experiments, and new approaches to SETI.
Our goal is simply to find the signal. If it contains information, it may require experts in linguistics or mathematics to decipher it.
Data will be recorded on high density tapes at the Arecibo telescope in Puerto Rico, about one 35 Gbyte tape per day, then mailed to Berkeley, then divided into 0.25 Mbyte chunks which get sent from the Seti@Home server over the internet to people around the world to analyse. Arecibo does not have a high bandwidth internet connection, so data must go by snail mail to Berkeley at first.
No, all computers receive the same size chunks. Faster computers will finish each chunk faster, then immediately get a new chunk to work on, so we'll keep them busy all the time.
We search for strong narrow band signals. It's like tuning your radio set to various channels, and looking at the signal strength meter. If the strength meter goes up, that gets our attention. More technically, it's a lot of digital signal processing, mostly Fourier Transforms at various chirp rates and durations.
We also search for pulsing and drifting signals, and signals which match the antenna beam pattern as the telescope slews across the sky. The analysis software searches for signals about 10 times weaker than any search done to date, because it makes use of a computationally intensive algorithm called "coherent integration" that no one else (including our Serendip program) has had the computing power to implement.
They are merged in a database using our computers here, interference is rejected, and various pattern detection algorithms are applied to search for the most interesting signals.
Yes. Without going into detail (for obvious reasons) we have a mechanism that detects forged results.
See the above question. Besides, it wouldn't matter - if there's a "hit", we will analyze that chunk of data ourselves to verify it.
It's possible. Up to a point, we will handle it by sending the same data to more than one user. Beyond that, if we can afford it, we will set up another data recorder at Arecibo and record a wider frequency range (our current system records only 2.5 MHz out of SERENDIP's 100 MHz bandwidth).
Questions about SETI in general
Earth is polluting space with radio and television signals that might be detected by nearby advanced civilizations, but it would be difficult for such a civilization to discover these signals if they only have Earth's current level of technology (eg: if they have an Arecibo like telescope and SETI@home like search).
Early TV shows like I Love Lucy and Ed Sullivan left the earth about 40 years ago, so have gone out 40 light years, reaching several thousand nearby stars. But these signals are relatively weak and SETI@home is not likely to detect the equivalent of Earth type TV transmitters, even on the nearest stars.
Earth's strongest transmitters might be somewhat easier to detect, such as those emitted by military radars, or some radio telescopes. The Arecibo telescope transmits very powerful signals when it is used as a radar system to study planets, asteroids and the ionosphere. These radar signals are powerful enough to be detected 10,000 light years away by searches like SETI@home, except for three big caveats:
a) The Arecibo transmissions are in a very tight beam (they are not omnidirectional, like TV and military radar), so they only cover a very small part of the sky at once (about a millionth of the total sky). It's is unlikely another civilization will be within one of these narrow beams.
b) The Arecibo transmitter's oldest signals left Earth about 30 years ago, so have only travelled 30 light years.
c) SETI@home is not searching the band of frequencies that the Arecibo transmitters utilize (although our older SERENDIP III program did survey one of those bands).