SETI@home (Search for ExtraTerrestrial Intelligence)

Подключайтесь к проекту! Адрес ниже!------------------------------------------------SETI, or the Search for Extraterrestrial Intelligence, is a scientific effort seeking to determine if there is intelligent life outside Earth. SETI researchers use many methods. One popular method, radio SETI, listens for artificial radio signals coming from other stars. SETI@home is a radio SETI project that lets anyone with a computer and an Internet connection participate. The Problem — Mountains of DataMost of the SETI programs in existence today, including those at UC Berkeley build large computers that analyze that data from the telescope in real time. None of these computers look very deeply at the data for weak signals nor do they look for a large class of signal types (which we'll discuss further on...) The reason for this is because they are limited by the amount of computer power available for data analysis. To tease out the weakest signals, a great amount of computer power is necessary. It would take a monstrous supercomputer to get the job done. SETI programs could never afford to build or buy that computing power. There is a trade-off that they can make. Rather than a huge computer to do the job, they could use a smaller computer but just take longer to do it. But then there would be lots of data piling up. What if they used LOTS of small computers, all working simultaneously on different parts of the analysis? Where can the SETI team possibly find thousands of computers they'd need to analyze the data continuously streaming from Arecibo?The UC Berkeley SETI team has discovered that there are already thousands of computers that might be available for use. Most of these computers sit around most of the time with toasters flying across their screens accomplishing absolutely nothing and wasting electricity to boot. This is where SETI@home (and you!) come into the picture. The SETI@home project hopes to convince you to allow us to borrow your computer when you aren't using it and to help us "…search out new life and new civilizations." We'll do this with a screen saver that can go get a chunk of data from us over the internet, analyze that data, and then report the results back to us. When you need your computer back, our screen saver instantly gets out of the way and only continues it's analysis when you are finished with your work.It's an interesting and difficult task. There's so much data to analyze that it seems impossible! Fortunately, the data analysis task can be easily broken up into little pieces that can all be worked on separately and in parallel. None of the pieces depends on the other pieces. Also, there is only a finite amount of sky that can be seen from Arecibo. In the next two years the entire sky as seen from the telescope will be scanned three times. We feel that this will be enough for this project. By the time we've looked at the sky three times, there will be new telescopes, new experiments, and new approaches to SETI. We hope that you will be able to participate in them too!Breaking Up the DataData will be recorded on high-density tapes at the Arecibo telescope in Puerto Rico, filling about one 35 Gbyte DLT tape per day. Because Arecibo does not have a high bandwidth Internet connection, the data tape must go by snail-mail to Berkeley. The data is then divided into 0.25 Mbyte chunks (which we call "work-units"). These are sent from the Seti@Home server over the Internet to people around the world to analyze.Extra Credit Section: How the data is broken upSETI@home looks at 2.5 MHz of data, centered at 1420 MHz. This is still too broad a spectrum to send to you for analysis, so we break this spectrum space up into 256 pieces, each 10 kHz wide (more like 9766 Hz, but we'll simplify the numbers to make calculations easier to see). This is done with a software program called the "splitter". These 10 kHz pieces are now more manageable in size. To record signals up to 10 KHz you have to record the bits at 20,000 bits per second (kbps). (This is called the Nyquist frequency.) We send you about 107 seconds of this 10 kHz (20kbps) data. 100 seconds times 20,000 bits equals 2,000,000 bits, or about 0.25 megabyte given that there are 8 bits per byte. Again, we call this 0.25 megabyte chunk a "work-unit." We also send you lots of additional info about the work-unit, so the total comes out to about 340 kbytes of data.Sending You the DataSETI@home connects only when transferring data. This occurs only when the screen saver has finished analyzing the work-unit and wants to send back the results (and get another work-unit.) We'll only do this with your permission and allow you to control when your computer connects to us or, we'll give you the option to set the screen saver to transfer data automatically as soon as it's done with the current work-unit. The data transmission lasts for less than 5 minutes with most common modems and we'll disconnect immediately after all data is transferred.We keep track of the work-units here in Berkeley with a large database. When the work-units are returned to us, they are merged back into the database and marked "done." Our computers look for a new work-unit for you to process and send it out, marking it "in progress" in the database. We send out each work unit multiple times in order to make sure that the data is processed correctly. Even properly operating computers can make mistakes from time to time. If you are unable to complete a work unit, or your computer crashes and you lose your result, don't worry. The data isn't lost. http://setiathome.ssl.berkeley.edu/-----------------------------------------------Регистрируйтесь как Republic of Moldova. Она сейчас на 122 месте из 226. Будем поднимать ей рейтинг! Программа работает вместо ваших экранных заставок, абсолютно не напрягаю Вас.