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spikegifted - SETI@Home

 


SETI@Home
... I think the best way for me to explain what SETI@Home is to use its own description on its website: "SETI (Search for Extraterrestrial Intelligence) is a scientific area whose goal is to detect intelligent life outside Earth. One approach, known as radio SETI, uses radio telescopes to listen for narrow-bandwidth radio signals from space. Such signals are not known to occur naturally, so a detection would provide evidence of extraterrestrial technology."

So, we're looking for ET... Yeap, we're looking for ET. If you think this is a complete stupid idea, I hope I can, through the explanation below, convince you that it is not that silly.

First of all, a couple of small disclaimers:
1) I believe in the existence of intelligent life forms outside this planet.
2) I believe in the existence of unidentified flying objects, but I believe they are not flown by aliens.


What is SETI?

The mission of the SETI Institute is to explore, understand and explain the origin, nature and prevalence of life in the universe.

In terms of the scale of the universe, we live in a very small and lonely place. The Earth is orbiting around an insignificant star on outer perimeter of one of the arms of an insignificant spiral galaxy ('The Milky Way'), which in itself is belong to an insignificant group of galaxies orbiting around the 'Great Attractor'. While there are trillions of trillions of stars out there, for the most part, the universe is a cold and lonely place. Why do I say that? All you have to do is to take a look at the sky at night - it is a blanket of black with a collection sparkles belonging to the star in our own galaxy and others far away. The fact that our planet, being altogether insignificant and unimportant, can support intelligent life suggests that there're plenty of other places in this universe can support form or forms of intelligent life.

Remember when you were a kid, you would have been, at one point or another, encouraged to have a pen-friend or two? Why a pen-friend? A typical pen-friend tend to live in another country and another culture. The climate, food, life-style and living conditions of the pen-friend's place tend to be quite different and he/she probably speak a different language. If you have had a pen-friend, can you remember your excitement when you hear from him/her? Can you remember how you'd compare how different/similar your way of life compare with his/hers?

That, in effect, is the very reason why we want to find other intelligent life forms in other parts of the universe, any part of the universe. Despite all the scientific and technological advances in the past 150 years, we, humans, have still only managed to travel physically to our satellite, the Moon. Ok, we also have made tens if not hundreds of satellites to monitor each other, to improve our communication back here on Earth and to take the 'big picture'. We also have send probes to our nearest planetary neighbors, the Moon and Mars, and we have send other probes to other planets (notably Pioneer 10 and 11) and beyond. Having cast our critical eyes on our neighbors, we've found that, within the Solar System, intelligent life forms only exists on Planet Earth.

We know that stars are just a large burning gas balls, no life is expected to be found on stars. Therefore, life, and intelligent life forms, can only be expected to be found on planets. On the other hand, if the Solar System is typical of star systems that exist in this universe, all we have to do is to find stars and we should be able to find the planets. However, even now, with all the technologies and scientific gadgets, we're struggling to see planets in other star systems. Planets, unlike stars, do not emit light, but merely reflect that light radiated by the host star and they're usually significantly smaller than the stars that they're orbiting means that any light will be so dim that we can't yet detect them on from Earth. News of planets being 'discovered' orbiting far away stars are not actually being 'seen' but 'detected' - tiny 'wobbles' of the host stars caused by the gravitation pull of the planets orbiting around them. The fact that these newly discovered planets of distant stars cannot be seen means that we can't observe them and without observation, we cannot ascertain whether there are intelligent life forms on these planets.

Therefore, we, humans, are still spending our lonely nights here on Earth staring at distance stars wondering if there're other intelligent life forms out there and hoping that if there are, we can somehow understand and communicate with these life forms. However, when we find 'it', 'it' is not going to any ordinary pen-friend! Since there is no inter-solar communication system (like the various postal or telecommunication systems) linking us and our new pen-friend, we'll have to use electromagnetic signals to try and communicate with them. Electromagnetic radiation travels at the speed of light (about 300 million meters per second) and considering that the nearest star to the Sun is 4.3 light years away (Proxima Centauri, in Alpha Centauri, and on average we're about 8 light years to the nearest dozen of stars, 4.3 to 12.8 light years), if we were to send a message with a question to a planet with intelligent life form orbiting this star, we would have to wait 8.6 years for a reply to arrive back, that is if they send us a reply immediately.

If you look at our own planet's civilization development, you'd realize that it is only in the last 100 years or so that we humans have developed the necessary technologies to send and receive electromagnetic signals (which travel at the speed of light) - the likes of telegraphs, wireless, radio, television, telephone, cellular phones, etc. However, if you take a look at this same period again, it is highly probably that we, as a civilization, have had plenty of chances of wiping ourselves from the face of this planet - notably after the invention of the atomic bomb and the post-WWII conflict ('Cold War') between the West and the Soviet Bloc. The fact that some terrifying weapons have been invented, manufactured and now decommission doesn't mean that some time in the near future, we won't once again position ourselves near the edge of self-annihilation.

The fact that 100-200 years in the time scale of this planet is incredibly short - written records go back as far as 4000 years ago, humanoids first appeared around 35,000 years ago, the last Great Extinction (the dinosaurs) occurred 65 million years ago and life on Earth probably first started over 3 billion years ago. The point of this is that for any given civilization on another planet on another star system far from this place will have a finite time period between its technologies are sufficiently advance to send and receive electromagnetic signals and before some kind of disaster strikes (either self-inflicted or natural). And this window is relatively small even in terms of the life and times of a planet.

It is the hope of finding intelligent life forms outside this planet that SETI Institute was founded, in 1984. One of SETI Institute's projects, Project Phoenix, is to 'listen' to radio signals from out of space. These signals can either be beamed to us intentionally or they can be inadvertently transmitted from another planet. Why radio signals? Edwin Hubble discovered that, on the whole, stars and galaxies in the universe are moving away from each other. Due to the Doppler effect, electromagnetic radiation (or any form of waves) are stretched as two objects move apart, relative to each other. The result is that higher frequency (shorter wavelength) electromagnetic radiation will be stretched out to lower frequency (longer wavelength). Radio waves (signals) have the longest wavelengths of all electromagnetic radiation.

Through the use of various radio telescopes and antennas positioned around the world, vast amount of data is gathered. Within this data, scientist are hoping that there're signs of signals being sent by intelligent life forms from another planet.

What is SETI@Home?

SETI@home is a scientific experiment that uses Internet-connected computers in the Search for Extraterrestrial Intelligence (SETI).

Project Phoenix started listening for radio signals in 1995. With the vast amount of data being gathered, a gigantic amount of computing power is required to go through the data and identify likely candidates of genuine radio signals from intelligent life forms from another planet. The amount of computation power required will dwarf even the most expensive super-computer available to any single organization (and the funding for the SETI Institute is limited).

In 1996, a group of scientist conceived the idea of SETI@Home and in1999 a piece of software was made public to download. The software is in a form of a screen saver. Screen saver is a remnant of the days when computer screens tended to form permanent images of the text if left alone for too long, as the phosphorus coating on the inside of the cathode ray tube (the monitor) burns up as the result of being repeatedly scanned by the cathode beam.  When a computer becomes idle, the screen saver becomes active. Since the screen saver only comes on if the computer is not being used but is still switched on, SETI@Home is utilizing 'unused' computation power of idle computers.

The way SETI@Home works is that once the client software (the screen saver) is installed, a small piece data that require analysis (a work unit) is downloaded onto the computer. When the computer becomes idle and the screen saver comes on, this piece of data, which in fact is a long string of radio signal, is analyzed by running some analytical algorithms. Once the work unit is completely analyzed, it will be returned to SETI to be recombined with other work units. Through this way, SETI obtains a cheap source of computing power to help analyze the vast amount of data gathered and the end-user get to participate in a worthwhile scientific project. Since 1999, over 4.5 million computer users from all round the world have participated in SETI@Home. Together these users donated over 1.6 million computing years and completed over 1 billion work units. With each work units being around 300kB, it means these users have analyzed over 300 terabytes (that's 300,000,000 megabytes or 300,000 gigabytes)!!

There is intense competition in SETI@Home. Users tend to group themselves into teams. When I first started participating in SETI@Home, I belonged to the BP6/VP6 User Group. Later on, my cousin, SeaTiger, and I joint forces and form out own little team. SeaTiger is now an inactive member and I've moved across to join the 2CPU.com SETI@Home Team (taking SeaTiger with me to add his contribution to the team). Competition is both inter- and intra-teams. Usually intra-team rivalries are good natured and encourage team members to get the most out of their computers, which, at the end of the day, helps their team to achieve better results overall. However, inter-team competitiveness are sometimes less humored. Some teams even cheat to achieve better stats, which completely defeats that object of the SETI@Home goal - to go through the data and identify likely radio sources.

While SETI@Home can harness huge amount of computing power through the generosity of its users, there are limitations. The biggest limitation is that data cannot be analyzed at 'real time' as it has to be separated into convenient 'bite-size' chunks for individual users to work on. Therefore, any interesting candidate signals identified will have to be followed up and revisited at a future date.

In June 2004, a new generation of SETI@Home was launched, based on BOINC (Berkeley Open Infrastructure for Network Computing). This is largely owing to the popularity of distributive computing and the desire to tap into a broad a client base as possible.


How to take part in SETI@Home?

To participate in SETI@Home cannot be easier. First you need to create a SETI@Home account at the website. Soon after this, you'd receive an e-mail confirming your user ID and a link to the project's website. Then, all you have to do is to download and install the the client software. You'd need to have your internet connection active to download the data (work unit) so that the client can start working. Also, internet connection is also required to return the completed analysis back to SETI.

For those who want to optimize their computer to improve their SETI@Home output, there is an excellent optimization page in Ars Technica, which, although it is based on SETI@Home Classic, will help you get the most out of existing computers. For those who plan to build computers with SETI@Home in mind, you should remember that SETI@Home loves clock speed, large caches and low memory latency.

Good luck and I look forward to seeing you on the SETI@Home roaster...

2CPU.com SETI@Home Team website
spike's SETI@Home official statistics
spike's SETI@Home public profile
2CPU.com BOINC SETI@Home Team official statistics
2CPU.com BOINC SETI@Home Team Statistics from SETI Synergy
2CPU.com BOINC SETI@Home Team Statistics from BOINC.dk
spike's BOINC SETI@Home Personal Statistics from SETI Synergy
spike's BOINC SETI@Home Personal Statistics from BOINC.dk
UK BOINC SETI@Home User Statistics from SETI Synergy