The discovery of other civilisations might abate much of the need for conflict here on Earth.
- Carl Sagan

The Search for Extra-Terrestrial Intelligence at Home Project (known as Seti@home for short) is the first ever worldwide event that the whole of humankind can take part in using their personal computers. The process is a 'distributed net project', meaning that it utilises the spare computing cycles of other people's computers to process data from a centrally located server. There are no bars, no impediments; anyone with a computer can join in. It represents a joint effort by the human race to find messages from intelligent species in other parts of the Cosmos.

Sounds unbelievable? Well, 30 years ago it was unbelievable. But these days, given the relative cheapness of computing equipment, and the widespread availability of Internet connections, we can now search while we're making a cup of coffee, walking the dog, or decorating the house.

And the goal? To find ET, the Extra-Terrestrial¹.

The idea behind the Seti@home project is simple to grasp. The raw data is collected by radio telescopes at Arecibo, Puerto Rico. This data is then transmitted to the Seti@home organisers in Berkeley, California, and divided into 90 second (350kb) blocks of data called units. These units sit on a server in Berkeley until a Seti@home participant requests one (or more) for processing. The unit is then sent to the home computer, where it is processed by the previously downloaded Seti@home software, or 'client'. The participant now has two choices. They can either run the software as a screen saver, so that the data is processed whenever the computer is not in use, or, for more powerful machines, the software can run constantly in the background.

These units can be completed² in anything from two hours to over 100 hours, depending on the processing power available to the program. The software can be downloaded from the Seti@home Homepage.

Once the software is up and running, you will see a green radar dish icon appear in your system tray. This is to show that the software is either running in the background, or waiting to cut in as your screen-saver. When the unit of data has been processed, your green radar dish icon will flash red, and a box will appear requesting you to 'connect now' to send your unit back. As soon as your unit has been sent, your new one starts downloading automatically, and your statistics are updated. It really is very simple, and you don't need to be a rocket scientist to participate in the search.

Why not join the h2g2 Seti Researchers Group and donate your own computer time? It would be quite something if an h2g2 Researcher managed to find the first alien signal!

Other Methods of Crunching

There are other methods by which to 'crunch' your units too, such as the Seti_Gate cache system, whereby you can download as many units as you require, and your Seti@home software sits and crunches away until it runs out of units. This is a good way to be able to keep crunching if you don't mind leaving your PC on all the time. You can then upload all your results at one go. It also allows you to keep stat tabs on your friends by adding their email addresses. When you upload your results, it automatically updates your statistics.

'Five-Minute Units'

One intriguing quirk is the 'five-minute unit'. That is, your unit uploads, the new unit downloads, and within a few moments the icon flashes red and asks you to send it off. This is a pleasant surprise, as it lowers your computer usage time statistics and also gives you something to talk about at your local Seti@home group. The reason for these mysterious short units is probably interference from either the Earth or a satellite, which the software can identify very quickly. One Researcher has received one that lasted approximately 6 and a half minutes, and another lasting 47 seconds.

The Drake Equation

Frank Drake is the current President of the Seti Institute. He devised the equation known as The Drake Equation. It is a mathematical tool for approximating how many possible life-bearing planets and civilisations there may be in the Universe.

So Why Haven't We Heard Anything Yet?

The Universe has been around for something like 10 to 15 billion years. The Earth has been around for about 4.5 billion. Life's been on the Earth for about 3.5 billion years. Mankind has been here for about 5 million. We've been able to broadcast electronic information into space for about 100 years.

Now, it happens that our planet is comparatively old in the Galaxy - indeed in the Universe. We see everything moving away from us fairly uniformly in all directions (perhaps we smell, or something). That last 100 years, in which we've been transmitting ourselves across the Galaxy, is a tiny, tiny proportion of the amount of time that life's been on this planet.

Now, imagine another civilisation in another part of the Galaxy that's had their planet exactly as long as ours. Let's say they've also had life on that planet as long as we have, and also, if you like, that they've had human-like beings evolving to the point where they have electronics and radar dishes and suchlike.

We'll assume they evolve as fast as we did as well - why not? Let's say their planet is 20,000 light-years away - still well within our Galaxy. They could have become able to beam messages into space 19,000 years ago, and their emissions will only just be reaching us. There could, in fact, be thousands of civilisations that evolved quicker than us and have been at it for 100,000 years, but their messages might only just be reaching us from the other side of the Galaxy.

Conversely, there might be a civilisation next door to us that just happens to be 1,000 years behind us in its evolution - it's a tiny amount of time compared to the age of planets and life on them. When you consider that some civilisations on Earth have been separated from others technologically speaking by at least 1,500 years (take Mayans and Spanish in the year 1600 as an example) - it's much more likely that completely separated planets will have vastly differing states of evolution.

It's all possible, and is worth considering as a theory as to why we've not heard anything from them yet. FBI/CIA cover-ups aside...

Satire

There are numerous sites(eg seti news and yeti news) on the Internet which 'send up' the Seti@home project. Although some might say that they represent misplaced creativity, they nonetheless provide a little light relief.

A Message from Aliens?

In 1977, a beguiling signal was registered by SETI and became known as the 'WOW' signal, because that's what was written on the print-out next to the large reading as it came out of the computer. Much has been made of this brief 'message', but no authoritative 'translations' have been forthcoming.

Crop circle makers now appear to have SETI in mind, having lain down a 'reply' (Message from ET?) to the message Frank Drake devised in 1974 and beamed to the M-13 cluster from the Arecibo observatory. The 'reply' seems to have been borrowed from the film and book Contact by Carl Sagan. Whoever is responsible has overlooked the fact that M-13 is 25,000 light years away. In other words, the message isn't due to reach M-13 for another 24,975 years.