"Galaxies evolve over billions of years, which is why like evolutionary biologists, we can't just sit there and watch galaxies change. Instead, we need to look at the fossil record contained in the galaxies around us which provides only *one* snapshot of the universe.
The way scientists get around this problem is by analysing pictures of galaxies with up-to-date technology in as much detail as possible. Astronomers have spent many decades trying to measure basic galaxy properties such as age, mass or dustiness that may give us some clues as to how they formed and evolved and what precisely the connection between spiral and elliptical galaxies is. However, most studies of galaxies so far have only looked at a few dozen or hundred galaxies in the nearby universe and many aspects of galaxy formation and evolution are still a mystery.
However, with the advent of the 21st century the age of large-scale astronomical surveys has arrived! The Sloan Digital Sky Survey (SDSS) is taking images of a large portion of the sky and will eventually find a million galaxies. With such a large number of galaxies, astronomers can finally begin to understand how they form and evolve by comparing various populations to each other with large enough numbers to draw real conclusions about their origin.
But out of these million galaxies, how do we know which are spirals and which are ellipticals? The answer is simple: look at them! Indeed, until now galaxies have been classified by visual inspection of their images. And in fact, technology is of little help here. It turns out that the human brain is far better than a computer at recognising the patterns that divide ellipticals from spirals. So visual inspection works well for a handful, or even several hundred objects....but one million? There are just too many galaxies for even the most dedicated of astronomers to look at. We need thousands of people to inspect galaxy images and to classify them as spiral or elliptical. We need you to help us."
Give the dedicated astronomers a break at Galaxy Zoo
Foldit is a revolutionary new computer game enabling you to contribute to important scientific research. This page describes the science behind Foldit and how your playing can help.
Now this one needs a bit more focus, involving transcribing scans of vintage (UK) data for the greater good....so possibly not for the faint-hearted (I've done a few stints, enjoyable but hard on the eyes!) They say "FreeBMD is an ongoing project, the aim of which is to transcribe the Civil Registration index of births, marriages and deaths for England and Wales, and to provide free Internet access to the transcribed records."
Find out more at FreeBMD
But let's just say you can't be arsed with all the above but you're quite happy for your computer to search for extraterrestrial life while you're having a nice cup of tea and your screen saver kicks in....no problem.....
"SETI@home is a scientific experiment that uses Internet-connected computers in the Search for Extraterrestrial Intelligence (SETI). You can participate by running a free program that downloads and analyzes radio telescope data.