This is a guest post written by Dr Chris Lintott, University of Oxford and founder of Galaxy Zoo and The Zooniverse
In 2006, I and a then graduate student at Oxford, Kevin Schawinski, were drinking in a pub. We were there because we were facing a difficult problem, the kind of everyday problem that we all face every now and then. We had too many galaxies, or rather too many images of galaxies. Kevin had classified 50,000 of them, sorting them out by shape.
By studying galaxies in all their variety, from enormous cities of stars we call ellipticals to the beauty of a spiral galaxy, we can understand the evolution of the Universe over the last 13 billion years or so. The shape of a galaxy – whether it’s spiral or elliptical – is a measure of its history, of how it has interacted with its surroundings and with other galaxies.The trouble is that assessing the shape of a galaxy is something that humans find easy but computers find hard, and so to deal with the size of modern datasets you need a lot of humans.
Back in that Oxford pub, Kevin and I hit upon the idea of asking for help over the internet. Before too long, galaxyzoo.org was born, and we were overwhelmed by the response – at one stage, we were doing 70,000 classifications per hour and while things haven’t quite continued at that pace the Galaxy Zoo database now contains more than a hundred million classifications. What’s more, the results from the public using their web browsers were more accurate than those from Kevin or from automated methods, which is why more than fifty separate papers have now made use of Galaxy Zoo results.
There turns out to be another benefit of asking people to help – they get distracted by the weird stuff. All sorts of unusual objects turn up amongst the Galaxy Zoo images, first amongst them a galaxy-sized gas cloud now known as Hanny’s Voorwerp, after its discoverer, Dutch schoolteacher Hanny van Arkel. The Voorwerp turns out to not only look interesting, but to be a fascinating object, bearing the signatures of a dramatic episode in the history of IC2497, its neighbouring galaxy.
Galaxy Zoo has since turned its attention to the distant Universe, looking at galaxies whose light set off on its journey to Earth (or, rather, to the Hubble Space Telescope in orbit around Earth) billions of years ago. We hope to compare the past and present galaxy populations, but for that we still need your help. Which brings me to my challenge. In a couple of week’s time, the Galaxy Zoo team and friends will be meeting in Sydney to talk through all the science that’s come from the project (thanks to generous support from CSIRO). Visitors from Australia are currently the 5th in the league table of contributors to the project, behind the US, UK, Canada and Germany.
If, by the final day of the conference, Australia is above the UK in the league table, I’ll buy all of my Australian colleagues a beer (each!). This means that by going to galaxyzoo.org and classifying in the next few weeks, you can both make a real contribution to science and beat the English at a game invented over here. Let’s call it a test match.
My background is in work on the chemistry associated with star formation, but these days I run citizen science projects to investigate galaxy formation, discover planets and more. To see the current range of projects and get involved visit The Zooniverse.
Dr Chris Lintott is a Researcher and Citizen Science Project Lead in the Department of Physics at the University of Oxford. He is a presenter on the BBC’s Sky at Night and co-author of the popular science books Bang! The Complete History of the Universe! and The Cosmic Tourist with Patrick Moore and Brian May.
He is giving a free public talk How to discover a planet from your sofa at 2pm on Sunday 22 September at Sydney’s Powerhouse Museum ahead of the Galaxy Evolution conference. Bookings are essential and places are filling up fast. On Wednesday 25 September at 6pm Chris will also be one of the presenters at a free workshop for teachers on how to use Galaxy Zoo and the Zooniverse with students. Again, bookings are essential.
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