Michael Banks speaks to the early pioneer of “citizen science” Chris Lintott, who has helped to create a whole host of projects that are changing how science is done
The task was simple but painstaking: to identify the shapes of over a million galaxies from images taken from the Sloan Digital Sky Survey. To help with the arduous task, in 2007 the astronomer Chris Lintott – together with astrophysicist Kevin Schawinski, both from the University of Oxford – set up a website called Galaxy Zoo that presented users with images of galaxies to classify. The pair hoped to initially get around 50 local amateur astronomers to help out, calculating that it could take around five years to trawl through the complete data set.
It took just three weeks – not because the amateur astronomers were unexpectedly quick but because thousands of people from all over the world flocked to the site to offer their help as extra pairs of eyes. At its peak, more than 70,000 galaxies were being analysed per hour, and in the first year of the site 50 million galaxies were classified by 150,000 people, who together made Galaxy Zoo the world’s largest database of galaxy shapes.
The instant success of Galaxy Zoo led to a plethora of similar “citizen-science” initiatives and Lintott is the driving force behind the resulting “Zooniverse”. Set up in 2009, this collection of online citizen science now boasts around 20 separate projects with tasks that range from searching for planets outside our solar system by analysing data from NASA’s Kepler spacecraft to helping marine scientists better understand whale communication. “I am surprised by how successful it has all been,” Lintott told Physics World. “And how many other people can say they have discovered a new planet in their spare time?”
The citizen scientist
Modern citizen science dates back to the late 1990s when the University of California, Berkeley released SETI@home – a computer program that analysed radio signals from the Arecibo radio telescope in Puerto Rico to look for signs of intelligent life in the universe. The program ran in the background on idle computers using each machine’s processing power when it was not needed. However, SETI@home only involved users installing the software; they did not analyse any data.
That all changed in August 2006 when NASA set up Stardust@home, which allowed volunteers to examine images taken by the space agency’s Stardust probe for evidence of tiny interstellar dust impacts in a set of aerogel blocks that the probe exposed in space. At its peak, some 20,000 users participated in Stardust@home and it was this project that inspired Lintott to set up a similar endeavour to analyse galaxy types, recognizing that in both tasks humans can easily outpace computer algorithms, which find it difficult to recognize patterns. So, in Galaxy Zoo’s case, when it comes to deciding whether a galaxy is elliptical or spiral – and, if spiral, whether it is rotating in a clockwise or anticlockwise direction – there is nothing better than the human eye.
If you have a pile of data, work with us and get people to help out
Four years on from its first project, Zooniverse is now a roaring success, with more than 860,000 volunteers taking part and more than 50 published papers – all based on the work of Zooniverse’s users, or “zooites”. In many cases, Lintott says that Zooniverse projects stemmed from requests from other scientists about how to get the public to help them analyse their data. Although he admits that such crowdsourcing fits some areas of science better than others, Lintott says that more scientists should think about how their research can be used as part of a citizen science project. “If you have a pile of data, work with us and get people to help out,” adds Lintott, who in February became the main presenter of the BBC TV programme The Sky at Night following the death of the show’s long-running presenter Patrick Moore.
Demystifying science
Someone who has adopted Lintott’s approach is Michael Doser, a particle physicist at CERN, who is working on an experiment called AEgIS that investigates how hydrogen and antihydrogen respond to gravity. The experiment works by plotting the trajectory of particles on a photographic emulsion plate, and it is currently only operating with protons and antiprotons, which are too light to measure the effect of gravity. Doser has just created software to test whether crowdsourcing could benefit the experiment by letting users – rather than computer algorithms – trace the direction of particle tracks. “I have been following Zooniverse with envy and admiration,” says Doser. “The Zooniverse projects not only share the fascination of doing science, but also unlock the deep desire to participate in science of many people who do not have the chance to do so in their daily work.”
Doser adds that such projects have helped to “demystify” science. “Contrary to conventional outreach, citizen science treats the public as an equal partner,” he says. “Involving citizens seems to me a powerful route to increasing scientific literacy.” More than that, citizen science is also making scientists rethink how they work with their data and fostering a new class of budding amateur scientists. “You find that people get really drawn in, start analysing the results and even reading new papers that come up on arXiv,” says Lintott. “You could say they have a career as a citizen scientist.”
