For more than 50 years, scientists at DESY have been exploring what holds the world together at its core. The smallest particles of matter, the most brilliant light sources and the technologies of tomorrow have always played a central role in the history of the research centre – and they will continue to do so in the future. The Deutsches Elektronen-Synchrotron DESY was founded in December 1959. Fifty years later, it celebrated its anniversary year 2009 with a wide range of exhibitions and events.