Prof Sir Anthony Leggett delivers a talk as part of the 750th anniversary celebrations of Balliol College, University of Oxford. Speaking at the Sheldonian Theatre, he addresses the topic of how the world might change over the next 75 years by explaining the theory of quantum mechanics and how it can apply to everyday life. One exciting way in which this may come to pass is the advent of quantum computing, which could revolutionise the way we deal with vast amounts of complex digital information.