Will machine learning allow robots to take over?

We are in an age of machines that learn how to solve complex problems. Yet while headlines are made when computers can beat humans at Go or outperform them in speed dating, more powerful computers and larger data sets means machine learning already affects us in far more subtle ways. Algorithms used by online giants such as Google, Netflix and Amazon shape what we buy, the films we watch and how the global economy operates. In chemistry, the same concept can help us develop new drugs, materials and processes. So what is machine learning, and how does it work?