Dread that the abominations people create will become their masters, or their executioners, is hardly new. But voiced by a renowned cosmologist, a Silicon Valley entrepreneur and the founder of Microsoft — hardly Luddites — and set against the vast investment in AI by big firms like Google and Microsoft, such fears have taken on new weight. With supercomputers in every pocket and robots looking down on every battlefield, just dismissing them as science fiction seems like self-deception.

The question is how to worry wisely.

The first step is to understand what computers can now do and what they are likely to be able to do in the future. Thanks to the rise in processing power and the growing abundance of digitally available data, AI is enjoying a boom in its capabilities. Today’s “deep learning” systems, by mimicking the layers of neurons in a human brain and crunching vast amounts of data, can teach themselves to perform some tasks, from pattern recognition to translation, almost as well as humans can.

As a result, things that once called for a mind — from interpreting pictures to playing the video game “Frogger” — are now within the scope of computer programs. DeepFace, an algorithm unveiled by Facebook in 2014, can recognise individual human faces in images 97% of the time.

Crucially, this capacity is narrow and specific. Today’s AI produces the semblance of intelligence through brute number-crunching force, without any great interest in approximating how minds equip humans with autonomy, interests and desires. Computers do not yet have anything approaching the wide, fluid ability to infer, judge and decide that is associated with intelligence in the conventional human sense. Yet AI is already powerful enough to make a dramatic difference to human life.