Einstein loathed the idea of entanglement, and famously derided it as “spooky action at a distance”. But it is central to quantum theory. And Van Raamsdonk, drawing on work by like-minded physicists going back more than a decade, argued for the ultimate irony — that, despite Einstein’s objections, entanglement might be the basis of geometry, and thus of Einstein’s geometric theory of gravity. “Space-time,” he says, “is just a geometrical picture of how stuff in the quantum system is entangled.”

This idea is a long way from being proved, and is hardly a complete theory of quantum gravity. But independent studies have reached much the same conclusion, drawing intense interest from major theorists. A small industry of physicists is now working to expand the geometry–entanglement relationship, using all the modern tools developed for quantum computing and quantum information theory.

“I would not hesitate for a minute,” says physicist Bartłomiej Czech of Stanford University in California, “to call the connections between quantum theory and gravity that have emerged in the last ten years revolutionary.”

I am not qualified to pass professional judgements on this approach, but I can say that this ‘feels’ like it is going in the right direction… at least in my non-expert opinion.

At its fundamental level, reality really must be something completely alien to our superficial experience of reality… just as quantum physics and (to a lesser extent) relativity are- but more so.