In 1994, following a widely publicised interview in which Kevin Bacon joked that he had worked with almost everyone in Hollywood, a newsgroup popped up proposing a theory. It suggested that Bacon was, as they put it, at the centre of the universe.

What followed was one of those strange cultural quirks that refuses to die.

Borrowing from the broader idea of Six Degrees of Separation, it focused on Bacon’s career and claimed that you could link him to anyone in Hollywood within six steps.

I have always found the theory fascinating. Not just the Kevin Bacon version, but the idea itself. That you can link any two people in the world through a chain of connections. People you know, people they know, and so on.

Is it scientifically sound? On the face of it, it sounds absurd. And yet, every time I’ve tried to disprove it, I’ve failed.

I even tested it recently. I asked ChatGPT to throw names at me. It was surprisingly easy to get from me to Keanu Reeves, even going through Bacon for the fun of it. It was just as easy to get to Kim Jong-un.

That’s what makes it so compelling. It...