"It's an issue of conflicting models," says Bridget. "Not that I think that's what's going on here, but the representation of electron flow in a circuit diagram and the actual behaviour of individual electrons is very different. It's a problem in microchip design, I believe; if you make a conductor thin enough, below some threshold number of atoms wide, you start getting quantum effects that turn your chip from a tiny intricate logic machine into a tiny intricate ongoing accident."

"No, I think this is just me making a silly mistake I haven't found yet," says Janine.

"Yeah, that happens too."