I’ve seen a lot of commentary from people about the recent news that researches have used an actual quantum computer to factor a number. The comments have mostly been along the lines of “this is probably cool, but I really don’t understand it” and this saddens me.

As I’ve formally studied more than a little quantum physics in my time I thought it might be useful if this could be explained in simpler terms.

You know the Schrodinger’s Cat Experiment, right? You put a dead cat in a box and there’s a 50-50 chance the special properties of a radioactive isotope will bring it back to life to briefly shamble around the laboratory mewing for brains. It’s taught in primary schools these days, though the practical itself was removed from most curricula some time ago.

In this case what they’re doing is similar, but slightly different. First, you take a cat and show it a video of the above experiment so it might fully grasp the gravity of the situation. Then you put it in the box with a cryptography textbook and a number written clearly on a ruled index card. You waft in the smell of some fresh tuna and you tell it it’s only getting some when it factors the number, and until then it’s both alive and dead and hungry all at the same time. In short order you should find yourself with some prime factors and a very relieved cat.

Of course, it’s not quite so simple, because crypto researchers have been doing this for years with lab-sized apparatus. The real breakthrough of this discovery is that this team has shrunk the cat, the box, the aroma of tuna and the crypto textbook down to the size where it can all fit on a silicon chip and be attached to a regular computer. No doubt soon every mobile phone will have one, allowing two thirds of the world’s population to straddle the barrier between life and afterlife on their weekly commute.