Things to Make and Do in the Fourth Dimension

by Matt Parker

I can’t resist retelling the already too-oft-told maths ‘joke’ based on just such a misunderstanding, normally seen in the form of a hilarious T-shirt with this written on it: ‘There are 10 types of people in the world, those who understand binary and those who don’t.’ To explain the hilarity: ‘10’ means 2 in a binary number system, so only those who understand binary would know it means 2 and not 10. I’ll give you a second to finish laughing and compose yourself. I am slightly scathing of this joke solely because, being a mathematician who also works as a stand-up comedian, I am told it all the time. Normally, people start with, ‘OK, have you heard this joke? Well, it kinda doesn’t work when you say it, but …’ and then proceed to try to tell a joke which only works when it’s written down. That’s the problem with binary jokes: they either work, or they don’t.