There’s nothing more intuitive, more obvious, more self-evident than the fact that we exist in three-dimensional space. We’re born into it. We move around in it. No one has to teach us how to see it. Look and it’s just there. While there are many things we need to learn in our lives, the existence of up/down, left/right, forward/ back isn’t one of them.
But there’s a problem with our naive understanding of space. It turns out that as soon as we stop looking at space and start thinking about it, our intuition breaks.
The Greek philosopher, Zeno of Elea – a staunch follower of Pythagoras – pointed out a little over 2,500 years ago that it’s intuitively obvious that the space between two points ought to be divisible. So if you are walking to the bus stop, you can imagine a point
