At work we somehow landed on the topic of how many holes a human has, which then evolved into a heated discussion on the classic question of how many holes does a straw have.
I think it’s two, but some people are convinced that it’s one, which I just don’t understand. What are your thoughts?
How many holes does a donut have?
Now make the donut higher. A lot higher. Now you have a donut-tunnel. Now make the walls thinner. Now shrink it. Now you have a straw.
One hole.
Mathematically It’s one. Think of a disk, like a CD, does it have one hole or two? One, right? Now imagine you can make it thicker, I.e. increase the height, and then reduce the outer radius… Making it progressively more straw-like. At what point does it stop having 1 hole and begin to have 2?
Topologically they’re the same shape.
I’m sure Matt Parker has a video on this topic in YouTube. Here
