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?
What if you bored from both ends of the cylinder until they meet in the middle?
There would be two holes until, at the moment of contact, it becomes one?
Does the method with which the straw shaft is created influence the number of holes it has?
No, topologically there would be no holes until the moment of contact. This is the same as there being no hole when drilling through from only one side until the surface on the opposing side is broken.
Yes, but topologists can’t tell a doughnut from a coffee cup so they’re clearly insane.
So how does one “dig a hole?” Straight to China? Or whatever is opposite of you?
Topologically, yes. Buy you could also go down a bit, make a lateral tunnel, then pop back up.
So what you are saying is, if I dig a hole that doesn’t go anywhere, then that’s not really a hole?
In topology, yes. It must go through to count.
That’s fascinating. So most of what I would call “holes” are what, in topographical terms, hollows? Depressions?
I don’t even know if they have a name for that since it can simply be undone by stretching the object, which is allowed under topological rules.
Topologically, yes. Coincidentally, “Hole to Nowhere” is the best Talking Heads parody album.
Heh I will have to check that out!
Not only that, but if you pinch it in the middle until the passage closes, could it still be called just one hole?