Twitter user Garratt Dennis agreed, writing: “Okay I could be wrong but I think a hollow cylinder (the paper towel roll) is homeomorphic to a torus which has one hole, therefore the roll of paper towels has one hole with two openings.”

To fully cook the insides of the dough, the dough would have to stay in the oil for a longer time, which would lead to the outsides becoming burnt. Punching a hole in the middle of the dough, however, allows the insides and the outsides to cook evenly, creating a perfect doughnut.

While most traditional donuts have holes in the middle, all donuts do not, in fact, have holes. A great example of a donut without holes is the jelly-filled style. These donuts are typically stuffed with a fruit-flavored filling, but can also be filled with other things.

Team “Two Holes” argues that a straw has an entrance and an exit, and thus has TWO holes. Imagine a pipe. If something goes in a pipe in your house, crosses town underground, and then comes out on the other end of town. The two ends of the pipe are part of the same system, but are two unique and distinct holes.

1 hole

It is a hollow cylinder with 2 openings at either end. However if we flattened it into a disc, there would only be one area that is completely “punched out”, which means one hole by this definition.

It’s called a tube – a hollow cylinder.

So the torus has two one-dimensional holes. There is a two-dimensional thing we can map into the torus that can’t be shrunk down to a point while staying on the torus, and it’s the torus itself. So if we know that the torus isn’t topologically equivalent to a point, we know that it has a two-dimensional hole.