People are like donuts–topologically, that is. My daughters and I explored this strange statement with a clay figure modeled around a pen (and then I pulled the pen out). What is topology?

Topology (Greek topos, “place,” and logos, “study”) is the branch of mathematics that studies the properties of a space that are preserved under continuous deformations. Topology grew out of geometry, but unlike geometry, topology is not concerned with metric properties such as distances between points. Instead, topology involves the study of properties that describe how a space is assembled, such as connectedness and orientability.

Here are the photos illustrating our adventure:

As you can see, humans have a hole running all the way through them, as do donuts. The above clay model oversimplifies the hole running through humans, which is not straight, but twisting and convoluted.

Nonetheless, we each have a hole running all the way through our bodies. That makes people the topological equivalent of donuts. In fact, all mammals are the the topological equivalent of donuts. This equivalence can be seen in the food tube of the giraffe, for example.

I took this extraordinary photo at the Field Museum in Chicago..

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.What else is the topological equivalent of a donut? A coffee cup, which you can see in this animation at Wikipedia.

Therefore, you can sometimes see the most extraordinary thing at a donut store. You can find “big” donuts shopping for little donuts.

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Here, for example, are my daughters getting ready to buy some Sunday morning donuts (photo taken in 2002).