You are what you eat… especially when it comes to doughnuts

Torus

   A doughnut is the classic culinary example of the three-dimensional geometric closed surface known as a torus.  Topologically* speaking, a doughnut is the same as any other object with one penetration, like a bagel, an inner tube, a hula hoop, a pipe (of any length, regardless of how many knots it might be tied into), a life-saver (confectionery or otherwise), a handbag with one handle, a car-key, an ankh, a 50-yen coin, a monstrance, or a mug.

   From the last observation comes the mathematical joke that a topologist cannot tell the difference between the coffee cup he is drinking from and the doughnut he is eating - or indeed the cigarette he is smoking (if you simplify the cigarette to a tube through which the smoke is drawn).

   Now, if you ignore the minor interpenetrations of the nose, the human body basically has one hole, the one starting at the mouth and coming out at the … ahem … other end.  So, yes, we are doughnuts!

   What this also means is that our food never actually goes inside us; it just passes over our surface, while bits of it get absorbed through that surface.  Furthermore, the trillions of bacteria that live in our gut are not really inside us, but on our surface, just like the bacteria on our skin.  We have about 10 million bacteria per square centimetre on our faces (remember that next time you kiss someone).  Overall, we have about 50 times as many cells living on us as we have making up our bodies themselves (which is about 50 trillion to start with).  It is when bacteria cross the boundary and get truly inside us that we get sick, which is why the essential treatment of wounds is to cover them up.

   As far as material food goes, what we eat becomes incorporated into our substance, so our food becomes us.  It is the opposite way around when it comes to spiritual food.  Saint Thomas Aquinas says it much more eloquently than I ever could:

The Blessed Sacrament at Tira Ora

   “Material food first changes into the one who eats it, and then, as a consequence, restores to him lost strength and increases his vitality.  Spiritual food, on the other hand, changes the person who eats it into itself.  Thus the effect proper to this Sacrament [the Holy Eucharist] is the con­ver­sion of a man into Christ, so that he may no longer live, but Christ lives in him; conse­quent­ly, it has the double effect of restoring the spiritual strength he had lost by his sins and defects, and of increasing the strength of his virtues.”  St. Thomas Aquinas, Commentary on Book IV of the Sentences, d.12, q.2, a.11.

   One last note, “torus” is a Latin word, one meaning of which is “cushion”, which should make sense to those suffering from haemorrhoids.

* Topology is the area of mathematics concerned with spatial properties that are preserved under continuous deformations of objects, for example, deformations that involve stretching, but no tearing or gluing.  If one surface can be deformed, in this way, into another, then the two are said to be homeomorphic.  In loose terms, we say they are topologically “the same”.