Zoology

Reponse of a 10-year-old child invited to write an essay about a bird and a beast:

The bird that I am going to write about is the owl. The owl cannot see at all by day and at night is as blind as a bat.

I do not know much about the owl, so I will go on to the beast which I am going to choose. It is the cow. The cow is a mammal. It has six sides — right, left, an upper and below. At the back it has a tail on which hangs a brush. With this it sends the flies away so that they do not fall into the milk. The head is for the purpose of growing horns and so that the mouth can be somewhere. The horns are to butt with, and the mouth is to moo with. Under the cow hangs the milk. It is arranged for milking. When people milk, the milk comes and there is never an end to the supply. How the cow does it I have not yet realised, but it makes more and more. The cow has a fine sense of smell; one can smell it far away. This is the reason for the fresh air in the country.

The man cow is called an ox. It is not a mammal. The cow does not eat much, but what it eats it eats twice, so that it gets enough. When it is hungry it moos, and when it says nothing it is because its inside is all full up with grass.

— Ernest Gowers and Sir Bruce Fraser, The Complete Plain Words, 1973

| Humor · Science & Math

Secondhand

https://commons.wikimedia.org/wiki/File:Albert_Anker_-_Das_Schulexamen.jpg

If nature be regarded as the teacher and we poor human beings as her pupils, the human race presents a very curious picture. We all sit together at a lecture and possess the necessary principles for understanding it, yet we always pay more attention to the chatter of our fellow students than to the lecturer’s discourse. Or, if our neighbor copies something down, we sneak it from him, stealing what he himself may have heard imperfectly, and add to it our own errors of spelling and opinion.

— G.C. Lichtenberg, quoted in W.H. Auden’s A Certain World, 1970

| Science & Math

Escort

https://pixabay.com/photos/moon-full-moon-sky-night-sky-lunar-1859616/

Steaming from New York to the Azores in 1867, Mark Twain noted a curious companion overhead:

We had the phenomenon of a full moon located just in the same spot in the heavens at the same hour every night. The reason of this singular conduct on the part of the moon did not occur to us at first, but it did afterward when we reflected that we were gaining about twenty minutes every day because we were going east so fast — we gained just about enough every day to keep along with the moon. It was becoming an old moon to the friends we had left behind us, but to us Joshuas it stood still in the same place and remained always the same.

(From The Innocents Abroad.)

02/11/2025 Reader Catalin Voinescu writes:

Mark Twain is talking absolute nonsense here.

The moon is in (almost) the same phase as seen from all over the world. It rises and sets at roughly the same local time, regardless of longitude, and the relation between phase and time of day when the moon is visible is the same everywhere (the full moon peaks at midnight; a week later, the last-quarter moon rises around midnight, peaks in the morning and sets around noon; and so on).

Even ignoring moon phase and local time, the moon rises, peaks and sets almost 50 minutes later every day, so gaining 20 minutes every day would not be enough.

(Thanks, Catalin.)

| Science & Math

Small Talk

(Until William Herschel’s advances in telescopes, stars seemed to have “rays” or “tails.”)

At a dinner given by Mr Aubert in the year 1786, William Herschel was seated next to Mr Cavendish, who was reputed to be the most taciturn of men. Some time passed without his uttering a word, then he suddenly turned to his neighbour and said: ‘I am told that you see the stars round, Dr Herschel’. ‘Round as a button’, was the reply. A long silence ensued till, towards the end of the dinner, Cavendish again opened his lips to say in a doubtful voice: ‘Round as a button?’ ‘Exactly, round as a button’, repeated Herschel, and so the conversation ended.

— Constange A. Lubbock, The Herschel Chronicle, 1933

| Science & Math · Society

The Octoplex

https://commons.wikimedia.org/wiki/File:Orthogonal_polyhedron_with_no_vertex_visible_from_center.svg
Image: Wikimedia Commons

An art gallery with n walls will always be safe with n/3 guards — the guards will always be able arrange themselves to observe the whole gallery.

That’s Chvátal’s art gallery theorem, discovered in 1973 by mathematician Václav Chvátal. Interestingly, it’s true only of two-dimensional floor plans — a three-dimensional gallery may not be safe even if you post a guard at every corner.

Take a 20 × 20 × 20 cube and remove a 12 × 6 channel from the front and back faces; a 6 × 3 channel from the left and right faces; and a 6 × 6 channel from the top and bottom faces, as shown. The result is the Octoplex, eight 4 × 7 × 7 theaters connected to each other and to a central lobby by passages 1 unit wide.

Remarkably, even if we mount a camera at every one of this figure’s 56 corners, there will remain a small region in the central lobby that no camera can see.

(T.S. Michael, “Guards, Galleries, Fortresses, and the Octoplex,” College Mathematics Journal 42:3 [May 2011], 191-200.)

| Science & Math