Shapes of Things

https://commons.wikimedia.org/wiki/File:Sierra_Leone-Mappa.gif

In 2016, University of Buenos Aires computer science student Gonzalo Ciruelos worked out that the roundest country in the world is Sierra Leone, with a roundness index of 0.934 on a scale of 0 to 1.

He’d been inspired by David Barry, who’d found that the world’s most rectangular country is Egypt (0.955 on the same scale).

Metropolitan France is known as the Hexagon. I suppose each country has its claim to fame.

(Gonzalo Ciruelos, “What Is the Roundest Country?”, Math Horizons 26:3 [February 2019], 26-27.)

The Art of Living

https://pixabay.com/photos/old-stove-hot-fire-flame-2568425/

When I am going out for an evening I arrange the fire in my stove so that I do not fail to find a good one when I return, though it would have engaged my frequent attention present. So that, when I know I am to be at home, I sometimes make believe that I may go out, to save trouble. And this is the art of living, too, — to leave our life in a condition to go alone, and not to require a constant supervision. We will then sit down serenely to live, as by the side of a stove.

— Thoreau, Journal, Feb. 20, 1841

In a Word

https://www.pinterest.com/pin/the-chevening-maze-in-kent-is-the-first-multiplyconnected-puzzle-maze-this-means-it-cannot-be-solved-by-the-put-your-left-hand--48624870947902374/

anfractuous
adj. having many windings and turnings

loof
n. the palm of the hand

penetralia
n. the innermost recesses of a building

swither
n. a state of perplexity

It’s commonly said that you can defeat a hedge maze by placing one hand on a wall and carefully maintaining that contact as you advance. If the hedges are all connected, this method will reliably lead you to the center of the maze (and, indeed, to every other part of it before you return to the entrance).

The Chevening maze, in Kent, was designed deliberately to thwart this technique. Its center is concealed in an “island” of hedges distinct from the outer wall, so following either a left- or a right-hand rule will return you to the entrance without ever passing the goal.

The Erdős–Faber–Lovász Conjecture

https://commons.wikimedia.org/wiki/File:Erd%C5%91s%E2%80%93Faber%E2%80%93Lov%C3%A1sz_conjecture.svg

This figure contains four “cliques” of four points each, with each of the four points in each clique connected to each of the others, and each pair of cliques intersecting at a single point. Four colors suffice to color all the points so that no two linked points share a color.

Is this always possible? If k cliques, each containing k points, are arranged in similar fashion, can the result always be colored properly with k colors? In 2021, half a century after Paul Erdős first posed the question, Dong Yeap Kang and his colleagues proved that, for sufficiently large k, the conjecture is true.

Noted

“A few precepts to repeat whenever you are in need of comfort,” by Gabriel Hanotaux, French minister of foreign affairs from 1894 to 1895:

  1. Anything can happen.
  2. Everything is forgotten.
  3. Every difficulty can be overcome.
  4. No one understands anything.
  5. If everyone knew what everyone said about everyone, no one would speak to anyone.

“Above all things, never be afraid. The enemy who forces you to retreat is himself afraid of you at that very moment.”

(Via André Maurois’ The Art of Living, 1939.)

Second Coming

Lord Dudley was one of the most absent men I think I ever met in society. One day he met me in the street, and invited me to meet myself. ‘Dine with me to-day; dine with me, and I will get Sydney Smith to meet you.’ I admitted the temptation he held out to me, but said I was engaged to meet him elsewhere.

Wit and Wisdom of Sydney Smith, 1856

Casualties

In May 1884, a group of schoolboys on a beach in Zanzibar came upon a large mass of pumice stone that had washed up at the tidemark. Evidently it had been floating in the sea for some time, as its bottom was crusted with barnacles and weed. Welded to its upper surface, they discovered, were dozens of skeletons, including humans, monkeys, and two big cats, probably Sumatran tigers.

It was a relic of the eruption of Krakatoa, which had taken place nine months earlier in the Dutch East Indies. The rock had floated 4,000 miles across the Indian Ocean to the east coast of Africa.

(From Simon Winchester’s Krakatoa, 2013.)