Podcast Episode 285: The Grasshopper Plagues

https://commons.wikimedia.org/wiki/File:Melanoplus_spretusAnnReportAgExpStaUM1902B.jpg

In the 1870s, new farmsteads on the American plains were beset by enormous swarms of grasshoppers sweeping eastward from the Rocky Mountains. The insects were a disaster for vulnerable farmers, attacking in enormous numbers and devouring everything before them. In this week’s episode of the Futility Closet podcast we’ll describe the grasshopper plagues and the settlers’ struggles against them.

We’ll also delve into urban legends and puzzle over some vanishing children.

See full show notes …

“A Remarkable Dream”

On Saturday morning a man about 30 years of age, named Benjamin Collins, was found drowned in a small dam belonging to the Whitehall pit, at Wyke. When found he was kneeling in the water with his head down, being only up to the shoulders in the water. He had been drinking for several days, and became restless. He got up about 2 o’clock in the morning, partly dressed himself, and said he could not sleep. Soon afterwards he went out, and about 4 o’clock his uncle, Mr. Mark Collins, of Lower Car Close farm, went in search of him in the barn and stables, but not finding him there returned to the house. Mrs. Collins then desired her husband to go to the place where the body was found, as she had just dreamt her nephew was drowned there. Mr. Collins acted as his wife requested, and, to his amazement and horror, saw the literal fulfillment of her dream.

York Herald, quoted in The Law Times, Dec. 17, 1864

Wooden Words

https://www.katieholten.com/public-realm/#/new-york-city-tree-alphabet/

Artist Katie Holten has created a New York City Tree Alphabet, a Latin alphabet in which each letter is assigned a drawing of an existing city tree or one that will be planted as a result of the changing climate. There’s a free font that you can play with here and download here.

Holten had planned to plant messages around the city using real trees last spring, and invited people to make suggestions, though I don’t know which were ultimately chosen. “Right now, we’re leaving it completely wide open, so we’ve no idea what messages we’ll be planting,” she told Fast Company in March. “I’m excited to see what people send us. People have been suggesting words like ‘Dream,’ ‘Hope,’ and ‘Peace.’ But we’re also receiving longer messages, love letters, poems, and short stories. We’re curious to see how we could translate a long text into a grove of planted trees. It’s an exciting challenge and we can make up the rules as we go along, so anything could happen.”

(Via MetaFilter.)

Building Tangents

ellipse tangents

Here’s a way to find tangents to an ellipse from a point outside it, say E. Use E to draw any two chords CD and FG. Now lines CF and DG will meet at H, and CG and DF will meet at J. The line HJ intersects the ellipse at A and B, and EA and EB are the tangents we sought.

In 2001 David Bloom of Brooklyn College wrote, “I owe the above to a course I took in 1958, taught by O. Zariski. The result seemed so beautiful that I’ve never forgotten it.”

(“Miscellanea,” College Mathematics Journal 32:4 [September 2001], 317-318.)

A Movable Lake

https://www.reddit.com/r/MapPorn/comments/f4gx39/map_of_hamburg_germany_during_wwii_camouflaged_to/

In order to confuse enemy aircraft during World War II, the residents of Hamburg disguised the Binnenalster, a lake in the main business district, as terrain and built a dummy viaduct parallel to the real viaduct, in effect “moving” an attractive target to a less vulnerable location.

Unfortunately the work was done in daylight and the change was too dramatic to be convincing. “Even so, the protection must have been of real value at least in Hamburg, where the addition of a dummy viaduct, displaced from, but parallel to, the real (Lombard’s) viaduct may have contributed to saving the latter very vital rail and transportation link.”

(U.S. Strategic Bombing Survey, Civilian Defense Division Final Report: Dates of Survey: 15 Jan.-15 Aug. 1945, 1947.)