A puzzle from the 1997 Ukrainian Mathematical Olympiad:
Cells of some rectangular board are coloured as chessboard cells. In each cell an integer is written. It is known that the sum of the numbers in each row is even and the sum of numbers in each column is even. Prove that the sum of all numbers in the black cells is even.
I just noticed this last night in Joseph Wood Krutch’s Treasury of Bird Lore — in 1832 ornithologist Alexander Wilson encountered a flock of passenger pigeons near Frankfort, Kentucky, that he estimated at 2,230,270,000 birds. If each bird ate only a pint of beech nuts in the course of a day, the flock would consume nearly 35 million bushels a day. A century and a half earlier, in 1687, Louis Armand, Baron de Lahontan, reported that pigeons had “so swarmed and ravaged the colonists’ crop near Montreal that a bishop was constrained to exorcise them with holy-water, as if they had been demons.”
Yet by 1914 human rapacity had reduced the species to a single bird, Martha, who died that year at the Cincinnati Zoo.
See The Eighth Plague.
In 1947 actress Gay Gibson disappeared from her cabin on an ocean liner off the coast of West Africa. The deck steward, James Camb, admitted to pushing her body out a porthole, but insisted she had died of natural causes and not in a sexual assault. In this week’s episode of the Futility Closet podcast we’ll review the curious case of the porthole murder, which is still raising doubts today.
We’ll also explore another fraudulent utopia and puzzle over a pedestrian’s victory.
By K. Makovsky. White to mate in two moves.
In The Two-Move Chess Problem (1890), Benjamin Glover Laws calls the first move here “ideal” and “splendid.” “[I]t is not always a composer’s good fortune to strike a vein which is susceptible of such an excellent opening move as is illustrated in this problem.” What is it?
Reader David Kastelan just let me know about this — in 2015 someone scammed €80 million from wealthy victims by donning a silicone mask to impersonate French defense minister Jean-Yves Le Drian. Ostensibly he was asking for financial help in raising ransoms for journalists held hostage by Islamists.
“Everything about the story is exceptional,” Le Drian’s lawyer told the BBC. “They dared to take on the identity of a serving French minister. Then they called up CEOs and heads of government round the world and asked for vast amounts of money. The nerve of it!”
Early contacts were made by phone, but eventually “Le Drian” appeared on Skype in a brief call from a poorly lit ministerial office. Many of the targets refused, but the Aga Khan lost €18 million, and an unnamed Turkish businessman lost at least €40 million.
No one knows who’s responsible, but one suspect is French-Israeli con man Gilbert Chikli. He’s currently in jail in Paris, and the calls have stopped, but it’s possible that other gang members are still at large.
In 2012 computer scientist Andrew Adamatzky set a plasmodium of the slime mold Physarum polycephalum into a maze with an oat flake at its center. By following a gradient of chemo-attractants given off by the flake, the plasmodium was able to solve the maze in one pass, extending a protoplasmic tube to the target.
The original recording was made at one frame per five minutes; this playback is 25-30 frames per second.
(Andrew Adamatzky, “Slime Mold Solves Maze in One Pass, Assisted by Gradient of Chemo-Attractants,” IEEE Transactions on Nanobioscience 11:2 [2012], 131-134.)
“I once spent all day thinking without taking food and all night thinking without going to bed, but I found that I gained nothing from it. It would have been better for me to have spent the time in learning.” — Confucius
“It is interesting that most of the human race has a reserve of the enzyme necessary to render alcohol harmless to the body — as if nature meant us to drink alcohol, unlike animals to which alcohol is a poison.”
— BUPA News, 1982, quoted in Richard Gordon, Great Medical Mysteries, 2014
In 1947 two Harvard undergraduates, William Burkhart and Theodore Kalin, built a primitive machine for doing propositional logic. They had been taking a course in symbolic logic with Willard Van Orman Quine and were tired of solving problems with pencil and paper, so they set about making a machine that would do their homework automatically.
The result of their $150 investment was a small machine that could handle problems involving up to 12 terms in the propositional calculus. The “Kalin-Burkhart machine” marks a milestone in the development of logic machines, but working in the machine’s language is so laborious that using a pencil is faster.
“It is interesting to note that when certain types of paradoxes are fed to the Kalin-Burkhart machine it goes into an oscillating phase, switching rapidly back and forth from true to false,” noted Martin Gardner in Logic Machines and Diagrams (1958). “In a letter to Burkhart in 1947 Kalin described one such example and concluded, ‘This may be a version of Russell’s paradox. Anyway, it makes a hell of a racket.'”
An epic contest from the Annual Green Fair and South West Scythe Festival in Somerset, U.K., June 2010.
One commenter wrote, “Now we know why Death carries a Scythe, not a brushcutter.”
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