Here’s one way to prevent ants from ruining your picnic — surround the tablecloth with parallel strips of electrically conductive material and attach them to a DC battery. Now any bug that crosses the border will close the circuit and get “a sensation which will discourage further travel across the edge of the cloth.” (Humans will feel only “a slight tingling sensation.”)
Imagine a die that exactly covers one square of a checkerboard. Place the die in the top left corner with the 6 uppermost. Now, by tipping the die over successively onto each new square, can you roll it through each of the board’s 64 squares once and arrive in the upper right, so that the 6 is exposed at the beginning and end but never elsewhere?
The solution above is unique. I think this puzzle was devised by John Harris of Santa Barbara, Calif., in 1964; I found it in Miodrag Petkovic’s Mathematics and Chess, 1997.
Costa Rica’s alligator bug, Fulgora laternaria, bears a protuberance that looks remarkably like a caiman’s head — a feature that may make a hungry bird think twice.
The leaf insects of Southeast Asia, below, so convincingly mimic living leaves that they even bear “bite marks.” This fooled Magellan’s companion Antonio Pigafetta, who encountered them in the Philippines in 1521:
In this island are also found certain trees, the leaves of which, when they fall, are animated, and walk. They are like the leaves of the mulberry tree, but not so long; they have the leaf stalk short and pointed, and near the leaf stalk they have on each side two feet. If they are touched they escape, but if crushed they do not give out blood. I kept one for nine days in a box. When I opened it the leaf went round the box. I believe they live upon air.
Yes. Because the camera is above the reflective surface, the two images are not identical. If the camera lens is, say, 5 feet above the water, then the reflected image appears as if viewed from 5 feet below it.
Suppose we have a complete wooden ship, and one day we replace one of its wooden planks with an aluminum one. Most people would agree that the ship survives this operation; that is to say, its identity remains unchanged. But suppose that we then replace a second plank, and then a third, until our wooden ship is made entirely of aluminum. Is this the same ship that we started with? If not, when did it change?
Thomas Hobbes adds a wrinkle: Suppose that, as we did all this refurbishing, someone had gathered up all the discarded wooden planks and used them to assemble a second ship. What are we to make of this? “This, without doubt, had also been the same numerical ship with that which was at the beginning; and so there would have been two ships numerically the same, which is absurd.”
And philosopher Roderick Chisholm adds another: “Let us suppose that the captain of the original ship had solemnly taken the vow that, if his ship were ever to go down, he would go down with it. What, now, if the two ships collide at sea and he sees them start to sink together? Where does his duty lie — with the aluminum ship or with the reassembled wooden ship?”
Fit a circle into one corner of a triangle. Now fit a second circle into a second corner so that it’s tangent to the first circle. Then fit a third circle into the third corner so that it’s tangent to the second circle.
Keep this up, cycling among the three corners, and the sixth circle will be tangent to the first one.
When Ernest Shackleton set out for Antarctica in 1914, his carpenter, Harry “Chippy” McNish, brought along a tabby who was quickly named “Mrs. Chippy,” though he proved to be a male. When the Endurance was crushed by pack ice, Shackleton ordered the “weakling” cat to be shot, a decision for which McNish never forgave him. Cat and carpenter were reunited in 2004, when a life-size bronze statue of Mrs. Chippy was added to McNish’s grave in Wellington.
Vilhjalmur Stefansson’s 1913 arctic expedition ended in disaster when the main vessel sank, but ship’s kitten Nigeraurak (“little black one”) was lugged safely home in a sack, “the only member of the expedition to survive the whole affair sleek and unscathed.”
And Matthew Flinders’ cat Trim accompanied him on several adventures, including the circumnavigation of Australia, a shipwreck in 1803, and imprisonment in Mauritius during the return to England. Today Sydney’s Mitchell Library bears a statue of the cat (below), with a plaque quoting Flinders’ own words:
TO THE MEMORY OF
TRIM
The best and most illustrious of his race
The most affectionate of friends,
faithful of servants,
and best of creatures
He made the tour of the globe, and a voyage to Australia,
which he circumnavigated, and was ever the
delight and pleasure of his fellow voyagers.
On June 1, 1873, during a visit to New College, Oxford, South Carolina planter William Heyward Trapier asked for a mint julep, “to the utter bewilderment of the butler,” according to the Oxford Companion to the Year.
When his hosts confessed their ignorance of the American drink, Trapier gave them his family recipe, a silver pot in which to share it, and instructions to prepare it every year on the anniversary of his visit. Thereafter it became a college tradition to substitute juleps for the after-dinner port on June 1 each year, and to leave a place empty for Trapier.
