A legal conundrum from Jonathan Swift and Alexander Pope’s Memoirs of Martinus Scriblerus (1741): Sir John Swale bequeaths to Matthew Stradling “all my black and white Horses.” Sir John has six black, six white, and six pied horses. Should Stradling get the pied ones?
On the one hand, “Whatever is Black and White, is Pyed, and whatever is Pyed is Black and White; ergo, Black and White is Pyed, and, vice versa, Pyed is Black and White.”
On the other, “A pyed Horse is not a white Horse, neither is a pyed a black Horse; how then can pyed Horses come under the Words of black and white Horses?”
Perhaps this will help — a proof that all horses are the same color, condensed from Joel E. Cohen, “On the Nature of Mathematical Proofs,” Opus, May 1961, from A Random Walk in Science:
It is obvious that one horse is the same colour. Let us assume the proposition P(k) that k horses are the same colour and use this to imply that k+1 horses are the same colour. Given the set of k+1 horses, we remove one horse; then the remaining k horses are the same colour, by hypothesis. We remove another horse and replace the first; the k horses, by hypothesis, are again the same colour. We repeat this until by exhaustion the k+1 sets of k horses have each been shown to be the same colour. It follows then that since every horse is the same colour as every other horse, P(k) entails P(k+1). But since we have shown P(1) to be true, P is true for all succeeding values of k, that is, all horses are the same colour.
The hedge maze at Hampton Court has been entertaining visitors since 1695, occasionally belying its reputation for ease. In Jerome K. Jerome’s Three Men in a Boat (1889), Harris says, “We’ll just go in here, so that you can say you’ve been, but it’s very simple. It’s absurd to call it a maze.” Then, after two miles of wandering:
‘The map may be all right enough,’ said one of the party, ‘if you know whereabouts in it we are now.’
Harris didn’t know, and suggested that the best thing to do would be to go back to the entrance, and begin again. For the beginning again part of it there was not much enthusiasm; but with regard to the advisability of going back to the entrance there was complete unanimity, and so they turned, and trailed after Harris again, in the opposite direction. About ten minutes more passed, and then they found themselves in the centre.
Mazes have exercised a peculiar fascination for the mathematically minded. The young Lewis Carroll composed this one for a family magazine — the object is to make your way from the outside to the central space; it’s acceptable to pass over or under another path, but a single line means your way is blocked.
Cambridge University mathematician W.W. Rouse Ball constructed this maze in his garden. He notes that unless a loop surrounds the goal, the wanderer can defeat any maze by trailing one hand along a wall, and “no labyrinth is worthy of the name of a puzzle which can be threaded in this way.”
Hampton Court is modest in comparison to the modern hedge maze at Longleat, a stately home in Somerset. Its 16,000 English yews enclose 1.75 miles of paths that require an hour and a half to traverse; the course includes six wooden bridges from which to plot a path to the goal, an observation tower.
And Tennessee’s Odyssey mirror maze covers 5,000 square feet with a field of eight-foot mirrors set at 60-degree angles to create the illusion of an enormous vaulted crypt:
In solving any of these, as Harris discovered, the chief danger is overconfidence:
Said a boastful young student from Hayes,
As he entered the Hampton Court maze:
“There’s nothing in it.
I won’t be a minute.”
He’s been missing for forty-one days.
– Frank Richards
From Pedro A. Pisa in Scripta Mathematica, September 1954 — this identity:
1234 + 2484 + 3674 = 1254 + 2444 + 3694
… remains valid when the digits in each term are permuted in the same way:
1234 + 2484 + 3674 = 1254 + 2444 + 3694
1243 + 2448 + 3647 = 1245 + 2444 + 3649
1324 + 2844 + 3764 = 1524 + 2444 + 3964
1342 + 2844 + 3746 = 1542 + 2444 + 3946
1423 + 2448 + 3467 = 1425 + 2444 + 3469
1432 + 2484 + 3476 = 1452 + 2444 + 3496
2134 + 4284 + 6374 = 2154 + 4244 + 6394
2143 + 4248 + 6347 = 2145 + 4244 + 6349
2314 + 4824 + 6734 = 2514 + 4424 + 6934
2341 + 4842 + 6743 = 2541 + 4442 + 6943
2413 + 4428 + 6437 = 2415 + 4424 + 6439
2431 + 4482 + 6473 = 2451 + 4442 + 6493
3124 + 8244 + 7364 = 5124 + 4244 + 9364
3142 + 8244 + 7346 = 5142 + 4244 + 9346
3214 + 8424 + 7634 = 5214 + 4424 + 9634
3241 + 8442 + 7643 = 5241 + 4442 + 9643
3412 + 8424 + 7436 = 5412 + 4424 + 9436
3421 + 8442 + 7463 = 5421 + 4442 + 9463
4123 + 4248 + 4367 = 4125 + 4244 + 4369
4132 + 4284 + 4376 = 4152 + 4244 + 4396
4213 + 4428 + 4637 = 4215 + 4424 + 4639
4231 + 4482 + 4673 = 4251 + 4442 + 4693
4312 + 4824 + 4736 = 4512 + 4424 + 4936
4321 + 4842 + 4763 = 4521 + 4442 + 4963
And everything above holds true if each term is squared.
At a certain moment yesterday evening I coughed and at a certain moment yesterday I went to bed. It was therefore true on Saturday that on Sunday I would cough at the one moment and go to bed at the other. … But if it was true beforehand … that I was to cough and go to bed at those two moments on Sunday, 25 January 1953, then it was impossible for me not to do so.
– Gilbert Ryle, Dilemmas, 1954
When the Cavendish Laboratory at Cambridge University instituted an annual dinner in 1897, it began a tradition of “postprandial proceedings” — typically songs sung around a piano. This air, “Ions Mine,” was sung to the tune of “Clementine”:
In the dusty lab’ratory,
‘Mid the coils and wax and twine,
There the atoms in their glory
Ionize and recombine.
(chorus) Oh my darlings! Oh my darlings!
Oh my darling ions mine!
You are lost and gone forever
When just once you recombine!
In a tube quite electrodeless,
They discharge around a line,
And the glow they leave behind them
Is quite corking for a time.
And with quite a small expansion,
1.8 or 1.9,
You can get a cloud delightful,
Which explains both snow and rain.
In the weird magnetic circuit
See how lovingly they twine,
As each ion describes a spiral
Round its own magnetic line.
From the arc of glowing lime,
Soon discharges a conductor
If it’s charged with minus sign.
Alpha rays from radium bromide
Cause a zinc-blende screen to shine,
Set it glowing, clearly showing
Scintillations all the time.
Radium bromide emanation,
Rutherford did first divine,
Turns to helium, then Sir William
Got the spectrum, every line.
The fourth verse was contributed by J.J. Thomson himself.
n. a visible manifestation of Satan
Potassium chlorate brings out the worst in gummy bears.
In their 1996 manual Chemical Curiosities, H.W. Roesky and K. Möckel introduce this demonstration with an invocation from the Talmud: “He who ponders long over four things were better never to have been born: that which is above, that which is below, that which came before, and that which comes hereafter.”
(Please don’t try this yourself.)
J.B.S. Haldane’s father was a physiologist who would sometimes take his son along while investigating mines in order to teach him the rudiments of science. At one point they were lowered by a bucket into a pit in North Staffordshire, where a tunnel’s low roof forced their party to crawl:
“After a while, we got to a place where the roof was about eight feet high and a man could stand up. One of the party lifted his safety lamp. It filled with blue flame and went out with a pop. If it had been a candle this would have started an explosion, and we should probably have been killed. But of course the flame of the explosion inside the safety lamp was kept in by the wire gauze. The air near the roof was full of methane, or firedamp, which is a gas lighter than air, so the air on the floor was not dangerous.
“To demonstrate the effects of breathing firedamp, my father told me to stand up and recite Mark Anthony’s speech from Shakespeare’s Julius Caesar, beginning ‘Friends, Romans, countrymen.’ I soon began to pant, and somewhere about ‘the noble Brutus’ my legs gave way and I collapsed on to the floor, where, of course, the air was all right. In this way I learnt that firedamp is lighter than air and not dangerous to breathe.”
The Man who thought about Proteids sat by the roadside, writing with an indelible pencil in a little notebook. And Spring, all in pink and white, came tripping by, and cried to him: ‘I will dance for you! Watch me dance!’ She danced very prettily, but the Man went on writing, and never looked at her once. So Spring, being young, burst into tears, and told her sister, Summer.
Summer said to herself: ‘Spring is very foolish to cry. Probably he does not like dancing. I will sing to him.’ She sang a beautiful sleepy song to him, but he never listened, being busy writing in his little notebook. Summer was indignant, and told her sister, Autumn.
Autumn said: ‘There are many good men who do not like dancing. I will give him some of my wine.’ So she went to the Man and offered him her purple wine, but he merely said, ‘I do not drink wine,’ and resumed his writing. Then Autumn was very angry indeed, and told her big brother, Winter, all that had passed.
Winter was an enormous fellow, with a dreadful roar and howl, and every time he moved, snowflakes came whirling from his flowing robes. ‘Show me the fellow,’ he bellowed, puffing out his cheeks. Then he saw the Man who thought about Proteids, still sitting by the roadside.
‘Do you know me?’ roared Winter, and the Man looked and his teeth chattered like dead men’s bones.
Then Winter seized him by the neck and whirled him round and round, and finally flung him over his left shoulder into space.
And the Man who thought about Proteids has not been seen since, but, the other day, a boy found the little note-book lying by the roadside.
– J.B. Priestley, Brief Diversions, 1922
“If it is feared by a schizophrenic that nothing feared by a schizophrenic is the case, then there must be at least one other schizophrenic fear besides this one.”
– P.T. Geach, quoted in A.N. Prior, “On a Family of Paradoxes,” Notre Dame Journal of Formal Logic, 1961
What’s unusual about these dice is obvious. But what’s normal about them?
When thrown together, they produce the same probability distribution as a pair of ordinary dice. There are six ways to throw a 7, five ways to throw an 8, etc. This the only possible alternate arrangement in which all the face values are positive.
They were discovered/invented by George Sicherman of Buffalo, N.Y. See also Nontransitive Dice.
A solution of glucose, sodium hydroxide, and indigo carmine, when shaken, will change from yellow to red to green. Left to sit, it will revert to red again, then yellow, and the process can be repeated.
The indigo carmine is green when oxidized, yellow when reduced, and red in the intermediate semiquinone state.
- Holmes and Watson never address one another by their first names.
- Until 1990, the banknote factory at Debden, England, was heated by burning old banknotes.
- The vowels AEIOUY can be arranged to spell the synonyms AYE and OUI.
- 741602 + 437762 = 7416043776
- “In all matters of opinion our adversaries are insane.” — Mark Twain
Two trick questions:
Who played the title role in Bride of Frankenstein? Valerie Hobson — not Elsa Lanchester.
Did Adlai Stevenson ever win national office? Yes — Adlai Stevenson I served as vice president under Grover Cleveland in 1893.
A tank of water has two holes of equal area, one at top and one at bottom. The top one leads to a downspout, so that both holes discharge their water at the same level. Ignoring friction, which hole produces the faster flow of water?
You actually don’t need to know the physics in order to solve this — it yields to an insight.
Arrange a deck of cards in alternating colors, black and red. Now cut the deck so that the bottom card of one pile is black and the other is red. Riffle-shuffle the two piles together again. Now remove cards from the top of the pack in pairs. How many of these pairs should we expect to contain cards of differing colors?
Surprisingly, all of them will. During the shuffle, suppose a black card falls first. It must be followed by either the next card in its own pile, which is red, or the first card from the other pile, which is also red. Either way, this first pair will contain one black card and one red card, and by the same principle so will each of the other 25 pairs produced by the shuffle. This effect was first identified by mathematician Norman Gilbreath in 1958.
Related: Arrange the deck in a repeating cycle of suits, such as spade-heart-club-diamond, spade-heart-club-diamond, etc. Ranks don’t matter. Now deal about half of this deck onto the table and riffle-shuffle the two halves back together. If you draw cards from the top in groups of four, you’ll find that each quartet contains one card of each suit.
See So Much for Entropy.
A calendar curiosity by Canadian magician Mel Stover:
Offer any month’s calendar to a friend and have him outline a 4×4 square of dates. Ask him to circle any date in that square and cross out the other numbers in its row and column. Have him do this three more times and then add the circled numbers.
You can predict his answer by totaling the numbers in either pair of diagonally opposite corners in the square and doubling that number. Why does this work?
‘Well, do you know the one,’ I began, ‘in which two geologists converse in a cafe? One of them says: ‘Yes, unfortunately fifteen billion years from now the Sun will cool, and then all life on Earth will perish.’ A card-player nearby has been half listening to the joke, and turns in terror to the geologist: ‘What did you say? In how many years will the Sun cool?’ ‘Fifteen billion years,’ the scientist replies. The card-player lets out a sigh of relief: ‘Oh, I was afraid you said fifteen million!’
– László Feleki in Impact of Science on Society, 1969
“Even if I could be Shakespeare, I think I should still choose to be Faraday.” — Aldous Huxley
We were staying in Ballater, a small town on Deeside in Scotland. In the town was a tiny shop which sold tourist attractions and picture postcards, and in its minute window was a very fine specimen of smoky quartz material. Buying a postcard, I said to the proprietor, ‘That’s a fine group of smoky quartz in your window’ and had this reply in very broad Scotch:
‘That’s no smoky quartz, that’s topaz. It’s a crystal. You can tell crystals by the angles between their faces. If you’re interested I’ll lend you a book on the subject.’
I knew enough (crystals being rather in my line) to be sure it was smoky quartz, and on return to base looked up a book on Mineralogy which said ‘Smoky Quartz, also known as Cairngorm, is called Topaz in Scotland.’
– Sir W.L. Bragg, quoted in R.L. Weber, A Random Walk in Science, 1973
n. ignorance; lack of knowledge
n. the study of ignorance
In 1927, Hungarian physiologist Albert Szent-Györgyi isolated a substance in lemons and oranges that seemed to prevent scurvy.
He couldn’t identify it chemically, so he called it “ignose,” meaning “I do not know.”
When the editors of the Biochemical Journal asked for a different name, Szent-Györgyi suggested “godnose.” Finally they settled on “hexuronic acid.”
It turned out to be vitamin C.
From Royal V. Heath, Scripta Mathematica, June 1952:
In the square above, all rows, columns, and diagonals produce the same sum. And:
16 + 11 + 13 + 10 = 9 + 14 + 12 + 15
16 + 17 + 14 + 3 = 11 + 22 + 9 + 8
2 + 15 + 20 + 13 = 5 + 12 + 23 + 10
16 + 5 + 17 + 12 = 20 + 9 + 13 + 8
2 + 11 + 15 + 22 = 14 + 23 + 3 + 10
10 + 16 + 17 + 23 = 11 + 13 + 20 + 22
2 + 8 + 9 + 15 + 11 + 13 + 20 + 22 = 3 + 5 + 12 + 14 + 10 + 16 + 17 + 23
Most remarkably, everything above holds true if you square each term.
In studying metabolism in the early 1600s, Santorio Santorio undertook a unique study: He conducted his daily activities on a platform attached to a steelyard scale. After years of readings, he learned that his food always weighed more than his excretions, and concluded that the rest was lost through “invisible perspiration,” the loss of matter through the pores and breath.
Santorio’s conclusions remained the state of the art for more than a century. When Ben Franklin wrote in 1742, “If thou art dull and heavy after Meat it is a sign that thou hast exceeded due measure,” he was essentially repeating Santorio’s aphorism of 150 years earlier, “Meats which promote Perspiration bring Joy, but those which obstruct it Sorrow.”
How to clean a 40-foot spectrograph, from R.W. Wood’s Researches in Physical Optics, 1913:
The long tube was made by nailing eight-inch boards together, and was painted black on the inside. Some trouble was given by spiders, which built their webs at intervals along the tube, a difficulty which I surmounted by sending our pussy-cat through it, subsequently destroying the spiders with poisonous fumes.
This was the least of Wood’s exploits. Walter Bruno Gratzer, in Eurekas and Euphorias, writes that the physicist “would alarm the citizens of Baltimore by spitting into puddles on wet days, while surreptitiously dropping in a lump of metallic sodium, which would explode in a jet of yellow flame.”
The north pole is the south pole. Earth’s north magnetic pole is actually the south pole of its magnetic field — a compass needle points “north” because opposites attract.