Command Performance

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.”

So It Goes

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

That’s Logic

http://commons.wikimedia.org/wiki/File:Yarrabend4.jpg

“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

Sicherman Dice

http://commons.wikimedia.org/wiki/Category:Die_faces

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.

A Chemical Traffic Light

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.

Misc

  • 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.

Outpourings

gedanken tank puzzle 1

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.

Click for Answer

Order and Chaos

http://www.sxc.hu/photo/573780

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.

Blind Dates

stover calendar trick

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?

Near Thing

‘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