Asked what condition of man most deserves pity, Ben Franklin answered, “A lonesome man on a rainy day who does not know how to read.”
“Calculating Girl”
In the spring of 1819, a little girl, about eleven years old, appeared at the Royal Exchange, and made some very extraordinary calculations. Several gentlemen asked her some intricate question, and while they were calculating it, she gave a correct answer. She was asked to multiply 525,600 by 250; which she answered in one minute, 131,400,000. A second question was, how many minutes there are in forty-two years? Answer, 22,075,200. She was next desired to multiply 525,000 by 450; answer, 236,250,000. Several other questions, equally difficult, were put, all of which she answered very correctly. It is remarkable, that the girl could neither read nor write. She stated herself to be the daughter of a weaver, living at Mile-End, New Town, of the name of Heywood.
— Cabinet of Curiosities, Natural, Artificial, and Historical, 1822
The Kruskal Count
Here’s a card trick devised by Rutgers physicist Martin Kruskal. Give a friend a deck of cards and ask her to follow these instructions:
- Think of a “secret number” from 1 to 10. (Example: 6)
- Shuffle the deck and deal the cards face up one at a time, counting silently as you go.
- When you reach the secret number, note the value of that card and adopt it as your new secret number. Aces count as 1; face cards count as 5. (Example: If the 6th card is a 4, then 4 becomes your new secret number.)
- Continue dealing, counting silently anew from 1 each time you adopt a new number. Remember the last secret card you reach.
That’s it. You just stand there and watch her deal. When she’s finished, you can identify her final secret card in any way you please, preferably through a grotesquely extortionate wager.
You can do this because you’ve simply played along. When she’s dealing, note the value of an early card and then silently follow the same steps that she is. Five times out of six, your “paths” through the deck will intersect and your final secret card will match hers. That’s far from obvious, though; the trick can be baffling if you refuse to explain it.
The Wheel of Orffyreus
On Nov. 12, 1717, German inventor Johann Bessler invited a committee of witnesses to a special room in the ducal castle at Weissenstein. In the room was a large wheel, 12 feet in diameter and 14 inches thick. At a push from Bessler it accelerated to about 26 rpm and maintained that speed. Under the committee’s supervision, the windows were secured and the Landgrave’s own seal was put on the door. The room was reopened twice in 54 days, and on both occasions the wheel was still spinning.
Bessler demanded 20,000 pounds for his secret. (He said the weights inside the wheel “could never obtain equilibrium.”) But while the Royal Society was debating whether to pay him, Bessler discovered one witness examining the axle, accused him of duplicity, and angrily smashed the wheel. He vanished into obscurity after that, dying in 1745.
The demonstration has never been explained. If Bessler had a secret, he took it with him.
Square Deal
In 1994, Leonard Gordon showed that all 37 presidential surnames to date can fit into a 22 × 18 rectangle:
Free Won’t
Zeno once caught a slave stealing and began to beat him.
Knowing the philosopher’s penchant for paradoxes, the slave cried, “But it was fated that I should steal!”
Zeno said, “And that I should beat you.”
Kaprekar’s Constant
Choose four distinct digits and arrange them into the largest and smallest numbers possible (e.g., 9751 and 1579). Subtract the smaller from the larger to produce a new number (9751 – 1579 = 8172) and repeat the operation.
Within seven iterations you’ll always arrive at 6174.
With three-digit numbers you’ll aways arrive at 495.
Strange Neighbors
The border between Delaware and Pennsylvania is a perfect curve.
It’s the arc of a circle centered on the cupola of the courthouse at New Castle.
It’s the only such boundary in the territorial United States.
Unquote
“We do not err because truth is difficult to see. It is visible at a glance. We err because this is more comfortable.” — Aleksandr Solzhenitsyn
Naturally
Someone once asked Jean Cocteau, “Suppose your house were on fire and you could remove only one thing. What would you take?”
Cocteau considered, then said, “I would take the fire.”