The Oxford Electric Bell

https://commons.wikimedia.org/wiki/File:Oxford_Electric_Bell.jpg
Images: Wikimedia Commons

The University of Oxford has a bell that’s been ringing almost continuously since 1840. A little 4-millimeter clapper oscillates between two bells, each of which is positioned beneath a dry pile, an early battery. Due to the electrostatic force, the clapper is first attracted to and then repelled by each bell in turn, so it’s been ringing them alternately for 179 years. The operation conveys only a tiny amount of charge between the bells, which explains why it’s managed to run so long. The whole apparatus is kept under two layers of glass, but the ringing is so faint that it would be inaudible in any case.

It’s estimated that the bell has produced 10 billion rings so far — it holds the Guinness World Record as “the world’s most durable battery [delivering] ceaseless tintinnabulation.”

In and Out

https://commons.wikimedia.org/wiki/File:Renato_Dulbecco.jpg

The briefest interview I’ve ever conducted was with Renato Dulbecco, who has since shared in a Nobel Prize for work in animal-cell culture and tumor viruses. Through his secretary, we had made an appointment. When I reached his office, he ushered me in, closed the door, sat down at his desk — and said that he was not going to talk to me. Startled, but respecting him at least for not having imposed on his secretary the task of rejection, I said something about the importance of getting scientific work across to the general public. Dulbecco replied, ‘We don’t do science for the general public. We do it for each other. Good day.’

— Horace Freeland Judson, “Reweaving the Web of Discovery,” The Sciences, November/December 1983

(“I thanked him for the interview and left, promising myself to use it someday. He was correct, of course, though unusually candid.”)

Black and White

van dehn chess puzzle

A remarkable thematic chess puzzle by Bodo Van Dehn, 1951. White to move and win.

The solution is 10 moves long, but all Black’s moves are forced. (That’s a very valuable hint.)

Click for Answer

Good Fortune

Letter from Albert Einstein to J.E. Switzer, April 23, 1953:

Dear Sir

Development of Western Science is based on two great achievements; the invention of the formal logical system (in Euclidean geometry) by the Greek philosophers, and the discovery of the possibility to find out causal relationship by systematic experiment (Renaissance). In my opinion one has not to be astonished that the Chinese sages have not made these steps. The astonishing thing is that these discoveries were made at all.

Sincerely yours,

A. Einstein

Magicker

walkington knight diagonals
Image: William Walkington (CC BY-NC-SA 4.0)

The “Lo Shu square” is the 3 × 3 square enclosed in dashed lines at the center of the diagram above. It’s “magic”: Each row, column, and long diagonal (marked in red) sums to 15. William Walkington has discovered a new magic property — imagine rolling the square into a tube (in either direction), and then bending the tube into a torus. And now imagine hopping from cell to cell around the torus with a “knight’s move” — two cells over and one up. (The extended diagram above helps with visualizing this — follow the blue lines.) It turns out that each such path touches three cells, and these cells always sum to 15. So the square is even more magic than we thought.

More info here. (Thanks, William.)

Podcast Episode 261: The Murder of Lord William Russell

https://curiosity.lib.harvard.edu/crime-broadsides/catalog/46-990080942200203941
Image: Harvard Digital Collections

In May 1840 London was scandalized by the murder of Lord William Russell, who’d been found in his bed with his throat cut. The evidence seemed to point to an intruder, but suspicion soon fell on Russell’s valet. In this week’s episode of the Futility Closet podcast we’ll follow the investigation and trial, and the late revelation that decided the case.

We’ll also marvel at Ireland’s greenery and puzzle over a foiled kidnapping.

See full show notes …

Revere’s Obelisk

revere's obelisk

To celebrate the repeal of the Stamp Act, Paul Revere designed an obelisk that was erected on Boston Common on the evening of May 22, 1776. Its four panels, painted on translucent waxed paper borne on a wooden frame, described the phases of the struggle against the act:

1. America in distress apprehending the total loss of Liberty.

2d. She implores the aid of her Patrons.

3d. She endures the Conflict for a short Season.

4. And has her Liberty restord by the Royal hand of George the Third.

At the bottom is the legend “To every Lover of Liberty, this Plate is humbly dedicated, by her true born Sons, in Boston New England.”

It was illuminated by 280 candles, and fireworks and Catherine wheels were launched from its sides. Unfortunately it “took Fire … and was consumed” a few hours a later. This is the only surviving copy of the engraving.

(Thanks, Charlie.)

A Flea’s Journey

https://commons.wikimedia.org/wiki/File:Euclid_Tetrahedron_4.svg
Image: Wikimedia Commons

A flea sits on one vertex of a regular tetrahedron. He hops continually from one vertex to another, resting for a minute between hops and choosing vertices without bias. Prove that, counting the first hop, we’d expect him to return to his starting point after four hops.

Click for Answer

“A Rabbit Tamed”

A notable detail from Alexander Morrison Stewart’s Camp, March and Battle-Field (1865): During the Battle of Malvern Hill, a terrified rabbit darted about the battlefield looking for safety until it came upon a Union regiment lying prone:

Ere the rabbit seemed aware, it had jumped into the midst of these men. It could go no farther, but presently nestled down beside a soldier, and tried to hide itself under his arm. As the man spread the skirt of his coat over the trembling fugitive, in order to insure it of all the protection in his power to bestow, he no doubt feelingly remembered how much himself then needed some higher protection, under the shadow of whose arm might be hidden his own defenceless head, from the fast-multiplying missiles of death, scattered in all directions.

It was not long, however, before the regiment was ordered up and forward. From the protection and safety granted, the timid creature had evidently acquired confidence in man — as the boys are wont to say, ‘Had been tamed.’ As the regiment moved forward to the front of the battle, it hopped along, tame, seemingly, as a kitten, close at the feet of the soldier who had bestowed the needed protection. Wherever the regiment afterwards went, during all the remaining part of that bloody day and terrible battle, the rabbit kept close beside its new friend.

“When night came on, and the rage of battle had ceased, it finally, unmolested and quietly, hopped away, in order to find some one of its old and familiar haunts.”