A puzzle by Russian mathematician Boris Kordemsky:
A house has 6 stories, each the same height. How many times as long is the ascent to the sixth floor as the ascent to the third?
A puzzle by Russian mathematician Boris Kordemsky:
A house has 6 stories, each the same height. How many times as long is the ascent to the sixth floor as the ascent to the third?
“A man doesn’t learn to understand anything unless he loves it.” — Goethe
“A man ought to read just as inclination leads him; for what he reads as a task will do him little good.” — Samuel Johnson
“We soon forget what we have not deeply thought about.” — Proust

Iranian hermit Amou Haji ate carrion, drank from puddles, lived in a hole, smoked dung, and died at 94, a few months after bathing for the first time in 60 years. He said he became a hermit due to “emotional setbacks” after a heartbreak.
English merchant Nathaniel Bentley became known as Dirty Dick when he stopped washing in his late 30s. His filthy shop became a tourist attraction. Interestingly, he too was said to have changed after a ruined love affair, allegedly after his fiancée died on the eve of their wedding. Charles Dickens knew of the story, which may have inspired that of Miss Havisham in Great Expectations.

The Wikipedia article on the Ship of Theseus has changed entirely since its inception.
19 can be expressed as the sum of four perfect cubes:
19 = 333 + (-29)3 + (-25)3 + 163
So can 6941:
6941 = (-3476)3 + 30903 + 23173 + 3843
Can every integer be expressed in this way? It’s conjectured that the answer is yes, but no one has yet managed to prove it.

Reading Maps plots the geographical course of hundreds of books and films, so you can see where and how events unfold on the earth’s surface. (Above is the track of the Pequod in Moby-Dick.)
Each narrative is followed to its conclusion, so beware of spoilers.
(Thanks, Sharon.)
I turn off the light when I leave the room and I turn it on again when I come back in a moment later. Is the shadow of the statue on the table the same one before and after the light is off? If we say it’s the same, then we accept the existence of strange, intermittent entities (in the same family as the flashing of the turn-signal light on a car). If we don’t like that idea, then we have to say that there are two different things: the shadow that was present before I turned off the light and the shadow present after I turn it on again. What’s different about them?
— Roberto Casati, The Shadow Club, 2003
(We might distinguish the two by observing that different photons are hitting the statue, but this seems to mean that a new shadow is produced every instant, and that doesn’t sound right either.)

Unusually, this puzzle may be easier for older readers.
The answer is R, the reverse gear on a manual gearshift.
This monster was found in the kingdom of Santa Fe, Peru, in the province of Chili and in the Lake of Fagua, located in the lands of Prosper Voston. It emerged during the night in order to devour the swine, cows and bulls of the area. Its length is eleven feet; its face is roughly that of a man; its mouth is as wide as its face; it is provided with teeth two inches long; it has twenty-four-inch horns like those of a bull; its hair reaches to the ground; it has four-inch ears like those of an ass; it has two batlike wings; its thighs and legs are twenty-five inches long and its claws eight; it has two tails, one very flexible and provided with rings that help it seize its prey, and the other ending in a dart which helps it kill; its entire body is covered with scales. The monster was captured by many men who had laid traps into which it fell. It was entangled in nets and brought alive to the viceroy, who succeeded in nourishing it with a steer, a cow, a bull, given to it every day with three or four swine, to which it is quite partial. As it would be necessary to load too great a quantity of cattle to nourish it during the crossing, which takes at least five or six months to pass Cape Horn, the viceroy has sent orders along the entire land route to provide for the needs of this unique monster while making it march by stages to the Gulf of Honduras, where it will embark for Havana. From there to the Bermudas, to the Azores, and in three weeks it will disembark at Cadiz. From Cadiz it will be taken by short trips to the royal family. It is hoped that the female will be captured so that the species will not die out in Europe. The species seems to be that of harpies, heretofore considered legendary.
— Courier de L’Europe, Oct. 22 and 29, 1784
(Another hoax, but a widely credited one. From the Bibliothèque Nationale: “This monster frequently emerged from Lake Fagua at night to devour pigs, cows and bulls. It has even been caught using nets; but needs feeding daily with an ox, cow or bull and three or four pigs.”)

In 2020 Brooklyn’s Honey & Wax Bookseller came into possession of a strange manuscript consisting of 7,000 illustrations, each 3 centimeters square. The images fill 106 loose sheets that often mimic European tourist brochures, and most bear captions that resemble no known language. The manuscript appears to have been created in Switzerland in the 1940s, but no one knows who created it or why. Notre Dame historian of science Robert Goulding wrote, “The fact that [the words] don’t seem to conform to any language or phonemes in any language is suspicious … suggesting to me that they are either a cipher, or there is some method or algorithm used to generate the words.”