One of these Vermeers is a forgery. Which is it?
One of these Vermeers is a forgery. Which is it?
In old Konigsberg there were seven bridges:
Villagers used to wonder: Is it possible to leave your door, walk through the town, and return home having crossed each bridge exactly once?
Swiss mathematician Leonhard Euler had to invent graph theory to answer the question rigorously, but there’s a fairly intuitive informal proof. Can you find it?
The following riddles have the same answer. What is it?
Another puzzle from Henry Ernest Dudeney:
“Here is a curious mechanical puzzle that was given to me some years ago, but I cannot say who first invented it. It consists of two solid blocks of wood securely dovetailed together. On the other two vertical sides that are not visible the appearance is precisely the same as on those shown. How were the pieces put together?”
A secret hoard of $20 million in gold and silver lies buried somewhere near Roanoke, Va. That’s according to a coded message left by adventurer Thomas Jefferson Beale in the 1820s:
I have deposited in the county of Bedford, about four miles from Buford’s, in an excavation or vault, six feet below the surface of the ground, the following articles, belonging jointly to the parties whose names are given in number “3,” herewith:
The first deposit consisted of one thousand and fourteen pounds of gold, and three thousand eight hundred and twelve pounds of silver, deposited November, 1819. The second was made December, 1821, and consisted of nineteen hundred and seven pounds of gold, and twelve hundred and eighty-eight pounds of silver; also jewels, obtained in St. Louis in exchange for silver to save transportation, and valued at US$13,000.
The above is securely packed in iron pots, with iron covers. The vault is roughly lined with stone, and the vessels rest on solid stone, and are covered with others. Paper number “1” describes the exact locality of the vault, so that no difficulty will be had in finding it.
Unfortunately, no one has been able to decipher paper “1” or “3”, and a hundred years’ digging has turned up nothing. Is it a hoax? Who knows?
This is a little embarrassing — the CIA is having trouble decrypting a sculpture on its own grounds.
The piece, called Kryptos, was dedicated 15 years ago by American artist James Sanborn. It’s inscribed with four different messages, each encrypted with a different cipher. Sanborn would say only that the sculpture contains a riddle within a riddle, which will be solvable only after the four passages have been decrypted. He gave the complete solution to CIA director William H. Webster, who has passed it on to his successors.
The first three messages have been solved by CIA analysts, but the fourth — and the final riddle — remains open.
If you don’t want to work on this yourself, you can wait for Da Vinci Code author Dan Brown — reportedly it’s the subject of his next book.
Everyone likes a good riddle. In Chapter 7 of Alice’s Adventures in Wonderland, the Mad Hatter poses a famous one: “Why is a raven like a writing desk?” Lewis Carroll intended that it should have no solution, but puzzle maven Sam Loyd offered these anyway:
In 1896, Carroll proposed an answer himself: “Because it can produce a few notes, tho they are very flat; and it is nevar put with the wrong end in front!” (“Nevar” is “raven” spelled backward.)
The Incompatible Food Triad is a culinary puzzle: Name three foods such that any two of them go together, but all three do not.
The puzzle originated with University of Pittsburgh philosopher Wilfrid Sellars, and some notable thinkers have taken a crack at it. Physicist Richard Feynman thought he’d stumbled onto a solution when he accidentally asked for milk and lemon in his tea (ick), but this doesn’t quite work, as one of the “good” pairs (milk and lemon) is bad.
Best attempts so far: salted cucumbers, sugar, yogurt; orange juice, gin, tonic. Honorable mention: “Get pregnant, and you can eat anything.”
Newcomers are told that the name of the game is important. Someone rolls five dice and announces the “answer,” which is always zero or an even number.
That’s it. On each roll, the initiate has to give the correct answer before he’s told. When he can do this consistently, he becomes a Potentate of the Rose, pledged “to be a cruel and heartless wretch who will never divulge the secret of the game to anyone else.”
I’m told that the puzzle is a good index of intelligence — smart people take longer to figure it out.
Theseus and the Minotaur is a series of Java-based puzzles in which you have to escape a maze without getting mashed by a computerized monster that moves predictably. There are 14 levels, and I can’t get past level 4.
The interesting thing is that the puzzles were designed by a computer, and they’re now being used in AI experiments at the National University of Ireland. So computers are now solving puzzles designed by other computers.