Three of a Kind

http://commons.wikimedia.org/wiki/File:2005-Penny-Uncirculated-Obverse-cropped.png

This trick seems to have been invented independently by Martin Gardner and Karl Fulves. A blindfolded magician asks a spectator to lay three pennies on a table, in any arrangement of heads and tails. The magician’s goal is to put all three coins into the same state, all heads or all tails.

If the three coins already match, then the trick is done. If not, then the magician gives three instructions: Flip the left coin, flip the middle coin, flip the left coin. After each step he asks whether the three coins now match. By the third flip, they will.

“It’s no surprise that the magician can eventually equalize all the coins,” writes MIT computer scientist Erik Demaine, “but it’s impressive that it always takes at most three moves.” The technique exploits a principle used in Gray codes, which are used to reduce errors when using analog signals to represent digital data. Demaine relates a similar trick involving four coins in the November-December 2010 issue of American Scientist.

See Lincoln Seeks Equality.

| Science & Math

Sound Rhymes

Peculiarly English limericks:

There was a young lady named Wemyss,
Who, it semyss, was troubled with dremyss.
She would wake in the night,
And, in terrible fright,
Shake the bemyss of the house with her scremyss.

A pretty school-mistress named Beauchamp,
Said, “These awful boys, how shall I teauchamp?
For they will not behave,
Although I look grave
And with tears in my eyes I beseauchamp.”

There was a professor of Caius
Who measured six feet round the knaius;
He went down to Harwich
Nineteen in a carwich,
And found it a terrible squaius.

There lived a young lady named Geoghegan,
The name is apparently Peoghegan,
She’ll be changing it solquhoun
For that of Colquhoun,
But the date is at present a veoghegan. (W.S. Webb)

An author, by name Gilbert St. John,
Remarked to me once, “Honest t. John,
You really can’t quote
That story I wrote:
My copyright you are infrt. John.” (P.L. Mannock)

See This Sceptred Isle.

| Humor · Language · Poems

All Roads

http://www.sxc.hu/photo/434247

A self-working card trick by New York magician Henry Christ:

Shuffle a deck thoroughly and deal out nine cards in a row, face down. Choose a card, look at it, and assemble the nine cards into a stack face down, with the chosen card at the top. Add this stack to the bottom of the deck.

Now deal cards one at a time from the top of the deck into a pile, face up, counting backward from 10 as you do so. If at some point the card’s rank matches the number said, then begin dealing into a new pile at that point, counting again backward from 10. If you reach 1 without a match occurring, then “close” that pile by dealing a face-down card onto it, and start a new pile.

Keep this up until you’ve created four piles. Now add the values of any face-up cards on top of the piles, count down through the remaining cards until you’ve reached this position, and you’ll find your chosen card.

This works because it always leads to the 44th card in the deck, but it takes some thinking to see this. You can put a sealed deck into a stranger’s hands and direct him to perform the trick himself, with mystifying results.

| Entertainment · Science & Math

Two in One

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

Look at this image closely and you’ll see the features of Albert Einstein.

But look at it from across a room and you’ll see Marilyn Monroe.

It’s a “hybrid image,” created using a technique developed by Aude Oliva of MIT and Philippe Schyns of the University of Glasgow. The image combines the low spatial frequencies of one picture with the high spatial frequencies of another, so that it’s processed differently at different viewing distances.

See their paper for the details, and this gallery for more examples.

| Oddities · Science & Math

Podcast Episode 55: The Dyatlov Pass Incident

https://commons.wikimedia.org/wiki/File:Dyatlov_Pass_incident_02.jpg

On February 1, 1959, something terrifying overtook nine student ski-hikers in the northern Ural Mountains. In this episode of the Futility Closet podcast we’ll recount what is known about the incident at Dyatlov Pass and try to make sense of the hikers’ harrowing final night.

We’ll also hear how Dwight Eisenhower might have delivered the Gettysburg Address and puzzle over why signing her name might entitle a woman to a lavish new home.

See full show notes …

| Oddities · Podcast

Insight

http://commons.wikimedia.org/wiki/File:Fran%C3%A7ois_de_La_Rochefoucauld.jpg

Maxims of François VI, Duc de La Rochefoucauld (1613–1680):

  • “An extraordinary Haste to discharge an Obligation is a Sort of Ingratitude.”
  • “Did we not flatter ourselves, the Flattery of others could never hurt us.”
  • “Before we passionately desire a Thing, we should examine into the Happiness of its Possessor.”
  • “Few Men are able to know all the Ill they do.”
  • “Fortune never seems so blind to any as to those on whom she bestows no Favours.”
  • “Happiness is in the Taste, not in the Thing; and we are made happy by possessing what we love, not what others think lovely.”
  • “Men may boast of their great Actions; but they are oftner the Effects of Chance, than of Design.”
  • “The Glory of great Men ought always to be rated according to the Means used to acquire it.”
  • “We should manage our Fortune as our Constitution; enjoy it when good, have Patience when ’tis bad, and never apply violent Remedies but in Cases of Necessity.”
  • “We bear, all of us, the Misfortunes of other People with heroic Constancy.”
  • “Whatever great Advantages Nature can give, she can’t without Fortune’s Concurrence make Heroes.”

And “Hope, deceitful as it is, carries us thro’ Life agreeably enough.”

| Literature · Quotations

Star Power

http://commons.wikimedia.org/wiki/File:Pentagram.svg

A puzzle by A. Korshkov, from the Russian science magazine Kvant:

It’s easy to show that the five acute angles in the points of a regular star, like the one at left, total 180°.

Can you show that the sum of these angles in an irregular star, like the one at right, is also 180°?

Click for Answer
| Puzzles · Science & Math