Time Trouble

A letter from 14-year-old Jim Nicholson to Wonder Stories, February 1931:

Some time ago you asked us (the readers) what our opinions on time-traveling were. Although a bit late I am now going to voice four opinions …

(1) Now, in the first place if time traveling were a possibility there would be no need for some scientist getting a headache trying to invent an instrument or ‘Time-Machine’ to ‘go back and kill grandpa’ (in answer to the age-old argument of preventing your birth by killing your grandparents I would say: ‘now who the heck would want to kill his grandpa or gandma?’) I figure it out thusly:

A man takes a time-machine and travels into the future from where he sends it (under automatic control) to the past so that he may find it and travel into the future and send it back to himself again. Hence the time machine was never invented, but! — from whence did the machine come?

(2) Another impossibility that might result would be:

A man travels a few years into the future and sees himself killed in some unpleasant manner, — so — after returning to his correct time he commits suicide in order to avert death in the more terrible way which he was destined to. Therefore how could he have seen himself killed in an entirely different manner than really was the case?

(3) Another thing that might corrupt the laws of nature would be to:

Travel into the future; find out how some ingenious invention of the time worked; return to your right time; build a machine, or what ever it may be, similar to the one you had recently learned the workings of; and use it until the time you saw it arrive, then if your past self saw it, as you did, he would take it and claim it to be an invention of his (your) own, as you also did. Then — who really did invent the consarn thing?

(4) Here’s the last knock on time traveling:

What if a man were to travel back a few years and marry his mother, thereby resulting in his being his own ‘father’?

Now I ask you, do you think traveling in time, in the manner most of your authors put it, is possible? (Now please don’t get the idea that I think it can’t be done, to some extent, because it might be done through Suspended Animation).

Editor Hugo Gernsback responded, “Logically, we are compelled to admit that he is right — that if people could go back into the past or into the future and partake of the life in those periods, they could disturb the normal course of events, as Mr. Nicholson has pictured it.”

Mission Accomplished

https://www.bbc.com/news/uk-england-cornwall-57670098

The Royal Mail just delivered this letter, correctly, to Catrina Davies of Cornwall, who had discussed affordable housing on travel documentarian Simon Reeve’s BBC series in November.

“It’s just great that they made the effort and didn’t just throw it away,” Davies said.

On the envelope, the sender had written, “Royal Mail never fails.”

(Thanks, Alex.)

Inventory

The following pair of sentences employ 2 ‘0’s, 2 ‘1’s, 9 ‘2’s, 5 ‘3’s, 5 ‘4’s, 4 ‘5’s, 5 ‘6’s, 2 ‘7’s, 3 ‘8’s and 3 ‘9’s.

The sentences above and below employ 2 ‘0’s, 2 ‘1’s, 8 ‘2’s, 6 ‘3’s, 5 ‘4’s, 6 ‘5’s, 3 ‘6’s, 2 ‘7’s, 2 ‘8’s and 4 ‘9’s.

The previous pair of sentences employ 2 ‘0’s, 2 ‘1’s, 9 ‘2’s, 5 ‘3’s, 4 ‘4’s, 6 ‘5’s, 4 ‘6’s, 2 ‘7’s, 3 ‘8’s and 3 ‘9’s.

(From Lee Sallows and Victor L. Eijkhout, “Co-Descriptive Strings,” Mathematical Gazette 70:451 [March 1986], 1-10.)

The British Flag Theorem

https://commons.wikimedia.org/wiki/File:British_flag_theorem_squares.svg

Draw a rectangle and pick a point inside it. Now the sum of the squares of the distances from that point to two opposite corners of the rectangle equals the sum to the other two opposite corners.

Above, the red squares have the same total area as the blue ones.

The Garden of Eden

https://en.wikipedia.org/wiki/File:Lower_East_Side_in_Adam_Purple%27s_Garden_1984..jpg

When a building was razed in 1973 on Eldridge Street on Manhattan’s Lower East Side, local resident Adam Purple cleared the lot, gathered manure left by horse-drawn carriages around Central Park, and designed a garden laid out in concentric circles around a central yin-yang symbol. As nearby buildings were torn down he added further circles, until the garden filled 15,000 square feet with corn, cucumbers, cherry tomatoes, asparagus, black raspberries, and strawberries.

The city bulldozed Purple’s lot in 1986, but Richard Reynolds’ London-based blog now documents similar “guerrilla gardening” initiatives around the world.

Harmony

A problem from the January 1990 issue of Quantum: Forty-one rooks are placed on a 10 × 10 chessboard. Prove that some five of them don’t attack one another. (Two rooks attack one another if they occupy the same row or column.)

Click for Answer

Quickie

One other quick item from Eureka, the journal of the Cambridge University Mathematical Society:

In its 1947 problem drive, the society proposed the following problem:

To find unequal positive integers x, y, z such that

x3 + y3 = z4.

“Although there were some research students in Theory of Numbers among those who tried, not one person succeeded in solving it within the time, yet the solution is extremely simple.” What is it?

Click for Answer

Podcast Episode 348: Who Killed the Red Baron?

https://commons.wikimedia.org/wiki/File:Captain_Manfred_Baron_von_Richthofen_with_dog,_Germany,_WWI_(29345003121).jpg

In 1918, German flying ace Manfred von Richthofen chased an inexperienced Canadian pilot out of a dogfight and up the Somme valley. It would be the last chase of his life. In this week’s episode of the Futility Closet podcast we’ll describe the last moments of the Red Baron and the enduring controversy over who ended his career.

We’ll also consider some unwanted name changes and puzzle over an embarrassing Oscar speech.

See full show notes …