The Necktie Paradox

http://www.sxc.hu/photo/599259

You and I are having an argument. Our wives have given us new neckties, and we’re arguing over which is more expensive.

Finally we agree to a wager. We’ll ask our wives for the prices, and whoever is wearing the more expensive tie has to give it to the other.

You think, “The odds are in my favor. If I lose the wager, I lose only the value of my tie. If I win the wager, I gain more than the value of my tie. On balance I come out ahead.”

The trouble is, I’m thinking the same thing. Are we both right?

| Oddities · Science & Math

Math Notes

73939133
7393913
739391
73939
7393
739
73
7

… are all prime. So are:

357686312646216567629137
57686312646216567629137
7686312646216567629137
686312646216567629137
86312646216567629137
6312646216567629137
312646216567629137
12646216567629137
2646216567629137
646216567629137
46216567629137
6216567629137
216567629137
16567629137
6567629137
567629137
67629137
7629137
629137
29137
9137
137
37
7

But see Not So Fast.

| Science & Math

Recursive Gratitude

Mathematician J.E. Littlewood once wrote a paper for the French journal Comptes Rendus. A Prof. M. Riesz did the translation, and at the end Littlewood found three footnotes:

I am greatly indebted to Prof. Riesz for translating the present paper.

I am indebted to Prof. Riesz for translating the preceding footnote.

I am indebted to Prof. Riesz for translating the preceding footnote.

Littlewood notes that this could have gone on indefinitely but “I stop legitimately at number 3: however little French I know I am capable of copying a French sentence.”

| Language · Science & Math

Pop Quiz

When calculating prodigy Truman Henry Safford was 10 years old, the Rev. H.W. Adams asked him to square the number 365,365,365,365,365,365 in his head. Dr. Adams wrote:

He flew around the room like a top, pulled his pantaloons over the tops of his boots, bit his hands, rolled his eyes in their sockets, sometimes smiling and talking, and then seeming to be in agony, until in not more than a minute said he, 133,491,850,208,566,925,016,658,299,941,583,225!

Safford (1836-1901) went to Harvard and became director of the Hopkins Observatory at Williams College. Strangely, his calculating abilities seemed to wane as he got older.

| Oddities · Science & Math

Euler’s Identity

You know these numbers:

constants

On the surface they appear unrelated. e is the base of natural logarithms, i is imaginary, π concerns circles. But, amazingly:

Euler's identity

Harvard mathematician Benjamin Peirce told a class, “It is absolutely paradoxical; we cannot understand it, and we don’t know what it means, but we have proved it, and therefore we know it must be the truth.”

| Science & Math