Tuesday, April 1, 2014

The Joy of Number Theory ;-)

Number theory is both one of the most interesting and arcane areas of all mathematics… arcane in that oftentimes findings or proofs within the field appear to have no practical application. Such was true of a finding from four decades ago which had no known application until this very week. As reported back in 1975:
"…when the transcendental number e is raised to the power of π times √163, the result is an integer. The Indian mathematician Srinivasa Ramanujan had conjectured that e to the power of π√163 is integral in a note in the Quarterly Journal of Pure and Applied Mathematics (vol. 45, 1913-1914, p. 350). Working by hand, he found the value to be  262,537,412,640,768,743.999,999,999,999,…. The calculations were tedious, and he was unable to verify the next decimal digit. Modern computers extended the 9's much farther; indeed, a French program of 1972 went as far as two million 9's. Unfortunately, no one was able to prove that the sequence of 9's continues forever (which, of course, would make the number integral) or whether the number is irrational or an integral fraction.
"In May 1974 John Brillo of the University of Arizona found an ingenious way of applying Euler's constant to the calculation and managed to prove that the number exactly equals 262,537,412,640,768,744. How the prime number 163 manages to convert the expression to an integer is not yet fully understood."
Only recently was it realized that this arcane mathematical number-theory result, which is now much better understood, could be put to practical use… by bloggers wishing to entertain on April 1st, 2014! ;-))

Yes, the above, for any who don't immediately recognize it, was an April Fool's fabrication from prankster Martin Gardner for his classic April 1975 column in Scientific American. While the reference to Ramanujan is true (except that Ramanujan knew the number involved was transcendental), and the computed number, as given, is accurate as far as it goes, the rest of the passage was a hoax that fooled many at the time ("John Brillo" was a play on the name of another number theorist). The next digit following the string of 9's that Martin listed, is actually a "2".
You can read a bit more about the interesting number from this old journal article (Pi Mu Epsilon Journal, Vol. 5, Fall 1972, No. 7, pgs. 314-15; "What Is the Most Amazing Approximate Integer in the Universe?" by I.J. Good):


My quotation above comes from chapter 50 of Martin Gardner's "The Colossal Book of Mathematics." Of course, after all these years he still entertains us.

Ohhh, and by the way, your shoelaces are untied!....

1 comment:

Unknown said...

Dear Shecky Riemann,

My name is David Elkins. I came up with a math idea. I was hoping that you would take a look at it.

a) 4/4 =1
b) 4/4/4 = 4
c) 4/4/4/4= 1
d) 4/4/4/4/4 = 4
e) 4/4/4/4/4/4 = 1

I'm starting with a 4 and moving to the right.

Best Regards, David Elkins,