The Value of Pi

THE VALUE OF PI….Warren Buffett writes today in the Washington Post that the United States House of Representatives is about to commit an act of lunacy. It is prepared to pass a bill mandating that stock options should be counted as an expense ? basically a good idea since they are, after all, an expense ? but that they should be counted as an expense only for the top five executives of a company. For some reason, options that count as an expense for the top five are mysteriously not an expense for anyone else.

Buffett is right that this is crazy, but the real provocation for posting about this is his comparison of this bill to an act of the Indiana House in 1897 mandating that pi be equal to 3.2. This is very close to correct, but since this is such a common story I thought I’d take this opportunity to set the record straight on what really happened. Here’s the complete story:

  • A bill written by a crank named Edwin Goodman was introduced into the Indiana legislature in 1897 by Goodman’s representative, Taylor I. Record. The bill specified that “the circular area is to the square on a line equal to the quadrant of the circumference, as the area of an equilateral rectangle is to the square on one side.”

    Assuming that this was just a transcription error for “equilateral triangle,” this mandates a value for pi of 9.23. In another section of the bill the value for pi appears to be 3.2, and in yet another section the author offers as “a gift to the State of Indiana” solutions to the trisection of the angle, duplication of the cube, and the squaring of the circle.

  • The bill was referred to the Committee on Swamp Lands, which passed it to the Committee on Education, which recommended passage. The House passed the bill 67-0.

  • In the Senate the bill was referred to the Committee on Temperance, which recommended passage. It was passed through a first reading without comment.

  • By chance, a Purdue mathematics professor named C.A. Waldo was visiting the State Capitol on other business while all this was going on. Upon learning what was in the text of the bill, Waldo did a little mathematical coaching and the Senate voted to postpone further consideration of the bill indefinitely. It hasn’t been heard of since.

It’s also worth noting that Goodman’s original intent was to coax Indiana into passing the bill by offering his discoveries for use within Indiana royalty free. Everyone else would have to pay.

This all comes from a very well documented chapter in Petr Beckmann’s excellent A History of Pi. Now you know.

UPDATE: Just to make something clear, there are many urban legends about some legislature somewhere mandating pi equal to 3 ? usually for Biblical reasons, not crank reasons as in this case. However, as far as I know (and as far as Petr Beckmann knows, which is more important), the 1897 Indiana bill is the only documented case of it actually (almost) happening in the United States.

UPDATE 2: Fixed the transcription in the first bullet. The handwritten copy of the bill (included in Beckmann’s book) does not match his transcription. He left out the underlined portion.