# From Perl to Pi

By Susam Pal on 15 Apr 2008

I was learning Perl last weekend from the book Learning Perl, 3rd Edition by Randal L. Schwartz and Tom Phoenix. While reading the book, I came across these lines:

It's easier to type \$pi than $$\pi,$$ especially if you don't have Unicode. And it will be easy to maintain the program in case the value of $$\pi$$ ever changes.379

The corresponding footnote mentions:

379 It nearly did change by a legislative act in the state of Indiana. http://www.urbanlegends.com/legal/pi_indiana.htm

I searched the web and found that the original urbanlegends.com website is no longer there. However while searching for it, I came across this brilliant piece of humour archived in the article titled Alabama's Slice of Pi on Snopes. It is a fictitious report on a state legislature redefining the value of $$\pi$$ to 3.

The Snopes artile mentions that this piece of humour was first posted in a newsgroup. Then people started circulating it as hoax from there. Here are some of the intriguing and funny bits from it:

Lawson called into question the usefulness of any number that cannot be calculated exactly, and suggested that never knowing the exact answer could harm students' self-esteem.
Scientists have arbitrarily assumed that space is Euclidean, he says. He points out that a circle drawn on a spherical surface has a different value for the ratio of circumfence to diameter.

In fact, with a little geometry we can see that if a flatlander living on a globe with diameter $$D$$ draws a circle of diameter $$d$$ assuming that he is on a flat surface, then the ratio of the circumference $$c$$ to the diameter $$d$$ is $\frac{c}{d} = \frac{\pi D}{d} \sin{\frac{d}{D}}.$

Here are a few more excerpts from the Snopes article:

"These nabobs waltzed into the capital with an arrogance that was breathtaking," Learned said. "Their prefatorial deficit resulted in a polemical stance at absolute contraposition to the legislature's puissance."
One member of the state school board, Lily Ponja, is anxious to get the new value of pi into the state's math textbooks, but thinks that the old value should be retained as an alternative. She said, "As far as I am concerned, the value of pi is only a theory, and we should be open to all interpretations." She looks forward to students having the freedom to decide for themselves what value pi should have.

By the way, the real event that the footnote in the Learning Perl book mentioned is the Indiana Pi Bill.