Pi Day, 300th Anniversary
By Tom Barnett
“Probably no symbol in
mathematics has evoked as much mystery, romanticism, misconception, and
human interest as the number pi (π).”
—William L. Schaaf, Nature and History of Pi
The Greek letter
π
was first used for the value 3.1415 in the publication, “Synopsis
Palmariorium Mathesios,” written by William Jones in 1706. So, 2006 will
be the 300th anniversary of the use of
π
as a mathematical symbol.
March 14 is an incredible celebration day this year. In the U.S., this
date is written 314, or 3/14, which uses the first three digits of pi,
3.14. In the international style, this would be written as 14/3, so this
is clearly an informal American celebration. A lot of technical writers
work with engineers who use a lot of mathematics, and they may be
familiar with Pi Day.
The “ultimate” pi day in history occurred on March 14, 1592, at 6:53:59
AM (3/14/1592 6:53:59), which uses the first twelve digits of pi,
3.14159265359 (with the last digit rounded).
The Math
For those interested in the mathematical side of pi, here’s some facts.

Pi is a constant equal
to about 3.14159 26535 89793 23846 26433 83279 50288 41971 69399
37510 58209 74944 59230 78164 06286 20899 86280 34825 34211 70679
82148 08651 . . .

Pi is equal to C/2r,
where C is the circumference of a circle and r is the
radius.

The area of a circle
is equal to 2πr,
where r is the radius of the circle.

The number of digits
of pi needed to calculate the circumference of the universe to
within one angstrom* is 35.
Birthdays
Coincidently, March 14 is
also the birthday of a famous quantum physicist, Albert Einstein who was
born in 1879 in Germany. Some familiar Einstein Quotes include:
Everything should be made as
simple as possible, but not simpler.
Reality is merely an illusion, albeit a very persistent one.
The ideas that have lighted my way have been kindness, beauty, and
truth.
I never think of the future. It comes soon enough.
March 14 is also the birthday of mathematician you might have heard of:
Waclaw Sierpinski (1882). He is famous for the Sierpinski Triangle. See
Wikipedia
for a description.
And, March 14 has a full moon to celebrate everything happening that
day!
* An angstrom is a unit of measure
equal to 1 hundredmillionth of a centimeter.
