Pi Day
Published on Mar 14, 2009 at 2:11 pm.
1 Comment.
Filed under math.
March 14 is celebrated as Pi Day here in the US. That is because we write March 14 as 3-14 (backwards from how many countries do it). 3.14 are the first three digits of pi.
Pi, in mathematics, is the ratio of the circumference of a circle to its diameter. It’s value is 3.14159265358979 through its first 15 digits. As it turns out, pi is an irrational number. It cannot be written as the ratio of two rational numbers. It also keeps going, never repeating, for an infinite number of digits. Pi has been computd out to over a trillion digits now, though there is no real need for the average person to ever have to use that many digits. Even non-average people don’t generally need that many digits! In fact, most people can get by with just the first three digits, 3.14. I usually go a few more digits when I use pi, and, of course, it is easy to just hit the pi button on the calculator, and that gives plenty of digits for anything that I’ve ever needed. Pi is used for a lot more than just figuring circles, though. It shows up over and over again in all sorts of applications. Of course, that is because many formulas are computed for situations of constant distance from some point. That description automatically means that you will deal with either a circle or a sphere, depending upon whether you are in two or three dimensions.
The Greek letter pi is used to symbolize the concept of the ratio of the circumference of a circle to its diameter because pi was the first letter in the Greek work for perimeter. Mathematician William Jones, apparently first used the letter in this manner, and the idea became wide spread after the famous mathematician Leonhard Euler picked up the usage.
In the US, Pi Day was created to further mathematical awareness. It even has its own web page! Since we desperately need more mathematical awareness among our students here, I thought that I’d also promote it here on my web page.
For those that are really interested, there are a number of good books about Pi, including the The Joy of Pi
So, go out and eat some pie today!
-Astroprof
Seeking Solace on March 14, 2009 at 3:49 pm: 1
And a Happy Pi Day right back!