## Friday, March 14, 2014

### The Logic of Pi Day

By Wendy Murray

Today is Pi Day. Why? -- "3", "1", and "4":  the first three digits of  Pi, or "π," in the decimal form, which technically continues infinitely without repetition or pattern. Pi is the ratio of the circumference of a circle to its diameter, which means it is an irrational number. An irrational number is a real number that cannot be expressed as a ratio "a/b," where "a" and "b" are integers and "b" is non-zero. (Other irrational numbers include Euler's number e, the golden ratio φ, and the square root of two √2.)

A real number is a value that represents a quantity along a continuous line.

An integer is a number that is written without a fractional component.

The Greek letter “π”  is the symbol used in mathematics to represent the constant which is approximately 3.14159. (A constant is is a "special number, usually a real number, that is 'significantly interesting in some way.'") It is possible to view Pi to the 10,000th digit and also to the 1,000,000th digit and to calculate it to the 2 billionth digit here. Good luck with that.

According to Pi Day. org, Pi’s infinite nature makes it a "fun challenge to memorize and to computationally calculate more and more digits," which is why some of us chose to major in English.

Coincidentally it is also Albert Einstein's birthday. He said, "If you can't explain it simply, you don't understand it well enough."

(Below is a screen shot of a portion of “π” to the 10,000th digit. Any mathematician who tries to make sense of it is doomed to frustration.)