By George Gibson
(From the editor: This article was published on 3-14-15 at 9:26 a.m. EDT. In the interest of math, I stipulate that it took 53 seconds for the article to move from “pending” status to “published.”)
We use pi to understand lots of things in our lives, because lots of things are described in terms of “waves.” (Waves on a lake, for example.)
This image (right) is about as technical as I will get.
It shows the simple, repetitive “up-ing” and “down-ing” of waves when you turn on things like the lights, a radio, or your microwave oven. Pi is central to how we describe these patterns.
How We See Pi in Our Lives
It’s true. The world runs on math, and pi is one of those numbers that we cannot do without. Here are a few examples:
Pi in the sky: Whenever you use your smartphone to connect to the world over WiFi, you become one with pi. The signals that connect you to the world cannot be described without pi.
Pi in the eye: Light also travels as a wave. In fact, the radio signals and microwaves I mentioned earlier are simply a different “color” of light. So when you drive through a toll booth that reads your license plate, pi helps us describe how the light gets to the plate to illuminate it, how the reflected light travels back to the camera, and how that light travels through the lens. Pi helps the camera begin to make sense out of the signals it receives.
What’s true for license plate cameras is true for other cameras as well. When you scan or copy a document — or when you scan a three dimensional object for your 3D printer — the algorithms that describe how the light that hits the object, bounces off it, collects the light and analyzes it, all have pi at their heart.
Patriots’ Pi: Want to know what happened to those footballs in New England? The pressure inside those balls depended on the amount of air that was in them, the temperature, and the volume of the inside of the ball. Guess what: You need pi in order to calculate that volume!
George Gibson is a research and development manager for PARC, A Xerox Company; he is listed as co-inventor on 56 patents. He spends a fair amount of his spare time creating sound waves (that can be measured with pi) on Waldeau, his Martin D35 guitar.
