How much excitement can an engineer stand? Just a few, short weeks ago we had a whole week in our honor, National Engineers Week. Just a few, short days ago we had another significant day, Pi Day. It’s almost overwhelming, don’t you agree?
On March 14, a growing celebration occurs: Pi Day. It sort of sneaks up on me, as the following day is the birthday of my only male child, along with my departed father. But then Pi Day starts to hit the news and social media. My pulse starts to quicken. Beads of anticipatory sweat line my brow. My palms get a bit clammy. I also get a sense of weird kinship with those on Facebook who put out pi-related posts. I might be a nerd.
Pi Day this year was especially significant, as we observed a once-in-a-century Pi Day. On March 14, 2015 at 9:26 (a.m. or p.m.), we experienced the historical moment when the first eight digits of pi existed in history…3.1415926. I KNOW, this is exciting! It might even be better than having a whole week for Engineers Week.
By now you may be asking yourself, “What in the world is he talking about?” I get that a lot.
Pi is defined as an irrational number. An irrational number is one that cannot be written as a repeating, or finite, decimal. It also cannot be written as a fraction, which is good, because who likes fractions, anyway? It was first developed by ancient Egyptians and Babylonians, which may explain how much free time they had ruling the world back then.
I think my first memory of pi was in grade school when we learned that the area of a circle is pi times the radius squared. It was a pretty memorable day, obviously, but as normal junior high kids my buddies and I did the typical “No, pie are round…” shtick. Hey, we thought we were funny then.
There are really only a very few formulae involving pi that affect my engineering life:
- Area of a circle A=πr2
- Circumference of a circle C=2πr
- Surface area of a sphere A=4πr2
- Volume of a sphere V=4/3πr3
Two of these drop out quickly, those involving spheres. I have not had to design a half-dome cover over a substation, for example. So, who cares how much material it would require or how much SF6 could be contained in the bubble?
Pi has played a significant role in my transmission line design life. The area of a circle is very important to determine the eventual volume of a drilled pier foundation that supports a steel transmission structure.
One time I was called on to help solve a foundation problem. The foundation was installed, but when the steel pole was attached, it swayed in the wind. The eventual problem was an inadequately installed foundation. I used pi to figure out the required volume of concrete. This calculation showed that the contractor had not even placed sufficient concrete to satisfy the original volume requirement. Pi was critical!
There are more stories from the utility industry that would relate to the “irrational” concept, but those are stories for another day…