## 3. 14159265358979323846264338…

Yes, pi, an important concept to mathematicians, is also a great number for engineers. Engineers don’t get all emotional, or verklempt, or sensitive about pi, like mathematicians do. Mathematicians can be so emotional – at least when compared to engineers. Mathematicians even celebrate pi day, March 14, or 3.14, as a tribute to pi, and as an excuse to eat pie. Trust me. I know this for a fact. I have a brother who, along with his wife, are both math professors and they have a pi day party every year.

But, whereas mathematicians get so very emotional about this concept pi, engineers simply use the number. It shows up in many places – tucked into equations, sprouting out of various engineering applications, and materializing in all sorts of engineering phenomenon. Mathematicians can talk about the theory of pi, like, “Is there an end to it?” But engineers simply use the number for improving our way of life.

Let the math nerds have their pie. Engineers, the cool ones, will continue to use pi and numbers like it to serve society in their everyday lives, superheroes in disguise.

## The Equation to Understand the Engineer and Public Speaking

As with most things engineering, an equation always helps to understand life. For the engineer giving presentations, this holds true. Let’s look at how good engineers do as public speakers, by analyzing the equation that explains how good the presentation is:

Q = (0.3*K)*(1/R)*(1/V)*(1/A)*(1/J)

where,

Q = Quality of the presentation by an engineer

K = Knowledge level of the subject

R = Resistance to speaking

V = Volume, or number of people in the audience

A = Deficiency of the visual aids

J = Inability to tell jokes

In this equation, the quality of the presentation is inversely proportional to the resistance to speak, the number of people in the audience, the deficiency of the visual aids, and the inability to tell jokes.  The sad truth for the engineer is that the values of all of these factors are typically quite high, meaning they bring the quality of the presentation WAY down.  To make things worse, the strong suit for engineers in public speaking, their grasp of the subject matter, though proportional to the quality of the presentation, only contributes by a factor of 0.3.  In other words, it doesn’t look good for the engineer as a public speaker.

But at least the engineer now can understand this lack of presentation quality. Equations are good.

## Engineer – Defined

I think it important to define: Engineer. To define the person may be difficult in one short post. There would need to be lot of writing to explain the person who is an engineer. But I’m talking about the word engineer.  From Oxford’s English Dictionary, it seems that engineer did NOT come from a word meaning geek, or socially inept, or poor public speaker, as some might think.  It originated from the Latin ingenium for which the original concept was ‘ingenuity, cunning’ (surviving in Scots as ingine). It’s where we get the word ingenious, which I take as a compliment. Engineers solve problems in creative ways. It is also where we get the word engine which is also a compliment. Engineers get things done.

So, for all the engineers out there, the next time someone asks you where your pocket protector is, or “pretends” to go to sleep while you explain something, or coughs while saying the word “geek” under his breath, well, I think it’s time for that person to learn a little Latin.

For the non-engineers out there, maybe now we can get some respect. Or else the next time you might need help with calculating the angle of trajectory to optimize your softball pitch, we just may conveniently not be around.

## It All Starts at an Early Age

When is a person an engineer? Officially, a PE license helps. Educationally, a BS in engineering will do. But, an engineer is frequently an engineer beginning at a young age. Make that a very young age.

I recently got talking to the wife of an engineer in the town I live. She said that when he was very young, under 10, I believe, he loved to take things apart and put them back together, but especially put things back together. He was going to be an engineer, whether he knew the the term or not.

His grandmother used to prepare for his visits by taking apart various things around the house – lamps, furniture, kitchen appliances – and “ask” him to help by putting them back together. It may have been when he was in his 30’s or 40’s when he finally found out that those things didn’t just fall apart by themselves, or his grandmother didn’t take them apart because they weren’t working, but she actually saw the engineer in him at that early age, and, well, encouraged it.

His wife said that he still puts things back together, but that she doesn’t take them apart for him. He has to do that himself. And he does.

## You Might Be an Engineer If…

– you’ve ever sketched out a graph on a scrap of paper or napkin in order to prove a perfectly logical point to your spouse, or a total stranger, only to receive a blank stare.

## 3600

What is so interesting to an engineer about 3600? Well, here’s the explanation. When an engineer goes on a trip, especially with the family, he does not want to be listening to what his kids call music, or what his wife calls conversation. Not when a road trip presents so many wonderful opportunities for calculations to be done – What mpg is the car getting? What is our average speed, even considering stops? What is our ETA?

3600 starts them all. The first thing to do is check to see if the speedometer is giving us the proper reading. Assuming you are on an interstate, lock in the cruise control, then measure the seconds between mile markers. And, here is the tricky part, divide that number of seconds into 3600. This yields the mph you are going. Then compare this to the speedometer. You can try this for different speeds – 60, 65, 70, etc. If there are differences, the family can discuss whether this is because the speedometer is actually off, or if the tires may be under-inflated, or other reasons.

So, put away the Disney DVDs, get out a stopwatch and calculator (or use your smart phone), and really enjoy the drive.

Use the number 3600. The engineer in the family will appreciate it.

(For a whole lot of fun, convert it to metric!)

## The Pizza Equation

A friend of mine who is an engineer asked his wife, a  non-engineer (NE), to join him and the other engineers in his office for a pizza lunch.  Upon her arrival, she apologized to the group by saying she was sorry if her presence meant less pizza for everyone.

“That’s OK,” they said.  “We already factored you into our pizza equation.”  Sure enough they had an equation for calculating the amount of pizza to order.  It was something like:

PA = Pm*ym + Pw*yw

Where,

PA = Area of pizza needed, in square inches

Pm = Average area of pizza eaten by a man, in2

ym = Number of men

Pw = Average area of pizza eaten by a woman, in2

yw = Number of women

The values Pm and Pw acknowledge, without casting aspersions at either gender, that men, on average, eat more than women.  Also, the values can be updated for the population group if continuing observational analysis warrants it. They kept track of Pm and Pw, simplified the equation and developed a table for the areas of the different sizes of pizzas, optimizing for cost, of course.

As for implementation, it is likely that at least one of the engineers in the group had already coded the equation in Fortran or in an Excel spreadsheet in order to automate this mundane task.

As engineers, we ask: What could be more logical?

(Note: A sharp-minded engineer will point out that the engineers in this example have already made a huge concession to the NE world by doing all the calculations in the English system.)