## 3

As an engineer, I have a preference for the number 3. This number is so incredibly meaningful and versatile.

There are 3 dimensions in space that make up the component vectors of any vector in that space.

One wants at least 3 quotes for the cost of a product or service in order to have the possibility of getting a sense of a reasonable price.

3 is a great factor of safety. Design anything, then multiply the answer by 3 just to be sure.

And since 3 is a great number for having as the number of reasons that 3 is a great number, then I hesitate to mention any more of them. Suffice it to say, 3 is an engineering number.

## 2.5

It may not be true of all engineers, but for many of them the number 2.5 is an important number to remember. Actually, it may be more important for the family members to know this number.

When a project needs to be done around the home, like building a porch, or a subfloor for the basement, the average person will take a certain amount of time called X. Multiply that value of X by 2.5 and one arrives at the amount of time it will take the average engineer to get this project done. This is certainly not because the engineer is slow. Rather, the engineer is methodical, taking in consideration all options, running the numbers on cost and service life, calculating and recalculating the number of components – from boards to bricks to bolts – and quantifying all this in a spreadsheet, which includes at least three quotes on price for each component.

At work, the engineer is at the mercy of the timetable of the client. But at home, the engineer is the client, and, well, he is somewhat lenient with the contractor, who also happens to be himself.

A great deal of marital friction could be eased if, when dealing with a home project, the engineer’s wife understands this 2.5 factor. This is particularly critical since the engineer will typically state at the beginning of the project that the time it will take him will be X, the amount of time it takes for the project to get done by the average person.

## 3

The number 3 is a hidden number of importance for the engineer. That means that the engineer may or may not consciously think of it as an important number, but it is important, nonetheless. I say that mostly to be able to use the word, “nonetheless”.

Anyway, 3 is the minimum number of estimates an engineer will want to be “comfortable” with a decision on buying an item. The item may be a new car, a computer, or a sandwich. The word “comfortable” is in quotes because we need to remember that this is not an emotional “comfortable”, rather one of having a sense that things are right. In that way, it is a logical “comfortable”.

The way an engineer thinks of this concept of 3 is the following: Getting one quote is just plain wrong. The seller can raise the price and you would never know, thus ripping you off. Having two quotes, well, that is better, but if they are quite different from each other, it is difficult to know what the true value is. Having 3, and here I should say at least 3, the engineer has a great chance of seeing either all three estimates bunch up together, or two be close and the third be the outlier. Outliers are bad. Consider the word itself, a combination of “out” which is negative, and “lier” which sounds like “liar”, also negative.

Having 4 or 5 or 6 estimates is better, but running around getting all those quotes gets somewhat wasteful at some point, and making sure it is the same product with the same features gets more difficult the more comparisons one makes. So the engineer is “content” (a logical content) with getting 3 quotes. This is helpful if shopping with an engineer, particularly if you are a spouse who thinks just walking into one car dealership and buying the first car you like (especially if color is one major factor) is the way to go…

## 1.0

When an engineer makes a decision, from which car to buy to how long to stay at a relative’s house, he will do a benefit/cost (b/c) analysis. We have discussed this before on engineeringdaze.com.

We may also have mentioned the importance of the number 1, more precisely 1.0, to include the significant digit to the tenths. Today, we will emphasize this. We could take this to the hundredth or the thousandth or the millionth, but for most simple calculations, the tenths or hundredths will do. For now, we will keep to tenths.

What makes this number important to the engineer is that it is the tipping point, or the figurative line in the sand for the engineer when making a decision. If a b/c calculation results in a number greater than 1.0, then the activity is worth doing. Again, this can be from buying a roll of toilet paper to driving to the store for Tylenol because one of his kids “says” they have extreme pain from a baseball hitting their shin.

The difficult aspect about calculating a b/c ratio is that frequently either the benefit or cost is not easily quantifiable. If everything was given a monetary value, that would make life easy. But how do you measure the amount of whining of a kid with shin pain? How would one measure the annoyance level of spending time at the house of the relatives? How about the cost of sleeping on the couch rather than in bed if one decides not to buy flowers for an anniversary?

Fortunately, engineers are very creative when it comes to putting value on things. In highway safety engineering, we put a value on human life. If that is the case, and it is, then we certainly can place a value on the whining level of a kid with a hurt shin, or the pain level that kid supposedly is enduring. And when we place a value on the benefit and the cost, it is a simple matter to find the b/c ratio and decide, quite logically, that, say, maybe flowers aren’t waste of money.

It all has to do with 1.0 – is the b/c greater than or less than this. Life can be no simpler.

## IV

A number of weeks ago, we introduced Tork, Caveman Engineer. He was the first engineer in history – make that pre-history. Later, we introduced Torkus, Medieval Engineer, who lived in the difficult time of the Dark Ages and tried as he could to make the world a better place to live, as engineers are made to do. This week, we will introduce yet another engineer from the past: Torkitus, Roman Engineer. Torkitus lived in the first century BC, when the Roman Empire was forming out of the Roman Republic.

The number important to Torkitus was IV, or to us non-Romans, 4. This was not an engineering term, but one that made Torkitus realize that contracting out engineering services was sometimes a good thing to do.

Torkitus was the best known, most well-respected engineer of his day, so much so that he was hired as the emperor’s chief engineer. But, the emperor had high demands on Torkitus. He gave him IV main tasks: I – build an aqueduct system that would bring water to the cities, from the mountain springs, and include indoor plumbing in that project; II – construct a road system that could support inter-region commerce and the movement of troops; III – design and build building with arches and columns; and IV – devise and construct defense and weapons for the military.

“Oh, that’s all?” Torkitus mused to himself, knowing that any one of the tasks would consume him. So he did what any understaffed government employee would do – he hired consultants. These engineers were all gifted and had to bid for the contracts, and, as Torkitus read the names of the winning engineers, he stated, “These are the engineers for whom the contracts shall be let – Marcus, Anthonium, Maximus, and you, Brutus.” (Not the best three words to end the meeting on.)

Torkitus then managed the major areas and the Roman empire flourished. All of this thanks to the engineer, Torkitus. His success was Rome’s success, which was good, because failure meant torture and a miserable death.

## 3

3 is a number of simplicity and engineers use it to count the number of essential questions to ask when deciding to purchase an item. Here they are:
1. How much does it cost?

2. How long will it last?

3. Will it cause me to socialize with people?

The answer to 1. should be very little.

The answer to 2. should be very long.

The answer to 3. should be, “No.”

There is an expanded list we may cover in later posts, but these three pretty much sum it up. The implications are simple. The answers should be straight forward. No whimpy, “Will I feel better with this item?” If it is needed (which is really the first deal-breaker of a question) then the engineer will work through these three questions.
What could be easier?

## 156

We are continuing our look at the Olympics here at engineeringdaze.com. 156 is not a number near and dear to engineers, but it is a number that came up in the Olympics recently and one that reminds me how engineers can have fun with the Olympics, and indeed, improve various sports.

Today’s sport to improve is basketball. The USA team scored 156 points against a quite inferior opponent in a recent game. This is in a basketball game where there are 8 less minutes than in an NBA game. The Olympic games are split up into four 10-minute quarters. After the first quarter the American team had 49 points. At that pace they could have scored 196 points, so scoring “only”156 was a sign they eased up in the last three quarters.

Scoring 156 points means the team averaged 39 points a quarter, and 3.9 points every minute. And that is with the other team also possessing the ball and scoring 73 points of their own.

This brings me to an idea I have had for a while about basketball and how the broadcast networks can make the game more intriguing to engineers. We are all about numbers – rates, ratios, interpolation and extrapolation. I propose that every 15 or 20 seconds throughout a game, an alternate scoreboard is kept that will extrapolate out what the score will be if the rate at which the teams are scoring is maintained. At the end of the first quarter of the game mentioned above, the score was 49-25. That translates into a final extrapolated score of 196-100.

People would greatly enjoy not only watching the score of the game, but the extrapolated score as it would be updated three or four times every minute. The announcer could say, “Even though there are only 3 minutes and 20 seconds gone in the game, at this rate the (team ahead) will be scoring 136 points! What a rate!”

Didn’t I say engineers could make this game more fun.

## 3

Yet another fine number for engineers is 3. This number is intrinsic to many basic qualities of life as an engineer sees it.

3 is the number of points that define a plane, and, therefore, are the number of legs of a stable chair or stool.

3 is also the number of coordinate lines in, what else, 3-dimensional space. When engineers break down forces into components, there are 3 directions into which the forces are defined. They are called, in very technical terms, x-, y-, and z-coordinates. Creative? Maybe not. But powerful? Most definitely.

An engineer can explain so many thing by breaking down the vectors of force or velocity into its 3 coordinate directions. Why did his kid wreck the car? 3-dimensional coordinate analysis of the speed and direction of the car, and the 3-dimensional interaction of the forces between the car tires and the road, should adequately explain why the car left the road and hit the tree. Sure, the engineer Dad could simply say that his son or daughter was going too fast. But a far better explanation, and possibly a far better punishment, would be to have the 3 dimensional forces and velocities sketched out in a very detailed explanation of the movement of the vehicle. A finite element analysis could be added, too, just for the fun of it.

3 can be a very powerful number.

## 10

To continue with the basics, an engineer can’t get any more basic than 10. Base ten is what we use in scientific notation and in the metric system. It is no wonder that people typically say, “On a scale from one to ten, what did you think of…”

10 is the basic of basic, other than, maybe, 1, but let’s not get into an argument about that now.

Just being the root of the metric system, 10 gets my vote as being one of the all time great numbers, possibly the greatest. We have discussed the power of 10 before, and covered the number 1000, but the these have their roots, literally and figuratively, in the number 10. In fact, if you bring up the number 10 to an engineer, he will have an affinity for the conversation, even if he doesn’t know why. That number is so powerful and ingrained in the engineer’s wiring.

For non-engineers, try it next time you, say, see a bunch of cute bunnies. There are 8 or 9 of them. But tell the engineer there are 10 of them, and he may well listen to you go on about how cute they are. Otherwise, if he thinks there are 8 or 9, the whole aesthetics thing just won’t sink in.

## 620

Technically, the 620’s, are all good numbers for engineers. Why? Is it because 620 represents some perfect constant that is representative of some natural phenomenon that engineers can use for the good of society? Could it be because the numbers in the 620’s are all used to calculate forces, or movement that can be of benefit to our way of life, since that is what engineers do?

No. The 620’s are where engineers, and you in particular, can find library books about engineering as arranged by our friend, the Dewey Decimal system. This is a great number to remember. Next time you are in your local library, go to any of the books from 620 to 630, and start perusing. Books on civil, electrical, and mechanical engineering will abound. Fascinating books about wastewater treatment facilities, engines that run on alternate fuels, and the joys of electric currents are there to be explored.

620, and more broadly, the 620’s are a nice number for engineers.