## 0 (Zero)

Ah, yes, the ubiquitous number 0 (Zero). This is wonderful number for engineers. We will even explain why without having to resort to zero’s intricate value in its use in base ten, and how zero has been such a great help in weights and measurements – a great help if one uses the metric system, otherwise you are on your own.

Zero is used in so many applications of engineering. Engineers set numerous equations to zero to solve for them. Most notably, if an object or point is in equilibrium, then all the forces acting on it will add up to, you guessed it, Zero. This will be the case for all three directions in a space into which the forces are broken down (x, y, and z). So Zero is essential for analyzing any static object or system. If one wants to make sure air pressure is maintained in a building, then the amount pumped and the amount taken out must be equal, or, put it another way, the sum of the in and out amounts must equal Zero. To maintain a temperature in room or building, the heat added plus the heat lost (which will be negative) adds up to Zero.

The other numbers may make fun of Zero, for being a nothing, a loser, a, well, a Zero. But to an engineer, it is wonderful number and one to be respected.

## 13.3%

engineeringdaze.com has some wrap-up thoughts on baseball, now that the World Series just finished the season.
This number, 13.3% is not a number that represents anything to an engineer, except frustration regarding the pure lack of logic of some baseball stats. While watching a playoff game recently, a player was batting and a guy was on second base. The announcers stated that this player got hits 13.3% of the time that a runner was in scoring position. That is all well and good, and, as an engineer, I appreciate statistics which break down the game and explore different facets of the odds. They could have broken that statistic down for the player to dissect his hitting percent against left- and right-handed pitchers, outdoors versus domed stadiums, at night or in day games, in his first or second or third at bat, if he had a fielding error in the previous ten games or not, or whether they were playing on real or artificial turf. That kind of examination is fascinating to explore.

However, the guy at second only got there after the count was 2-1, by stealing second. The announcers didn’t talk about that. They didn’t state was this guy’s hitting percent was with men in scoring position but only getting there by stealing a base part-way through the batter’s at-bat which would obviously skew the hitting percent seeing as that he would have less opportunities to get a hit.

Here they are, and by “they” I mean the baseball “people”, with all these statistics and they fail to completely inform us of the true odds of what will about to take place. Disappointing? Most definitely. But, I will be OK. Baseball season is over and now I watch football. Which brings me to some illogical statistics from this past weekend…

## 10

Tork, caveman engineer, the first engineer in history, make that pre-history, returns for this week on engineeringdaze.com.

Tork noticed that when measuring things like the volume of water in the lake, or the distance to the cute cavewomanâ€™s cave, cave people used small numbers first, then when they need to go to a bigger measurement, they used a larger unit, but it was always a strange one. They multiplied the smaller measurement by 8. Why? Because the biggest caveman who always told all the other cavemen what to do had 8 fingers, not ten like Tork had, and most all other cavemen had.

For centuries, people blindly used this painfully difficult system of measurement based on the number 8, while the system Tork developed, based on the number 10, what became known as the Metork system, eventually lost favor with those in control who thought it might be too difficult to change systems.

Oh, how things could have been different.

## 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.

## 0.68

0.68 may be an important number to an engineer. Or it may be 0.67, or 0.69, or 0.70. Why are these numbers, bunched up in this area of the number line important to engineers. It comes down to one word: pace.
Engineers, moreso ones that are in the field frequently, sometimes have to measure distances by pacing. The pace is simply how far one goes with each step is taken, or the pace length. 0.68 is a typical distance, in meters, that an engineer may take in a pace, so that if that engineer were to pace off a field and take 88 paces, then the length of the field is approximately 88 x 0.68 = 59.84 meters, or about 60 meters. Sure, the pace may vary due to slope, wind, slickness of the surface, amount of clothing, etc., but many engineers know their pace length and will use it if ever forced into a situation when a distance is needed and no good measuring device is handy. Fortunately, the pace is always handy (which is ironic considering one uses the foot).

When you see an engineer seemingly walking along and it looks like he is counting, please do not ask what he is doing, nor ask him the time, or how far it is to Albuquerque, or anything else that will take his mind off the task. Let him pace and allow him the joy of measuring a long distance without the use of a tape measure or wheel or GPS device.

## METRIC WEEK – 5280

This week on engineeringdaze.com, we will pull together in one week some of the posts that were written to inform and to promote the metric system, an incredibly obviously superior system of measurement to the one we here in the United States use.

Hoping you are not like my coworker, “Wade”, who says that the problem with the English System is that it does have a metric…

Some may know that the number 5280 represents the number of feet in a mile. Many people don’t remember that. Why such a strange number? Who knows.

But because it is so strange and difficult to understand and remember, the engineer considers this a great number. It’s like a politician who doesn’t have to use negative advertising because his or her opponent keeps saying stupid things. 5280 is a great number because it represents the failure of the system of measurement we use in the USA. Who wants to or can remember numbers like that?

Instead, go with the metric system. With numbers like 10 and 1000, trust me, it’s much easier. It’s much easier than remembering numbers like 5280.

## 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.

## 8

A couple weeks ago, we learned that there are three basic questions that an engineer asks, either to himself, or to the family member spending family money, when considering the purchase of an item. The three are:

1. How much does it cost?

2. How long will it last?

3. Will it cause me to socialize with people?

Those, however, are simply the screening questions. A more complete list contains at least 8 questions when considering to purchase an item, the first three, plus five more (therefore, 8 – done without, but checked by, using a calculator):

4. What is the likelihood of the it breaking before the normal useful life?

5. What are the maintenance costs?

6. What are the costs to run or use the item? (like gas in a car or electricity in an electric toothbrush)

7. Will it help in any way to understand my wife (or girlfriend, or any female) better?

8. Will I ever have to make a presentation in front of people because I bought this item?

To go through all the answers favorable to purchase:

The answer to 1. should be very little.

The answer to 2. should be very long.

The answer to 3. should be, “No.”

The answer to 4. should be very low.

The answer to 5. should be very low.

The answer to 6. should be very low.

The answer to 7. should be yes, but skepticism to this answer means the weight of the answer is low.

The answer to 8. should be “No.” That’s a deal-breaker.