Science is Applied Engineering

We were designing and building things long before we had a “scientific” methods and mathematical solution techniques – and we still do today.  Did we need to wait for mathematical understanding of a hanging chain before we could build catenaries?  Of course not.   We didn't need to wait for Galileo and Bernoulli to create architecture.   We didn't need Euler to design columns.  We as structural engineers should recognize that while science and math are critically important to what we do, they do not define us - and history tells us, they never did.  How can we be defined as applied scientists when engineering predates science? I am particularly suspicious of the idea that our masterbuilders, craftmen, and masons of the past did not understand flexure and compression basics (top of beam is in compression for example or rules for column slenderness).    They may not have had the proper formulas but they certainly had a better intuition than we give them credit.  Yes, Leonardo Da Vinci and Galileo were the first to "discover" bending stress by writing it down, but it was used as rules of thumb by our builders well before that time.

In the book "Structural Engineering:  The Nature and Theory of Design" William Addis quotes the following statement from Karl Terzaghi challenging the idea that theorey leads to practice:

History shows us that there is hardly a single concept of practical importance in the field of structural engineering that was not instinctively anticipated and used with success in design and construction by individuals or groups of engineers many centuries before applied mechanics came into existence.

In Henry Petroski's book Remaking the World, he states:

Some of the first modern engineers did not apply science but rather led science.  The science of thermodynamics may be viewed as an application of steam engines, and rational structural analysis as an application of bridge building.   The view of scientific discovery as depending on the ingenious craftsmanship of instruments, and thus following technology, convincingly flies in the face of the conventional wisdom that technology is mere applied science.  [Petroski, 1997, 17]

So according to this, Science is Applied Engineering

Visual Vs Verbal Thinkers

Can you describe this crankshaft in words?  Drawing/Modeling is our language (hands/eyes - visual).

Nervi's Aesthetics and Technology in Building

Like artists, Engineers want to create beautiful words – when appropriate -  as well as satisfying the science of efficiency and the art of economy.  Nervi (1956) states that in order to do that, ones simply needs to work honestly.

Every improvement in the functionality and the technical efficiency of a product brings out an improvement in its aesthetic quality . . . there is no doubt that any product of high efficiency is always aesthetically satisfying. In the field of architecture, in which functional, statical, and economic needs are intimately mixed, truthfulness is an indispensable condition of good aesthetic results. [Nervi, 1956]

In addition, it is the engineer's personal ability that contributes to great works of structural art. The engineer that seeks personal excellence will see that transcend themselves into the built world – just like building with LEGOs as a kid, it just takes longer.

I remember visiting a project where I designed all the connections for a large box truss that supported four stories of concrete and spanned 100 feet. The erector and welder was proud to show me his work and described the installation, welds and details as a master craftsman would. He was not being self-serving—he was describing the work itself. He and I both knew that this was going to be covered up for no one else to see.  He was still deeply satisfied, as was I. I realized much later that the satisfaction was not really about the truss or even the workmanship (craft).  What he was really showing me was a manifestation of himself in the steel connection. The weld was beautiful and well-crafted, of course, and that was satisfying, too; but that is not really what he was feeling.  He was really showing me that he was a good human being; that he is quality just like the connection - he was virtuous.  The inanimate object was a reflection of him and it was beautiful. We can learn a great deal about how the outcome of our work is conceived in our minds the same way. While we are not particularly goal oriented, although we do see our work as a actively progressing towards "Quality" (in the present only - the future is unhealthy to think too much about). Just like this erector, we are not spectators. We like private concentration, working autonomously or in teams, and delivering quality work (not ourselves) to others.  The work is us, but that is our secret.  Maybe that is why virtue is the most important trait to engineers to contribute and create beautiful works.  Nervi thought so.

Can Engineers be Replaced by Robots?

For robots to be programmed to do engineering design, they would first be fed all the code information. That is easy, but AI would need to be amazing if it were to compete with humans on design (unrelated to codes and science). We are not there yet, and likely not for 50+ years or more.

Science and the building codes provide minimal information that is helpful to solve a particular problem. This is obvious to me as a practicing engineer so I get surprised when asked by some “what do you mean the code allows flexibility”, or “how can you say the code is of little importance”, or “I don’t understand you when you agree that the code is huge in content but will never help solve 95% +of problems we face”.   Allow me to explain why engineering has little to do with codes (yes the code and science portion can replace engineers - but that is a small part of us). 

“But they (computers) are useless. They can only give you answers.” (P. Picasso)

There are engineers (mostly academics who think wrongly that we are applied scientists) that actually believe structural engineering is just about stress and strain - (ie. about science).  Let me respond to the main question about how engineering decision making is not procedural and can not be within codes by asking another question...

What do codes say about designing a simple steel beam?

Codes tell us not exceed 0.9 Fy Z for moment checks and something else for shear and that is about it.   Codes do not say anything about the following...

• what is an optimum spacing of beams?

• how do I weigh economy vs efficiency -in other words should I use a lot of the same beam or optimize every beam for diff spans

• should I consider camber and how to evaluate cost of camber vs increase size of beam without camber

• constructability - should I make sure the girder is as deep or deeper than the beam even if the girder is a small span

• should I evaluate the vibration of the beam

• should I allow for shear tabs instead of double clips angles at the ends to save money in the details

• while I am designing a beam to girder connection of the same depth, should I verify the connection works with a double cope by doing shear rupture and block shear calcs

• should I verify the studs should be a max of 1 per foot, or go to 2

• should I size the beam to be not composite

• how do I evaluate costs of studs, etc

• do I feel comfortable with a 1" deflection even if the code allows it for this 30ft member or should I stick to my arbitrary 0.75" I made up

• should I evaluate the ponding of the concrete and add additional dead load when the beam deflects

• is a wide flange the best solution for this or should I consider a channel instead

• I decide for this beam I am unhappy about a previous job where I cambered the beam 1" and the tolerance the fabricator is allowed increased that to 1.5" and the SC connection provided some rotational restraint at the connection, so the camber didn't come out and those damn studs were actually sticking out of the top of concrete at midspan - so I am not going to camber that much again!

• I don't trust the code deflection criteria and invent my own

• what is my min percent composite action or max stud per foot or min length to use camber, etc

• when is it a good idea to just optimize a beam for efficiency (code stuff), if I was designing the smallest possible beam it could have 3" of camber and 4 studs per foot!

• should I use ASD or LRFD, does it matter, when does it matter and how or should I stick to my old ASD 89 green book and say to hell with 2005 and omega factors

• what should I use as a max live load deflection when supporting CMU or Brick walls, L/600 or L/900 or ?

• why am I designing steel in the first place, should we consider concrete or wood or ??? for this beam

• am I comfortable assuming this beam is braced to 1.5" metal deck (parallel) or and should I check lateral torsion bucking with the wet concrete loads

• should I assume that there is a true pin at the shear connection, or is there some rotational stiffness there. If so can I get relief from not meeting the code live load deflection criteria – sure why not.

• can I assume the beam is fully braced if the top flange if supporting a wood framed floor with joist hangers and how do I evaluate whether a joist hanger can brace my steel beam effectively

• why did I just check shear yielding when shear yielding never ever controls the shear strength of the beam, what a waste of time but this was something I learned in school, so I will procede to check rupture, etc ,etc

• do I need to check block shear of a beam web when the cope is less wide than the dist to the bolt line

• what should I be optimizing when design a beam and how do I prioritize efficiency, economy, connectivity, constructability, deflection camber and stud count

• etc etc

I can go on this forever!  The code says nothing about these questions.  So my point is - even in the design of a simple beam, the code (or computer or Robot) plays a small role! If we extend that to the infinite number of problems we face than we will see the code (programming code information) is of importance on a small fraction of problems.  So again...the code helps a little but for the most part we are on our own.  

Robots will take the 80% of the codes and science part of engineering soon, and already have to some extent, but not much beyond that. Humans can just decide to choose wood instead of steel and for no reason whatsoever.

Humans create the questions to answer too, not just answers to questions.

The Truth of Structural Design

There seems to be a progression of understanding as one designs structures. At first, as college students, we have well defined analytical techniques that appear objective and clear (there is truth). Later we learn this idea of structural design is naïve. What we do is not clean. As the years go by, there is an improvement of the design of structures which combines the simple objective science with more complex subjective decision making requiring sound judgment (heuristics). There is not truth anymore, what is left is "good enough". Problems encountered by the structural engineer are complex and nuanced and require experience and judgment to better sift through the multiple design ideas. If there was a progression in the mind of a structural engineer, I think it is similar to the one that the philosopher Friedrich Nietzsche wrote about in “Twilight of the Idols” (see MSC article). While Nietzsche was generally referring to raising the human spirit to a higher level, it is similar to my experience, going from 1 to 6, as a structural engineer over the fifteen years:

1. The ”truth” of structural design – is attainable for the sage, the pious, the virtuous man.

2. The “truth” of structural design - unattainable for now, but promised for the sage, the pious, the virtuous man.

3. The “truth” of structural design - unattainable, indemonstrable; but the very thought of it - a consolation, an obligation, an imperative.

4. The “truth” of structural design - unattainable? At any rate, unattained. And being unattained, also unknown. Consequently, not consoling, redeeming, or obligating: how could something unknown obligate us?

5. The “truth” of structural design - an idea which is no longer good for anything, not even obligating - an idea which has become useless and superfluous - consequently, a refuted idea: let us abolish it!

6. The “truth” of structural design — we have abolished. What world has remained? The apparent one perhaps? But no! With the true world we have also abolished the apparent one.

Thus, we have abolished truth in practice even if we pretend it still exists in school. Good enough is enough in practice (i.e. a good enough design decision = a correct answer). That doesn't make it easy, “good enough” is actually very hard. It is apparent in this progression the great extent to which the individual engineer can influence the design. I have found that the design of structures is less dispassionate and logical than I used to earlier in my career. There are no clear-cut answers to the complex and diverse problems we face. This is not to diminish the role of analytical tools to assimilate knowledge of phenomenon, it is just that it is simply not enough.

(E Nelson,  portion of MSC Twilight of the Idols)

Published “Twilight of the Idols” Modern Steel Construction Magazine

Dreams, Mistakes and Uncomfortable Decisions

I woke up at 3am today again.  It was the same dream, or similar dream to what I have been having over the last decade.   I forgot to check something.  I missed something in the code or I missed something more structurally egregious.    This latest dream was something that surprised me because I was actually wrong, I did check it!   I came to work early to discover that I did check this beam for additional load due to this or that, so no big deal.   Sometimes my dreams help me, I get a sort of eureka moment and I am better able to tackle such and such problem.   Other dreams are harmful, and they make me nervous and anxious and I can’t get back to bed.   There are two main themes to these dreams:  (1) Mistakes, whether real or imagined, and (2) Uncomfortable Decisions.  Uncomfortable decisions are by far the most common of my dreams.  These are engineering decisions that are made without the best understanding of how the part or system will perform (very common daily decisions when unique details or structures are developed).  This is why engineering is a profession.   We need to pull things out of a hat sometimes and live with them.  Part of the anxiety of a structural engineer is that we are solving problems that never existed before, we are inventing something new.    Yes, physics doesn’t change, but that is about the only thing that doesn’t.   Every building has traits that no other building in the world has, and have we verified everything?   Of course not.   But have we verified everything we know how to verify?  After all the calculations are applied, we still have to make a decision about whether it should be built a particular way or be changed.  Eventually we have to say yes, “no exceptions taken” and live with it the rest of our lives.   Crazy things get built and amazing engineers are the creative force behind all of them.  How many structures out there do we lose sleep on?  Maybe 2-3 per year on average?

What makes an Engineer, an Engineer?

03/2012 ASCE-SEI Structures Congress Procedings “What makes an Engineer, an Engineer”   Click here for What Makes An Engineer An Engineer ENelson.

Engineering Beginnings

Future Engineers?

When I was about two-three years old, my parents were concerned because I did not talk. I struggled in social situations and preferred being on my own with building blocks or trucks. I didn’t have a picture of myself, but here you can see my 3 boys doing essentially what I was doing – playing with things that have wheels.  Anything with wheels or toys for building were the most appealing.

I learned much later that I was considered a "non-verbal" thinker. I did not do well in kindergarten or first grade and flunked second grade.  I was given speech therapy and slowly caught up to others my age, but it really was not until high school that I felt comfortable reading and comprehending what I was reading.  What I lacked in social skills, writing, or reading was offset by considerable skill in making stuff. I built pretty amazing castles and boats out of wood blocks and LEGOs. While upbringing specifics will obviously vary from Engineer to Engineer, I have yet to meet one who wasn't the master of LEGOS on the block.

Engineering predates Science

We were designing and building things long before we had a “scientific” methods and mathematical solution techniques – and we still do today.  We can actually do engineering without science (Pantheon is an example), but science does indeed help and is absolutely necessary today.  A calculator helps too.  Did we need to wait for mathematical understanding of a hanging chain before we could build catenaries?  Of course not.   We didn't need to wait for Galileo and Bernoulli to create architecture.   We didn't need Euler to design columns.  This “pre-science” type of engineering is design and it is still 90% of what we do today.  Have you witnessed the architect August Perret's Church of Notre Dame du Raincy?   Were the methods of proportion used in the past flawed?   Sure.   Did they work?   Sure, sometimes.  Are current state-of-the- art methods that are good at mimicking nature still flawed?    Absolutely, less so, yes, but certainly flawed.  We as structural engineers should recognize that while science and math are critically important to what we do, they do not define us - and history tells us, they never did.  How can we be defined as applied scientists when engineering predates science?

Art Without Craft?

The New York Times published a bunch of wonderfully funny "doodles" by the artist David Shrigley.   Here is one of them:

‘‘I’m not trying to draw badly,’’ says Shrigley, who graduated from the Glasgow School of Art. ‘‘I’m just trying to draw without any consideration of craft."

I wonder what architecture (or engineering) looks like without consideration of craft.

What is Structural Engineering, Exactly?

02/2012 Published “What is Structural Engineering, Exactly?” February  2012 Structure Magazine What is Structural Engineering Exactly

Indeed, Socrates, I do not know.

Is it a good idea to teach a class that is new like “Sustainability in Civil Structures” or the highly technical “Advanced Matrix Analysis” and replace classes that reinforce the basics?   There are only so many hours in the current curriculum.   Regardless of which class we may add (and consequently which class we remove), every class needs to foster enquiry.   We need to resist cramming their heads with more and more knowledge (whether it is more mathematics, new theory based on a particular research agenda or trends in the marketplace).  This may numb the minds of our future engineers.  Teaching should be about assisting the student in discovery (a liberal education), not supplying the knowledge or listing the latest facts.  Let’s turn to what liberal learning means from the master of inquiry, Socrates.Socrates can best help us understand the importance of a liberal education.  He is someone who literally lost his life in defense of the spirit of inquiry (read the Apology or Crito).   I think his most telling debate on the importance of inquiry is in the dialog Meno.   It is in the work written by Plato where we find Socrates asking fundamental questions about learning itself.   I am going to borrow and edit heavily the entire dialog (even replace words for the heck of it) because I think this is exactly the type of dialog that should exist in all of our classrooms.

Meno.  Can you tell me, Socrates, whether structural engineering is acquired by theory or by practice; or if neither, then whether it comes to man through testing nature, or in what other way?

Socrates. O Meno, I am certain that if you were to ask anyone this, he would laugh in your face, and say: "Stranger, you have far too good an opinion of me, if you think that I can answer your question. For I literally do not know what structural engineering is, and much less how it is acquired”.  And I myself, Meno, I confess with shame that I know literally nothing about engineering.

Meno.  And how will you enquire, Socrates, into that which you do not know?  How do we learn something that we have no knowledge of?

Soc. I will tell you how: all enquiry and all learning is but recollection.  We do not learn, we recollect.

Men. What do you mean by saying that we do not learn, and that what we call learning is only a process of recollection? Can you teach me how this is?

Soc. I told you, Meno, and now you ask whether I can teach you, when I am saying that there is no teaching, but only recollection; and thus you imagine that you will involve me in a contradiction!

Men. Indeed, Socrates, I protest that I had no such intention. I only asked the question from habit; but if you can prove to me that what you say is true, I wish that you would.

Soc. It will be no easy matter, but I will try to please you to the utmost of my power. Suppose that you call one of your numerous uneducated slaves, that I may demonstrate on him – the question of learning is recollection.   We will have to get to what structural engineering is another day – and concentrate on how one knows things.  I will however use the area of a column as an example - something I am sure is used by the structural engineer.

Men. Certainly. Come hither, boy.

Soc. Meno please attend now to the questions which I askthis boy, and observe whether he learns of me or only remembers.

Men. I will.

Soc. Tell me, boy, do you know that a figure like this section of a column.   Is it not a square?

Boy. Yes, I do.  It is a square.

Soc. And you know that a square figure has these four lines equal?

Boy. Certainly.

Soc. And these lines which I have drawn through the middle of the square are also equal?

s1

Boy. Yes.

Soc. A square may be of any size?  So a column may be of any size?

Boy. Certainly.

Soc. And if one side of the column be of two feet, and the other side be of two feet, how much are will the whole column be? Let me explain: if in one direction the column was of two feet, and in other direction of one foot, the whole would be of two feet taken once?

Boy. Yes. So two by two would be four square feet.

Soc.  Good.  And might there not be another square column with an area twice as large as this? And what is the area of that doubled column?

Boy. Eight square feet of course.

Soc.  Correct.  And now try and tell me what is the length each side if the area of the square column is eight?

Boy. Clearly, Socrates, it will be double the length of the side, so each side will be four.

Soc. Do you observe, Meno, that I am not teaching the boy anything, but only asking him questions; and now he fancies that he knows how long the side of the column is necessary in order to produce a column of eight square feet; does he not?  And does he really know?

Men. Certainly not.

Soc. Observe him while he recalls the steps in regular order. (To the Boy.) Tell me, boy, do you assert that double the area comes from doubling the side? Remember that I am not speaking of an oblong, but of a figure equal every way, and I want to know whether you still say that a double square comes from double line?

s2

Boy. Yes

Soc. But does not this line become doubled if we add another such line here?

Boy. Certainly.

Soc. And are there not these four divisions in the figure, each of which is equal to the figure of four feet?

Boy. True.

Soc. And four times is not double is it?

Boy. No, indeed. It is four times as much.   Sixteen!   Oh no - that column is huge!

Soc. So what side length would give you a space of eight square feet?   Is not a space of eight, half the size of sixteen?

Boy. Certainly.

Soc. Then the line which forms the side of eight square feet ought to be more than this line of two feet, and less than the other of four feet?

Boy. It ought.

Soc. Try and see if you can tell me how much it will be.

s3

Boy. Three feet.

Soc. And how much are three times three feet?

Boy. I am counting and I am close but nine is not eight.  So I was wrong again!

Soc. But from what length of line would give you eight square feet?  Tell me exactly; and if you would rather not reckon, try and show me the line.

Boy. Indeed, Socrates, I do not know.

Soc. Do you see, Meno, what advances he has made in his power of recollection? He did not know at first, and he does not know now, what is the side of a column of eight square feet: but then he thought that he knew, and answered confidently as if he knew, and had no difficulty; now he has a difficulty, and neither knows nor fancies that he knows.

Men. True.

Soc. Is he not better off in knowing his ignorance?   If we have made him doubt, and given him the "torpedo's shock," have we done him any harm?  We have certainly, as would seem, assisted him in some degree to the discovery of the truth; and now he will wish to remedy his ignorance, but then he would have been ready to tell all the world again and again that the double the area should have a double side.   He would of lived his entire life with false knowledge - and this is just area stuff, I haven't even discussed buckling!

Men. True.

Soc. But do you suppose that he would ever have enquired into or learned what he fancied that he knew, though he was really ignorant of it, until he had fallen into perplexity under the idea that he did not know, and had desired to know?

Men. I think not, Socrates.

Soc. Mark now the farther development. I shall only ask him, and not teach him, and he shall share the enquiry with me: and do you watch and see if you find me telling or explaining anything to him, instead of eliciting his opinion. Tell me, boy, is not this a square of four feet which I have drawn?

Boy. Yes.

Soc. And how many times larger is this space than this other?

Boy. Four times.

Soc. But it ought to have been twice only, as you will remember.  And does not this line, reaching from corner to corner, bisect each of these spaces?

Boy. Yes.

s4

Soc. And how many spaces are there in this section?

Boy. Two.

Soc. And four is how many times two?

Boy. Twice.

Soc. And this space is of how many feet?

Boy. Of eight feet.

Soc. And from what line do you get this figure?

Boy. From this.

Soc. That is, from the line which extends from corner to corner of the figure of four square feet?

Boy. Yes.

Soc. And that is the line which the learned call the diagonal. And if this is the proper name, then you, boy, are prepared to affirm that in order to double the area of the column, you would square the diagonal?

Boy. Certainly, Socrates.

Soc. What do you say of him, Meno? Were not all these answers given out of his own head?

Men. Yes, they were all his own.

Soc. And yet, as we were just now saying, he did not know?

Men. True.

Soc. But still he had in him those notions of his-had he not?

Men. Yes.

Soc. Then he who does not know may still have true notions of that which he does not know?   Without any one teaching him he will recover his knowledge for himself, if he is only asked questions?  And this spontaneous recovery of knowledge in him is recollection?

Men. True.

Soc. And this knowledge which he now has must he not either have acquired or always possessed?

Men. Yes.

Soc. But if he always possessed this knowledge he would always have known; or if he has acquired the knowledge he could not have acquired it in this life, unless he has been taught geometry; for he may be made to do the same with all geometry and every other branch of knowledge. Now, has any one ever taught him all this? You must know about him, if, as you say, he was born and bred in your house.

Men. And I am certain that no one ever did teach him.

Soc. And if there have been always true thoughts in him, both at the time when he was and was not a man, which only need to be awakened into knowledge by putting questions to him, his soul must have always possessed this knowledge, for he always either was or was not a man? .

Men. I feel, somehow, that I like what you are saying.

Soc. And, Meno, I like what I am saying. Then, as we are agreed that a man should enquire about that which he does not know; that is a theme upon which I am ready to fight, in word and deed, to the utmost of my power.

In other words, we should want our students to acquire the freedom that allows them to acknowledge the one certainty in life: “Indeed, Socrates, I do not know.” Recognition of that certainty, we are all ignorant, is the pathway to learning.   Then learning things will belong to them, instead of just repeating things that belong to others (memorization of facts, test taking, etc).  Future engineers need to process the tools resulting from a liberal education to help them to listen and to read attentively and deeply, to express themselves intelligibly and precisely, to measure and question the world, and to seek truth.   This will help them become lifelong learners.  Another useful result, it will make them better at understanding the highly technical and theoretical aspects of engineering too.     We don’t want engineers who regurgitate what they have been taught and memorized.  We want them to struggle and to engage the world and people in a meaningful ways.  We want engineers with a spirit of inquiry and love of learning that will last a lifetime.   So even if we add classes that submit to trends in the marketplace or wrongly decide our students need more mathematics, we better make sure that Socrates joins every class.

Very Good But Long Definition of Structural Engineering

"Structural engineering is the art of protecting human lives and property by exercising practical judgment to use physical principles and time-tested heuristics in the intentional conception, description, and justification of an arrangement of materials in a building, bridge, or other structure that safely resists anticipated forces and satisfies other applicable performance requirements with efficiency, economy, and elegance."  [SEphil Yahoo Group]

Engineers want and have Meaning

I think for the most part Engineers are pragmatists and want to work to provide value for humanity. Engineering itself has obvious meaning.  The final construction of the building, highway, or treatment plant is useful and therefore meaningful. Since the built thing has meaning, we have meaning. There are many professions that lack this, but we choose this profession partly because of this. Living a meaningful life is critical to one’s well-being. Engineers, at a minimum, are visual thinkers, artists, scientists, risk takers, worriers, and self-reflective professionals who value intuition, logic, and living meaningful lives. We are in constant search for the knowledge to be able to do things (know-how) not necessarily knowledge itself (know-that). We want to actively participate in creating a better built world. These are some of the common traits that make us who we are.

Engineers are Rigorously Logical Creative Artists

The most important trait is curiosity about the built world, the will to tackle difficult problems, and self-reflective methodology. The will is strengthened by confidence in using logic as a method to solve problems. Engineers are rigorously logical and independent thinkers.  We do not just want to understand the system, but also to improve it. We want to know how and why things work, and how we can get them to work better.  That is why we also invent new things, we are in a constant surprise at how much the built world could be improved. It is not uncommon for an engineer to think "Why in the world is this the way this thing is?  It could be so much better if I just change this and add that." We are rational problem solvers who like to analyze things to understand how they work and how they can work better.

Engineering is more of an art than a science; not in the sense that it is uncertain, but because the design process is a true art, not unlike that of an artist/sculptor/poet.  In Engineering and the Mind's Eye, Ferguson (1992) concludes:

Necessary as the analytical tools of science and mathematics most certainly are, more important is the development in student and neophyte engineers of sound judgment an intuitive sense of fitness and adequacy.  No matter how vigorously a "science" of design may be pushed, the successful design of real things in a contingent world will always be based more on art than on science.  Unqualifiable judgments and choices are the elements that determine the way a design comes together.  Engineering design is simply that kind of process. It always has been; it always will be. [Ferguson]

Engineers are Self-Reflective

Most engineers at a young age are unusually self-reflective.  This is a necessary trait to be able to solve puzzles, build towers from blocks, or fix things.  The curiosity to start a problem needs to be maintained by self-reflection and patience, and to complete the task takes a strong will.

Engineers are not spectators; we have to diagnose the problem and self-reflect to create ideas to help find the solution. We actively engage projects to reveal solutions to problems or yield new ideas.  Matthew Crawford, in the terrific book Shop Class is Soulcraft, describes the difference between an expert mechanic and a procedural thinker:

"The forensic perceptual expertise of the engine builder is active in the sense that he knows what he is looking for.  But with the idiot we see the result of a premature conceit of knowledge” (Crawford 2009).

Thus knowledge itself is not what separates an engineer, or a mechanic, from an idiot.  The most important difference is the humility to recognize one’s own ignorance, combined with a good amount of skill acquisition through experience. An engineer, like a master mechanic, is self-reflective and constantly aware of the possibility of making a mistake.  Before taking a hammer to the problem, the engineer (or master mechanic) reflects and asks questions regarding the solution such as, “Is this the best solution of all the possibilities?” or “Is this the right material choice?” or “Am I correct in assuming that this can be treated in this simplified fashion?”

Being skeptical of our own thoughts and that of others is another common characteristic. We are proud of ourselves when we see our own ingenuity and analytic skills improve something or shape something properly or solve a forensic problem.  Mistakes will still reveal themselves in projects, but engineering is not about that past, it is about taking action now and bringing the project to a lower state of imperfection. Experience is necessary to be able to see a few good potential solutions to a problem within an infinite amount of options.  Our intuition is strengthened every year of our careers. Since problems in engineering are rarely simple or straightforward, it takes a high level of self-reflection and intuition to tackle them.

Are Chefs Applied Non-Burners?

No doubt safely resisting forces is the most important thing we do (the applied science portion of engineering) – but that doesn’t make it the defining thing.   Saying Structural Engineering is about safely resisting forces is like saying “Chefs are Applied Non-Burners”.  The most important thing for a chef is to make sure they do not burn the food (or undercook).  Obviously this is not a defining characteristic of being a Chef.  Stress and Strain calcs are actually the easiest part and account for a small portion of our time (10-20%) - so similarly, we are not applied scientists.  If an engineer tells me “Not true, I spend 30 hours a week on FEM or Calculations so I am doing science and spending my day resisting forces”.   I would say, “Are you really doing science?  That is an enormous amount of time spent on analysis – but what is it really that you are doing in those 30 hours?  In your Etabs model, why did you choose a steel channel?   Is that because of the stress?  Why did you use an HSS brace?  Because of the forces or because it has worked pretty well in the past in this type of building in this location, etc.  Did the deflection cause the structural system, or vice versa?   If vice versa, what caused the structural system?   How did it become?  It became because you made it become, not by science or numbers, but by a creative force formed by know-how experience.  

“Engineering is a community of people who are practitioners of a creative form of cognition, engineering design, akin to that practiced by artists.” [Layton, 1984] 

Engineers Make and Fix Stuff

In order to answer, "What makes me an Engineer?" allow me to start with my childhood and reflect on key moments that led to my decision to go into engineering.  I will later generalize to the type of person that typically enters this profession.   When I was about three years old, my parents were concerned that I might be autistic because I did not talk. I struggled in social situations and preferred being on my own with building blocks or trucks. Anything with wheels or toys for building were the most appealing.  I learned much later that I was considered a "non-verbal" thinker (more on that later). I did not do well in kindergarten or first grade and flunked second grade. I specifically remember my mom telling me that I was going to stay in second grade and my twin brother was going to advance to third grade. I was given speech therapy and slowly caught up to others my age, but it really was not until high school that I felt comfortable reading and comprehending words. What I lacked in social skills, writing, or reading was offset by considerable skill in making stuff. I built pretty amazing castles and boats out of wood blocks and LEGO bricks. While upbringing specifics will obviously vary from Engineer to Engineer, I have yet to meet one who wasn't master of LEGOS.  

The first time that I heard about engineering was when I was about ten. My mother told me that I would be a good one after I had fixed the back door of our AstroVan. It had two doors that opened like a refrigerator. There was a nylon strap that got disconnected from a steel bar that prevented the door from swinging too far. After fixing this and hearing from my mom, I thought to myself that engineering must be an easy profession. I was also a sort of family mechanic, setting up the new VCR, fixing the phone, taking apart the sewing machine and putting it back together.  Being mechanical takes curiosity to understand how something works, along with the trial-and-error method.  It is not only curiosity, it is the will to do something without help. My Mom would read the manual on how to connect the VCR and then she would worry. I didn't read the instructions, I just tried different plugs. It was actually very simple.  

As a sophomore in high school, I received an assignment to write and present on what I wanted to be when I grew up. I heard from others the typical white-collar professions such as doctors, lawyers, businessmen, politicians, etc. Surprising my teacher but not my family, I wanted to be a car mechanic. I wanted to understand the car engine. Being a car mechanic made sense and was exciting. I loved cars as a kid and still do; what could be more exciting than understanding the car engine and developing the skills to be able to fix it? I was always good at math and physics, but I did not want to do math and physics; I wanted to design and build real things. Math was like a fun puzzle similar to Sudoku, but it was not something that felt real or tangible. 

In college, I continued to excel at math and physics, but I did not really enjoy sitting and solving homework problems. I was a math major but I expressed concern with my adviser after finishing a test on Abstract and Discrete Mathematics. "How does the idea of Infinity or Set Theory relate to real things of this world?  Just refuting the non-existence of infinity, does not make infinity real? It is all in the mind. What is it exactly and where is it constructed in material reality?" He asked me what interested me and realized something more concrete and obviously pertaining to this world would be a better fit, specifically mentioning three options:  architecture, structural engineering, and mechanical engineering.  I changed schools and chose structural engineering. 

My early path in life described above may or may not be similar to that of other engineers, but there are likely similarities in abilities. We all choose a profession that is grounded in material reality and has obvious meaning and importance to humanity.  We are also good at building or making stuff, fixing things, and taking things apart and understanding them; but why is this?

Engineering requires Competence/Proficiency, not "Intelligence"

In Jon Schmidt's excellent article "Contemplating Competence" in EOR Viewpoint (11/18/11), he describes how competence is based on skill acquisition, not attainment of information or classroom learning.   Below he describes skill acquisition based on Drefus's phenomenological study:

Philosopher Hubert Dreyfus and his brother Stuart, an industrial engineer, conducted a phenomenological study of various "unstructured" problem areas, such as task environments that contain a potentially unlimited number of details that may or may not be pertinent. The resulting model of skill acquisition:

1. The "novice" complies with strict rules based on context-free features of the task environment.

2. The "advanced beginner" recognizes situational aspects of the task environment and follows maxims to adjust his or her actions accordingly.

3. The "competent performer" does not try to account for all discrete elements of the task environment; instead, he or she selects a plan, goal or perspective to establish which elements are relevant and which may be safely ignored.

4. The "proficient performer" no longer reflects on the task environment as a detached observer; without having to evaluate multiple options, he or she simply sees what needs to be done and then chooses how to go about doing it.

5. The "expert" intuitively perceives both what needs to be done and how to do it, making extremely subtle and refined discriminations in a variety of task environments that are sufficiently similar to those previously encountered. [Schmidt]

The higher levels are attained when one becomes an engineer, and that requires extensive experience working in the industry.   Jon  suggests these should become the standards for licensure (and perhaps they should).  But I think what separates the competent from the expert is the ability to intuitively understand the problem, identify the solutions and decide on the best solution for the problem with little need to exhaustively analyze each possible solution.  How can a test be structured to account for this design ability?  (for another topic)  Currently, in the United States, one is able to practice enigneering after four years of experience and passing two tests (EIT and PE test).

He goes on to say:

However, when confronted with an unfamiliar set of circumstances, even experts inevitably revert to the behaviors of novices and advanced beginners. They must fall back on rules and maxims because they lack the kind or amount of experience that would enable them to discern the appropriate course of action. [Schmidt]

So, engineering does not require intellegence in the normal sense of the word.   It requires competence and proficiency.  The best of us, the experts, are those who work intuitively and able to make refined discriminations based on past successes and failures in order to make the best design decisions.   This is a combination of natural ability, education, and experience (I guess that is obvious).

Engineers are Visual Thinkers

We engineers are good at math, not necessarily because we are smart, but because we learned math differently others. Most of the population are verbal thinkers, but we are predominately visual. Visual thinkers can skip the reading in a physics textbook, focus on the figures and images, and then better understand the mathematical manipulations. Engineers do not memorize formulas, they internalize them and play with them by altering one variable in their heads. We can see a pendulum in our head while changing the length of the string. Then we can recognize that the period of a pendulum is independent of the mass and solely dependent on the length.  We can see the formula and the swinging at the same time. This is very different from another student who might need to memorize the formula and be able to follow a procedure to solve a particular problem. Visual thinkers can have full intuitive understanding, which has obvious advantages over the verbal thinker in fields such as engineering. I suspect that some people do mathematic only by following procedures, while others really understand it by taking the concepts further beyond just following established procedures.  When math becomes procedural, it becomes boring and uncreative. Those who claim that they are bad a math say so because they have trouble visualizing the representation of it. Engineers are able to visualize equations as physical representations within the mind.

Engineers are visual or non-verbal thinkers in general.  Not only do we represent physics in our minds, we are also able rotate static objects to understand them better. Our engineering designs live in our minds a spatial objects and we can enter our projects whenever we demand. We certainly are not talking to ourselves, we are seeing the thing in our mind. In Eugene Ferguson's book, Engineering and the Mind's Eye (Ferguson 1992), he quotes Richard Feyman (1988) when he discovered the difference between a visual thinker from a verbal one:

I said, "Thinking is nothing more than talking to yourself."

"Oh yeah", Bennie said, "Do you know the crazy shape of a crankshaft in a car?"

"Yeah, what of it?"

"Good.  Now tell me: how did you describe it when you were talking to yourself?

So I learned from Bennie that thoughts can be visual as well as verbal.

 Research by child development theorist Linda Kreger Silverman indicates that less than 30% of the population strongly uses visual/spatial thinking (Silverman 2001).  According to Silverman (2001), "Visual/Spatial learning is the common phenomenon of thinking through visual processing using the part of the brain that is emotional and creative to organize information in an intuitive and simultaneous way."  It is the ability to mentally manipulate two and dimensional figures in the brain. Engineers tend to be good at this.