Tag Archives: Engineering

Sharpen Your Pencil

Photo Credit: freeimages.com/Beate W

“Let me sharpen my pencil and see if we can’t make that beam size work with the extra load the owner wants.” What does sharpening pencils have to do with designing beams? That’s simply an old expression in engineering regarding the need for greater accuracy in some particularly critical calculations. We tend to use a lot of approximations and rules of thumb that we know are not exact but will err on the side of caution. While a safe design is our duty to the public; a safe design produced in a timely manner makes for happy clients and keeps us in business. But sometimes, those typical procedures and quick approximations result in a design that doesn’t meet some project requirement. And while computers have replaced nomographs and graphical analysis methods – and the need to keep a sharp point on one’s pencil to get a more accurate result – we still use that expression to signify when the situation warrants a more detailed design. Back in the days of solving something by drawing similar triangles, the method – pencil and paper and straightedge – was often the limiting factor on our accuracy. Now, computerized methods allow us to be as accurate as we could ever need, so sharpening the pencil now is more about our assumptions. Did I assume a higher typical load than what is actually present on the current project? Did I use a simpler formula that doesn’t account for various load reductions or strength increases that actually could be applied to my current project? However, sometimes, in sharpening the pencil and wading into the details, we find that a particular situation isn’t quite as similar to past projects as we thought, and our assumptions we thought were conservative are actually overlooking critical factors. And that’s an issue I see outside of engineering as well.

One’s eternal fate is of critical importance. No one is promised their next breath, so where you’ll be a few minutes after your last breath, whenever it comes, is not something you want to miscalculate. What assumptions are you making that you need to revisit?

  • “The idea of God is outdated stone-age superstition and simply unnecessary now.”  Regardless of how old the idea of God is, that doesn’t make it unnecessary. We still need an explanation for the world around us, and scientific observation can only go so far. You can scientifically measure water boiling all day long and precisely explain how it’s boiling, and never explain why it’s boiling if you’re unwilling to admit that somebody put the kettle of water on the stove and turned it on.
  • “Science will answer everything someday.” The idea that science is the silver bullet to all our problems has a problem of its own: not all questions (and their answers) are scientific in nature. Metaphysical questions about the meaning of life and ethics are on the “ought” side of the ought-is dilemma, outside the scope of science, which can only observe what is, and not how it ought to be.
  • “Science has explained away God.” This idea that explaining the mechanics of our world does away with the need for God is a common assumption today, but this is akin to thinking one has explained the origin of a car by explaining how it works. The scientific method has allowed us to advance our knowledge of the mechanical workings of our world tremendously, but it is useless in a universe not governed by causality and logic. Our universe exhibits an organization that is best explained by a Master Designer. Indeed, modern science was based on the idea that the universe could be investigated and understood because God had created it in an orderly manner conducive to study.
  • “Religion just causes arguments and isn’t worth thinking about.” Maybe you’ve assumed that discussions about religion are just a waste of time and a needless source of feuding. But what’s the real problem there? Is it the subject matter, or the way we discuss it? Maybe civility and sound reasoning are the solution, and not indifference. Suppose you and I have gone for a flight in a mutual friend’s airplane. Beautiful, wide-open countryside passes below his Cessna 182 as we bask in the view. But then our friend passes out at the yoke. Now we are left with a very serious problem: what went up will eventually come down, one way or another. To make matters worse, we have very different ideas of how to fix the problem. But does our disagreement mean we should simply ignore the entire question of how to revive our pilot friend and/or land the plane? No! The problem remains even if we ignore it. In fact, it’s likely getting worse with each passing second. Likewise, the question of whether God exists, what we can know about Him, and what He may want of us are some of the biggest questions we can ask in life. No part of our lives are unaffected by the answers to this issue, and the urgency of finding the answer only grows the more we ignore it.

If any of those initial assumptions described your thoughts on the matter, I’d like to kindly suggest it’s time to sharpen your pencil and work through that problem again, my friend. But “time waits for no man”, and like the ground filling more and more of the Cessna’s windshield,  “the God question” can only be put off for so long before it’s too late.

Dangerous Assumptions

Ever assumed you knew something that turned out to be completely different? I know I have. It doesn’t take long to learn how embarrassing hasty assumptions can be. Yet we still have to make a lot of assumptions in life every day. I have to assume when I go to bed each night that my truck will start in the morning, and I don’t actually need to get up at 2 in the morning and run an ultra-marathon just to get to work on time. A dead truck is a possibility, but practically speaking, my assumption of reliable transportation is a fairly safe assumption given that truck’s history of dependability. In engineering, we have to make a lot of assumptions that can drastically change the results, and we’re expected to be able to judge whether those assumptions are justified or not. Assuming certain vibrational characteristics for a project, only to find out your structure’s resonant frequency actually matches the frequency of the average person’s walking gait, can change a client’s bold, cantilevered office building with a view into a nauseating life of trying to do office work on the end of a diving board. Assuming a connection to be rigid when it’s not, or assuming a high frictional resistance that may or may not be present can completely alter load paths, and divert force into components never designed for it. Assuming a beam is adequately braced when it’s not can change the mode of failure from a nice slow yielding to a sudden lateral-torsional buckling, drastically lowering the safe load on the beam, and possibly resulting in a structural failure. Just like assuming a snake isn’t poisonous, a lot of engineering assumptions can pack a deadly bite.

So what is it about assumptions that can be so disastrous? The issue is how close they are to, or how far they are from, reality. In essence, it’s a matter of how truthful the assumption is, for truth is simply correspondence to reality. If I assume the max unbraced length of a 30 foot long beam is 5 feet and it turns out to be 6 feet, then I’m fairly close to the truth of the matter , and I’ve erred on the side of caution, so my design should do well. If I assume it’s 30′ and I don’t need any bracing at all, then I’m working off a false premise, and I’m flirting with disaster. Sadly, a lot of people are making an even more dangerous assumption every day, many never realizing it until it’s too late.

What is this deadly assumption, you ask? Let’s work through some examples of it and find a common denominator:

  • “God is love, so that means everybody goes to heaven, right?” This assumes a very one-dimensional caricature of God, who is also just and righteous and holy. One could just as easily state, “God is just and we’re all sinners, so that means everybody goes to hell, right?” Or we could see Him as He has revealed Himself to us, and recognize that His love provided a way for us to be reconciled and justified before His perfect unbending justice, but only if we don’t reject it. Thus, some will be saved and some won’t.
  • “I’m a pretty good person, so God surely wouldn’t send me to hell.” This assumes that an absolutely perfect and holy God grades on a curve. We may lower our standards but why assume a perfectly just God would do the same?
  • “I don’t need God to be a good person, and that’s what counts, right? – Leaving the world a little better place than I found it?” This common misconception is based on a relativistic notion of “goodness”. But unless you happen to be the one perfect person in the whole world, good isn’t good enough to meet God’s perfect standard. And besides that, a lot of people throughout history have convinced themselves their heinous actions were actually for the “greater good.” So beware of subjective standards of “goodness”.
  • “I don’t like this God yours, so I’m going to just find one I like better.” My preference often has little to do with reality, and this dangerous assumption makes the mistake of thinking one’s dislike and rejection of God somehow circumvents the need to deal with God’s independent existence (and our potential obligations to Him) on His sovereign terms.
  • “I hadn’t really thought about what happens when I die, but I’m sure it’ll all work out in the end.” When has apathy and sticking one’s head in the sand ever been a good strategy for anything? The person saying this isn’t really sure of anything other than that they don’t want to think about anything that might require them to change course.

There’s a common assumption at the base of all of these statements – that we, as individuals with our finite comprehension, somehow know better than our omniscient Creator how He should’ve done things. It’s the notion that our way – our personal and very subjective way – is the right way, instead of God’s way. Ultimately, it comes back to pride, which, as the Bible wisely warns, “goes before destruction” [Prov 16:18]. So be wise and learn from the mistakes of others, and avoid the eternal consequences of these most dangerous assumptions.

No Extra Screws

Leftover screws… and washers… and dowels…

There’s a joke that when engineers put together objects with “some assembly required”, whether assembling a kid’s toy or rebuilding a car, they end up with extra screws left over at the end because they made the object “more efficient” by only using what was actually needed. Of course, if the original designer was careful, then there really was a purpose for those “extra” parts, and we just didn’t see it from our perspective (or didn’t bother reading the instructions…).  Why does Flap A have to go in Slot B before attaching Part C that I attached 3 steps ago? What is this extra screw I’m left with, and does that have anything to do with why my wife’s car won’t start now?

Seriously though, have you ever felt that your life was just one of those “extras” in the grand scheme of things, like the extra screws that come with a lot of boxed furniture? This useful, practical – maybe even beautiful – object is constructed, but there’s extra supplies left over that played no part in it. They either get thrown out or stuffed in a drawer somewhere on the off-chance there’s a use for them later. Sometimes, even Christians, who understand that the Creator of the universe loves us dearly, even though there are no works we could do to justify that love, can still feel disappointed by our ordinariness and our lack of “big” accomplishments. Sure, Paul talks about the goodness of living a “tranquil and quiet life in all godliness and dignity” [1Ti 2:1-2], but we still want to do big things.

Billy Graham, probably the most famous evangelist of the last century, died last week at the age of 99. It’s estimated that he preached the good news of Jesus Christ live to 200 million people all over the world, and reached many more via radio, TV, and print. That’s certainly an amazing accomplishment. Most of us will never do that, or even a millionth part of that. And yet, that’s OK.

That may not be God’s plan for us, but it may be part of His plan for us to reach the one who will go on to reach millions. Think about Billy Graham. He wasn’t born saved; nobody is. Someone preached the Gospel to him [Rom 10:13-15]. Do you know who that person was? I got curious about that several years ago and looked him up. That someone was one Mordecai Ham. He was descended from eight generations of Baptist preachers.[1] That’s quite the preaching pedigree, but even as famous as Ham was for a time in the American South, Billy Graham delivered the gospel to more people in more places than Mordecai and his previous 8 generations of preachers – combined! In that respect, one might be tempted to forget about people like old Mordecai (or people like you and I), and focus on who the next “superstar” might be. But Ham didn’t need to reach millions to fulfill his part in God’s plan; he just needed to reach the people God ordained for him to reach, like a teenager named Billy. And the same applies to each of us. 57 years after he died, Ham’s name is only a footnote in history, but it’s better to be a footnote in God’s story than the star of our own story.[2]

We can know God’s overall plans for world history, and often we see parts of those plans acted out by certain people who become famous in the process, but we don’t realize all the contingencies that God orchestrated in between to bring about His sovereign will. Just like with a race car, we can see the driver hit the gas and shift gears, and see the amazing results as the car accelerates out of sight, but we overlook the complex series of gears and pistons and belts and timing chains and whatnot hidden under the hood, all of which have to consistently do their small individual tasks to accomplish the driver’s intent. Likewise, the Christian can take comfort in knowing that we don’t have to have millions of Twitter followers, or run a “megachurch” with thousands attending every week, or have best-selling books on the store shelves to be successful before God. In fact, those who compromise God’s truth to achieve those things would actually be the failures, regardless of the worldly success they may have. Rather, all God asks is that we be obedient in the little things He has called us to do. Does God need you or me or Billy Graham to accomplish what He wills? No, of course not. I think another Mordecai, from the book of Esther, made it clear that if we refuse to do the task God offers us the privilege of performing, our refusal won’t stop Him from accomplishing it [Es 4:13-14]. But it will keep us from being part of His plan, and we’ll reap the consequences of that. Yet if we are faithful to obey in the little things, God will use that in ways we won’t even be able to understand until glory when we shall “know fully” [1Co 13:12]. For there are no extra screws or throwaway parts in God’s designs.


[1] https://www.preaching.com/articles/past-masters/past-masters-mordecai-ham-the-southern-revivalist, accessed 2018-02-26.
[2] To borrow an expression from a 2013 sermon from one of my church’s teaching pastors, Ben Parkinson.

Armchair Engineers

I just got back from representing my state structural engineering association at the National Council of Structural Engineering Associations 2017 Summit. Besides the normal business side of being a representative in an organization, and getting to learn about new products from vendors at the accompanying trade show, there were also lots of great educational sessions on things like blast design, progressive collapse, wind and seismic design, and even design of wood skyscrapers. A little slice of “nerdvana”. We even got to hear a keynote presentation from 2 of the engineers involved in the repairs to the National Cathedral and the Washington Monument after a 2011 earthquake damaged those two masonry structures. It made for a very busy but fun week. But one thing I was reminded of repeatedly that is worth noting here is that there really is no perfect design. What do I mean by that? Let’s work through that today.

We can arrive at an optimum design, but as long as there are conflicting parameters, there can never be an actual design that maximizes everything we want to maximize (like strength or flexibility) and simultaneously minimizes everything we want to minimize (like weight or cost). We have to pick and choose, and so any designed item will always fall short of perfection in one aspect or another. And this isn’t just a structural engineering issue. The session that most brought this point home was an extended session looking at the recent publication of ASCE 7-16, the “Minimum Design Loads & Associated Criteria for Buildings and Other Structures”. I know, we can’t even design a short name for our standards, but long names aside, that book is an integral part of most of our structural design. Changes there have major impacts on our daily work. A gripe from many engineers, myself included, has been the ever-increasing size and complexity of the overall building code, and this portion in particular. In fact, the growth from one volume into two this version was a particular incentive for a meeting to discuss on a national level the direction this was going. But as the committee chairman pointed out, we have 3 main goals – safety of structures designed to the standard, economy of structures so designed, and simplicity of applying the provisions of the standard – but you can only achieve two out those three! We certainly don’t want to  have a simple code that allows for cheap buildings at the expense of life safety. But do you make a standard that is simple and extremely conservative, that makes buildings too expensive to actually build? As it turns out, we engineers have tended to emphasize the third way: safety and economy at the expense of design simplicity. Hence, the now 800 page, 2-volume standard that is just one of an entire shelf of standards with which structural engineers are expected to be familiar. And let’s not forget all the revisions to each one of those each code cycle. So while information overload and lack of transparency are problematic, design simplicity is one of those competing parameters that just ends up having to take a lower priority.

Now, what does any of this have to do with Christianity? Well, there are some “armchair engineers” out there that like to try to say that nature testifies against the existence of God because it is evidence of “bad design” which an all-knowing and all-powerful Creator wouldn’t use. And just like the “armchair quarterbacks” out there, so insistent on what play the real quarterback should’ve executed, these skeptics are great at second-guessing God, but pretty bad at proposing better alternatives. Like armchair quarterbacks, they can criticize what’s currently in play, and sometimes throw out some quick, “obviously better” alternative, but they come up sorely lacking when the pros and cons of each option are subjected to a careful, rigorous analysis. Just like me, I could gripe about the new 2016 design standard, but sitting in a room with the chance to actually vote for how I would like to see the standard changed for the 2022 edition, I found myself reluctantly accepting of the current version. When it came to actually fleshing out what any proposed changes might entail, I found myself a lot more understanding of the ASCE 7 committee’s final version of the current standard that I had complained about before. Alternatives that seemed so much better couched in  vague terms like “less complicated”, “clearer”, and “more practical” ended up having unintended consequences that I liked less than the current book when it came to working out the real effects of those ill-defined wishes. It reminds me of what’s been said about God’s choices: “If God would concede me His omnipotence for 24 hours, you would see how many changes I would make in the world. But if He gave me His wisdom too, I would leave things as they are.”[1]

Can I always explain how God’s design is the best choice? No – I am all too aware of my limitations in knowledge. But I can easily see cases in daily life where, not seeing the big picture, I would make ultimately worse choices trying to fix what I initially perceived to be a bad choice. Then I am reminded all the more why we should always approach God with humility. It seems the drive-by allegations by skeptics of bad design in nature  are highly suspect given our very limited human perspective, especially when we do investigate certain cases and find them to be astonishingly well-designed. So I would encourage my skeptical readers to approach the possibility of design in nature pointing to God with at least as much humility and openness as we engineers (try to) give our colleagues when critiquing their designs. After all, we often don’t know all the reasons behind the decisions with which we disagree, and learning those reasons often puts our criticism to rest.


[1] J.M.L. Monsabre, source unknown.

Our Responsibility

Author’s personal photo.

I’m reading Dan Barker’s book “godless”, about his deconversion from a Christian preacher to a prominent atheist. It’s a rather heartbreaking tale of one person who should know better (but apparently didn’t) walking away from God for some bad reasons, and then proceeding to influence a lot of other impressionable people to do the same. If that isn’t a true tragedy, I don’t know what is. But what is worse is seeing how his friends and family couldn’t answer his questions/objections when he first “came out” as an atheist.  That deafening silence only strengthened his impression that Christianity had no answers. Sadly, Barker grew up in an environment that was  theologically, philosophically, and scientifically shallow, and mistakenly thought that represented Christianity, and no one he knew was able to correct those errant ideas. These were the people who had influence in his life and whose responses might’ve been meaningful early on before he hardened himself against any correction.

That brings up an important point. It’s not the job of your pastor or some famous evangelist/apologist/speaker/writer/blogger/etc to answer your friends’ or family members’ questions and objections. It’s yours. It’s mine. It’s every Christian’s responsibility – and a sacred one – to be able to answer those who ask us for the reason for the hope that we have [1Pe 3:15 NIV].  My pastor, according to the apostle Paul, isn’t expected to do it all, but rather is to equip me for works of ministry or service [Eph 4:11-15]. There are a lot of places I go to as an engineer that my pastor will never go to, and the same is true for every Christian. We all serve on a mission field whether we recognize that fact or not.

Maybe that thought makes you nervous.  Good! Becoming aware that you’re not as prepared as you should be is the first step. So what’s the next step after recognizing the responsibility we have? Recognizing the gift we’ve been given. Even though we may often get nervous about what kind of unexpected questions someone may ask us, as Christians, we sit on the richest resources one could ever hope for. In my office, I have a whole bookcase of books on structural steel design, connection design, finite element analysis, seismic design, and on and on. I have an overclocked powerhouse of a computer sitting on my desk, loaded with advanced and rather expensive analysis and design software from multiple companies dedicated to engineering computing, with thousands of pages of user manuals on how to use this advanced software. And I have knowledgeable colleagues in my office, and attend a ridiculous number of continuing education seminars and webinars every year on a variety of engineering issues. Plus, I have access to various restricted online resources for engineers as a member of several technical organizations, besides the plethora of (somewhat reliable) design information freely available on the internet. Being a Christian, in America, and not being able to answer basic objections, is like an engineer sitting on the wealth of resources I just described and saying, “The client wants to know whether this beam will support this additional load, and I just can’t figure out how to analyze it. Oh well, guess I’ll just let that work itself out.” As an engineer obligated to protect the public health and safety first and foremost, that’s really not an option. Whether I can answer immediately because I’m familiar with the issue, or whether I have to spend the next week researching and talking to other engineers, I have to be able to answer one way or another. If I don’t know, the correct answer is not saying “I don’t know” and forgetting about it; the correct answer is saying “I don’t know yet, but I’ll find out.”

As an engineer, people’s lives are on the line with my designs. And yet, if I’m in a building that collapses because another engineer made a mistake, I may die physically in the collapse, but I will simply be “absent from the body, present with the Lord.” [2Cor 5:8] On the other hand, when I choose to not answer someone’s questions about our eternal fate, I’m helping that person toward a fate worse than mere physical death. Of course, people like Dan Barker make their own choices and are responsible for them, but I surely don’t care to be an accomplice. So I desperately want to be prepared to explain both what I believe, and why I believe it. Opportunities to speak truth into someone’s life when they are willing to listen are often moving targets we don’t get a second shot at, so I’d rather be over-prepared than under-prepared. That said, I’ll leave you with something to chew on, regarding just what’s at stake, from performer (and atheist) Penn Jillette:

“I’ve always said that I don’t respect people who don’t proselytize. I don’t respect that at all. If you believe that there’s a heaven and a hell, and people could be going to hell or not getting eternal life, and you think that it’s not really worth telling them this because it would make it socially awkward — and atheists who think people shouldn’t proselytize and who say just leave me alone and keep your religion to yourself — how much do you have to hate somebody to not proselytize? How much do you have to hate somebody to believe everlasting life is possible and not tell them that? I mean, if I believed, beyond the shadow of a doubt, that a truck was coming at you, and you didn’t believe that truck was bearing down on you, there is a certain point where I tackle you. And this is more important than that.”[1]


[1] “Penn Says: A Gift of a Bible”, https://www.youtube.com/watch?v=6md638smQd8, accessed 2017-10-02.

General vs Special Revelation

I was listening to an atheist present his case a while back, and one of his complaints was Christian apologists wanting to start from scratch, trying to prove the existence of generic theism ad nauseam, rather than the Christian Trinitarian God we supposedly believe in. Since his talk was about why he was an atheist, addressing his rejection of theism didn’t seem that unreasonable of a place to start.  But regardless of where we start, there are two fundamental questions to deal with: does God exist? and is the biblical presentation of Him true? The claims of Jesus and the Bible are foolish at best and deceitful at worst if God doesn’t even exist. But these two questions take us into aspects of how God reveals Himself to humanity. Let’s work through that today.

Revelation is simply the revealing of something, and God reveals Himself to us in two ways: general and special revelation. General revelation is also called natural revelation, or natural theology, because it is God’s disclosure about Himself and His relation to His creation, made manifest in physical nature, human nature, and history.[1]  This is the primary focus of apologetics, because we are often talking to people who reject the authority of the Bible. But, of course, God does not leave Himself without a witness, and astronomy, biology, genetics, geology, archeology, history, and philosophy are some of the disciplines that all reveal calling cards of God, consistently pointing us back to Him. Special revelation, on the other hand, is His direct revelation as recorded in the 66 books of the Bible, written by human authors inspired for His purpose, to specific people or groups of people, but also for people of all times and places.

I think of general revelation like the title sheet of a set of contract drawings for a building, while special revelation is the drawings themselves:

  • The title sheet of the drawings tells you who’s responsible for the design of the project: the various architects, engineers, and specialty consultants. Each designer is responsible for their portion, but the architect over the project will have his stamp on there. It’s not his biography, just his stamp certifying that the drawing set is ready to be used for construction. Similarly, we only get a stamp of divine authority in the wonders of nature. You have to go to the Bible for the rest of the story.
  • There will often be a scaled map of the project site showing where the building is in relation to different streets and how it will be oriented. Nowadays, there is often a nicely rendered 3D view of the project, with cars and people to show the scale of the project.  I can tell a lot about the project just from a good title sheet. Is this from a qualified design team known for good work? Is the project in Miami, Florida or Valdez, Alaska? I would expect pretty different types of buildings depending on the location. The first would need to be designed for hurricanes, while the second would need to account for massive snow loads and earthquakes. Just seeing the project location on the title sheet can tell me about some of the design issues dealt with on that project. The 3D view of the building model might tell me that this is a narrow, 50-story office tower in a one-city-block parcel in a crowded downtown environment, or that it’s a sprawling 1-story retail store with acres of parking all around. Natural revelation tells us where we’re situated and gives us an idea of the scope of this “project” we are part of. Going from the smallest cellular machines up to the grandeur of the universe, we realize our own smallness, and God’s awesome majesty to have created everything encompassed by such extremes (and God’s love that He would care about us on this “pale blue dot” of earth).
  • Most importantly, I can’t build off of that title sheet. Sure, I do know a lot about the project from it. I know where to build, roughly how big to build, some of the loads the building will have to be able to handle. But it’s pretty obvious that that isn’t enough. I don’t know any of the internal layout of the building, or how it’s braced against those various loads like hurricane winds, or the critically-important foundations that will support it. That general overview of the project isn’t enough to actually build it. For that, I need to open up the dozens, sometimes hundreds, of pages of detailed drawings and other contract documents. In the same way, I can observe the world around me and learn that God exists, and even that He is a conscious being, is powerful, intelligent, immaterial, and eternal. But that’s not enough. Just like I need detailed plans to go with that general knowledge of a proposed building if I want to build anything that will last, I need the detailed message of the gospel if I want to spend eternity with my Creator.

When it comes to your eternal fate, don’t stop at the title page and try building your life on insufficient information, when the Master Designer has made available to you the detailed plans needed to build a life that will endure forever. And don’t ignore the drawings and title sheet altogether, and say there is no Designer as you try building a life on your own. Atheists are fond of saying religion is only a crutch for weak people, but really, it’s simply that making a mess of our lives is usually what it takes to force many of us to reach out to our life’s Designer and ask for help. Sad but true. As an engineer, I put my contact info on any of my structural drawings or reports so that people will reach out to m before they build something wrong and cause a disaster. Likewise, God has left His contact info. Don’t wait until your life comes crashing down before you call your life’s Designer to figure out how it was supposed to go together.


[1] “Revelation, General”, Norm Geisler, Baker Encyclopedia of Apologetics (Grand Rapids: Baker Books, 2000).

 

The Utopia of Certainty

John Ratzenberger’s character Cliff Claven in the sit-com “Cheers” appearing on “Jeopardy”

Ever play a trivia game or watch a game show where you absolutely knew the answer? It’s like you were born to answer that question. That  felt pretty good, didn’t it? No hesitation, no second guessing, just an instant answer. Ever find yourself in one of those scenarios and get the answer wrong? Maybe you felt bewildered, wondering how you could possibly get that question wrong. Or maybe embarrassed that you got it wrong in front of all your friends. Experiences like that might lead one to a) desire complete certainty before committing to anything, or b) believe that if certainty is impossible then so is any degree of confidence. I’d like to suggest a middle way.

First off, what is certainty? The World Book Dictionary defined it as “freedom from doubt,” or “a sure fact.”[1] Wikipedia, that fount of unchanging knowledge, currently offers this definition: “perfect knowledge that has total security from error, or the mental state of being without doubt.”[2] If you notice, the definitions relating certainty to a lack of doubt are addressing our subjective views, and not the objective truth of a statement. We can have no doubts about something, but still be wrong. The definitions of “perfect knowledge that has total security from error” and  “a sure fact” relate to the objective truth of a statement. But do we actually need complete certainty in life?

In structural engineering, certainty is like Utopia – nonexistent. While we engineers are often thought to be overdesigning stuff, our paranoia comes down to certainty, or the lack thereof. Our environmental loads, like earthquakes and storms and floods are very uncertain, but even the man-made loads can be unpredictable.  Our material properties are uncertain, the quality of fabrication and construction are uncertain, the accuracy of our analytical models are uncertain — do you see a trend here? As an engineer, I have to live in a very uncertain world, and yet I still have a job to do. I have to be comfortable with a particular level of uncertainty, and finally ask myself, “Am I justified in considering this a safe structure that satisfies the project requirements?” If so, then it’s time to stop obsessing about it and move on to the next project. That obsession with being certain that I’ve covered every conceivable issue is an easy trap for me to fall into, but I’ve found that I can go over a design multiple times and still not see a particular problem. Meanwhile, a fresh set of eyes in the form of a peer review might see a particular oversight immediately. We each have different blind spots, so together we have more complete vision and achieve far more confidence in the adequacy of the design. The desire for absolute certainty leads to what we call “paralysis by analysis”; you can make every aspect of the project into an unending analysis and never actually finish the project. It’s good to try to foresee how things could go wrong, and plan to prevent that, but at some point, you have to stop looking at all the possible ways events could unfold, and look at what’s most reasonable.

I see a similar problem in talks with skeptics about the existence of God, or the reliability of the Bible. There is often a tendency to want absolute certainty rather than reasonable confidence before being willing to accept that God exists or that the Bible really is reliable. But as Pascal would say, “There is enough light for those who only desire to see, and enough obscurity for those who have a contrary disposition.”[3] There will almost always be alternate possibilities that one can take shelter in to explain away God, because almost anything is possible. But we have to ask ourselves what’s more probable? In doing a failure investigation, I might be able to think of a  series of freak accidents, unguided by any human interaction, and happening with the worst possible timing, that explains a structural collapse — the “perfect storm”, so to speak. But if a  worker forgetting to bolt up a connection or making a bad weld also explains it, then it’s pretty clear what the more reasonable cause was.  Just like in engineering, we have to look at what’s the most reasonable explanation for something, and when it comes to this world of intelligent life residing in a finely-tuned universe, God is clearly the most reasonable explanation. Anything less is like expecting a record-setting skyscraper to appear without any engineers, architects, fabricators, erectors, or even building materials! We can also see the opposite response, of denying the possibility of any confidence in our knowledge. While there may be few things we can be absolutely certain of in this life, if you can be 99% sure of something, you’d be a fool to ignore that because of that last 1% of doubt.

Now, for the skeptic, my question is, what will you do with the evidence for God? Are you demanding a level of certainty that you would not expect of anything else in life? Both the demand for absolute certainty and the denial of any possible warrant for belief will only keep you from seeing the reasonable conclusion that’s right in front of you. Don’t hold out for Utopia when Heaven awaits.


[1] “Certainty”, World Book Dictionary, 1987 ed.
[2] https://en.wikipedia.org/wiki/Certainty, accessed 2017-08-22.
[3] Blaise Pascal,  Pascal’s Pensées (Ney York: Dutton & Co, 1858), p. 120,  Kindle ed.

“What is Truth?”

“What is Truth? Christ and Pilate” – by Nikolai Ge, 1890

“What is Truth?” Pilate asked those words of Jesus almost 2 millennia ago. Johnny Cash had a song with that title back in 1970. Some questions never go away, I suppose. While there are actually several theories of what “truth” is, I want to focus today on the classical version that, I think, is still the best. Let’s dig in!

The classical view of truth is the correspondence theory of truth: a statement is true simply if it corresponds to reality. Aristotle expressed this well when he said that to speak truth is “to say of what is that it is, and of what is not that it is not.” This seems like simple common sense, but since our culture today seems to be struggling with the very notion of truth, let me provide an example.

In engineering, we know that when we idealize a joint, it doesn’t correspond perfectly to reality, and we accept some loss in fidelity in favor of simplification for analysis… to a point. But sometimes we have to say, “This has gone beyond simplification and is now misrepresenting the object being analyzed.” Our model doesn’t correspond to the real object anymore.

For instance, we tend to model truss joints as being “pinned” – i.e. not rigid. And for most trusses like the open web steel roof joists you might see in a retail store, that’s a relatively accurate model.

Now compare that “simple” pinned truss joint to a giant truss joint like the one pictured here. That’s a pretty beefy connection and probably more accurate to assume a high degree of stiffness in that joint. Somewhere in between those 2 extremes, our model passes a point of unacceptable noncorrespondance to real joint behavior. What about these in-between situations? Just because that point is in a gray area doesn’t mean we deny the idea of truth being what corresponds to reality. Sometimes, in critical applications, it’s warranted to invest the extra work in modeling the joint as a rotational spring to capture that behavior in between a rotating pin or a fully rigid joint. Likewise, in diaphragm design, we are allowed to assume flexible or rigid diaphragms for the obvious extremes like thin metal or wood decks versus thick concrete slabs. For those unclear areas in between, we use the more accurate method of a “semi-rigid” diaphragm using a finite element analysis to analyze our floors or roofs. Why? Because our profession recognizes that truth still exists, even in gray areas. It’s just more difficult to ascertain, and requires more thorough investigation to find it. So in real life, the existence of gray areas and difficult situations doesn’t preclude the existence of a “right”, or true, answer; rather, what we are recognizing when we classify something as a gray area is our uncertainty of the truth we are seeking in those situations.  But we stillrecognize that the truth is there, somewhere, or else we wouldn’t seek more accurate answers. And this recognition of a reality holding the right answer, outside of our own interpretations of reality, points to the premise that truth is objective and not subjective. In other words, the truth about an object is based on the object itself, not on our subjective perceptions of it.  If I’m colorblind, I might perceive an object’s color very differently from another person, but the object is absorbing and reflecting photons of light in a manner independent of either observer. Therefore, the true color of the object is based on the properties of the object itself, and I describe the object truthfully when I call it by the color it has rather than the color I think I see.

Gray areas in moral and ethical questions are often used to undermine the idea that there are objective moral truths as well as physical truths like my examples above. Yet this is a similar situation to those examples: just because we can recognize the right answer in the easy,  obvious cases doesn’t mean there isn’t a right answer for those less-obvious cases. It just means we might have to dig a little deeper, and possibly remain unsatisfied with potential answers until we find the right one.  But there’s a shortcut, of sorts. The one true God who created the physical universe with its objective physical truths also established the moral truths we seek.  In God, we have that independent “third-party” that can referee between competing truth claims from different people, cultures, times, or places. And who better than the very source of moral truth, for whom it is impossible to lie? [He 6:18, Ti 1:2] Until next time, never waver in the relentless pursuit of truth!

Misplaced Confidence

What do you get when structural steel connection design deadlines and blogging collide for a workaholic engineer and amateur blogger? Worldview analysis doesn’t pay the bills like engineering analysis, so you get… this week’s post.  But a couple of recent projects did get me thinking about the things we put our confidence in.

Engineers don’t like to reinvent the wheel, so once we get something laid out to our satisfaction, we reuse those details whenever we can. One typical detail I see over and over again from engineers all over the country is for column moment connections with stiffener plates but no web doublers. For this post, let me just say these are 2 different configurations of reinforcing that mostly address different conditions. These engineers  feel like they’re covered for their designs and can sleep well at night because they required the fabricator to reinforce that area. “When in doubt, make it stout”, right? But then they delegate the tedious part of actually designing the connection to the fabricator, who hires me. But I have to actually go beyond just the conceptual intent and make the connection actually withstand the specified loads and be buildable. And I have to provide calculations to the Engineer of Record (EOR) proving that what I came up with actually works. And that’s where problems begin to crop up. Too often, the stiffener the EOR showed in his typical detail is reinforcing for a failure mode that isn’t even close to governing. Panel Zone Shear is often the limiting condition, but those stiffener plates do nothing for that. The engineer telling the fabricator to install stiffener plates but not doubler plates has a misplaced confidence. He’s trusting one component to protect against a certain type of failure, when the column will fail in another way first. The extra work he’s creating for the fabricator (and me) actually isn’t helping because it’s not putting reinforcing where the critical load is. To borrow a military analogy, it’s like putting all your guards at the front gate while your enemy sneaks in the back. Well, too often, by the time the project gets to me, the columns and beams  are already ordered from the mill, and it’s too late to go changing sizes because of the connection design. While they are adequate for the overall building design, the framing  may be sorely undersized for addressing the bottleneck of load paths at the connections. To quote the maestro of connection design, Bill Thornton, “Many, if not most, collapses are caused by inadequate connections… Yet, connections are often an afterthought.” [1]

Do we do the same? Too often we put our confidence in things that will let us down. Sometimes, it’s because we really did try to investigate thoroughly and failed to see some significant problem. But often, we do it because we never even bothered checking; like those tedious connections, it was an afterthought. But in spiritual matters, finding out you were wrong after it’s too late has the most serious and eternal consequences. That’s why Pascal, in the 17th century, considered this such an important task: “The immortality of the soul is something of such vital importance to us, affecting us so deeply, that one must have lost all feeling not to care about knowing the facts of the matter.”[2] Are you putting your faith in ungrounded atheist dogma that there is nothing to be concerned with after our physical bodies die? Or, as is a common error in our time, trusting in an almost magical “science” to solve everything, assigning to science properties it never has had, nor ever can have? Are you trusting that the human race is getting better and better, and that we’ll eventually evolve to ever higher forms of life?

Everything that depends on fallible humans can disappoint you and let you down. In the end, there is only One whom we can always be confident in. An encounter with that One led the Apostle Paul, a former opponent of Christians who did everything he could to stamp out Christianity, to become a Christian himself, and later say, “I know whom I have believed and I am convinced that He is able to guard what I have entrusted to Him until that day.” [2 Tim 1:12] Paul was able to go to his death for being a Christian, with no regrets, and no fear, because he knew he had placed his confidence in the one true God – the only infallible, perfect, sovereign Creator and Ruler.


[1] Bill Thornton, “Connections: Art, Science, and Information in the Quest for Economy and Safety”, Engineering Journal, 4th qtr, 1995.
[2] Blaise Pascal, Pensée # 427, from Peter Kreeft’s “Christianity for Modern Pagans: Pascal’s Pensées Edited, Outlined, & Explained”

The Fallacy of “Sub-Optimal” Design

Ever hear people like Richard Dawkins rant about the so-called “sub-optimal designs” in nature that must obviously disprove the existence of any omniscient Supreme Designer? As a practicing professional engineer, I find it a little annoying. Let me explain why.

What exactly is an “optimal design”? When I worked for a steel joist manufacturer, our designs were typically all about minimizing weight. It was often a very tight-margin business, and if we could save another pound of steel, that was a good thing. But, least weight doesn’t always equal least cost to produce. Sometimes, it was worth it to consolidate a bunch of different optimized least-weight designs into a big run of identical pieces, even if it meant some of them were a little heavier then needed. Just think about how much faster you could work at producing something if your instructions said that the next 1000 pieces would be made exactly like the first one, instead of having to look at the directions before every piece to see what had changed. The efficiency of repetition in our shop sometimes made a design that was not optimized for weight actually the most optimal design for us regarding least total cost (i.e. we traded a small material cost increase for a large labor cost decrease).

In my current role as a structural engineer, I’m reviewing shop drawings right now on a colleague’s project where I designed the seismic bracing for him. He unfortunately had some severe architectural constraints on his project with regard to permissible beam depths and flange widths in the walls these braces were in. After spending a couple of weeks trying to work out a solution with more conventional means, I finally came across an example of a different configuration in one of my reference books that we were able to make work in our situation. Would I call it an optimal design? Not hardly, but I was thrilled just to find anything that would meet those kinds of high demand loads with the restrictions we had.

Why do I bring up these two examples? To illustrate a couple of general points regarding optimum designs.

  • Optimization is always with respect to specific parameters. If you’re paying by the ton of steel, the most optimum design may very well be the one that weighs the least. If you’re the contractor erecting the building, the most optimum design might be the one that can be erected the fastest, or with the fewest jobsite workers. If you’re the owner of the new building, the best design may be the one that balances material costs, construction costs, and lifecycle costs for an overall lowest cost of ownership. Parameters like weight, cost, speed, strength, resilience, flexibility, lifespan, redundancy, etc. are always optimized at the expense of others. It is meaningless to talk of an optimal design without specifying what parameter is optimized. By the same measure, it is also meaningless to speak of something being a sub-optimal design without knowing what the original designer was trying to optimize for. I can say a military tank design is suboptimal for speed, and that may be true, but that isn’t where the tank was designed to excel: that heavy 4″ thick armor that slows it down so much also responds to incoming fire far better than trying to drive a race car into battle! Just because you would optimize for a particular parameter, doesn’t mean the original designer (or anyone else) would.
  • Constraints limit what is possible with regard to optimization. Looking at the end product of our seismic bracing design might appear to the fabricator to be a little odd when building it, not knowing the limits we were having to work within. Even a peer reviewer, knowledgeable of engineering design, might wonder why we didn’t simply use a much bigger beam, as is typical for these types of braced frames. But, if they’re like me, they’ve learned to ask why a puzzling design was chosen before they start throwing stones at it. In engineering, we deal with design every day – creating our own designs, reviewing the designs of colleagues, even sometimes having to try to guess the original design intent behind 100+ year-old buildings being renovated. And though it can be tempting to immediately deride some design that isn’t how I would design it, I’ve found an attitude of humility very appropriate when looking at the designs of others. For sometimes, the designs I thought were poor were actually quite innovative solutions to constraints I wasn’t aware of. But then I tried to run an alternate design that should’ve been “better,” and I ran into the same constraints the original designer did, and found the original design to be the only viable option after seeing the complete picture.

This is just a couple of reasons I think the bad design argument fails. It essentially reduces to saying “Because I, a person of limited knowledge, can’t comprehend some particular design chosen by an allegedly all-knowing Designer, He must not exist.” What hubris! Moreover, it seems to go even further by thinking that these odd cases outweigh the abundance of cases of brilliant-appearing designs in nature, many of which have spawned a whole field called biomimetics.  This field of study, which attempts to improve existing human designs or innovate new ones based on designs seen in nature, would not exist except that so many natural objects solve design problems we struggle with in ingenious ways. Indeed, I would say we have sufficient positive examples of exceptional design in nature to warrant an humble, inquisitive stance toward the supposedly “sub-optimal” cases we don’t fully comprehend yet. But really, isn’t that the attitude good science is founded on anyway?


Photo credit: By Bundesarchiv, Bild 183-23805-1665 / CC-BY-SA 3.0, CC BY-SA 3.0 de, https://commons.wikimedia.org/w/index.php?curid=5349654