Category: Critical thinking

I made some comments earlier about anecdotes of engineers not accepting the theory of evolution and natural selection (link) and that got me thinking about the engineering process that is, or closely resembles, evolution.

There is a reason we don’t see a half-crocodile, half-duck (the famous crocoduck) in nature – because those two species had a common ancestor millions of years ago and at that point they parted ways and evolved independently into the current two species.  This is analogous to why we don’t see the tail of a Sopwith Camel on an F-16.  They both have tails, but the design of aircraft has evolved over the years so the F-16 has a tail that is appropriate for itself, not some older airplane.

And engineering does the same kind of testing before accepting a new feature or process, just like nature.  A random change in nature is tested by the environment and if beneficial to the individuals, it is more likely to be retained (a greater percentage of the population survive and breed if they have the change) for future generations and slowly the change becomes part of the species.  In engineering, many designs start from a previous, successful design and add such changes that are deemed necessary for the mission, but also that are affordable and have an acceptable risk of failure.  If those changes are successful, then they will be the starting point for the next design.  Hence moving from the Sopwith to the F-16.

Continue reading “Evolution and Engineering” →

As in Science, and in Life, critical thinking is a vital part of an engineer’s mental toolbox. One basic tenet of critical thinking for an engineer is the simple question, does this make sense?

This question can be applied to almost any situation, idea, solution, or information. It is particularly useful (and necessary) when reviewing others’ computer generated or assisted calculations. More times than I care to remember have I been handed final reports that have gone through a checking process and look great, but which contain errors that I’ve spotted immediately just by asking that question. Yes, sometimes it takes years in the job to be able to spot those things quickly, but even if you don’t have the instinct of the numbers yet, a few minutes with a scratch pad and calculator will go a long way to answering the question.

Even some quick Nuke-math (as some call it in the Navy) done in your head can often uncover, or verify, whether the answer is in the right order of magnitude or if it is the right sign or direction, or if the units are right (or if the formulas will produce the units shown in the answer), or if the initial assumptions are reasonable, or if they included all the factors and variables in the calculations.

I remember one particularly egregious case where a report was submitted with no indication of anything wrong but which indicated that the ship had negative stability and should have been floating upside down at the pier if the report had been right. Here they never asked the question when they saw the negative number and the didn’t understand the significance of that number being negative. A fail on both accounts.

So keep asking that question—no matter how the information is presented or who gave it to you. And don’t stop when you leave the office. Does that total at the grocery store or restaurant make sense? Or the claims of that infomercial? Or the latest idea from that politician?

One simple question and a modicum of common sense can do great things.

What do you think? Post a comment below if you’ve got something to say.

I was attending a live podcast of The Skeptics Guide to the Universe (www.theskepticsguide.org) and one of the questions from the audience asked about the seemingly preponderance of non-critical thinking in the engineering community. Specifically, the questioner was concerned about an engineer who was being used as an expert by some anti-evolutionists.

So how does skepticism and the scientific method fit into the engineering world? I’ll probably revisit this topic in the future since I think it is important to promote critical thinking, but for today let’s just look at the broad picture.

First, we have to recognize that the human brain is fully capable of containing two or more contradictory thoughts at one time. Yes, it causes some cognitive dissonance, but most people can deal with that pretty easily. Especially if the thoughts don’t overlap greatly. For instance, it is easier for an otherwise intelligent, say, businessman, to believe that the 9/11 towers collapse was a government conspiracy than it would be for a structural engineer. Likewise, I’d bet that it is easier for engineers to maintain a faith in a religion than it is for a scientist who spends more time contemplating the workings of the universe than many of us.

So do we need to be skeptical to be good engineers? Maybe not, in the traditional, wide viewpoint of the word. I am sure there are any number of good engineers who also believe the earth was created in six days, about 6000 years ago (I’m not one of them, BTW). With little overlap in the brain, the engineering probably doesn’t suffer too much.

But what concerns me is the underlying fuzzy thinking and the willingness to disregard facts. I understand that one can’t be logical about all things, but I think we should try to apply critical thinking in all aspects of our life, not just in our chosen profession. Otherwise it may start to be difficult to keep a solid wall in the mind between facts and belief.

Why go in that direction, some of you may ask? Because science and engineering work. Despite the Monty Python sketch, you can’t keep a building up on belief alone. Belief may be comforting, but it has nothing to do with the physical world in which we work. The more we practice critical thinking in all parts of our lives, there will be less chance of belief encroaching in our engineering decisions, and the better engineers we’ll be.

What do you think?