Dear Colleagues,

As I was cycling into work this hot morning — forty degrees today —I was thinking about four incredible laws that we frequently use in engineering. Many of you would be familiar with them, but I see them come up so many times that I would thought I would revisit them.


The First Law: When there is any doubt, there is no doubt.

(Courtesy of the actor, Robert De Niro, I believe).

If you are contemplating a structure, such as a support, and are worried about some evidence of corrosion weakening it, you would be virtually guaranteed that there is a problem with the structure because of corrosion. I notice that in a major bridge collapse in Johannesburg, there were some questions asked during the construction about the efficacy of the support, but no one applied this Law. It could have saved lives and avoided injuries if people had been more critical and acted on their doubts.

Another example (from personal experience); you are testing some software for a power station control system, which, when switched onto the grid, will be providing critical power to a town. If you are a little concerned that there may be some unexplained glitches with the software, well — you know for sure — that these glitches will appear as you put the power station onto the grid. You would drop the power to the town unless you test the software meticulously and fix these bugs.

So, if there is any element of doubt in a design or in troubleshooting a situation, you are guaranteed that your worse fears will be realized if are you aren’t proactive. Presumably, this law is related to Murphy’s Law.


The Second Law: the KISS Principle

As most of you unerringly know, this means Keep it Simple Stupid. When building something or interfacing with people — simplicity is the best (and a great example of this is Steve Jobs’ initial work with the Apple iPhone).

Oddly enough, engineering professionals often are so overwhelmed with a design or project — probably because many other stakeholders are wanting to provide their input — that they forget it. And one ends up with a horribly complicated design or interface with people.

This is also related to the simplicity principle, traditionally referred to as Occam’s razor, which is the idea that simpler explanations of observations should be preferred to more complex ones.


The Third Law: The Law of Unexpected Consequences

This was illustrated to me many years ago. Traffic police — in Portland, Oregon, I believe —   were puzzled by the increase in accidents after all the traffic lights in the town had been upgraded with the most reliable super duper LEDs. These were supposed to provide greater reliability and a sharper, more intense light.

However, the LEDs are very efficient and therefore do not waste their energy in heat (as per the older incandescent traffic lights which were hot to the touch).

The Law of Unexpected Consequences came into play, as despite an improvement in the new traffic lights operation, reliability, and quality of lighting, they did not melt the snow, which built up during winter. This obscured the lights to the oncoming traffic. The older incandescent lights melted the snow build up around them because they were hot – thus giving a clear light to oncoming traffic.

So any design changes you make often have some consequences you may not think of. Try and always think laterally about other issues that may result from the changes you put in place.


The final law is Newton’s Third Law: The Law that for every action, there is an equal and opposite reaction. As engineers, you would be hyper familiar with this law; but I believe it also applies to any activity you undertake — there is always resistance against an initiative (perhaps inertia). For example,  if you decide to change a particular software design program to something which you believe is more efficient — you will unleash a torrent of abuse and disinterest in moving over — no matter how useful and improved the new software is.

The trick is always to get buy-in from all players and to educate them gradually to get them on board and supportive of the changeover or initiative.

Finally, I always love this quotation: A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.

Yours in engineering learning


Mackay’s Musings – 4th December’19  #689

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