A quick note: For the next few weeks, I won’t able to work on the car which I’m hoping to use as the basis for my projects, so you’ll have to put up with this less practically-minded format for the time being.
One thing that I’d like to address is possible misunderstandings about engineering itself. I am going to base this off what my impressions were before I got into the field and assume yours might be similar. The biggest misconception I had was the fact that there is a right answer. With engineering now being taught as a science and math heavy subject and actually being lumped in with them as “STEM”, it’s easy to equate it to a grade school math class where each problem ends up with something equaling something else. Nice and neat.
Reality is far messier. The answer is never one hundred percent clear because even knowing which question to ask is murky in the first place. What engineers have at their disposal are what I’ll call models, or simplified representations of how the world works. Unless you are building something that has an extremely narrow use - let’s say a table that will be kept in exacting laboratory conditions of temperature and humidity with the exact same weight on it forever - you’re going to have to make assumptions and simplifications. Sure, you can use or solve models fairly precisely but how well are those models representing reality?
This is the reason behind safety factors. We can never represent reality perfectly, whether it be the way something was made vs the way it was designed, imperfections in the material that weren’t accounted for, or use cases that weren’t anticipated. A safety factor is a multiplier (usually around 1.5 in aerospace) that is tacked on to all of the final sizing as a buffer for reality. So if your model says that something should be an inch thick, you’ll multiply that by your safety factor, and build a part that’s an inch and a half thick. If that doesn’t seal the deal as engineering as an inexact science, I don’t know what will.
Another factor often overlooked is that engineering is a human endeavor (despite what you might think about some engineers you’ve encountered). There are an infinite number of ways you can design something to solve a problem. For a simplistic metaphor, think about water bottles. They essentially just need to hold water, but with individual opinions about plastic, threads on caps, and measurements on the sides to name a few, we end up with a near infinite variety. It’s a similar situation on a smaller scale for each engineering decision - opinions reign supreme. Sure there might be data presented to show “unbiased” comparisons between ideas, but data can be made to tell a story. Putting a proverbial poison pill in something that you don’t want to work on is not difficult. So when you step on an airplane, you can be sure its design is not a pure distillation of our current state of knowledge but rather a smoothie of decisions made as a result of biases, education, personal vendettas, relationships, experience, etc.