Taylor Made: Inherent engineering
In class, we are taught to recognize various principles of engineering (and physics) as they apply to topics of design and problem solving. Outside of class, we often use these same principles, be it in complex or basic applications, without realizing.
For example, some of our foundational principles can be found hiding in arts and crafts projects. Building a hanging mobile is a practice in the art of balance, and concurrently in the application of torque. You can calculate arm length x force of hanging object to get the torque of a single component, and then arrange neighboring components accordingly. However, cold calculations are not a necessity in the actual build process—while doing so would eliminate the need for any trial and error, you can also build by feel and ultimately get the same result.
You can play what some call a ghost fiddle by pouring different amounts of water into glasses and rubbing the rims with your fingers, or fashion a recorder by cutting holes out of a drinking straw and blowing through it. You could use air column resonance calculations for an open cylinder to determine precisely where to cut your holes in the straw, and determine how much water to pour in each glass based on material properties. However, in real life, you’ll probably pour until it sounds right, or cut roughly where you think each note should be, and you’ll get a close enough result.
Speaking of music, instruments that require manual manipulation of wavelengths, such as a trumpet or viola, cause the musicians to inherently invoke principles of sound (remember v = f * λ ?). Brass instrument players manipulate their lips to produce different pitches, while those playing string instruments produce different notes by changing the length of each string with their fingers. Singers can control and manipulate every aspect of sound production, as their body, instead of a foreign object, is the platform through which sound is produced. The shape of the mouth, the degree of use of the diaphragm, the thrust of air through the trachea; these and many other aspects all factor into vocal quality.
On a different note, anyone who drives a stick shift is doing for the car what engineers have designed automatic transmissions to do. Lots of calculations and energy-based analysis goes into designing an automatic transmission—I think the best summary for this type of design is to note that the higher the gear, the more inertia the gear has. Keeping the car in the power band (range of RPM that encompasses peak power output) during all stages of the drive, from rolling out of a stop to cruising on the interstate, requires shifting gears as necessary to manage the car’s efficiency. In a manual car, the driver does this, which means that even if you’re not thinking in terms of engineering, you’re still outputting the same calculations that an automatic would. You can figure out when to shift based on sensory signals coming from the car, such as the sound and feel of the engine, as well as mechanical signals such as the rate of rpm.
Take a step back to look critically at day-to-day life, and you’ll no doubt find many more examples of inherent engineering.