John Siau writes:
As an engineer I like to use "rules of thumb" to make quick estimates that help explain what can be expected from the physical world around me. These rules of thumb are easy-to-remember approximations that eliminate the need for complicated and needlessly precise calculations.
If you learn a few key rules of thumb, you can gain a tremendous understanding of the world around you. For those of you who feel discombobulated by the complexities of high school physics, there is hope! I encourage you to step back and take a fresh look at the world around you. If you learn a few simple rules of thumb, you can begin to unravel the mysteries of physics while amazing your friends and yourself.
In this paper I will present 15 simple rules that I find useful when working with audio. I have assigned numbers to each in order to make the discussion clearer. Memorize the rules, not the rule numbers.
Let's begin with a simple but very fundamental rule of thumb: We all know that .......