Comments by "Solo Renegade" (@SoloRenegade) on "Numberphile" channel.

slide rule
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in high school science, I realized I didn't have to memorize everything, only the fundamental concepts, and that I could use them to recreate other concepts as I needed them. Little did I know I had independently stumbled across the concept that I would many years later learn people refer to as "First Principles". So I set about practicing recreating formulas and such from scratch. I actually came up with the equation for the volume of a sphere in this manner, without using calculus. Unfortunately I don't remember the method and logic I used to solve it. Wish I did. Of course at the time I didn't realize it would be something that frustrated me for years to come. If I'd of known then, I would have written down how I solved it. I used only logic and math, no actual physical experiments, and it took me maybe 15min to reason my way through it. I just can't remember where I started and how I reasoned it, but I ended up with the correct answer.
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