cybergarp · 1398 days ago · link · · parent · post: Is mathematics an effective way to describe the world?

I took transistor theory years ago. I remember almost nothing of the formulas, but I do remember the presentation. The engineering professor started with a quantum mechanical model, and he expanded the formula till it filled a chalk board. Then he said, notice that the dominate term is, and circled one of the terms. Then he took and erased everything but that term, and said we'll treat this as equal. He did this three times, with one of the formula expansions taking up 3 chalkboards. In the end, he said

- and that is why we treat transistors as a linear amplifier, and it only applies across a certain range.

It's like Box said,

- all models are wrong, some are useful