In the 20 years that I have been working in the physical sciences, I've
never (ever!) seen customary units used for anything except mechanical
designs. I just got a big surprise reading a famous physics textbook
published in 1966. Much of the book is in feet, inches, pounds, etc.
This is a really pleasant surprise, because it shows how much progress
we've made since 1966. I think any scientist today (regardless of age)
would burst out laughing if someone performed a calculating in feet or
pounds, assuming it was intended as a joke.
