Part of learning engineering is learning what requires precision and learning to let go and be imprecise when necessary.
I recall being in Dr. O’Malley’s circuits class at the University of Florida in the mid 90s. He drew an op-amp on the board and said it’s a very high-gain differential voltage amplifier. Someone asked what gain we should use. He said, “You can use whatever big number you want. For this example let’s use, I don’t know, say a million.” Several people laughed thinking it was a joke. O’Malley didn’t appear to understand the laughter. He continued, “You could use a similar number like two hundred thousand or five million. Anyway, that’s not the point. I hope it’s obvious that…”
I was amazed that 200,000 and 5,000,000 were very similar for the purposes of understanding an op-amp, so amazed that I remember it 15 years later. The statement seems perfectly natural now. Engineering has changed my mindset on precision.
This mindset affects aspects of life completely outside of engineering. The other night my wife, who is an attorney, said our baby was 10 minutes away from needing another dose of Tylenol for teething. “10 minutes?” I asked, “The tolerances can’t be that tight. That’s only a few percent of the dose duration.”
“It says 80mg every four hours” she said matter-of-factly, as if quoting the Uniform Commercial Code.
“But it doesn’t give a tolerance. I bet if you plotted the half-life of Tylenol in population of healthy babies, you’d find a distribution with half-lives varying by more than an hour. Even accounting for that, different babies will experience a therapeutic response at different blood concentrations.”
She said she felt more comfortable with a very clearly defined rule. Those tolerances made her uneasy. I felt more comfortable with a system that does not depend on any element having very tight tolerances. I wonder to what extent similar professional mindsets affect the daily lives of people in other fields such as accounting, medicine, science, teaching, and so on.