Today my father forwarded this to me and my sister:
Dear Professor Pearle,
This THANK YOU note is more than 50 years late.
I was in your freshman physics class at the Case Institute of Technology in the Fall of 1967.
I really enjoyed your lectures; I particularly remember your ad hoc demonstration of calculating the period of a pendulum. You made a pendulum by swinging the cord of the Venetian blinds in our classroom. And then you estimated the length of the pendulum and initial displacement by using your shoe. That was very cool !! That class contributed to my decision to major in physics at Case. In hindsight, I made a good decision.
Even though I enjoyed physics, I did not have the talent to become a great physicist; so I never did physics professionally. Nevertheless, after I retired, I began to read popular science books in physics and math. I was pleasantly surprised to see you cited in several books (e.g, Adam Becker’s “What is Real?” and Giancarlo Ghirardi’s “Sneaking a Look at God’s Cards”). Thanks to Google Scholar, I eventually found some of your publications (and your email address). I am very impressed that you were working in the foundations of quantum theory long before it became popular.
Wow. Of course this made his day, and that of his incredibly proud daughters. We talked about saying thank you years after the fact (my father said he’d written to his favorite teacher/dissertation advisor at about the same interval as this email) and how appreciated it is. I know I’ve blogged about this here, here and here, And I’m not implying that hearing a thank you from a student or colleague is why I do any of my job! But to know — particularly after the fact — that something you did, possibly a throw-away something, meant a lot to someone else, or inspired them, makes all the times that a program or idea failed, or when you’re convinced that this one class just never got anything you said, easier.
There are people I wish I could thank, but they’re either unfindable or dead. Perhaps somehow they know. And for those I can thank, well, it’s now summer vacation and that’s at the top of my To Do list.