I was a 3rd year physics student when news broke that Carlo Rubbia, co-winner of the Nobel Prize in Physics in 1984, had been hired by my university. He was not supposed to teach any course (he was hired mainly to lead the construction of a large neutrino detector) but he’d give a one-off lecture series on Particle Physics, the subject I liked. It was very exciting!
The first lecture was held in the main auditorium, which was chock full with students, even younger ones who had no business being there, but´wanted to see The Man in action. I don’t remember much of the first lecture, but one thing I have learned is that very intelligent and learned persons tend to overestimate the knowledge and skill of other people. The lecture was barely comprehensible.
By the second lecture, the number of attendees had halved. One of the topics was Heisenberg’s Uncertainty Principle, which states that certain pairs of physical properties can be measured with a limited precision. In mathematical terms, one can write for example:
dx * dp >= hcut/2
which means that the position (dx) and the speed (dp) of a particle can be measured no better than hcut/2 (where hcut is Planck’s constant).
Now, Rubbia wrote that equation on the blackboard, but flipped the sign:
dx * dp <= hcut/2
which is a forgivable mistake, but negates the Principle: now speed and position can be measured with infinite precision.
One of my favourite teachers (arguably everybody’s favourite teacher in the Physics Department) was present at the lecture, and immediately notified Rubbia of the mistake. They had been colleagues for a long time, speaking on first name terms, so it seemed a natural thing to do.
Rubbia, visibly flustered, corrected the mistake on the blackboard, then blurted:
“Are you happy? Now you can [a-z]{4} off!” (redacted)
That’s what did it for me. I was already being let down by the poor didactical delivery of Rubbia, but he had no business being mean to another person (and a much, much, much better teacher) when he was obviously in the wrong.
I stopped following the lectures. I was not alone in doing that. I peeked through the auditorium door a few weeks later, and only a handful of brave students were attending.
I think the Department made a mistake in advertising the course to everybody. Students which had no business being there swelled the number of attendees, and this probably made Rubbia nervous, which can explain (but still not justify) why he blurted out when he was found out making a mistake. The level of the lectures was also assuming too much prior knowledge from the undergraduate students. It would have been better to restrict the course to graduates.