Modern Physics

From the late 19th Century until Einstein published his work on special relativity in 1905, a great number of scientists believed that physics had gotten to the point of a near complete understanding of the universe.

This was probably due to a form of conceit, i.e., that all forces, particles, fields, etc., conform to human intuition.  What we’ve learned since, of course, is that phenomena that are either very small or very large contain huge paradoxes.

I took one semester of quantum mechanics.  I got a C+, for which I was grateful.  It never entered my mind to take a second semester.