Modern Physics

Michael Fowler, University of Virginia

What is “Modern Physics”?

“Modern” physics means physics based on the two major breakthroughs of the early twentieth century: relativity and quantum mechanics.

Physics based on what was known before then (Newton’s laws, Maxwell’s equations, thermodynamics) is called “classical” physics.

This course traces in some detail just how the new ideas developed. We examine the experimental and theoretical paradoxes that forced thinking out of the traditional path.  This is a valuable exercise—the classical ideas are in much better accord with common sense (defined by Einstein as the layer of prejudices in place by age eighteen), so seeing how the new physics came about is helpful in overcoming that “common sense” and getting a better understanding of nature.

But this is not just a course on concepts: the lectures and homework are sufficient to give the student a basic technical grasp of special relativity, and of Schrödinger’s quantum mechanics.


Special Relativity

Kinetic Theory of Gases



Particles and Waves

Schrodinger Equation

Atoms and Nuclei

Some Extra Course Materials

The Lecture Notes on Special Relativity have been put together in one PDF File here.

For German Readers: All the lectures on Special Relativity have been translated into German by Christoph Scholz, who teaches high school physics (pupils aged 10-19) in Hagen, Germany. They can be downloaded in pdf format at einstein-deutsch.pdf. Scholtz' school URL is // These notes are copyright. Students can make one copy for personal use, but the notes are not to be distributed commercially without permission of the author and the translator.

Old homeworks and exams can be found here.