Waves

Lecture notes for From Classical to Modern Physics, PHYS20040

Preface

These pages form the lecture notes for the Waves component of PHYS20040 - From Classical to Modern Physics. Keep an eye on these pages, as these notes will grow as the course progresses.

Errata and misunderstandings

If you discover any mistakes, no matter how small, please inform me via email or via the unit discussion boards. I would like to know about any typos, spelling mistakes, bad punctuation, etc. so that I can correct them for future students. If there is an error in the mathematics or physics, then definitely let me know — as a teacher, the last thing I want to do is confuse my students with bad mathematics.

If you find a part of the notes that you don’t understand, again feel free to contact me. I may be able to provide an alternative explanation that works better for you. Alternatively, I might be able to clarify that part of the notes or perhaps you have found an error in the notes without realising it. In any case, by requesting help to understand something in the notes, you may also be helping me to improve them.

I will endeavour to fix the lecture notes as any errors are found. Any recent edits will be listed below, so that you are alerted to any changes.

Updates

• (12th Oct 2025) Initial release.

Recent fixes and clarifications

• (3rd Nov 2025) Fixed equation in section 5.1 by adding an overall factor of \(1/c\).
• (17th Dec 2025) Fixed equation for arbitrary linear polarisation at the end of section 3.2, replacing \(\hat{\mathbf{x}}\) with \(\hat{\mathbf{z}}\). I also now specify the polarisation direction \(\hat{\mathbf{n}}\) in more detail on the previous line.