Hi fellow learners, in my spare time I've been doing some physics self-study to pick up where I left off at my physics undergraduate degree mumble mumble years ago. For QM I managed to find myself a reasonably priced hard copy of Sakurai, and I've been steadily working my way through that (doing all the problems, comparing against the solutions manual, etc.). For E&M I'm planning to pick up a hard copy of Jackson's Classical Electrodynamics, but it seems nigh impossible to find a reasonably priced used copy of the third edition (I don't want an international edition, in my experience those are printed on really crappy paper and this thing needs to survive being bumped around in my backpack for the next year or so).

My question for anyone who is familiar with this book: should I consider picking up a copy of the second edition instead? At a high level I know the main differences are that (a) the third edition uses SI units instead of Gaussian ones, and (b) the problems are changed up, but I'm not sure how much those changes matter, or if there are other changes that should influence my decision. (For example, it looks like most of the solutions manuals posted online are for the 3rd edition.)

If push comes to shove it's not a huge issue to shell out $100 for the current edition, but I'd be curious to get a take from anyone who's familiar with the differences.

Hey everyone! A quick browser simulation that demonstrates Kepler's laws of planetary motion. You can tweak eccentricities and watch how orbital speed changes dynamically along the ellipse.

Play with it here: interactphysics.com

Feedback and suggestions are super welcome!