Hello all. I am currently using Jackson's Electrodynamics book to study the subject and was wondering how different is the 1st edition from the 3rd. So far, I have read the first chapter and have done most of the problems from the first edition. My question is, how much will I miss out on if I use the first edition over the 3rd for the remainder of the book? (I found the 1st edition for free so I don't really want to spend money on the 3rd if it's not completely necessary). Thanks.