Instruct: Classify Amazon reviews into positive or negative sentiment
Query: reply to the guy from the schwarzchild radius

The notation comes from German: K for Kraft (force), b for Beschleuningung (acceleration), m for Masse (mass). It might be outdated, but that does in no way disqualify the content of a text. As for learning calculus in order to understand relativity: I believe Einstein once said he could explain relativity (maybe he meant special relativity) to a barmaid. Knowing calculus and differential geometry (for general relativity) would indeed provide one with a much deeper understanding of the theory, but one can get a good feel for the subject without it. So if you are looking for a basic introduction to relativity don't discard this one for those reasons. One good reason to choose this book is that it presents relativity in its natural context of electrodynamics, which really gives one a much clearer perspective, I believe.