This article is intended for anyone who wants to start a thread here at PhysicsForums on the twin paradox. There are already many, many threads here on this topic, and they tend to cover the same ground over and over again, so it seems useful to put a description of that ground into an article that everyone can read before starting yet another thread. If you are in that category, and what is here answers your question, great! But even if it doesn’t, hopefully, this article will help you to frame whatever questions you still have after reading it, in a way that will help you to get better responses without repeating things that have already been said here many times before.
Having said that, the first thing we will do is shamelessly borrow an already existing article on the twin paradox, the one that is part of the Usenet Physics FAQ. Before you go any further, please read it, all pages. It’s not long. Here it is...
