Version Date: May 2007
This is the web version of the Usenet Physics FAQ (Frequently Asked Questions). Its purpose is to provide good answers to questions that have been discussed often in sci.physics and related usenet newsgroups. The articles in this FAQ are based on those discussions and on information from good reference sources. That does not mean that they are always perfect and complete. If you have corrections, updates or additional points to make please send an email to the editor, (his cv is here). If you want to write up an article following a news group discussion about a subject not yet covered here then feel free to send it to the editor, but please do not use this address to ask new questions. Ask them in the appropriate newsgroup instead.
If you are new to the Physics newsgroups, welcome! Please read the article An Introduction to the Physics Newsgroups. It will help you find the right newsgroup for your questions and will give you other crucial advice about appropriate netiquette for these groups. Above all you should check carefully to see if your questions are answered in this FAQ before posting.
This FAQ was created by Scott Chase in 1992. The web version was created, maintained and enlarged by Michael Weiss and Philip Gibbs. Others who have written for the FAQ are credited at the top of the items they submitted while many more who have made smaller contributions have been thanked privately.
The FAQ is not available in text only form and is no longer posted to the usenet groups. This is because it is too big and some articles use images and equations which cannot be transformed into text.
This document is copyright. Please read the copyright notice for copyright details and archival information.
There are many other places where you may find answers to your question. This is a list of other FAQs and answer archives that are related to physics.
Thanks go to John Baez, Jay Brown, Jon Butterworth, Alan Cairns, Dave Edsall, Harald Falkenberg, Philip Gibbs, Chung-rui Kao, Matthew Parry, Johan Wevers, and the various organisations for hosting us! If any other non-commercial sites would like to mirror this FAQ, please contact the editor.