| MadSci Network: Physics |
Hi! Actually, your question is a very common question - I wondered about the same thing many years ago.
In fact, because so many people wonder about it, this question has been submitted to MadSci Network at least 2 times before. So, here are the links to the previous answers - the two replies give the same information, but in two different ways, so hopefully you will find at least one of the two approaches will be helpful.
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Try the links in the MadSci Library for more information on Physics.