Thank you for allowing me to join Physics Forums. My understanding of physics is somewhat naive, although I do have an undergraduate degree in Environmental Science and Technology. (That and Geology were the only science degrees available in the county at that time, and I had to live at home for family reasons.) Now I am retired, so I have time to learn the things I want to, but without any teachers I have many questions. I hope this will prove to be a good place to find answers.