I'm currently working in consulting engineering (in the U.S.) and working on my MS degree through night classes. I took 4 years off of school between graduating from my BS degree (Math) and going back to school for my MS (Mechanical Engineering). I'm realizing that I like the academic world a lot better than the construction world. Therefore, I'm considering quitting my job and going full time for my PhD, either in Physics or Engineering, and I'm curious of what my options would be with a PhD. Could I make decent money? What career options would I have other than teaching/research? What is engineering research really all about? One thing I'm interested in is new technologies for heating and cooling buildings (the industry I work in now). Is there research in these fields going on at universities, or is it all private industry? What do engineering PhD students do for money while they are in school? Are they paid for their research? I know these are kind of vague questions, and I think a lot of it will be cleared up over the next couple of years as I get further into the MS program, but I'm interested in what anyone has to say about it. Thanks for your input.