|MadSci Network: Engineering|
Hi Pam, You are thinking in the right direction. It's not just a thought experiment. What you describe is known as a waveguide: http://en.wikipedia.org/wiki/Waveguide_%28electromagnetism%29 Transmission lines and some types of optical fibers also fall into the same category. As you suspected, waveguides are used to transport electromagnetic power over long distances with low loss. Here is some detailed information on transmission lines: http://en.wikipedia.org/wiki/Transmission_line http://madhu.com - http://madhu.com/blog
Try the links in the MadSci Library for more information on Engineering.