ValI've mentioned her book in other posts, but Barbara Ann Brennan has one of the best explanations in print I've seen. "Hands of Light" is presented with lots of pictures, tables and pure science, while still completely intune with the energy. Barabara is (was) a NASA scientist who happens to also see human auras! It is an excellent text book with plainly written explanations and with coroborating evidence and research to support much of her material. Once you see it in print, you'll understand just how comperhensive a book it is when it comes to energy work.