Brennan's description of the flow of energy sounds very similar to what many people describe as being an orb. In her section "Exercise to "See" the Universal Life-Energy Fields", she Brennan says,
The easiest way to begin to observe the universal energy field is to simply relax on your back in the grass on a nice sunny day and gaze at the blue sky. After some time you will begin to see tiny globules of of organ making squiggly patterns against the blue sky. They seem to be tiny white balls, sometimes with a black spot, that appear for a second or two, leave a slight trail mark, and then disappear again. When you continue this observation and expand your vision, you will begin to see the whole filed pulsate in a synchronized rhythm. On sunny days these balls of energy will be bright and move fast. (Hands of Light, pages 37-38)
Orgone is a term developed by Wilhelm Reich a protege of Freud, to describe prana, chi and energy in the ether.
When we see, or photograph orbs chances are that they are globules of white light, prana/chi/orgone, that Brennan describes. Rarely, if we are lucky, we may see/photograph a Nature Spirit, or being in another world. I believe Peter Shell and I did so in a picture in a previous post, The Elementals probably Fairies of Some Sort are observing our Survey of the Ledges