https://github.com/davepinch/pinchy.cc/blob/master/content/topics/places/creeks/bolt-creek/bolt-creek.md
As the coherent resonance produced by the human heart in a state of profound relaxation reaches the fluid layer surrounding the brain, it sets up a rhythmic pattern in which the brain moves up and down approximately 0.005 to 0.010 millimeters in a continuous pattern.
