Sensory deprivation has been used for millennia by humans as a tool to sharpen the mind, prepare for a rite of passage, conduct rigorous meditation, and to reach Nirvana. Shaman, witch doctors, monks, mystics, Buddha, and even Jesus retreated to deserted mountain tops or remote caves to endure extended periods of isolation in an effort to reach enlightenment. Along those lines but available to us all without the days-long walk through a desert or blinding climb to a mountaint