Hopping into a soundproof, light-proof box filled with saltwater may be a popular relaxation therapy today, but those just discovering it are likely asking themselves: “who came up with this strange device, and when were float tanks developed?” In order to answer those questions, we first have to ask “why did they want to make them in the first place?” In the early 1950s, neuroscience was a relatively new field of study, and how the brain worked was much less understood than it is today. One prevalent theory at the time was that our brains were designed to react to stimulation and that everything we did was solely a reaction to something external. Because of this, some scientists thought that if we were to remove all sensory stimulation, our brains would simply shut down. Early experiments to test their theories involved rooms with white noise (such as fans) blocking out sound and goggles with bright lights to keep participants from seeing anything clearly. Physician and neuroscienti