Sensory deprivation involves a large tank which is filled up with water heated to 37 degrees Celsius, the same temperature as the body, and 1000 lbs., or some variation of this in smaller tanks, of Epsom salts are added, so that half of the body is underwater and half of it is above because of the density of the salt within the water. Human beings have low fat content on average and need this salt otherwise a participant would sink. An observer cannot distinguish between water and air because when within the tank as it feels the same, and after a short period of time, because there are no visual queues being that the tank is completely dark, in the absence of sensory input, an observer typically begins to think differently as the brain has more resources dedicated to thought as less surface area is compartmentalized for sensory stimuli. This process is extremely similar to meditation, however meditation takes both time and practice to achieve upon a consistent, reliable, and meaningful level, as opposed to a sensory deprivation tank in which reaching such a state is essentially automatic provided enough time passes within the tank for the observer. This experience ends instantaneously once the tanks door is opened however, unlike meditation or the use of pharmacological agents to achieve a psychedelic or intrinsic experience