John Cunningham Lilly was an American physician, neuroscientist, and inventor, born in 1915, who became known for pioneering the isolation tank in the 1950s. This tank, designed to minimize external stimuli, was intended as a tool to explore the nature of consciousness. Lilly was part of a counterculture intellectual circle and often courted controversy with his unconventional research methods and ideas. His work extended to attempting communication with dolphins and experimenting with psychedelic substances, often while in his isolation tanks. These pursuits inspired popular culture, including two Hollywood films. Lilly's early life was marked by a wealthy background and an early aptitude for science, leading him to study biology at Caltech and later medicine at Dartmouth and the University of Pennsylvania. He embraced the principle of experimenting on himself before others, a practice that influenced his career.

Lilly's most famous invention, the isolation tank, emerged from his work in neurophysiology. Developed in 1954, the tank provided a unique environment for sensory deprivation, allowing individuals to float in a dark, soundproof, warm saltwater environment. Lilly viewed these tanks as a crucial tool for delving into the depths of human consciousness, seeking to understand its nature by removing external distractions. This fascination with the inner workings of the mind, particularly under altered states, led him to experiment with psychedelics, such as LSD, often within the confines of his isolation tanks. His research in this area positioned him as a figure exploring the intersection of technology, the human mind, and altered states of awareness.

Beyond human consciousness, Lilly dedicated significant effort to understanding and communicating with dolphins. Beginning in the mid-1950s, he established research centers, first in Florida and later in the U.S. Virgin Islands, to study bottlenose dolphins. His work involved observing their vocalizations and behaviors, aiming to bridge the communication gap between humans and these marine mammals. In the 1980s, he directed a project focused on teaching dolphins a synthesized computer language. Lilly envisioned future 'communications laboratories' where humans and dolphins could interact as equals, fostering a shared language and understanding. His efforts in this field contributed to discoveries about dolphin anatomy and communication patterns.

Lilly's contributions spanned multiple scientific disciplines, including biophysics, neurophysiology, electronics, and computer science. During World War II, he researched high-altitude physiology and developed instruments for measuring gas pressure. His early work at the University of Pennsylvania involved creating an electrical capacitance diaphragm manometer for blood pressure measurement and exploring early computer technology. A defining aspect of Lilly's scientific approach was his commitment to self-experimentation, influenced by J. B. S. Haldane's philosophy. He frequently tested his own hypotheses on his body, sometimes to the point of endangering his health, as seen in his early experiments with diet and his later psychedelic explorations.