Liar, Liar, Plants on Fire

In 1966, Cleve Backster, an interrogation specialist for the CIA, claimed to have discovered something shocking: plants seemed to respond to human thoughts and emotions. He came to this conclusion by hooking up plants to a polygraph machine to measure their response. His controversial experiments with polygraphs suggested that living things might share a hidden form of communication, and sparked a wave of fascination and skepticism that still lingers today.