On April 16th in science history, one significant event took place in 1943 when Swiss chemist Albert Hofmann accidentally discovered the psychedelic effects of lysergic acid diethylamide (LSD) while working in his laboratory in Basel, Switzerland.

Hofmann had first synthesized LSD in 1938 as part of his research into ergot alkaloids, but he had not initially tested its effects. On April 16th, 1943, while re-synthesizing LSD, Hofmann accidentally absorbed a small amount of the substance through his fingertips. He soon began to experience unusual sensations and a remarkable shift in perception.

Intrigued by this unexpected discovery, Hofmann decided to intentionally ingest 250 micrograms of LSD three days later on April 19th, 1943. This day became known as "Bicycle Day" as Hofmann experienced intense hallucinations during his bicycle ride home from the laboratory.

Hofmann's discovery of LSD's psychedelic properties sparked a wave of research into the potential therapeutic applications of psychedelics in the 1950s and 1960s. LSD was investigated as a possible treatment for various psychiatric disorders, including depression, addiction, and anxiety.

However, the widespread recreational use of LSD and its association with the counterculture movement of the 1960s led to its prohibition in the United States in 1968. Despite this, research into the therapeutic potential of LSD and other psychedelics has experienced a resurgence in recent years, with promising results in the treatment of depression, post-traumatic stress disorder (PTSD), and end-of-life anxiety.

Albert Hofmann's serendipitous discovery on April 16th, 1943, marked a significant milestone in the history of psychopharmacology and continues to influence research into the potential benefits and risks of psychedelic substances.