May 01

Species Plantarum catalogued over 7,000 plant species and established the two-part Latin naming convention still used today. Linnaeus's systematic approach classified plants based on reproductive structures, revolutionizing botanical science. The book's May 1 publication retroactively became the official starting point for botanical nomenclature under the International Code. Its clear criteria and standardized names facilitated global communication and study among naturalists. Linnaeus's work laid the groundwork for subsequent taxonomic developments across biology. The enduring influence of Species Plantarum is celebrated annually by botanists and gardeners alike.

Following Clyde Tombaugh’s discovery of a distant solar system object at Lowell Observatory in February 1930, astronomer Vesto Slipher announced on May 1 that 'Pluto' would be the planet’s official name. The suggestion drew on Roman mythology, as Pluto was the god of the underworld, reflecting the object’s remote and cold nature. Public enthusiasm surged, and the name was adopted by the international astronomical community. Over time, Pluto’s status evolved from planet to dwarf planet, but its name endured. The naming marked a memorable moment in 20th-century astronomy, symbolizing human curiosity about the outer solar system. Pluto’s discovery and naming inspired fascination with space exploration that continues to this day.

After extensive trials, Dr. Jonas Salk's groundbreaking polio vaccine was released on May 1, 1956. Poliomyelitis had devastated communities worldwide, causing paralysis and death, especially among children. Salk's vaccine, developed at the University of Pittsburgh, used killed virus to safely induce immunity. Nationwide immunization campaigns soon followed, leading to a dramatic decline in polio cases. This public health triumph paved the way for modern vaccine development and near-eradication of the disease.