Learn about the history of science by reading about the significant scientific events that took place on this day in history.
1984 - India chemical plant accidentally kills thousands.A Union Carbide plant outside of Bhopal, India accidentally released methyl isocyanate gas used in the production of pesticides. The heavy gas enveloped the city in a fog and exposed nearly a million people, killing nearly 4000 people and an estimated 20,000 needing medical attention. This was one of the world's worst industrial disasters.
1973 - Pioneer 10 becomes first to reach Jupiter.
NASA's Pioneer 10 spacecraft reached the planet Jupiter. It began sending back the first close up photographs of the planet and conducted many different measurements of the Jovian system. The spacecraft passed through Jupiter's system on its way out of the solar system.
1933 - Paul Jozef Crutzen was born.Crutzen is an Dutch chemist who shares the 1995 Nobel Prize in Chemistry with F. Sherwood Rowland and Mario J. Molina for their research on the ozone layer. Rowland and Maria discovered that man-made chlorofluorocarbons (CFCs) were a major contributor to the destruction of ozone in the atmosphere. Crutzen's demonstrated the effect nitrous oxide had on the depletion of ozone. Nitrous oxide is largely unreactive and could rise high into the atmosphere and interact with ultraviolet light. This would begin a chain of reactions that where one product was converting ozone into molecular oxygen.
1920 - William de Wiveleslie Abney died.Abney was an English chemist, astronomer and photographer who made several contributions to the chemistry of photography. He introduced the use of hydroquinone as a photographic developer and replaced wet emulsions with a dry emulsion. He developed a new photographic emulsion that would react to infrared light. He used this film to investigate the infrared spectra of organic molecules and the Sun.
1900 - Richard Kuhn was born.Kuhn was an Austrian-German biochemist who was awarded the 1938 Nobel Prize in Chemistry for his research into carotenoids and vitamins. Carotenoids are the organic pigments in plant cells or created by algae or bacteria. Kuhn discovered, purified and determined the composition of eight of these compounds and purified them. He also isolated vitamins B6 and B12.
1886 - Karl Manne Georg Siegbahn was born.Siegbahn was a Swedish physicist who was awarded the 1924 Nobel Prize in Physics for his work on x-ray spectroscopy. He discovered the M series of x-ray spectral lines and demonstrated the shell nature of atomic electrons. He also demonstrated the refraction of x-rays through prisms to illustrate their wave nature.
1882 - James Challis died.
Challis was an English astronomer who is best known for not discovering the planet Neptune. English mathematician John Couch Adams computed an orbit for an unknown planet that would exist to cause the peculiar orbit of the planet Uranus and passed that information to the Astronomer Royal, George Airy. Airy passed the task on to his successor at the Greenwich Observatory, James Challis. Challis undertook the task with little enthusiasm. It wasn't until the German group Galle and Le Verrier announced their discovery of Neptune that Challis' work suddenly became much more important. It was later determined that Adams' prediction was within 2° of the actual position and Challis had observed it twice without recognizing the planet.