Learn about the history of science by reading about the significant scientific events that took place on this day in history.
1952 - Soviet Luna 2 spacecraft 'lands' on the Moon.
The Soviet spacecraft Luna 2 impacted the Moon's surface. It would become the first man made object to reach the surface of the moon. Luna 2 also confirmed Luna 1's discovery of the solar wind.
1936 - Ferid Murad was born.Murad is an American physician who shares the 1998 Nobel Prize in Medicine with Robert F. Furchgott and Louis J. Ignarro for their discoveries involving nitric oxide as a signal molecule for the cardiovascular system. Murad was the first to show nitroglycerin worked as a drug by releasing nitric oxide into the body which caused blood vessels to dialate. Furchgott and Ignarro determined the intermediate chain of events and reactions that cause this effect.
1882 - Georges Leclanché died.
Leclanché was a French electrical engineer who developed one of the first dry cell batteries. The Leclanché cell used an electrolyte of ammonium chloride with terminals made of zinc and manganese dioxide and was the predecessor of the modern battery design used in flashlights and portable electronics.
1849 - Ivan Petrovich Pavlov was born.
Nobel Prize Foundation
Pavlov was a Russian physiologist who is best known for his work on conditioned behavior in an experiment involving dogs and bell ringing before feeding. His initial research was into the physiology of the digestive system of dogs and was collecting saliva for analysis when he noticed the dogs would start to salivate before the food even reached their mouths. Further research showed dogs could be conditioned to show a reflex response to an unrelated stimulus. Although he was known for this research, it was his research into the digestive system that earned him the 1904 Nobel Prize in Medicine.
1712 - Giovanni Domenico Cassini died.
Cassini was an Italian astronomer and mathematician who co-discovered with Robert Hooke the Giant Red Spot on Jupiter. He also discovered four of Saturn's moons: Iapetus, Rhea, Tethys and Dione. The Cassini Division is the name of the dark gap he discovered that divides Saturn's rings. He suggested the rings were made of small particles rather than a solid mass that was the common belief at the time.
1698 - Charles François de Cisternay du Fay was born.Dufay was a French scientist who was one of the earliest investigators of electricity. He discovered there were two types of electricity that he called vitreous and resinous depending on the methods used to produce it. Today they are known as positive and negative charge. He also identified that like charges repelled each other and opposite charges would attract.
1638 - Pierre Vernier died.
Vernier was a French mathematician who introduced the vernier scale for measurements. A vernier is a small movable scale that allows for extra significant figures or more precision in the measurement. When a measurement is made with a vernier equipped device, the initial digit in the measurement is the last primary fixed rule before the '0' mark on the venier scale. The next digits are where the mark on the venier is lined up on the primary fixed rule.