Anders Celsius was born on November 27, 1701 in Uppsala, Sweden, into a family of scientists. His grandfather and father were both mathematicians and astronomers. In 1730, he became a professor of astronomy at Uppsala University, succeeding his father in the same position. At Uppsala University, he focused on astronomy and experimental physics. He made significant contributions to astronomy, particularly in the study of the aurora borealis (northern lights) and in the measurement of arcs of the meridian to determine the size and shape of the Earth.
In 1742, Celsius published a paper titled, Observations on Two Persistent Points on a Thermometer. In that paper, he proposed that the temperature scale be defined by two fixed points:: the temperature at which water boils, and the temperature at which water freezes. He originally proposed that the temperature at which water boils be assigned the value 0 and the temperature at which water freezes be assigned the value 100. A celsius degree would then be one-hundredth of the difference between these temperatures. After his death, his temperature scale was adopted but in a reversed form, i.e. the temperature of boiling water was fixed at 100˚ C and freezing water at 0˚C. The Celsius scale became widely adopted and is now used as the standard temperature scale in most countries around the world.
Before the Celsius temperature scale had been adopted, the world used the Fahrenheit scale named in honor of German physicist Gabriel Daniel Fahrenheit (1686–1736). On that scale, the freezing point of water is 32˚F and the boiling point of water is 212˚F.
The equation for the conversion of degrees Fahrenheit, F, into degrees celsius C is: C = (5/9)(F – 32).
The equation for the conversion of degrees celsius C, into degrees Fahrenheit is: F = (9/5)C + 32
Anders Celsius died from tuberculosis on April 25, 1744 at the age of 42. Despite his contributions to various scientific fields, Anders Celsius is most widely remembered for the temperature scale that bears his name.