For Good Measure
On November 27, 1701,, Swedish astronomer and mathematician Anders Celsius was born. He has become most famous outside of his native Sweden for the temperature scale he created. There were a number of temperature scales in use in different countries and regions during his time. The scale evolved from Celsius’ own requirements.
His own scale might not have had such attention paid to it except he had already become a famous scientist at a very young age. Celsius had discovered, after hundreds of observations of the aurora borealis, that the greater the visible activity of this phenomenon, the larger the deflection it produced in compass needles. He had participated as the astronomer in an expedition to measure the arc or length of a degree near the North Pole as part of an experiment to calculate the shape of the Earth and had returned to confirm Newton’s view that the Earth was not a sphere and was flatter at the poles. Celsius was funded to set up a modern observatory and founded Uppsala Astronomical Observatory.
Celsius created his scale from 0 at the point of water boiling and 100 at the point of water freezing. He was the first person to test his scale within variations of latitude and atmospheric pressure.
Aware that atmospheric pressure affected boiling point, he also stipulated that the boiling point be determined and calibrated at the barometric pressure of sea level. Following these conditions, his scale could then be used anywhere in the world. To refer to his scale, Celsius used the French word centigrade from the Latin centum [hundred] + gradus [step].
Soon after his death, the production of thermometers reversed the two fixed points, to show the scale from 0 at the point of water freezing and 100 at the point of water boiling. The centigrade scale was renamed Celsius in his honour by an international conference on weights and measures in 1948. Celsius has become the global standard temperature scale everywhere except the U.S.A.
B Bondar