Celsius, Anders
Celsius, Anders
(b. Uppsala, Sweden, 27 November 1701; d. Uppsala, 25 April 1744),
astronomy.
Celsius’ father was professor of astronomy at the University of Uppsala, and his son early followed in his footsteps. He studied astronomy, mathematics, and experimental physics; and in 1725 he became secretary of the Uppsala Scientific Society. After teaching at the university for several years as professor of mathematics, in April 1730 Celsius was appointed professor of astronomy. From 1732 to 1736 he traveled extensively in other countries to broaden his knowledge. He visited astronomers and observatories in Berlin and Nuremburg; in the latter city he published a collection of observations of the aurora borealis (1733). He went on to Italy, and then to Paris; there he made the acquaintance of Maupertuis, who was preparing an expedition to measure a meridian in the north in hopes of verifying the Newtonian theory that the earth is flattened at the poles and disproving the contrary Cartesian view, Celsius joined the Maupertuis expedition, and in 1735 he went to London to secure needed instruments. The next year he followed the French expedition to Torneå, in northern Sweden (now Tornio, Finland). During 1736–1737, in his capacity as astronomer, he helped with the planned meridian measurement; and Newton’s theory was confirmed. He was active in the controversy that later developed over what Maupertuis had done and fired a literary broadside, De observationibus pro figura telluris determinanda (1738), against Jacques Cassini.
On his subsequent return to Uppsala, Celsius breathed new life into the teaching of astronomy at the university. In 1742 he moved into the newly completed astronomical observatory, which had been under construction for several years and was the first modern installation of its kind in Sweden.
Although he died young, Celsius lived long enough to make important contributions in several fields. As an astronomer he was primarily an observer. Using a purely photometric method (filtering light through glass plates), he attempted to determine the magnitude of the stars in Aries (De constellatione Arietis, 1740). During the lively debate over the falling level of the Baltic, he wrote a paper on the subject based on exact experiments, “Anmärkning om vatnets fö -minskande” (1743). Today Celsius is best known in connection with a thermometer scale. Although a 100-degree scale had been in use earlier, it was Celsius’s famous observations concerning the two “constant degrees” on a thermometer, “Observationer om twänne beständiga grader på en thermometer” (1742), that led to its general acceptance. As the “constant degrees,” or fixed points, he chose the freezing and boiling points of water, calling the boiling point zero and the freezing point 100. The present system, with the scale reversed, introduced in 1747 at the Uppsala observatory, was long known as the “Swedish thermometer.” Not until around 1800 did people start referring to it as the Celsius thermometer.
BIBLIOGRAPHY
Celsius’ most important writings are De observationibus pro figura telluris determinanda (Uppsala, 1738): De constellatione Arietis (Stockholm, 1740): “Observationer om twänne beständiga grader pa en thermometer,” in Kungliga Svenska vetenskapmkademiens handlingar (1742). 121–180; and “Anmärkning om vatnets förminskande.” ibid. (1743), 33–50. “Observationer…” may be found in German as no. 57 in Ostwald’s Klassiker der exakten Wissensehaften (Leipzig, 1894). Many of his minor writings were published as academic treatises or appeared in Kungliga Svenska vetenskapsakademiens handlingar. Philosophical Transactions of the Royal Society, and other journals. His personal papers, including letters from Maupertuis, J. N. Delisle, and Le Monnier, are at the Uppsala University library.
There is a comprehensive biography by N. V. E, Nordenmark, Anders Celsius (Uppsala, 1936), and a shorter version by the same author in S. Lindroth, ed., Swedish Men of Science, 1650–1950 (Stockholm, 1952).
Sten Lindroth
Celsius, Anders
Anders Celsius
Born: November 27, 1701
Uppsala, Sweden
Died: April 25, 1744
Uppsala, Sweden
Swedish astronomer
Anders Celsius was an astronomer who invented the Celsius temperature scale, the most widely used in the world today. Celsius was primarily an astronomer and did not even start working on his temperature scale until shortly before his death.
Early life and career
Anders Celsius was born in Uppsala, Sweden, on November 27, 1701. The son of an astronomy professor and the grandson of a mathematician and an astronomer, Celsius chose a life in the world of academics. He studied at the University of Uppsala, where his father taught, and in 1730 he, too, was awarded a professorship there. His earliest research concerned the aurora borealis (also known as the northern lights, which are an unusually spectacular illumination of the night sky), and he was the first to suggest a connection between these lights and changes in the Earth's magnetic field.
Celsius traveled for several years, including an expedition into Lapland with French astronomer Pierre-Louis Maupertuis (1698–1759) to measure a degree of longitude (an angular distance of the earth). Upon his return he was appointed steward (manager) to Uppsala's new observatory, a building designated for studying the universe. He began a series of observations using colored glass plates to record the magnitude (size) of certain stars. This was the first attempt to measure the intensity of starlight with a tool other than the human eye.
The Celsius scale
The work for which Celsius is best known is his creation of a hundred-point scale for temperature; although he was not the first to have done so, as several hundred-point scales existed at that time. What set Celsius's scale apart from all of the others was his decision to assign the freezing and boiling points of water as the constant temperatures at either end of the scale.
When Celsius introduced his scale in 1747, it was the reverse of today's scale, with the boiling point of water being zero degrees and the freezing point being one hundred degrees. A year later the two constants were switched, creating the temperature scale used today. Celsius originally called his scale centigrade (from the Latin for "hundred steps"). For years it was simply referred to as the Swedish thermometer. In 1948 most of the world adopted the hundred-point scale, calling it the Celsius scale.
On April 25, 1744, at the age of forty-two, Anders Celsius died of tuberculosis, a terrible disease that attacks the lungs, bones, and other body parts. He left behind many dissertations (long writings) on astronomy, as well as a well-received book entitled, "Arithmetics for the Swedish Youth," published in 1741. But for all of his accomplishments in his life's work of astronomy, the name Celsius is forever tied to an instrument used every day throughout most of the world.
For More Information
Bruno, Leonard C. Math and Mathematicians. Vol. 3. Detroit: Gale, 2002.
Shimek, William J. The Celsius Thermometer. Minneapolis, MN: Lerner, 1975.
World of Invention, 2nd ed. Detroit: Gale, 1999.
Anders Celsius
Anders Celsius
1701-1744
Swedish Astronomer and Mathematician
Anders Celsius opened Sweden to modern European science and initiated reforms in his country's astronomy curriculum. Known as the founder of Swedish astronomy, he is today remembered for establishing the centigrade scale, which bears his name.
Celsius was born in Uppsala on November 27, 1701. He studied astronomy and mathematics, and in 1725 became secretary of Uppsala's Scientific Society. After teaching mathematics for a few years he succeeded his father as professor of astronomy at Uppsala University (1730).
An ecclesiastical ban on teaching of Copernican theory and lack of astronomical instruments in Sweden obliged Celsius to travel abroad to complete his studies and practical training. His first stop was the new observatory in Berlin where he assisted Christfried Kirch (1694-1740) in taking observations (1732-33). He then traveled to Nuremberg where he initiated an international astronomical review and published his aurora boerealis observations. He then visited Venice, Padua, and Bologne before proceeding to Rome and then Paris.
His arrival in Paris coincided with an ongoing debate over Earth's shape. Isaac Newton (1642-1727) had argued Earth's axial rotation would cause bulging at the equator and flattening at the poles where as René Descartes' (1596-1650) vortex theory implied Earth would be flattened about the equator and elongated along the polar axis. Most Academy of Science members supported Descartes' theory; but, Pierre Louis Maupertuis (1698-1759) spoke out in support of Newton (1732). More accurate measurements were required to settle the matter. In 1733 Charles-Marie La Condamine (1701-1774) proposed an expedition to measure Earth's curvature where it was expected to be greatest—the equator. His expedition departed in May 1735.
Maupertuis proposed a similar expedition to measure Earth's curvature in the Arctic. Celsius, having already made Maupertuis' acquaintance, was consulted about a suitable location. Torneå in Swedish-Finnish Lapland was selected, and Celsius was invited to join the expedition.
Preliminary preparations made, Celsius left for London in July 1735 with the dual purpose of continuing with his studies and purchasing instruments for the expedition. He departed England in April 1736 and soon after sailed from Dunkerque with Maupertuis' expedition. Their work was completed in less than a year, with their measurements supporting Newton's theory. But their work was challenged, and Celsius participated in the ensuing debate. The matter was only decisively settled in Newton's favor with the return of La Condamine's expedition (1744).
Upon resuming his academic post at Uppsala in 1737, Celsius undertook the establishment of Sweden's first modern observatory, which opened in December 1742. While engaged in this project, Celsius also attempted to determine the magnitude of stars in the constellation Aries by purely photometric means (1740) and worked at reforming academic instruction of astronomy.
From early on Celsius began taking daily meteorological measurements. His efforts were however hampered by inaccurate thermometers, and he sought to make a more reliable instrument by employing a fixed scale based on two invariable, naturally occurring points. His lower fixed point was determined by immersing the instrument in melting ice, the upper point by placing it in boiling water. He set the upper point at 0° and the lower at 100° thus producing the first centigrade thermometer. His instrument was ready for use on December 25, 1741.
Confusion still exists over priority for the centigrade thermometer. Carolus Linnaeus (1707-1778) inverted the scale shortly after Celsius' death in 1744 and is sometimes given credit. But a centigrade thermometer with the freezing point at 0° had been built sometime before 1743 by Jean Pierre Christian (1683-1755). If one considers the scale with a freezing point of 100° as the one used today then Celsius was first. If not, the strongest priority claim is Christian's.
STEPHEN D. NORTON
Anders Celsius
Anders Celsius
Anders Celcius (1701-1744) was an astronomer who invented the celcius temperature scale the most widely used in the world today.
Celsius is a familiar name to much of the world since it represents the most widely accepted scale of temperature. It is ironic that its inventor, Anders Celsius, the inventor of the Celsius scale, was primarily an astronomer and did not conceive of his temperature scale until shortly before his death.
The son of an astronomy professor and grandson of a mathematician, Celsius chose a life within academia. He studied at the University of Uppsala where his father taught, and in 1730 he, too, was given a professorship there. His earliest research concerned the aurora borealis (northern lights), and he was the first to suggest a connection between these lights and changes in the earth's magnetic field.
Celsius traveled for several years, including an expedition into Lapland with French astronomer Pierre-Louis Maupertuis (1698-1759) to measure a degree of longitude. Upon his return he was appointed steward to Uppsala's new observatory. He began a series of observations using colored glass plates to record the magnitude of certain stars. This constituted the first attempt to measure the intensity of starlight with a tool other than the human eye.
The work for which Celsius is best known is his creation of a hundred-point scale for temperature, although he was not the first to have done so since several hundred-point scales existed at that time. Celsius' unique and lasting contribution was the modification of assigning the freezing and boiling points of water as the constant temperatures at either end of the scale. When the Celsius scale debuted in 1747 it was the reverse of today's scale, with zero degrees being the boiling point of water and one hundred degrees being the freezing point. A year later the two constants were exchanged, creating the temperature scale we use today. Celsius originally called his scale centigrade (from the Latin for "hundred steps"), and for years it was simply referred to as the Swedish thermometer. In 1948 most of the world adopted the hundred-point scale, calling it the Celsius scale. □