Anders Celsius

Anders Celsius
Olof Arenius · Public domain · source
Name	Anders Celsius
Caption	Portrait of Anders Celsius
Birth date	27 November 1701
Birth place	Uppsala, Sweden
Death date	25 April 1744
Death place	Uppsala, Sweden
Nationality	Swedish
Fields	Astronomy, Physics, Mathematics
Alma mater	Uppsala University
Known for	Celsius scale
Influences	Isaac Newton
Academic advisors	Erik Burman
Notable students	Mårten Strömer
Awards	Fellowship in the Royal Society of Sciences in Uppsala

Anders Celsius. He was a pioneering Swedish astronomer, physicist, and mathematician best known for creating the eponymous temperature scale. A professor at Uppsala University, he made significant contributions to the measurement of Earth's shape and was an early advocate of the Gregorian calendar in Sweden. His work in observational astronomy and precise measurement left a lasting impact on the Scientific Revolution in Scandinavia.

Early life and education

He was born in Uppsala, a major academic and ecclesiastical center, into a family of scholars. His father, Nils Celsius, was a professor of astronomy, and his uncle, Olof Celsius, was a noted botanist and historian. This environment fostered an early interest in the sciences. He received his initial education at the Uppsala Cathedral School before enrolling at Uppsala University. There, he studied under the mathematician Erik Burman and was deeply influenced by the works of Isaac Newton and the emerging field of experimental physics. He completed his doctoral dissertation in 1730, focusing on celestial mechanics, and was soon appointed secretary of the Royal Society of Sciences in Uppsala.

Scientific career and contributions

His early career was marked by extensive travels to major European centers of learning, including observatories in Germany, Italy, and France. These journeys, which included meetings with figures like the astronomer Jacques Cassini in Paris, were crucial for his development. Upon his return, he was appointed professor of astronomy at Uppsala University in 1730. He played a key role in the French Geodesic Mission, an international effort to measure the shape of Earth by comparing meridian arc measurements in Lapland with those taken near the equator in Peru. He led the Swedish expedition to Torne Valley in 1736, collaborating with the French mathematician Pierre Louis Maupertuis. His meticulous astronomical and geodetic observations helped confirm Newton's theory that Earth is an oblate spheroid, flattened at the poles.

Celsius temperature scale

In 1742, he presented a seminal paper to the Royal Swedish Academy of Sciences detailing his novel temperature scale. Originally, his system defined 0 degrees as the boiling point of water and 100 degrees as the freezing point, the inverse of the modern standard. This scale was calibrated using the atmospheric pressure at sea level in Stockholm. He advocated for a standardized, reproducible system based on these fixed points, a significant advancement over the myriad scales then in use, such as those by Daniel Gabriel Fahrenheit and René Antoine Ferchault de Réaumur. Shortly after his death, fellow Uppsala University scientist Carl Linnaeus and the instrument maker Daniel Ekström are often credited with inverting the scale to its now-universal form, where 0° represents freezing and 100° represents boiling.

Later life and legacy

He remained an active researcher and teacher at Uppsala University until his premature death from tuberculosis in 1744. His legacy is profound and multifaceted. The Celsius scale, adopted as part of the metric system and later the International System of Units, became the world's most common temperature measurement system. His work in geodesy and astronomy strengthened the empirical foundations of Newtonian physics. Institutions like the Celsius Lecture Series at Uppsala University and features such as the lunar crater named in his honor commemorate his contributions. His meticulous approach to measurement and standardization epitomized the Enlightenment's spirit, influencing subsequent generations of Scandinavian scientists.

Category:Swedish astronomers Category:1701 births Category:1744 deaths