Friedrich Bessel
Early Life and Education
Friedrich Wilhelm Bessel was born in Minden, Westphalia, on July 22, 1784. He was the son of a civil servant and showed an early interest in mathematics and astronomy. Despite his family's limited means, Bessel was able to receive a good education, thanks to his exceptional abilities. He attended the Gymnasium in Minden for four years but had to leave school at the age of 14 due to his family's financial situation.
Career in Astronomy
Bessel started his career as a clerk in the import-export business in Bremen. During his free time, he studied astronomy and mathematics. His first significant work was a careful investigation of the solar parallax, which he calculated from the observations of the transit of Venus made in 1761 and 1769. This work, which he carried out with the aid of only a small telescope and a sextant, brought him into notice among astronomers.
In 1807, Bessel was appointed director of the newly established Königsberg Observatory by the Prussian government. He held this position until his death in 1846. During his tenure, Bessel made significant contributions to the field of astronomy. His most notable achievement was the determination of stellar parallax for the star 61 Cygni. His precise measurements and calculations provided the first accurate determination of the distance from the Earth to a star other than the Sun.
Bessel developed mathematical methods for the precise calculation of the positions and motions of celestial bodies. These methods, now known as Bessel functions, are still widely used in physics and engineering. He also made significant contributions to the understanding of the proper motions of stars and the refraction of light in the Earth's atmosphere.
Contributions to Mathematics
In addition to his work in astronomy, Bessel made significant contributions to mathematics. He is best known for his development of Bessel functions, which are solutions to a differential equation known as Bessel's equation. These functions are widely used in many areas of physics, including acoustics, optics, and quantum mechanics.
Bessel's work in mathematics was largely motivated by his astronomical research. He developed his functions as a tool for his investigations into celestial mechanics and the precise calculation of astronomical observations. However, Bessel functions have since found applications in many other areas of science and engineering.
Later Life and Legacy
Bessel continued his work at the Königsberg Observatory until his death on March 17, 1846. His contributions to astronomy and mathematics have had a lasting impact. The Bessel functions he developed are still widely used in science and engineering, and his methods for the precise calculation of astronomical observations remain fundamental to the field.
In recognition of his contributions, several astronomical objects and mathematical concepts bear his name, including the Bessel crater on the Moon, the asteroid 1552 Bessel, and Bessel's equation in mathematics.
See Also
Astronomy in the 19th Century History of Mathematics Celestial Mechanics