Tuesday, January 11, 2011

Quarter 2 Astronomer: Heinrich Olbers


            Heinrich Wilhelm Matthias Olbers was a German astronomer. He was born on October 11, 1758 in Arbergen, near Bremen, Germany. He was the eighth child out of the sixteen children of Johann Jürgen Olbers. His father was a Protestant minister. He became interested in astronomy when he was around fourteen, but the institution he attended in Bremen at the time barely taught any mathematics or science. So, to better understand astronomy, he taught himself mathematics and tried to compute the solar eclipse of 1774.
            In 1777, he started to study medicine in Göttingen under the guidance of Blumenbach and Ernst Baldinger. He also started to attend lectures in physics and mathematics by G. C. Lichtenberg and A. G. Kästner. Kästner was in charge of the small observatory at Göttingen. Even though he learned from all these people, he still mainly studied astronomy on his own. His biggest interests were with comets. His interest started in January 1779. He used his observations of Bode’s comet to calculate its orbit. In 1780, he independently discovered a comet that was also being observed by Montaigne at the same time.
            Even with his great fascination for astronomy, he was still mainly a physician. In 1781, after he received his medical degree, he went on a study trip to Vienna. He visited hospitals during the day, and spent his nights in the Vienna observatory. At the end of that year, he settled down in Bremen and started an extensive medical practice. Mainly through his efforts, inoculation was introduced in Bremen and he was praised for his work during several cholera epidemics.
            In 1785, he married Dorothea Köhne. She would die a year later after their daughter was born. In 1789, he was remarried to Anna Adelheid Lurssen. They would have a son. After his daughter’s death in 1818 and Lurssen’s death in 1820, he finally retired from active medical practice to devote the rest of his life to astronomy. He had an observatory put in on the second floor of his house using its two large windows for his telescopes. His library became one of the best private astronomical collections in Europe. For over fifty years he carefully collected astronomical literature and cometography that was almost complete.
            At first he was too busy with medicine to do astronomy when he first moved to Bremen. But in 1786, he met J. H. Schröter. Schröter had a private observatory in nearby Lilienthal which was one of the best equipped on the continent and they worked closely together for many years. In 1796, Olbers discovered a comet and calculated its parabolic orbit with a new method that was easier than the one used by Laplace. He wrote a letter to F. X. von Zach, the director of the newly found observatory on the Seeberg, near Gotha. He asked him whether his argument on this new method should be printed and asked advice for how it should be done. After von Zach read the argument and used it to receive excellent results to find the orbit of the comet of 1779, which gave many astronomers difficulty, von Zach took it upon himself to see that Olber’s argument was printed. It appeared at Weimar in 1797 titled, Über die leichteste und bequemste Methode, die Balm eines Kometen am einigen Beo-bachtungen zu berechnen. His new method would make instantly establish him among the leading astronomers of his time. His new method was used throughout the nineteenth century.
            When the first asteroid was discovered by G. Piazzi on Jan. 1, 1801, he noticed a star like object that moved during the following days. He sent out this information to other astronomers. Even though it was soon realized to be a new planet that Piazzi would name Ceres, it disappeared before more observations could be made. At that time it was still impossible to compute an orbit from such a small arc without assuming the eccentricity. However, Gauss was able to calculate it by a new method, and it was Olbers who found the new planet a year later where Gauss had calculated it to be. This was the start of their lifelong friendship.
            After Ceres, Olbers discovered a second asteroid, Pallas, on March 28, 1802. With the discovery of a third asteroid, Juno, by Harding at Lilienthal in 1804, Olbers was able to use their orbits where they approached each other to discover Vesta on March 29, 1807.
            One last thing that he was greatly known for is Olber’s paradox. According to the paradox, if we accept an infinite, uniform universe, the whole sky would be covered by stars shining as brightly as our sun. He explained the paradox of the dark night sky by assuming that space isn’t absolutely transparent and that some of the interspace matter absorbs a very small percentage of starlight. This effect is sufficient enough to dim the light of the stars so they look like points in the dark sky.
Olbers was respected and admired by many of his contemporaries. He worked with many of them including Gauss, Bessel, Encke, and Schröter. He also encouraged many young astronomers and helped them gain positions at various observatories. He died on March 2, 1840, but being the humble man that he was, he would claim that his greatest contribution to astronomy was leading Bessel to become a professional astronomer.
Works Cited
"Heinrich Wilhelm Matthias Olbers." 1911 Encyclopedia Britannica. 27 Oct. 2006. Web. 05 Jan. 2011. <http://www.1911encyclopedia.org/Heinrich_Wilhelm_Matthias_Olbers>.
"Olbers, Heinrich Wilhelm Matthias." Complete Dictionary of Scientific Biography. Vol. 10. Detroit: Charles Scribner's Sons, 2008. 197-199. Gale Virtual Reference Library. Web. 5 Jan. 2011.

No comments:

Post a Comment