Biography - Heinrich Olbers

Heinrich Wilhelm Matthaus Olbers was born in Arbergen, Germany on October 11 in 1758. He originally studied to become a doctor but built an observatory on the top floor of his home. Apparently blessed with the need for only four hours of sleep at night, he spent his days practicing medicine and his nights “relaxing” by studying the stars, comets, and asteroids.
Heinrich Olbers discovered a new way of calculating a cometary orbit. There were previous methods, but they were long and tedious and required many observations. Olbers basically figured out a way to expedite the process, by using observations from two different places on Earth. This method accurately predicted a comet with a seventy four year orbit (much like Halley’s comet) and was published under the title Ueber die leichteste und bequemste Methode die Bahn eines Cometen zu berechnen in 1797. Olbers discovered the asteroids Pallas and Vesta and suggested that the asteroid belt was actually the remains of a great planet that had been destroyed (the term ‘asteroid’ did not exist so the rocks were referred to as ‘minor planets’ and ‘planets’). He also discovered five comets (one of which now bears his name).
The Olbers paradox essentially states that if the universe is infinite and static (not expanding or contracting) with a uniform amount of stars populating it. The paradox was considered by earlier astronomers such as Kepler, Halley, and Cheseaux but is commonly attributed to Olbers. The paradox makes several important assumptions that basically define it: First, that brightness does not diminish with distance and so all stars should give off the same light regardless of distance (later found to be incorrect due to the inverse-square law); second, that no matter where you look in the sky your eye will see a star due to their numbers; and finally that give the first two assumptions, every point in the sky should be as bright as a star. So basically, the sky should be as bright during the night as it is during the day. So the paradox itself is the fact that the sky is dark at night. This was important because it meant that one of the assumptions was wrong. Astronomers of the 1950s and 60s decided that the paradox is also explained by the finite age of the galaxies, the finite speed of light, and the expansion of the universe (Olbers’ paradox has been used as evidence for the Big Bang theory). According to astrophysicist Paul Wesson in 1991, the reason for the night’s darkness has more to do with the age of the galaxies than with the expansion of the universe. The implications of Olbers’ paradox have interested astronomers for centuries.
Olbers assisted in the baptism of Napoleon II of France and died on March 2, 1840. Though he had contributed much to astronomy, he considered his greatest contribution to the scientific community to be helping another young astronomer gain renown.

Works Cited:
"Heinrich Olbers." Dictionary of Scientific Biography. New York: Charles Scribner's Sons, 1981.
"Heinrich Wilhelm MatthäUs Olbers." Wikipedia. 10 Jan. 2008 .
"Science News: Vol. 139, No. 8, P. 125." JSTOR. 23 Feb. 1991. 10 Jan. 2008 .
"Wilhelm Olbers." NNDB. 10 Jan. 2008 .