Johannes+Kepler

-German astronomer (1571-1630) -born in the Swabian town of Weil to a poor family -he was a sickly child and was raised by his grandmother -began working on an almanac in Graz in April of 1594, in which he predicted two unlikely events: a Turkish invasion and a severe winter. This established his reputation. -married Barbara Muehleck and had 5 children- only one girl and one boy reached adulthood -became assistant to asrtologer-mathematician Tycho Brahe. When he dies in 1601, Kepler is chosen to be his successor. -Had a strange, conflicting relationship with Galileo. Although Galileo was unappreciative of Kepler's work, Kepler writes a booklet that celebrates Galileo's "Starry Messenger." However, he argued in his "Conversation with the Starry Messenger" that in his work "Optics," one could find all the principles needed to construct the telescope. They did agree, however, on the theories of Nicolaus Copernicus.
 * __media type="file" key="Smoot Kepler Pod Project.mp3"Johannes Kepler__**
 * Jaki, S. (Ed.). //Kepler//. (1973). Kepler. New York: Vol. 6). McGraw-Hill.**

Kepler was forced to leave his teaching post at Graz due to the counter Reformation because he was Lutheran and moved to Prague to work with the renowned Danish astronomer, Tycho Brahe. He inherited Tycho's post as Imperial Mathematician when Tycho died in 1601. Using the precise data that Tycho had collected, Kepler discovered that the orbit of Mars was an ellipse. In 1609 he published //Astronomia Nova//, delineating his discoveries, which are now called Kepler's first two laws of planetary motion. And what is just as important about this work, "it is the first published account wherein a scientist documents how he has coped with the multitude of imperfect data to forge a theory of surpassing accuracy" (O. Gingerich in forward to //Johannes Kepler New Astronomy// translated by W. Donahue, Cambridge Univ Press, 1992), a fundamental law of nature. Today we call this the scientific method. In 1612 Lutherans were forced out of Prague, so Kepler moved on to Linz. His wife and two sons had recently died. He remarried happily, but had many personal and financial troubles. Two infant daughters died and Kepler had to return to Württemburg where he successfully defended his mother against charges of witchcraft. In 1619 he published //Harmonices Mundi//, in which he describes his "third law." In spite of more forced relocations, Kepler published the seven-volume //Epitome Astronomiae// in 1621. This was his most influential work and discussed all of heliocentric astronomy in a systematic way. He then went on to complete the //Rudolphine Tables// that Tycho had started long ago. These included calculations using logarithms, which he developed, and provided perpetual tables for calculating planetary positions for any past or future date. Kepler used the tables to predict a pair of transits by Mercury and Venus of the Sun, although he did not live to witness the events. Johannes Kepler died in Regensburg in 1630, while on a journey from his home in Sagan to collect a debt. His grave was demolished within two years because of the Thirty Years War. Frail of body, but robust in mind and spirit, Kepler was scrupulously honest to the data.

**A List of Kepler's Firsts** In his book //Astronomia Pars Optica//, for which he earned the title of founder of modern optics he was the: In his book //Dioptrice// (a term coined by Kepler and still used today) he was the: In addition: Koch, A. Johannes Kepler: His Life, His Laws, and His Times. Retrieved September 30, 2008, from http://kepler.nasa.gov/johannes/****
 * First to correctly explain planetary motion, thereby, becoming founder of celestial mechanics and the first "natural laws" in the modern sense; being universal, verifiable, precise.
 * First to investigate the formation of pictures with a pin hole camera;
 * First to explain the process of vision by refraction within the eye;
 * First to formulate eyeglass designing for nearsightedness and farsightedness;
 * First to explain the use of both eyes for depth perception.
 * First to describe: real, virtual, upright and inverted images and magnification;
 * First to explain the principles of **how** a telescope works;
 * First to discover and describe the properties of total internal reflection.
 * His book //Stereometrica Doliorum// formed the basis of integral calculus.
 * First to explain that the tides are caused by the Moon (Galileo reproved him for this).
 * Tried to use stellar parallax caused by the Earth's orbit to measure the distance to the stars; the same principle as depth perception. Today this branch of research is called astrometry.
 * First to suggest that the Sun rotates about its axis in //Astronomia Nova//
 * First to derive the birth year of Christ, that is now universally accepted.
 * First to derive logarithms purely based on mathematics, independent of Napier's tables published in 1614.
 * He coined the word "satellite" in his pamphlet //Narratio de Observatis a se quatuor Iovis sattelitibus erronibus//

__His Three Laws of Planetary Motion:__

Kepler's First Law:

 * **I. The orbits of the planets are ellipses, with the Sun at one focus of the ellipse.** ||

Kepler's Second Law:

 * **II. The line joining the planet to the Sun sweeps out equal areas in equal times as the planet travels around the ellipse.** ||

Kepler's Third Law:
Johannes Kepler: The Laws of Planetary Motion. Retrieved October 1, 2008, Web site: http://csep10.phys.utk.edu/astr161/lect/history/kepler.html
 * **III. The ratio of the squares of the revolutionary periods for two planets is equal to the ratio of the cubes of their semimajor axes:** ||
 * [[image:http://csep10.phys.utk.edu/astr161/lect/history/kepler3.gif width="142" height="87" align="center"]] ||

You may also be surprised to learn that Kepler was a very religious man, who found a way to credit God for each and every discovery he would make, not to mention his own life and career paths. Kepler had originally planned on becoming a priest, but was drawn into the world of science. Furthermore, he was of the Lutheran faith, which caused him many problems throughout his life, since Germany was part of the Holy Roman Empire until its dissolution 1806. Always being subjected to persecution by the Catholics, Kepler had to relocate several times due to pressure from the Church, yet he would not convert. Also, mathematicians were not in great demand at the time, and Kepler did not have very much money to support his family. He lived in poverty, and died in poverty, but one thing is for certain, he was very prolific, and his work did not die with him. Like so many geniuses before and after him, Kepler has never known fame or fortune, but without his perseverance and strength of character, not to mention his many important discoveries, who knows how long it would have taken for us to even begin understanding the true structure of the universe. (2002). Johannes Kepler (1571-1630). Retrieved October 1, 2008, from Johannes Kepler Web site: http://www.johanneskepler.com/

How does a telescope work? How do the eyes perceive depth? How do the planets move in orbit? The answers to these questions and many others are found in the discoveries, achievements, and explanations of Johannes Kepler. The German astronomer was born in the Swabian town of Weil in 1571. Despite the poverty faced by his family and the health problems he faced as a child, this didn't prevent him from making some of the most important discoveries in astronomy and optics.
 * __Script__**

--cue start of "The Final Countdown" by Europe (0:14 to 0:55)

His reputation was established by his predictions in an almanac in April of 1594, which were a Turkish invasion and a severe winter. Later, after fleeing to Prague due to the Counter-Reformation, he became an assistant to the Danish astronomer Tycho Brahe. After Brahe's death in 1601, Kepler became his successor. He then used the data that Brahe had collected to discover that the orbit of Mars was an ellipse. In 1609, he published //Astronomia Nova//, which revealed his discoveries, now called Kepler's first two laws of planetary motion. Kepler's first law states that the orbits of the planets are ellipses, with the sun at one focus of the ellipse. Kepler's second law states that the line joining a planet to the sun sweeps out areas in equal times as the planet travels around the ellipse. In 1619, he published //Harmonices Mundi,// in which he describes his third law, which states that the ratio of the squares of the revolutionary periods for two planets is equal to the ratio of the cubes of their semi-major axes. This is better understood as P sub-one squared over P sub-two squared is equal to R sub-one cubed over R sub-two cubed.

--play a sci-fi sound effect

Explaining the three laws of planetary motion was certainly not Kepler's only major accomplishment. In his book //Astonomia Pars Optica,// he was the first to investigate the formation of pictures with a pin-hole camera, the first to explain the process of vision by refraction within the eye, the first to formulate eyeglass designing for nearsightedness and farsightedness, and the first to explain the use of both eyes for depth perception. In his book //Dioptrice,// he was the first to describe real, upright, virtual and inverted images and magnification, the first to explain the principles of how a telescope works, and the first to discover and describe the properties of total internal reflection. Also, his book //Stereometrica Doliorum// formed the basis of integral calculus, he was the first to explain tides are caused by the moon, first to derive the birth year of Christ, which is now universally accepted, and was first to coin the word "satellite."

--play a different sci-fi sound effect

Another interesting fact about Kepler was that he was a very religious man, and he gave God credit for each and every one of his discoveries, and even his own life and career paths. This was because Kepler originally wanted to become a priest, but was drawn into the world of science. Also, being of Lutheran faith casued him many problems throughout his life, since Germany was part of the Holy Roman Empire at this time. This meant he often faced the chance of being persecuted by Catholics, and had to relocate several times to escape the Church, yet he would not convert. In addition, mathematicians were not of great demand at this time, so Kepler and his family lived in poverty. Although he was never known for fame and fortune, his discoveries live on today. Without these accomplishments in the fields of astronomy, mathematics, and optics, who knows how long it would have taken us to understand the true structure of the universe.

-- "The Final Countdown" (4:37-end)