Johannes
Kepler was born in 1571 in the town of Weil der Stadt, Germany, the inventor of the legal movement of planets. Kepler discovery in only twenty-eight years after the publication of De revolutionibus orbium coelestium, ledger in which to load the Copernican theory that the planets revolved around the sun rather than the earth. Kepler studied at the University of Tubingen, earn a bachelor's degree in 1588 and an undergraduate degree full three years later. Generally, the scientists at the time rejected the theory of "heliocentric" Copernicus: but, when Kepler in Tubingen he heard that his heliocentric hypothesis and memperincinya with high intelligence, he finally believed it. After leaving Tubingen, Kepler became professor for several years at the academy in the city of Graz.

While teaching he wrote his first book on astronomy (1596). Although Kepler's theories presented in the book turned out to be completely off the mark, the book clearly shows Kepler's mathematical ability and purity of mind, so that the great astronomer Tycho Brahe invited so his assistant at the star shots near Prague. Kepler accepted this invitation and joined Tycho in January 1600. Tycho died the following year, but Kepler has succeeded in presenting a good impression in the months before so that the Holy Roman Emperor - Rudolph II - Tycho soon replace appointed as royal mathematician. Kepler held that position for the rest of his life. In lieu of Tycho Brahe, Kepler inherited a huge pile of records carefully observed particulars planets Tycho who has worked for years. Since Tycho - the last major astronomer before telescopes were found - also a careful observer and meticulous world has ever known, the notes were very big price. Kepler believed that the record of careful mathematical analysis Tycho enabling it to conclude that the theory of planetary motion are true: Copernican heliocentric theory, theories of Ptolemy geocentris more lamaan, or even a third theory formulated Tycho himself.

However, after years of doing some careful calculations, Kepler found that the anxiety is not consistent with the observations of Tycho theories anywhere! Finally, Kepler realized that the problem was: he, like Copernicus and Tycho Brahe, and all classical astronomers had suspected that keplanitan orbit consists of circles or a combination of circles. But the reality is that the orbit is not circular keplanitan, but rather oval, ellipse. Even after finding a solution to the principal, Kepler still have to spend months immersing themselves in work calculations are complicated and exhausting to assure that satisfactory theory Tycho observations. Big book Astronomia Nova, published in 1609, presents she had the first of two laws of planetary motion. The first law confirms each planet to orbit the sun in an oval or elliptical orbits with the sun at one focus. The second law asserts that the planet moves faster when it is closer to the sun, planetary different speeds in such a way that the line joining the planet and the sun during the rotation, crossing equal areas within the same timeframe. Ten years later, Kepler's third law issued: the further the distance of a planet from the sun, the longer it takes to complete a turnaround or when the velocity squared planets is proportional to the cube of the average distance to the sun. Kepler's laws, by presenting a complete picture of the subject and the proper motion of planets around the sun, solve major problems in astronomy, which even geniuses like Copernicus and Galileo terliwatkan. Of course, Kepler does not explain why the planets move in their orbits like that; issue is resolved in the next century by Isaac Newton.

However, Kepler's laws is a vital precursor for the synthesis of Newton. ("If I look ahead of everyone else," he once Newton said, "this is a result of me standing on the shoulders of giants." No doubt, Kepler was one of the giants is Newton). Donations Kepler to astronomy almost be equated with Copernicus. And indeed, in some ways the work of Kepler is even more impressive. He's more original, and math difficulties faced mounting like. Mathematical techniques that are not as perfect as its development as well as present, and when there was no engine calculators that help in the task of counting Kepler-computation. Terms of the importance of the work of Kepler, it is hardly surprising when the first people ignored, even by great scientists such as Galileo. (Galileo did not grab the attention of Kepler's laws is staggering because the two men were each corresponding to one another, as well as the work of Kepler can help test the theory of Ptolemy). But if others rather slow to appreciate the height of the work of Kepler, it can be understood by Kepler himself.

In a tone burst of excitement Kepler wrote, "... The book has been written! Had I give something sacred gift of pleasure. He will be read both by people sejamanku or the generation after me. I do not care. Could be that the book had to wait 100 years to find a reader , like God waited 6000 years someone who can understand the greatness of his work. " Although slowly-slowly, after going through several decades, the significance of Kepler's laws became clear to the world of science. In the next century the opinions in favor of the theory of Newton said that Kepler's laws deduced from the theories. The opinion pointed out, Newton's laws of motion, Newton's law of gravity inferred from Kepler's laws. But to do so requires that technique, Kepler, fairly easy to catch the problem and proposed that planetary motion is controlled by the power coming from the sun. In addition to the laws of motion planets, Kepler donated many small happenings in the field of astronomy.

He also made important contributions to the theory of optics. At the age of late - too bad - he's plagued by personal problems. Germany declined so chaotic as "thirty years war" and the rare person who can escape from serious difficulties. One issue is a matter of living. The Holy Roman Empire is slow in paying his salary, albeit in a non-emergency situation. In a state of chaos of war, Kepler salary arrears continue. Because Kepler married twice and had twelve children, money trouble is really heavy. Another problem related to her mother who in 1620 was arrested for allegedly so "witch." Kepler lot of wasted time until the mother could be released without torture. Kepler died in 1630 in Regensburg, Bavaria. In the period of "thirty years war" that raged that his grave was ransacked. However, the laws of motion becomes memorable planitnya proved more sustainable than a tombstone.