Tuesday, May 06, 2008

Happy Birthday to the universe


click the universe to enlarge

I never actually got around to posting this at the end of April, but on April 27th, in 4977 B.C., the universe was created, according to German mathematician and astronomer Johannes Kepler, considered a founder of modern science. Kepler is best known for his theories explaining the motion of planets.

Kepler was born on December 27, 1571, in Weil der Stadt, Germany. He studied Copernicus' theories of planetary ordering. Copernicus (1473-1543) believed that the sun, not the earth, was the center of the solar system, a theory that contradicted the prevailing view of the era that the sun revolved around the earth, and a theory that earned him the title "heretic."

In 1600, Kepler went to Prague to work for Danish astronomer Tycho Brahe, the imperial mathematician to Rudolf II, emperor of the Holy Roman Empire. Kepler's main project was to investigate the orbit of Mars. When Brahe died the following year, Kepler took over his job and over the next decade, Kepler learned about the work of Italian physicist and astronomer Galileo Galilei (1564-1642), and another heretic, who invented a telescope with which he discovered lunar mountains and craters, the largest four satellites of Jupiter and the phases of Venus.

Kepler corresponded with Galileo and obtained a telescope of his own. In 1609, Kepler published the first two of his three laws of planetary motion, which held that planets move around the sun in ellipses, not circles, and that planets speed up as they approach the sun and slow down as they move away. In 1619, his third law came out, which used mathematical principles to relate the time a planet takes to orbit the sun to the average distance of the planet from the sun.

Kepler's research was central to Sir Isaac Newton's (1643-1727) law of gravitational force.

In our century, we developed the Big Bang theory, which showed that his calculations were off by about 13.7 billion years.
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