27 軌道は楕円、ケプラーの法則♪

1571年12月27日 は、天文学者ケプラーの生まれた日♪

ヨハネス・ケプラーは、「ケプラーの法則」を唱えた。ドイツの天文学者、数学者。

1599年、観測家ティコ・ブラーエ に共同研究者として招かれた。ティコは21年間も天空観測を続けていて、この観測データは望遠鏡のなかった当時として最高の精度があった♪

　　　　　　　　　　　　↓　ケプラー初期の多面体太陽系モデル

惑星の軌道を楕円と仮定すると、ティコの観測した結果が説明できることを考察、後に「ケプラーの法則」とされた。

また、ケプラーは「太陽と惑星の間に、磁力のような力が存在する」と気付いてはいたが、その力の正体は分からなかった。後にアイザック・ニュートンによって、その力は万有引力であると解明されたんだ♪

Johannes Kepler ( December 27, 1571 – November 15, 1630) was a German mathematician, astronomer, and astrologer. A key figure in the 17th century scientific revolution, he is best known for his laws of planetary motion, based on his works Astronomia nova, Harmonices Mundi, and Epitome of Copernican Astronomy. These works also provided one of the foundations for Isaac Newton's theory of universal gravitation.

During his career, Kepler was a mathematics teacher at a seminary school in Graz, Austria, where he became an associate of Prince Hans Ulrich von Eggenberg. Later he became an assistant to astronomer Tycho Brahe, and eventually the imperial mathematician to Emperor Rudolf II and his two successors Matthias and Ferdinand II. He was also a mathematics teacher in Linz, Austria, and an adviser to General Wallenstein. Additionally, he did fundamental work in the field of optics, invented an improved version of the refracting telescope (the Keplerian Telescope), and mentioned the telescopic discoveries of his contemporary Galileo Galilei.

Kepler lived in an era when there was no clear distinction between astronomy and astrology, but there was a strong division between astronomy (a branch of mathematics within the liberal arts) and physics (a branch of natural philosophy). Kepler also incorporated religious arguments and reasoning into his work, motivated by the religious conviction and belief that God had created the world according to an intelligible plan that is accessible through the natural light of reason. Kepler described his new astronomy as "celestial physics", as "an excursion into Aristotle's Metaphysics",and as "a supplement to Aristotle's On the Heavens", transforming the ancient tradition of physical cosmology by treating astronomy as part of a universal mathematical physics.