Urbain Jean Joseph Le Verrier

French astronomer. Prophet of the existence of Neptune. His father was a middle-class real estate agent in Normandy, but sold his house to send Le Verrier to study at the Ecole Polytechnique. He studied chemistry, but was more interested in astronomy, and after graduation he was hired as an astronomy instructor at his alma mater in 1837. He promoted the celestial mechanics of Laplace and others, calculated the limits of variation in the eccentricity and inclination of the orbits of the planets, and proved the stability of the solar system. At the recommendation of Arago, the director of the Paris Observatory, he calculated the motion of Mercury as a staff member and discovered that the movement of its perihelion was greater than that calculated by Newtonian mechanics, the cause of which was later elucidated by the theory of general relativity. He became a member of the Academie des Sciences in Paris in 1846, and a professor of celestial mechanics at the Sorbonne (University of Paris) in 1849. While studying the perturbations of Jupiter, a periodic comet, he calculated that the unexplained perturbations of Uranus were due to the presence of an unknown planet (1846). This prediction was correct, and a new planet was discovered by Galle in Berlin. This was Neptune, and it was praised as a "triumph of celestial mechanics." In 1854, he became director of the observatory as successor to Arago, and in light of the storm disaster (Balaclava Storm) that occurred during the Crimean War in 1858, he established weather observatories throughout Europe, produced the first weather charts, and established a weather forecasting system.

[Shimamura Fukutaro]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

フランスの天文学者。海王星の存在の予言者。父はノルマンディーの中流不動産業者だが、家作を売ってルベリエを理工科大学校（エコール・ポリテクニク）で学ばせた。化学を学んだが、興味はむしろ天文学にあって、卒業後1837年に母校の天文学講師に採用された。ラプラスらの天体力学を推進し、諸惑星の軌道の離心率および傾斜角の変動限界を算定して、太陽系の安定性を証明した。パリ天文台長アラゴの勧めで、台員として水星の運動を計算し、近日点の移動がニュートン力学での算定より大きいことを発見、その起因はのちに一般相対性理論により解明された。1846年パリ科学アカデミー会員、1849年ソルボンヌ大学（パリ大学）天体力学教授となった。周期彗星(すいせい)の木星による摂動を研究中、天王星の原因不明の摂動を未知の惑星の存在によるものと計算した（1846）。この予報は的中し、ベルリンのガルレにより新惑星が発見された。これが海王星であり、「天体力学の勝利」とたたえられている。1854年アラゴの後任として台長となり、1858年のクリミア戦争時におきた暴風禍（バラクラバ暴風）にかんがみ、ヨーロッパ各地に測候所を設け、最初の天気図を作製し、天気予報の体制を敷いた。

［島村福太郎］

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