E183 -- Part of a letter from Leonhard Euler, Prof. Math. at Berlin, and F.R.S. to the Rev. Mr. Caspar Wetstein, Chaplain to His Royal Highness the Prince of Wales, concerning the gradual approach of the Earth to the Sun.

(based on Eric J. Aiton's introduction (written in English) to Opera Omnia Series 2, Volume 31)
In this letter, Euler informs Wetstein that the astronomer le Monnier is going to publish a translation of an Arabic manuscript that he (le Monnier) found in Leiden. Euler expresses his impatience to see this work since it contains observations that he has used in determining why the years have gotten shorter in length. He goes on to explain that the shortening of the year is the result of the resistence of the aether, and this resistance entails the gradual approach of the earth to the sun. As a result, the system of planets had a beginning and must also have an end.


According to the remark on p. 203, the letter is dated June 28, 1749 and was presented to the “Royal Society” on November 2, 1749.

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