Letter 109Euler to Teplov
Berlin, December 23,1749 / January 1750
Synopsis: Presentation of papers to the Imperial Academy. Continuation of the Newtonian/Liebnitzian rift in European scientific circles on the subject of moon apogee calculations.
[...] Even though the celebrations on the occasion of the New Year have been abolished, I would be the blame if I missed my duties in your regard. The memories of your friendship and the marks of the exceptional beneficence that you have given to me until now vibrate the very best of wishes in my heart for your safety and happiness. That God should heap onto you all sorts of happiness and bless your help for the good and the glory of the Academy.
I was extremely happy to learn of the glorious success of the last public assembly of the Imperial Academy. The papers that were delivered on that occasion are worthy of the most meritorious praises from all wise men and especially for the laudatory nature of Mr. Lomonosov's paper which appeared to me to be a work of art in its category. The beautiful illumination also brought a relief of which no other Academy is capable. I have just received the price on the proof, which could not be better under the circumstances. Due to the times, it is the subject/148r/ which the greatest minds of Europe have found to stimulate and interest them. There are some that support Newton's Theory, which supposes that the celestial bodies are mutually attracted for the reason of the square of their distances, which is not sufficient to explain reciprocals. All the inequalities, which can be observed during the movement of the planets and especially of the moon, support the contrary. The greatest controversy at the moment is on the subject of the apogee of the moon, which advances by 40 degrees every year. Even Newton does not consider this point in his principles. In following his method we find that this movement should not be more than 20 degrees a year, and that there really is evidence that Newton having noticed this difference kept silent on the matter. All those who afterwards applied themselves to this subject found the same defect with the theory, and if there have been those who have wanted to reconcile the theory with the observations , their explanations are devoid of clarity and insufficient in fundamentals throughout. But that which is so remarkable in this thorny issue, is that Mr. Clairaut after having brought up the issue of the insufficiencies of Newtonian theory in reference to the apogee of the moon, retracted himself suddenly on the issue and declared publicly that he had made mistakes in his calculations, and after which having corrected the mistakes, found that Newton's theory was in perfect accord with the observations. Mr. Bernoulli concurs with Mr. Clairaut on this subject and insists that he was the first to point him in the right direction. For me, I must admit to you, Monsieur, that I am of an entirely different bent on this subject and that my calculations are entirely too clear for me to doubt, that the theory allows for more than a 20 degree apogee movement of the moon annually. Inspired of this Mr. Clairaut persists in his way despite my entreaties. From here, Sir, you will judge that this question is not only one of the most profound and worthy that the Academy could have selected, but that she can expect exceptional clarification on the matter. Until now Mr. Clairaut, has made a mystery of his new method, but once he publishes, it is a matter of mathematics and we must be resolved beyond a doubt of its correctness or that we will find some fault. No matter what happens, astronomy, physics and analysis will all benefit in a considerable way. Because it is from there that all the small iniquities that we see in terms of the movement of the moon and also with all of the other planets. With this in mind one can say with reason, that never has an Academy set such an important question for an explanation which promises to bear such fruit for the advancement of science. Even though I have worked a long time on the topic, I will resume work on the matter with all of my energies, however, it matters little how great my hope of succeeding is when there is still an opening for my place at the Academy. I will renounce my seat with pleasure, in the case that, His Excellency the President, judges it worthwhile to use my abilities as one of his commissioners, who will be nominated to examine the papers sent on this matter. For it is a sort of examination of long and complicated numbers and perhaps I will be able to make a great contribution to the Academy to which all of my works are dedicated. Finally, I implore you to continue Your precious affection and friendship, I am with the most perfect consideration,
Translated from the French
by J.S.D.Glaus
