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## Summary:

- How does the tidal effect of the Sun on the Earth affect the Earth's spin, the Moon's orbit about the Earth, and the Earth's orbit about the Sun?

It's well known that the tidal effect of the Moon on the Earth causes the Earth's rotation to slow down and the radius of the Moon's orbit to increase over time. However, the Sun also exerts a tidal effect on the Earth, which should also contribute to slowing down the Earth's spin. This raises two questions:

(1) Does the Sun's tidal effect, by changing the total tidal bulge on the Earth, change how the Moon's orbital radius increases over time?

(2) Does the Sun's tidal effect change the Earth's orbit about the Sun? If so, how?

Please note that I have put this thread in Classical Physics because I do not want to complicate the analysis with relativistic effects; I want to stick to Newtonian gravity and Newtonian mechanics. (Relativistic effects should be extremely small for this scenario in any case.)

(1) Does the Sun's tidal effect, by changing the total tidal bulge on the Earth, change how the Moon's orbital radius increases over time?

(2) Does the Sun's tidal effect change the Earth's orbit about the Sun? If so, how?

Please note that I have put this thread in Classical Physics because I do not want to complicate the analysis with relativistic effects; I want to stick to Newtonian gravity and Newtonian mechanics. (Relativistic effects should be extremely small for this scenario in any case.)