Physics, Astronomy & Cosmology / Re: Is acceleration downwards due to gravity less when the Moon is overhead?« on: 15/10/2018 16:20:47 »
Kepler's laws don't take influences like tidal circularization into account. Just like they don't consider the tidal acceleration that is slowly increasing the size of the Moon's orbit.So how does an orbit circularize? The tidal forces would seem to give the moon the greatest thrust at perigee, which increases the apogee, and the least thrust at apogee, which minimizes the lifting of perigee. So that would seem to amplify the eccentricity of the orbit, not circularize it.
Of course the duration of the thrust at preigee is less than the duration at apogee, so maybe that's what I'm missing.