Over the billions of years that the Earth has been orbitted by the Moon, its rotation has slowed by the slight resistance to the tide as it travels round the planet (relative to the Earth of course, it would appear static relative to the Moon).  The tide is of course caused by the gravitational pull of the moon and the equal and opposite gravitational forces of the Earth and the Moon keep the Moon nicely in orbit around the Earth.

As the force causing the braking effect of the tide is exerted by the Moon's gravity, there should be an equal and opposite force to the braking that is being exerted on the Moon.  As the tide is working as a brake on the rotation of the Earth, it would be expected that the bulge of tidal water is slightly ahead of the Moon with the Moon's gravity pulling it back.  I suspect that this bulge slightly offsetting the Earth's centre of gravity out of line with the Moon's centre of gravity and the Moon's centre of rotation might have some such effect.

Admittedly the effect would be rather small, but over the periods of time such as the time it has taken for the Earth's rotation to change from 6 hours per day to 24 hours per day surely there has been some effect.  If so, am I right in thinking that the Moon's orbit has quickened over time?  If so, I hope the Moon has stayed in equillibrium by adjusting its altitude (is that the right word?) and isn't thinking of leaving us to it once it has built up an escape velocity...

I know the earth's orbit around the sun is in the shape of an ellipse.

The sun is one focal point, but what is the other.

Baffled ! :)

My limited understanding of science tells me that

a year is the period taken for the earth to orbit the sun, but

seasons are dictated by the tilt of the earth.

Why should there be a link between these?

Aside from bone and muscle differences, which have already been covered.

For example, someone who grows up without being spun around at 400m/s as the world spins; would they feel as if they were spinning when they set down or entered orbit?

I was reading today that the Indians have lost contact with their lunar orbiter. The moon has a negligible atmosphere so there should be no drag. The only non-gravitational force I can think of is the solar wind. This force is very small and complicated to calculate so the answer to how long the Indian satellite will orbit the moon has eluded me. Has anyone got an idea?