Even as a physics major I have to scratch my head looking at the varied descriptions of why there is a tidal bulge of water on the side opposite the moon. Some argue it's centrifugal force, some argue it's gravitational gradient. So here's a serious question -- if the Earth and the Moon were simply held apart by a big stick, and not rotating, would there still be a bulge of water on the side away from the moon?
High tides are created by the alignment of the sun and the moon, so why was today’s tide (4th Jan 2011 with a solar eclipse) just a moderate high tide?
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...
Is it possible to reliably define the times (for a specific location on earth) when the tidal gravity from astronomical objects (moon, sun etc.) are at their weakest & strongest?
I have considered using sea & ocean tide times, but these factor in unwanted variables, such as ocean currents and coastal water flows, which would invalidate the results somewhat.
I am attempting to define whether any noticeable effects occur from the moon on athletic performance, but need specific times with which to test and compare (hence the strongest & weakest times are my targets).
Is there a reliable method to calculate the times of strongest and weakest gravitational pull of the moon upon objects at a specific location on earth, in effect a high and low tide? We considered using tide times, but they factor in variables such as ocean currents and coastal flows, which would adversly affect our results. Is there a formula that can give us a good answer?
Is there a formula to give the times when the lunar gravitational effects are strongest and weakest for a location on earth? We considered the tide times, but they factor in variables such as coastal flows and ocean currents, which would adversly alter the calculations