centrifugal force- force that occurs when objects spin fast around a center point that tends
to make the object move away.
* Gravity and centrifugal force are balanced between the Earth and the sun, but not
balanced every place on Earth.
* The strength of gravity lessens as one moves away from the sun.
* The moon's gravity affects the tides more since the moon is closer to earth, even though
the sun's gravity is much greater.
* The sun's gravitational effect is about half on the tides of what the moon is.
* It takes about 50 additional minutes every 24 hours for the moon to be above the same
position on the Earth�s surface it was over the previous night.
* Spring tides have very large tidal ranges because the effects of both the sun's and the
moon's gravity are combined.
* Spring tides occur during the full moon and new moon phases.
* Neap tides have very small tidal ranges because since the sun and moon's position
relative to the earth are 90 degrees apart and their gravities work against each other.
* Neap tides occur during the first quarter and third quarter moon phases.
* The different declinations of the sun and moon's positions can explain why the two tides
in a single day can be of widely different height.