Answer to Question #1151 in Mechanics | Relativity for Robert

Question

The gravitational pull of the Sun on the Earth is stronger than the pull on the moon, yet the moon is the major source of tides. Is this true? and if true, why is the Sun not a major factor in the tides?

Answer 1

Although the globe gravitational pull of the Sun is almost 200 times greater than the gravitational pull of the moon, the tidal forces generated by the moon, almost twice as much generated by the sun. This is due to the fact that tidal forces do not depend on the degree of its inhomogeneity (gradient) of the gravitational field, not on its magnitude. With increasing distance from the source of the field gradient decreases faster than the magnitude of the field itself. Since the Sun is almost 400 times farther from Earth than the moon, the tidal forces caused by the solar attraction is weaker.