the gravitational pull exerted by a celestial body that raises the tides on another body within the gravitational field, dependent on the varying distance between the bodies.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
A secondary effect of the gravitational forces between two objects orbiting each other, such as the Earth and the Moon, that tends to elongate each body along the axis of a line connecting their centers. Tidal forces are responsible for the fluctuation of the tides as well as for the synchronous rotation of certain moons as they orbit their planets.
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