Tidal range Tidal range Tidal range is the height difference between high tide and low tide. Tides are the rise and fall of sea levels caused by gravitational forces exerted by the Moon and Sun and the rotation of Earth. Tidal range is not constant but changes depending on the locations of the Moon and Sun. The most extreme tidal range occurs during spring tides, when the gravitational forces of both the Moon and Sun are aligned (syzygy), reinforcing each other in the same direction (new moon) or in opposite directions (full moon). During neap tides, when the Moon and Sun's gravitational
Discourse on the Tides is the motion of water relative to the earth, but annual revolution is the motion of the earth, and its water, relative to the sun. Annual revolution results in a force that accelerates the earth-water system but does not accelerate the water relative to the earth, in the same way that an observer standing on Earth's surface does not feel the gravitational attraction of the sun because the observer and Earth are moving together around the sun. The discourse does not include gravitational forces in its theory to explain the Earth's orbit and does not consider the relation between the