Does the Moon Lift the Ocean to Create the Tides?

We tend to think of the Moon's gravity "lifting" up the ocean underneath the moon in order to create the tidal bulge.  This is not how it works.  The earth's gravity is far too strong, and the ocean is too heavy, to be "lifted" by the Moon, 240,000 miles away.  Do you feel lighter when the moon is overhead?  Probably not, since the Moon's vertical force has been calculated to be one ten millionth of the Earth's gravity at points directly underneath the Moon.

At points directly under the moon, such as point Z in the figure below, the gravity vector caused by the moon is perpendicular to the Earth's surface and has zero effect on the tides.  However at points not directly underneath the Moon, the gravity vector towards the Moon has a horizontal component which produces a "tractive force."  This force operates horizontally along the surface of the sea, and the sea presents relatively little resistance.  The sea is pulled from both sides to create a bulge underneath the Moon in the idealized figure below.

For a fuller exposition of the forces, including those on the far side of the Earth, see:

NOAA's Detailed Explanation of the Differential Tide Producing Forces

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