This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Tides are often explained as the Moon simply pulling the ocean toward itself, which explains the high tide on the side of the Earth facing the Moon but leaves an obvious puzzle: there is also a high tide, at the same time, on the exact opposite side of the planet. The full explanation needs one more piece. The Earth and Moon do not orbit a fixed Earth; they orbit their shared center of mass, a point inside the Earth but off its exact center, and every point on Earth is swinging around that shared center along with the planet as a whole. On the side facing the Moon, the Moon's gravitational pull is slightly stronger than the average pull felt at the Earth's center, producing a bulge of water toward the Moon; on the far side, the Moon's pull is slightly weaker than average, and the orbital motion produces a matching bulge away from the Moon. The two bulges, one toward the Moon and one away from it, are what produce two high tides roughly every lunar day rather than one.
The Sun contributes a smaller version of the same effect, roughly forty six percent as strong as the Moon's despite the Sun's far greater mass, because tidal force falls off with the cube of distance rather than the square, and the Sun is vastly farther away. When the Sun and Moon align, at new moon and full moon, their tidal effects add together, producing the largest tides of the month, called spring tides. When the Sun and Moon sit at right angles to each other, at the Moon's first and last quarter, their effects partly cancel, producing the smallest tides of the month, called neap tides.
A lunar day, the time it takes the Moon to return to the same position overhead, runs about fifty minutes longer than a twenty four hour solar day, because the Moon is also moving in its own orbit around the Earth in the same direction the Earth is rotating. That fifty minute lag is why high tide arrives roughly fifty minutes later each day rather than at the same clock time. Isaac Newton's Principia, in 1687, gave the first correct account of tides as a consequence of gravity acting between the Earth, Moon and Sun, but Newton's own equilibrium theory assumed an idealized ocean with no landmasses or currents in the way; it took Pierre-Simon Laplace's later dynamic theory of tides, accounting for the real ocean's basin shapes and the momentum of moving water, to explain why real coastlines see tidal timing and height that diverge substantially from Newton's simpler prediction.