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# Paradox: what governs ocean tides: the moon, or the Sun?

Most people believe that the gravitational pull from the moon creates the ocean bulge (resulting in tides) on Earth. Yet if you look at gravitation, the sun's pull should be 27,000,000 / ( 390 * 390) = 177 times stronger than moon's pull, according to the first sentence from the extract below

The sun is 27 million times more massive than the moon, but it is also 390 times farther away. As a result, the sun has 46 percent of the tide-generating forces (TGFs) that the moon has, according to the National Oceanic and Atmospheric Administration.

Source for picture.

Yet, my multiplier 177 is wrong. We all know that moon influences ocean tides much more so than the Sun, and these tides are very easy to predict anywhere on Earth: it's a rudimentary data science / predictive analytics problem.

At the same time, my 177 factor is justified by the fact that gravitation pull is proportional to the mass of the body generating the gravitational force, and inversely proportional to the square of the distance between the two bodies (the sun, and the oceans, in this case).

I'm not an astrophysicist,  but my explanation is that the Sun's gravitational pull on the oceans is almost identical, whether it's day or night (that is, on both sides of Earth), because Earth's 6,000 kilometers radius is too small to make any difference about the Sun's gravity force (the Sun is 150,000,000 kilometers away). To the contrary, the moon - which is just 300,000 kilometers away - combined with Earth's not-so-small 6,000 kilometers radius, is enough to have a real impact.

Anyone interested in commenting on this? I don't claim that my explanation is correct, frankly, I don't know, but I'm curious to know the real explanation.

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