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Comment on The other day I heard a friend talking about how "the moon's gravity affects our internal organs." This sounds like bull, but is it? And if so, how would I correct their misinformation?

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excel@lemmy.megumin.org ⁨10⁩ ⁨months⁩ ago

I don’t think that last part is entirely accurate. The reason the weak gravity causes tides is actually because it’s acting over the entire ocean all at once.

It turns out that the ocean is a bit heavy… when you add up the entire mass of all of the water, this imparts quite a substantial bit of potential energy. This can be seen as a “bulge” outward in the moon’s direction, making the planet look a little “squished”.

If the planet were perfectly smooth, this probably would be fairly stable as the bulge wrapped around the planet… however, because we have continents and the sea floor, this movement of water crashes into the land and causes ripple effects with a huge amount of kinetic energy.

I don’t think it would take more that a few years for this process to ramp up to our current level of tides, if there were some way of doing such a ramp up in a controlled way.

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Izzy@lemmy.world ⁨10⁩ ⁨months⁩ ago
Good point. You are probably right.

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cizra@lemm.ee ⁨10⁩ ⁨months⁩ ago
The ocean is not only very heavy, it’s also very long (tall, viewed sideways from POV of the Moon). This means the bits near the moon are more affected by gravity, pulled harder.

There’s so much fun to be had with this effect. When the moon is overhead, you’re stretched out an unmeasurably tiny bit, for example. It also causes tall objects to orient themselves perpendicular to moon (one end is lighter, the other end is heavier. Just like a weighted stick floats upright in water).

Oh, and then there’s the fact that your head (which could be seen as kinda momentarily orbiting the moon, with orbital period of once a month) has a higher orbital velocity than your feet, thus your head is constantly dragged sideways, and lying down helps alleviate this effect (only your nose is now pulled off your face, not your whole head). This is the reason why it’s easier to fall asleep when lying down.

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