I think the reason some people might believe this claim is because we’re taught in school that the moon’s gravity causes the tides. I think the reasoning goes, “well if the moon’s gravity can affect the tides, surely it can affect smaller things too”
Edit: The moons gravity affects everything on the planet. That doesn’t mean it is harmful. It’s going to be very insignificant.
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.
Good point. You are probably right.
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.
The moon would affect the tides regardless of how long it’s been there. Calculating the effect of the moon’s gravity on the earth is a standard exercise in a graduate classical physics course. In essence, the moon’s gravity “squashes” the earth at the two poles, causing tides at the nearest and farthest end of the earth.
Why is this being upvoted when it is blatantly false?
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Is it time that’s allowed the moon’s gravity to affect the tides? I think it would cause tides even if it suddenly appeared out of nowhere into orbit.
Now, I’d need someone else to explain why the effect on the tides is so visible. I’d suggest that it is because the water in the oceans both has a huge mass and is fluid, so its shape can change easily. There’s a difference between the moon pulling a portion of the water closer to it on one side of the planet and the moon “stretching” a person who is caught between the Earth’s and moon’s gravities.
The bulge on the opposite side of the Earth from the moon is because the Earth is being pulled away from the water.
Maybe bacteria could be affected by the gravity
If the bacteria has a mass of 1 millionth the mass of a human, the gravitational effect the moon has on it, would similarly be 1 millionth the effect it has on a human.
Stupid physics. 🙄
For billions of years. There was once a time when tides were massive and the moon took up most of the night sky (it’s slowly being slingshoted out of orbit and will eventually become a dwarf planet orbiting between earth and mars, but the sun will likely engulf the earth system before that happens)