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Sorry, but you’re incorrect. Have you ever noticed how the ocean rises and falls sometimes? We call these tides, and they are caused by tidal forces (gravity) p

Sorry, but you’re incorrect. Have you ever noticed how the ocean rises and falls sometimes? We call these tides, and they are caused by tidal forces (gravity) predominantly from the moon and sun. This is by far the most commonly observed gravitationally powered distortion from a perfect sphere. I understand that you might never have seen a body of water large enough to witness the phenomenon, as many folks live far inland, but I assure you, tides are real, and are no conspiracy. Additionally, the earth rotates rather rapidly. I know this may come as a surprise, but it actually causes the earth to bulge out at the equator - hardly a perfect sphere. The below articles might help you, but only if you choose to read them under the understanding that you might need to learn something new. If you don’t want to, that’s also fine. https://en.m.wikipedia.org/wiki/Tide https://en.m.wikipedia.org/wiki/Tide https://en.m.wikipedia.org/wiki/Geoid https://en.m.wikipedia.org/wiki/Geoid https://en.m.wikipedia.org/wiki/Equatorial_bulge https://en.m.wikipedia.org/wiki/Equatorial_bulge https://simple.m.wikipedia.org/wiki/Tide https://simple.m.wikipedia.org/wiki/Tide

lurquer 9y ago
The intuition that prompted my post was wrong. A fluid encompassing a solid with nonuniform density will not form a sphere, but will be 'warped'. Duh. Disregard my post. Cheers.
- madaxe_again 9y ago
  No worries. I think I know what you fell into, which is that were the distortion always and only due to gravity, the value of g at actual (not mean) sea level would always be the same, as the additional displaced water would perfectly compensate for the variance caused by any underlying variation. Sorry that I was snarky - I have a hard time helping myself first thing in the morning. Glad to have shed some light.
  - lurquer 9y ago
    I was thinking that any solid -- such as a planet -- can be replaced by a point at its center with equal mass, and its neighbors -- such as a moon -- wouldn't notice. But that's not entirely true.... For instance, replace the earth with an equal size ball of styrofoam, and place two super-dense basketball-sized masses, one in Californis and the other in Africa (I.e. on the opposite sides of the globe.) And, assume, the entire system is the same mass as our earth, assume the 'center of mass' is at the core of the styrofoam planet, and assume the styrofoam is magically able to keep our two Neutron-star-dense basketballs in place. Phew.... Now, the moon probably wouldn't notice s thing. From its point of view, it will 'feel' the same attraction as it would from our planet. But, something much closer -- such as a mile or two of water -- would definitely bunch up around the basketballs and would not form a sphere around the center of our imagine planet. Is that right?

lurquer 9y ago

The intuition that prompted my post was wrong. A fluid encompassing a solid with nonuniform density will not form a sphere, but will be 'warped'. Duh. Disregard my post. Cheers.

madaxe_again 9y ago
No worries. I think I know what you fell into, which is that were the distortion always and only due to gravity, the value of g at actual (not mean) sea level would always be the same, as the additional displaced water would perfectly compensate for the variance caused by any underlying variation. Sorry that I was snarky - I have a hard time helping myself first thing in the morning. Glad to have shed some light.
- lurquer 9y ago
  I was thinking that any solid -- such as a planet -- can be replaced by a point at its center with equal mass, and its neighbors -- such as a moon -- wouldn't notice. But that's not entirely true.... For instance, replace the earth with an equal size ball of styrofoam, and place two super-dense basketball-sized masses, one in Californis and the other in Africa (I.e. on the opposite sides of the globe.) And, assume, the entire system is the same mass as our earth, assume the 'center of mass' is at the core of the styrofoam planet, and assume the styrofoam is magically able to keep our two Neutron-star-dense basketballs in place. Phew.... Now, the moon probably wouldn't notice s thing. From its point of view, it will 'feel' the same attraction as it would from our planet. But, something much closer -- such as a mile or two of water -- would definitely bunch up around the basketballs and would not form a sphere around the center of our imagine planet. Is that right?