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Tides aren't caused by centrifugal force but by differing gravity. You would be ripped apart by tides falling straight into black hole. The near part of Earth
by ianburrell 10mo ago
Tides aren't caused by centrifugal force but by differing gravity. You would be ripped apart by tides falling straight into black hole.
The near part of Earth experiences more gravity from the Moon, the far part less. The Earth moves in the center so the water bulges on the ends. Important part is that the Earth pulls things out their natural orbits.
With circular orbits, gravity and centrifugal force are balanced so could be considered difference on centrifugal force. But that isn't true for all orbits.
- matusp 10mo agoSimple illustration of what you are explaining in 1D. Imagine a simplified Earth: Water -- Ground -- Water Now let's add a Moon with gravitational pull. The pull stretches the system, because gravity is stronger the closer you are to the Moon. Water ---- Ground ---- Water -//- Moon The water is farther away from the ground on both sides now, since both sides stretched.
- heavenlyblue 10mo agoso why is left water further away from ground? this example make 0 sense
- nicwolff 10mo agoThe Earth is being pulled away from that water, just as the water on the right is being pulled away from the Earth.
- adammarples 10mo agoBut the water on the left is being pulled by everything to the right of it, moon, earth, other water. Why is it left behind? Every single thing is being attracted by the same centre of gravity on the right of the earth
- lostmsu 10mo agoIt's further away so it's pulled less, so it shifts less.
- mcswell 10mo ago"You would be ripped apart by tides falling straight into black hole." I'm aware of that--Larry Niven "Neutron Star". (The Puppeteers reportedly wouldn't have understood, though.) That still doesn't explain why the water bulges at the side of Earth away from the Moon, because that water would be attracted toward the Moon just as much as the rock it's next to. (There's a trivial difference in mid-ocean, where the water ranges from direct contact with the ocean floor, to a few miles above it. But that's not the same as the gravitational difference of thousands of miles between the Earth's center of mass vs. the far edge.)