Philosophy Of The Cosmos - Earths Centrifugal Forces
Earths Centrifugal Forces
Upon hearing last week that one of the reasons why the earth was considered stationary was that if it was spinning everything would fall off due to centrifugal forces, got me wondering does the earth create any centrifugal forces that slightly negate the effect of gravity? I assume it must. And would it be possible to have a body rotate at a speed that it almost completely negates its gravitational forces. I know this isn't a particularly deep question I just think it's pretty interesting!
[[black I think my Physics might need some fixing up here. When it was reasoned that the Earth couldn't rotate because we would be flung out into space, mathematicians/physicists haven't figured out gravity. The centrifugal force is the force that points outwards when you're in circular motion (which the Earth is in when it rotates) and gravity attracts (pulls you inwards)- so I guess that the centrifugal force does "negate" gravitational force. But of course the gravitational force is much stronger, or else we'd be floating somewhere up there. If an object rotates really really fast so that its centrifugal force is greater than/equal to its gravitational force, I think that that object will be torn apart. This is because if the force of gravity is no longer present then there won't be anything holding it together. Then again, that is only what I think (think!).
Ly- u 4677579 ]]
The reason we're not flung out into space is that our MOMENTUM is almost the same as the momentum of the Earth's surface. This is because the Earth is only rotating once every 24 hours, so the momentum of a point on its surface is almost exactly horizontal.
[[black As I recall the centripetal acceleration at the equator works out to be about 0.2% of the gravitational acceleration, so it's a reasonable effect if mainly negligible. With increasing the rotational velocity it'd have to be a problem of scale, insofar as a spinning marble wouldn't raise any eyebrows if it failed to explode - thanks to the electromagnetic force - but get big enough (and gaseous enough) and you might just end up with accretion disks, or other kinds of fun.
Tokamak - u 2541959 ]]