3 ms·
Surprisingly not so. If you have a body with a spherically symmetric mass distribution, from the outside it always has exactly the same gravitational field as
by hugh3 16y ago
Surprisingly not so.
If you have a body with a spherically symmetric mass distribution, from the outside it always has exactly the same gravitational field as a point mass at the centre.
Proof: http://hyperphysics.phy-astr.gsu.edu/hbase/mechanics/sphshell.html http://hyperphysics.phy-astr.gsu.edu/hbase/mechanics/sphshel...
- cryptoz 16y agoWait, but didn't I specifically say I was referring to a body without a spherically symmetric mass distribution? Maybe I'm incorrect in my understanding of symmetric, but I was definitely referring to a non-symmetric case in my text.
- hugh3 16y agoSpherically symmetric means that it looks the same no matter which way you rotate it. You talked about a dense core, less dense middle-region planet, which is spherically symmetric. If the planet had an ultra-dense region off to one side then it wouldn't be spherically symmetric and it would have gravity slightly stronger on one side than on the other... it's hard to imagine such a planet existing though.
- cryptoz 16y agoAh, gotcha. Thanks!