- #246
heusdens
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Originally posted by Mr. Robin Parsons
Yes very clear, but your vectors need to cross all of the matter that is in the planets body, it is NOT A SHELL, GOT THAT?
Vectors don't cross anything, they just denote symbols, which are handy when doing physics. THERE ARE NO VECTORS IN THE REAL WORLD, so why should we bother about them?
The "shell" thing was just a matter of a helping hand when doing the mathematical calculation. I was not suggesting that in the real world, the Earth consits of embedding "shells".
And the force of gravitation itself is not energy, but it accomplishes work when this force is done over some distance.
When the force of gravity overcomes the inner pressure of the material, work is done, and this work is released in form of kinetic energy or heat. But that is just basic physics stuff.
So explain the distal cancellation effect, how they cancel across all of that FULL SPACE!
Just vector summation in the mathematical model, and nothing more as that. The vectors are not across anything. We just model all the vectors exerted on some test mass at the center of earth, from the force of gravitation of all the matter components of Earth's interior.
Right at that point, we imagine to have a whole bunch of vectors, in different directions and different magnitudes. Now the application of some math allow you to pick pairs of vectors with same magnitue and opposing directions, which sum to a resultant vector of zero magnitude, and the "proof" includes that this can be done in such a way that all the vectors can be removed. Resulting in this zero gravity force at the center.
Talking about energy and/or pressure, will just confuse this, and isn't any helpfull.
And if you STILL don't get this vector stuff then let's us try to do it in a more rigorous way. We just cut the Earth in two equal halves, right through the center of gravity. Now both halves have their own center of gravity, which are at equal distances towards the center of gravity in opposing directions, and both halves have the same mass.
Note: this is a rough approximation, in reality there will be a slight differences in the physical measurements, but for sake of simplicity, we will cut our these details.
Now do your very best, and calculate for me the nett resultant force at the center of gravity. First calculate the distance towards the center of gravity of each halve, and then calculate the mass. Then use Newton's law: F = G m M / r 2.
Can you do that?
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