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Tom Booth wrote:How about the gas in the upper atmosphere ?
They are attracted by the Earth too. Otherwise they would expand off into space, similar to moons, comets, and asteroids. Since no gas is above the top most layer, they are at the lowest pressure level. Darn near zero, but not quite.
Tom Booth wrote:Gas particles attract.
You are not reading me. Gas molecules attract and repel, but the speed of the gas molecules, overrides the attractive force, bounces off the repulsive force, and produces the macroscopic property of pressure, always pushing, never pulling. No such thing as gas contraction, only outside force compression fighting the never zero gas pressure.
Tom Booth wrote:that is why the gas is compressed at sea level, by the weight of all the gas on top
Yes. Compressed by something outside or above it. That is why it goes to zero at greater altitudes. Gravity is the outside force. If there were no gravity, there would need to be a ceiling above it, being pulled down by spring force, or it would expand off into space. As it has done for much lower mass bodies in space. Poof! Gone! If there were no gravity, there would be no planets. No liquid. No solid. Only gas leftover from the big bang.
Tom Booth wrote:And the earth formed from gas molecules in space attracting to form a planet numbskull. [/Quite]
Large masses of gas, LARGE, will coalesces into a gas giant planet, or star, but they are many times more massive than Earth. Earth sized planets need more massive gas particles than nitrogen, to form. Then it is the 'dirt' that attracts the air to the planet, not the gas attracting the gas to the planet. Gasses don't attract if above the boiling temperature. Coalescence requires cooling before the attraction kicks in, during.
Kinetic energy from momentum, bounces off from repulsive potential energy, streaking passed attractive potential energy, when above the boiling temperature/speed/energy.
Again planet coalescence isn't from intermolecular attractions, until cooling and gravity have done their jobs. Those weak and short distance attractions, only apply when the gas drops below the boiling point, or freezing point.
Gasses have too much energy to 'stick'. They bounce.
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