Indeed the pressure gradient is a curious question, regardless of the model. If there's no vacuum of space, and a container, it's explainable by the denser molecules moving down toward the earth and then less dense ones moving upward. We find the same conditions in the ocean, where the pressure increases as you go lower. There was even one under-ocean "lake" discovered that consisted of an extremely dense pool of salt water. Pressure decreases as you move higher. Then above the oceans you have the far less dense atmosphere. Question then is what's above the atmosphere. Traditional science holds there's a vacuum.
Density is ordered only by gravity, as in itself it's just a quantity, which helps to form a relative ratio between heaver and lighter elements. Gravity is what brings the vertical acceleration into it and acts as a force, so forces like buoyancy can even exist.
density of the fluid times the displaced volume multiplied by the gavitational acceleration constant is how the force of buoyancy is defined.
"Gravity" would have to hold everything down and resist the force of an infinite vacuum, which I simply can't comprehend. I've seen vacuum experiments where you had a bowl of water on the bottom with air around it, and then a vacuum at the top. When the vacuum was "turned on", not only did the air evaculate the chamber, but the water evaporated, turned into gas, and then also evacuated the chamber ... gravity notwithstanding. So in a sense there was a pressure gradient already. It be interesting if within a chamber, on a small scale, we could recreate a simulation of the pressure gradient we have in our atmosphere and then give it a shot. I'm very skeptical that gravity can overcome an infinite vaccuum.
I think the problem is that you think a vacuum "sucks" or exerts a force - it's actually always the gas at a specific density which will try to expand into an empty volume (vacuum), it actually pushes outwards into the empty space of the vacuum in a container. Now, the fact that the atmospheric pressure gradient fades to zero shows that there's a key difference between a closed system with a container and the large gas system that is the atmosphere around earth (or other planets where we observe an atmosphere).
So, let's start with a vacuum and have a blob of matter in there. Attracting other masses around it, that blob keeps growing and growing, thus creating an increasingly stronger gravity well. A it attracts more and more matter that's also floating around it, the inner layers get compressed slowly. Heavy elements like metals and minerals will be attracted more strongly (F=ma), while lighter elements like gasses will be attracted more lighlty, letting the heavier elements sink or "push" lower. But with enough gas, even that start to layer around the blob of matter. That's how we get pressure, by layers of gas or liquid all being attracted to a common center, and that's why the pressure gets less as we move away from that common center, because gravity, like many natural phenomena that act over distance, follows the inverse square law.
Electrostatics, same law:
Hope that helps.
Topic: Space is fake and gαy (Read 99898 times)