How does the Earth provide “support force”?

Question

I don’t understand how all of the weight on the Earth doesn’t force it to collapse on itself? What is the Earth using to provide this force that is stopping us from falling through. Obviously gravity is a thing but I don’t even understand that well enough lol.

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Answer 1

So as you can see, this subject is a little bit difficult to explain in an ElI5 manner but I’ll give it a go.

Take a piece of paper, now ball it up. Try to squish it as much as you can. This would be earth in this analogy and you squishing it down, we could say, is gravity (its more complicated than that but let’s just go with it for now).

You can probably squish the ball of paper to a pretty small size by hand but then it stops right? So we could use something more heavy/strong like a vice or something to get it even smaller (increase “gravity”) but you’d still have a hard limit on how small you can make the ball. Now why is that?

Paper is a material made of molecules, which are made up of atoms. In other words: paper is made of “matter” and this takes up a certain amount of space. The amount of space gets determined by the electromagnetic forces in the atoms. We’ll leave this at that for now, just remember, these forces are extremely strong.

So these forces try to push back against you (the “gravity”) trying to make the ball smaller. So you’ll eventually create a state where you cant get the ball smaller because you use the same amount of force as the paper ball is pushing back. You created an equilibrium.

Now take this back to earth. Gravity is pushing on the earth to make it smaller (again extremely oversimplified but just go with it) and the material in the earth is pushing back in an equilibrium. Now gravity is way stronger then we can exert on the planet because it is on such a big scale. The earth’s material has no issue pushing back against even multiple metric tons worth of weight. This provides the “support” you are talking about.

Earth doesn’t collapse in on itself because gravity doesn’t increase, it is a constant meaning that as far as we know it will always be the same, so equilibrium has been reached and thats it.