If there were a hole that went all the way through the earth, what would happen when you fell in it?

Question

Would you fall all the way through the earth, coming out the other side, and fly into the sky, or would gravitational foces crush you at the center? Would you come to an immediate stop at the center, or be suspended in space weightless?

Answer 1

First some caveats: We assume the hole is evacuated (not air) and goes from pole to pole (to avoid Coriolis effects). Newton first figured out the solution to this problem, first posed and answered qualitatively by Robert Hook. From Gauss's law applied to the universal law of gravitation, one finds that the force is proportional to the distance from the center of the earth. The motion is, therefore, "Harmonic", meaning you'll oscillate back and forth about the center of the earth with a sinusoidal time dependence, reaching opposite surfaces after each pass through the center.

Answer 2

Ignore the effects of falling all that way on a living being. First assume that the earth is not rotating. As you fell the force of gravity would decrease until you got to the center. At the center the earth's gravity is pulling at you from all directions equally so the force would be zero. Still you would accelerate until you reached the center. Then as you leave the center towards the other side you would start to slow down. The force of gravity would increase until you got to the surface. Assuming that the mass of the earth is equally distributed, the forces that accelerated you to the center would exactly balance the forces that decelerate you as you ascend. So you would come to a stop just as you reached the surface. If you didn't grab onto something you would fall back and repeat the process. If there is air in the hole then air resistance would slow you down some and you wouldn't quite reach the other surface. Each time you passed through the earth you would rise a little less each time until you came to rest at the center.

The earth however is rotating. Unless the hole goes through the poles (in which case the earth might as well not be rotating) you will have a sideways speed equal to the speed of the surface as it rotates. But as you descend the inner parts of the earth are traveling slower because they don't have to go as far in one rotation. So you wind up hitting the side of the hole before you get through. Your whole trip just got a lot more complicated.

Answer 3

If the high temparture in the inner eath is not ignored, then you would burn up.

But lets see what happens if the tunnel is not super heated.

Crudly speaking, the Earth's gravity results from the all mass of the earth pulling on you. If you weigh 120 pounds, than all of the earth mass only has 120 pounds of pull on you. This 120 pounds of pull is what makes you speed up and hit the ground if you fall off a ladder.

When you fall in the hole, you will pick up speed as long as most of the Earth's mass is below you (and pullin on you). Once you pass the center, most of the mass is now behind you and pulling to slow you down.( At dead center speed would stay constant.) Once you reach the surface on the other side, you will have slowed down enough to stop. Now you fall back in from the other side. Again you pick up speed until you pass center, then start to slow down. Again you stop at the surface. Again you start falling. back in. The cycle will keep repeating forever if air friction is ignored.
I mentioned earlier that speed stays contant at the center. So if you were to be placed at zero speed at the center, you would stay at the center, suspended. You need to be moving in order to cross the center.

Answer 4

Theoretically, gravity "begins" at the center of earth's mass and is more or less the same at any point on the surface of that mass. Gravitational forces would not crush you since you feel the maximum amount of gravity on the surface. As you moved toward the center of the mass, the amount of mass creating the gravity would lessen, therefore at the center of the mass you would be more or less weightless, in the sense that gravity would be acting on your body from all directions. Gravity is merely molecular attraction, and the earth has lots of molecules. The crushing of lungs others here speak of relates to air pressure, not gravity. So long as you were not holding your breath, the lungs would not collapse since they would be taking in ambient air, and pressure would be equal. The body is mostly water in its makeup, and water does not compress.

Answer 5

Christopher is incorrect, the gravity lessens as you frame of mind the middle (ie gravity = 0 on the middle because you're attracted both from all sides of the earth (such as the faraday cage result) 20 minutes to achieve the different area and then 20 minutes to come back decrease back lower back... etc. Assuming no lack of speed through air friction you'll change right into a perpetual yo-yo. yet actually, through terminal speed you'll absolutely no longer truly attain the different area before falling decrease back to the starting up, and then lose slightly of distance every time with the help of till you finally finally end up contained in the middle - floating weightlessly.

Answer 6

Well if gravity was still working, the hole would overheat and collapse, before you even passed the center.

But suppose a hypothetical hole existed.

Gravity is not well enough understood to explore this hypothesis. Because you would need to now if gravity moved faster than light, Einstein couldn't explain this.

You wouldn't fly out the other side though, unless you were "blasted" through.

Answer 7

You would hit a maximum speed after a little while and just be falling for a few minutes. I want to say that you would burn up far before you hit the center. The inner portion is pretty hot.

Answer 8

Short terse answer not taking into account life science:- You will oscillate like a yo-yo in simple harmonic motion, and that is because of gravity, with the mid point of this oscillation being the center of the earth.

Answer 9

Well, you'd melt before you got to the center. At the center I thing the pressure would kill you, but other than that, I think you would float in thin air (actualy molten iron or whatever)

Answer 10

you would be crushed before you hit the center, starting with your lungs. but yes once you got to the middle you would just be there and stop moving