Pretty interesting. I don't get why a cannonball dropped down a mile deep mineshaft wouldn't hit the bottom though.
[QUOTE=nox;37436377]Pretty interesting. I don't get why a cannonball dropped down a mile deep mineshaft wouldn't hit the bottom though.[/QUOTE]
Sciene
Sciene Crossing is my least favorite Battlefield map.
My favourite genre is sciene friction.
ive been asking that question myself for a very long time now (what would happen if you jumped down a straight tunnel from one side of the earth to another)
ty science
[QUOTE=nox;37436377]Pretty interesting. I don't get why a cannonball dropped down a mile deep mineshaft wouldn't hit the bottom though.[/QUOTE]
Because when you release it the earth rotates. So the ball would end up hitting the side of the tunnel. It wouldn't at the poles though as shown in the video.
So it would reach the bottom, after hitting the wall a few times.
Anyway, they're wrong about the hollow Earth having the same acceleration due to gravity, they're fucking retarded on so many levels.
The mass of the planet would change and therefore so would the acceleration due to gravity. Also, you wouldn't just float around inside, you'd float to the nearest edge, because the force due to gravity is proportional to d^2.
This stuff is almost as addicting as TV tropes.
[QUOTE=download;37440569]So it would reach the bottom, after hitting the wall a few times.
Anyway, they're wrong about the hollow Earth having the same acceleration due to gravity, they're fucking retarded on so many levels.
The mass of the planet would change and therefore so would the acceleration due to gravity. Also, you wouldn't just float around inside, you'd float to the nearest edge, because the force due to gravity is proportional to d^2.[/QUOTE]
Watch the video again. He clearly says that the mass is the same just concentrated at some thin shell.
It would probably just get stuck in the sides of the tunnel due to its huge velocity it would gain.
The beginning with a tunnel going to both ends was used in the New Total recall, it was pretty cool for the first bit then got meh.
[QUOTE=download;37440569]Anyway, they're wrong about the hollow Earth having the same acceleration due to gravity, they're fucking retarded on so many levels.
The mass of the planet would change and therefore so would the acceleration due to gravity.[/QUOTE]
Bad listening. Same mass as earth was before, just concentrated into a shell rather than a ball.
[QUOTE=download;37440569]Also, you wouldn't just float around inside, you'd float to the nearest edge, because the force due to gravity is proportional to d^2.[/QUOTE]
Bad mathing. Nope. No matter where you are in the shell, all gravitational forces would cancel.
[editline]28th August 2012[/editline]
Think of it like this: If it's at the middle, there's obviously no force. If it's not in the middle, you can draw a line through the object that divides the sphere into symmetric halves. No force in either of those directions due to symmetry. Then there's the other directions. The mass will be closer to the edge on one side, so the mass elements there pull harder, but there will be more mass elements on the opposite side. Those two things precisely cancel out.
A line cannot divide a sphere btw
[editline]28th August 2012[/editline]
Oh and there are actually some people who believe our earth is hollow!
[editline]28th August 2012[/editline]
It's a bit of a complicated integral.
[editline]28th August 2012[/editline]
Actually not that bad I just can't be bothered.
[QUOTE=ellibob;37443382]A line cannot divide a sphere btw[/QUOTE]
Sure it can, in a sense. A sphere with an off-center mass in it will have cylindrical symmetry.
Technically not dividing it, but delineating symmetric and asymmetric parts.
[editline]28th August 2012[/editline]
Really I was thinking in 2d though because the shell theorem extends to 3d anyway
[editline]28th August 2012[/editline]
also also a sphere is a 2-manifold so yes a line can divide it (but a line on the surface :v:)
I knew what you meant I was just being overly-critical. It's the same for a magnetic sphere and an electrically charged sphere.
Indeed. We used the shell theorem and symmetry arguments so goddamn often in electricity and magnetism
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