Center of the earth and gravity

Center of the earth and gravity [+ favourites]

Heres a thought that occured to me the other day.

Suppose you could drill a hole all the way through the earth and clear out the other end.

What would happen if you dropped a tennis ball into that hole, provided it could withstand the heat and pressure - in theory of course.

Would the ball reach the centre of the earth and stop due to gravity?

"If you know the candle is fire then the meal was cooked a long time ago"
[  Edited by Decius at   ]

if you are disregarding heat and pressure, doesn't that encompass gravity?

"In the beginning, night was memory was water, and in the cool aquamarine depths dreams swam freely."

That im unsure of, however isnt gravity linked to the mass of an object? The heat and pressure of motlen rock and metal within the earth produces the earths magnetic which protects us from harmful radiation.

"If you know the candle is fire then the meal was cooked a long time ago"

Yes I have had this thought. I figure that it will fall all the way through and keep going till it is sling shot back and forth and finally stops in the center.

"Dark and silent and complete."

interesting

However that would mean being suspended in mid air! Could the tennis ball be held at the centre of the earth purely by the earths gravity?

Ideas people!

"If you know the candle is fire then the meal was cooked a long time ago"

I belive that in the center of the earth, there is simply so much pressure that any object pressurized at the surface would be be immobilized after a short slingshot, as Ancient has described. If there was a slingshot effect, it would be very quick, and the object in itself would have to be at a great velocity to create the slingshot effect, If there is not much velocity, I believe an object would be immobilzed upon acquisition of the point of the center of the earth.

""As I sit before the fire, I wonder how many before myself have been burned.'"

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The heat and pressure of motlen rock and metal within the earth produces the earths magnetic

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"Terrorist or tyrant, few may come to the Truth that both are poor choice."

cturtle, it sounds like you know so much but are unable to convey it in a coherant way. In all honesty, I have not understood maybe more than one of your posts. This is not meant to be a stab at you, but more a possible improvement in the way you transfer your thoughts to words.

As far as this tennis ball theory goes, if you dropped it in the hole, once it reaches the center it would most likely get sucked into one of the sides of the dense molten nickel (its nickel right?). Unless the core was perfectly circular (if thats even possible) and pulled the tennis ball in equal directions from all directions (assuming the tennis ball could withstand the enormous force, and prevent itself from being shredded) only then could the tennis ball float perfectly in the center. If the tennis ball had enough density and velocity, I agree that you would probably see a slingshot effect.

"I try my best to be just like I am but everybody wants you to be just like them."

The immobalizing pressure theory is right if you are falling through the magma in the core. However, if you are dropping an object through a vacated hole, there will be no pressure. What causes gravity is the mass of the earth, so at the very center of the earth, you will have an equal amount of the earth's mass on every side of you, so the forces will cancel out, making you weightless at the center. Therefore, and object dropped through would be accelerated until it reached the center, at which point gravity would slow it down until it reached the other side of the planet, and started to fall back to the center.

"He who does not question is lost."

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However, if you are dropping an object through a vacated hole, there will be no pressure. What causes gravity is the mass of the earth, so at the very center of the earth, you will have an equal amount of the earth's mass on every side of you, so the forces will cancel out, making you weightless at the center.

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of course, the geometric center doesn't neccessarily imply the center of mass.

If we're talking pure hypotheticals here, then yes, the tennis ball would indeed be suspended at the center given a small amount of time. Let's not forget that a tennis ball doesn't have very much mass and therefore has an extremely low terminal velocity. Therefore, it would fall to the center of the earth and after a few passes back and forth, it would stop near the center and move about according to the tidal forces from the moon.

Of course this is purely hypothetical and therefore only as valid as one's personal opinion. =)