Dropping a ball through the Earth...

[itsallyellow]

If you dug one hole directly down through to the other side of the world and dropped a ball into it, and if there was no friction and forget the fact it gets very warm down there and there isn't a molten core at the centre would the ball carry on falling until it came out the other side and then fall again until it came to a stop perhaps in the centre of the earth???

[Loosehead]

Yes it would oscillate back and forth past the centre until eventually stopping at the centre, where the gravity would be equal in all directions.

[tamd88]

How do you know?? Have you ever tried it??

[itsallyellow]

I guess thats what the molten core does anyway, just floats there not attached to anything. Any more opinions on this???...

[Loosehead]

Because, tamd88, I understand gravity. I don't have to jump off a building to know I'll hit the ground.

[brachiopod]

* snigger * Nice one, Loosehead !

[Loosehead]

Too easy Brachio, couldn't resist!

[Ralph]

If there was no friction, it would continue to oscillate back and forth for ever.

[spaced]

but it would still have resistance against air, which would have a very slight impact on its speed over time. good question though!

[CT]

This would be easier to achieve on the moon. Certainly more feasable than on Earth. No atmosphere, smaller distances, no plate tectonics.

[bernardo]

Loosehead may not have actually tried it (and may be relying merely on theory and calculations) but I have. I did it this afternoon in my back garden. It took me all afternoon to dig the hole, otherwise I would have been the first to answer. It took about an hour and a quarter for the ball to fall through and then back up to where I dropped it from.

[brachiopod]

I was wondering why there's now a bleeding volcano in my next-door neighbour's garden.

You've got magma seeping out from the mantle now, you fool. Oh, and isn't about time you fixed that fence? I've beeen on at you for months about it now.

(*rolls eyes* who'd have bernardo as a neighbour, eh?)

[magpie]

i think that it would pick up so much speed that it would give give a kiwi a surprise squatting in a field. maybe we could discover a cheap way to get to the antipodes!