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Posted: Tue Apr 05, 2005 12:11 am
by tnf
pete wrote:If I may give it a try...
I was thinking of a vacuum like kind of a tunnel that could aspired an underground ship chuttle by the core 0 gravity and with the help of a human made arm tunnel vacuum that would help the chuttle to continue it's travel once it passed the core. Once it passed the core at a precise moment a door should be shut behind it in order to keep the suction of the artificial human made vacuum arm to propel it to the surface. The rest of its travel would be just made from the suction velocity it would have acquired after passing the closing door.

Pete
Pete, there is no such thing as suction.
Posted: Tue Apr 05, 2005 12:14 am
by Guest
tnf wrote:pete wrote:If I may give it a try...
I was thinking of a vacuum like kind of a tunnel that could aspired an underground ship chuttle by the core 0 gravity and with the help of a human made arm tunnel vacuum that would help the chuttle to continue it's travel once it passed the core. Once it passed the core at a precise moment a door should be shut behind it in order to keep the suction of the artificial human made vacuum arm to propel it to the surface. The rest of its travel would be just made from the suction velocity it would have acquired after passing the closing door.

Pete
Pete, there is no such thing as suction.
Good evening tnf.
Since there is 0 gravity in the inner corpse, can we call it a suction type of way?
Pete
Posted: Tue Apr 05, 2005 12:19 am
by tnf
Its a pressure issue...things don't get 'sucked'.
Posted: Tue Apr 05, 2005 12:20 am
by tnf
And are you saying there is 0 gravity at the center of the earth's core? That is incorrect.
Posted: Tue Apr 05, 2005 12:25 am
by Guest
tnf wrote:And are you saying there is 0 gravity at the center of the earth's core? That is incorrect.
Sorry, I read it wrong then in many articles.
Then there is no correlation whatsoever about it?
Pete
Posted: Tue Apr 05, 2005 12:27 am
by losCHUNK
i thought someone in this thread said the gravity at the core is 0 ?
anyway, another question, how come it would be a vacum ?
a vacum is somewhere with no air no ?
forgive me but ive been out of schooling for 5 years and half of what i learned has either been lost or needs brushing up on

Posted: Tue Apr 05, 2005 12:29 am
by tnf
It's all relative....gravity is a function of the masses and distance between two objects, along with the gravitational constant. Force of gravity = (gravitational constant x mass 1 x mass 2)/distance squared
So, look at that and figure out how you can get 0 gravitational force.
Posted: Tue Apr 05, 2005 12:29 am
by phantasmagoria
it wouldn't be a natural vacuum.
Posted: Tue Apr 05, 2005 12:30 am
by tnf
losCHUNK wrote:i thought someone in this thread said the gravity at the core is 0 ?
anyway, another question, how come it would be a vacum ?
a vacum is somewhere with no air no ?
forgive me but ive been out of schooling for 5 years and half of what i learned has either been lost or needs brushing up on

Yea, a vacuum is something with nothing. Some space completely devoid of matter.
Posted: Tue Apr 05, 2005 12:32 am
by losCHUNK
edit: sorry just saw the post above you
thought the above post was the only added post in the thread (i gotta stop holding space bar

)
Posted: Tue Apr 05, 2005 12:34 am
by phantasmagoria
phantasmagoria wrote:it wouldn't be a natural vacuum.
dammit

Posted: Tue Apr 05, 2005 12:37 am
by losCHUNK
phantasmagoria wrote:phantasmagoria wrote:it wouldn't be a natural vacuum.
dammit

i said im sorry

Posted: Tue Apr 05, 2005 12:38 am
by Guest
Then what about if we start from the south pole with a magnet like type of a chuttle to the notrh pole.
Crazy Hey!
Pete
Posted: Tue Apr 05, 2005 12:39 am
by phantasmagoria
that's actually a really good idea, you could just reverse the magnet to send it back. Shame it would be utterly useless because noone lives at the poles.
Posted: Tue Apr 05, 2005 12:40 am
by tnf
I think there are a few misconceptions regarding fundamental physics and mechanics here...or a miscommunication.
Posted: Tue Apr 05, 2005 12:40 am
by losCHUNK
phantasmagoria wrote:that's actually a really good idea, you could just reverse the magnet to send it back. Shame it would be utterly useless because noone lives at the poles.
we could invent penguin holidays
Posted: Tue Apr 05, 2005 2:32 am
by Fender
Sorry tnf, but there is no gravity at the core. You have equal mass in all directions. By "no" I mean relative to the earth. Of course the sun and all other matter pulls on you...
Posted: Tue Apr 05, 2005 2:36 am
by tnf
I agree that there is no "net" gravity. But that is different than saying there is "no gravity."
And I was referring to the big picture stuff.
Plus I believe you are talking equal force in all directions, not equal mass in all directions?
EDIT: NVM - I can see what you mean by equal mass in all directions.
Posted: Tue Apr 05, 2005 2:51 am
by [xeno]Julios
I think because of the nature of gravitational forces, a net gravity of zero is identical, in all aspects, to zero gravity.
I might be wrong, but this is my strong intuition.
Posted: Tue Apr 05, 2005 3:20 am
by tnf
No, because there are still gravitational forces. They are cancelling each other out (in relation to the earth and the object), but the forces in any given direction still exist.
Perhaps we are splitting haris here - you mentioned zero gravity, someone else said "No gravity" - a difference, IMHO. For example, you could calculate the gravitational force in any given direction...and it would have the same force in the opposite direction, netting you zero overall...
Do you get what I am trying to say?
Posted: Tue Apr 05, 2005 3:28 am
by tnf
Foundt this same discussion on another board...haven't read all of it yet, but it looks like there are more details there:
http://www.physicsforums.com/archive/t- ... arth!.html
And - the cannon ball paradox
http://www.physicsforums.com/archive/to ... radox.html
Good one here, too, with diagrams:
http://www.gi.alaska.edu/ScienceForum/ASF5/537.html
Posted: Tue Apr 05, 2005 3:31 am
by tnf
Galileo was the first to assess the outcome correctly. If one were to drop, say, a cannon ball into such a hole it would fall with increasing speed, but decreasing acceleration, until it reached the exact center of the earth where its speed would be about 18,000 miles per hour (29,000 km/hr) and the acceleration would be zero. Subsequently, its speed would decrease with increasing deceleration until it reached the surface at the opposite side of the earth, at which point it would fall back again. If it were not for air resistance, it would continue oscillating back and forth in this manner forever. Air friction, however, would eventually bring it to rest at the exact center of the earth. In actuality, such an event, even if it were possible, could only happen if the hole were drilled from pole to pole, since at any other orientation, the Coriolis effect of the earth's rotation would soon have it bouncing off the walls of the tunnel.
Posted: Tue Apr 05, 2005 3:43 am
by [xeno]Julios
tnf wrote:No, because there are still gravitational forces. They are cancelling each other out (in relation to the earth and the object), but the forces in any given direction still exist.
Perhaps we are splitting haris here - you mentioned zero gravity, someone else said "No gravity" - a difference, IMHO. For example, you could calculate the gravitational force in any given direction...and it would have the same force in the opposite direction, netting you zero overall...
Do you get what I am trying to say?
it depends on what you mean by "there are still gravitational forces".
From a vectorial analysis, we can talk about there being multiple forces that cancel each other out, but from an ontological view (that is, what is
really happening), I think that the configuration of matter (being in the centre of a sphere) actually means that there
is no gravity.
It's not as if there are multiple gravitational forces that exist and then cancel each other out. It is simply that there is no gravity to begin with. Gravity is a function of the configuration of matter around the point in question, and for calculation purposes, we can conveniently divide up reality as if there really
were all these interacting forces, but the fact of the matter is that there really
is no gravitational force there, since the configuration of matter doesn't allow there to be any.
but the forces in any given direction still exist.
This is the key mistake - there
are no forces in any given direction, unless you count a force of zero as being a force. See my reply to foo, where I mention the incorrect metaphor of a horse pulling strings attached to a person. Gravity is not like this.
Posted: Tue Apr 05, 2005 4:01 am
by tnf
I'm speaking strictly from a vector analysis point of view, not an ontological point of view.
But yes, at the exact center, you could essentially superimpose the center of the ball over the center of the earth...resulting in a distance of 0 between the two centers of gravity, giving you a distance value of 0...which would result in an answer wherein you had to divide by zero.
Posted: Tue Apr 05, 2005 4:06 am
by tnf
I'm going to go back to the physics books, draw this problem out and crunch some numbers...julios I really think that we are actually thinking the same thing in one aspect, but I am interpreting things from a slightly different perspective (i.e. a purely vector based method).