If you dug a hole through the center of the earth would you......

[spirit]

dear oh dear - Gravity originates from mass, not the center point of a planet.
The misconception is a product of Newton's thereom, which proved that in a spherically symmetric distribution of matter, a particle feels no force from matter at greater radii, and the matter within the radii gives the same force as one would expect from a point source located at r=0. if you were at r = 0, assuming the earths matter distribution to be sherically symmetric, you would feel no contribution to gravity. Ergo, you would not be squashed, or pulled apart.

(of course, you would oscillate around this point if you had net motion to begin with)

I can't believe he waited to prove that spheres act like point masses before publishing!!! (at least thats what my teacher said)

 

[AJUK]

Not this again, although I will give Zip 5* for his excellent diagram, go to the top of the class.

 

[Pickers]

I can't believe he waited to prove that spheres act like point masses before publishing!!! (at least thats what my teacher said)

Its not as simple as spheres - its just thats where the mainstream application is for. Its a fundamental assumption in the foundation of cosmology and isnt as intuative as it appears to be for a spherical mass.

 

[spirit]

Its not as simple as spheres - its just thats where the mainstream application is for. Its a fundamental assumption in the foundation of cosmology and isnt as intuative as it appears to be for a spherical mass.

what was it he proved then

 

[Pickers]

Newton's thereom proved that in a spherically symmetric distribution of matter, a particle feels no force from matter at greater radii, and the matter within the radii gives the same force as one would expect from a point source located at r=0.

erm... that ^^

He didnt trivially prove just that spheres act as point mases, but generally the matter enclosed in a spherical contribution is analagous to a point mass. This does not mean that gravity comes from the center of the planet (cf: "digging a hole through the center would mess up gravity").

 

[spirit]

erm... that ^^

He didnt trivially prove just that spheres act as point mases, but generally the matter enclosed in a spherical contribution is analagous to a point mass. This does not mean that gravity comes from the center of the planet (cf: "digging a hole through the center would mess up gravity").

err yeah i remember now.. i remember seeing my teacher do this stuff on the board man - i didnt really care but some guys did..

i always remember it for spheres, 'cause thats what i always used it for

 

[Foghorn Leghorn]

There is know why of burning or melting to death in this question. Ive taken that out of the scenario

Dear god

Do they not have schools in oz?

Fog


And yes I did see the other mistakes but I thought this pair were quite spectacular

Cool planet pic btw

 

[Zip]

Dear god

Do they not have schools in oz?

Fog

I have no idea how i managed that

 

[Amleto]

Thanks for clearing that up

no problem

 

[aardvark]

i think people have already said it but you would gradually become weightless as you approached the center as the forces of gravity cancel each other out from the surrounding matter.

 

[Docaroo]

remember that there is not a black hole or any **** like that in the core of the Earth - gravity is a function of MASS... the whole mass of the Earth is NOT concentrated in the core in some pin sized point like you guys are saying... The Earth's gravity is a result of it's entire mass, throughout the mantle aswell...

I would expect that you would be drawn towards the inner core (which is solid) after passing through the liquid outer core and just bang against the solid inner core.

You wouldn't be torn apart by gravitational forces, you would most certainly completely melt by the time you are anywhere near the core but hypothesising that you had a craft that was resistant to the Temp and Pressure I can't see you being squished as if you fell into a Black hole (where the mass/gravity is concentrated into a very small space)

There's my fifty pence...

 

[Psyk]

dear oh dear - Gravity originates from mass, not the center point of a planet.
The misconception is a product of Newton's thereom, which proved that in a spherically symmetric distribution of matter, a particle feels no force from matter at greater radii, and the matter within the radii gives the same force as one would expect from a point source located at r=0. if you were at r = 0, assuming the earths matter distribution to be sherically symmetric, you would feel no contribution to gravity. Ergo, you would not be squashed, or pulled apart.

(of course, you would oscillate around this point if you had net motion to begin with)

That's assuming a person to be a single particle. If the mass of the planet was great enough then gravity on opposite sides of your body would be pulling in opposite directions, pulling you apart. Of course earths gravity is no where near strong enough. After all your arms don't rip off if you hang from a tree branch so there's no reason it would be stronger in the centre of the earth.

 

[singist]

That's nice dear, now get back to your dictionary ....





























Isn't Oz philosophy great?