Message from @hgb

Discord ID: 675488747713855508


2020-02-07 23:48:29 UTC  

Imagine Minecraft, gravity would act downwards in that case.

2020-02-07 23:48:44 UTC  

Because a sufficiently far object exerts no force on you.

2020-02-07 23:49:04 UTC  

And you have the same mass uniformly radially around you and under you.

2020-02-07 23:49:19 UTC  

The problem with that is there is a centre of gravity somewhere

2020-02-07 23:49:34 UTC  

There's no problem with that at all.

2020-02-07 23:49:37 UTC  

An infinite plane with uniform mass does not exist

2020-02-07 23:49:41 UTC  

There is

2020-02-07 23:49:41 UTC  

Hehe

2020-02-07 23:49:47 UTC  

It doesn't need to be infinite

2020-02-07 23:49:51 UTC  

Just large enough

2020-02-07 23:50:01 UTC  

It does because then a centre of the object can be found

2020-02-07 23:50:07 UTC  

which is its centre of mass

2020-02-07 23:50:07 UTC  

And force would be uniformly downward.

2020-02-07 23:50:14 UTC  

which is where force would be applied from radially

2020-02-07 23:50:24 UTC  

making it crumple in on itslef

2020-02-07 23:50:25 UTC  

g = GM/r2 correct?

2020-02-07 23:50:32 UTC  

Well no.

2020-02-07 23:50:51 UTC  

Because it has uniform gravitational forces at all places expect its boundaries.

2020-02-07 23:50:56 UTC  

Except.

2020-02-07 23:51:02 UTC  

Unlike the earth

2020-02-07 23:51:07 UTC  

In a round sense

2020-02-07 23:51:19 UTC  

as the mass of such size would create such an immense gravity that it collapses in on itself

2020-02-07 23:51:22 UTC  

Which would have more gravitation at different parts in it.

2020-02-07 23:51:37 UTC  

@Monticks ha but no. Again, the radius makes it not matter.

2020-02-07 23:51:49 UTC  

No. You cant wrap your head around the idea that gravity comes from the centre of mass

2020-02-07 23:51:55 UTC  

which is the object is unifrom

2020-02-07 23:51:58 UTC  

It's like saying: gravity exists therefore the universe must collapse.

2020-02-07 23:52:00 UTC  

so your saying , g = GM , then

2020-02-07 23:52:01 UTC  

it is the centre of the object

2020-02-07 23:52:18 UTC  

boy xD

2020-02-07 23:52:33 UTC  

It would be insignificant at large distances

2020-02-07 23:52:48 UTC  

So it would be uniform

2020-02-07 23:52:58 UTC  

The centre is still the centre

2020-02-07 23:53:32 UTC  

Perform an experiment. Have a large plane perpendicular to the earth, place an object near it, see where the gravitational force acts on that object.

2020-02-07 23:53:53 UTC  

You're saying it would be towards the centre of the plane.

2020-02-07 23:54:01 UTC  

I'm saying it would be horizontal

2020-02-07 23:54:16 UTC  

Because centre of mass doesn't account for shape of the object

2020-02-07 23:54:23 UTC  

So it's a crude approximation.

2020-02-07 23:54:23 UTC  

There is an experiement you can do to test the centre of mass. You hold a ruler over the edge of the table and find the exact point where it doesnt topple over. Now repeat this on top of the previous ruler over and over again until you have a ruler of the edge of the desk

2020-02-07 23:54:33 UTC  

each time you have found the centre of mass

2020-02-07 23:54:45 UTC  

You're not understanding what I'm saying.