Question

does earth rotate alongwith its atmosphere? or just mass of earth rotate?

Answer 1

Rotation of Earth is a consequence of gravitational force and even the atmosphere (because it has mass) experiences it.

Although, this doesn't means the atmosphere around you will be static (with respect to you).

Answer 2

rotation of earth is consequence of it's own gravitational field or sun's ?

Answer 3

"Rotation of Earth is a consequence of gravitational force".. are u sure? o.O.. earth rotates cause of its own inertia .. not because of some gravitational force !

Earth REVOLVES around the sun because of gravity ..

Answer 4

I tried to correlate the question with the of clustering of mass in the universe to generate a feeling that physical contact is not a necessary condition for rotation as every unit of mass would be (in a way) falling towards the center of mass.

I was waiting for a response to further clarify.

Btw @Mashy how can an object rotate on account of its own inertia? (1st law of motion)

Answer 5

if u take an object to outer space and spin it, it will keep spinning forever and ever and ever .and everr.. :P.. thats why all astronomical objects are always spinning!

Answer 6

^^ If you somehow shield (although even theoretically impossible) every unit of the object from the gravitational field of the rest, the object won't spin (each unit will follow a tangential trajectory).

Answer 7

its not gravity..
its eletric force :P.. gravity doesn't keep atoms together, electricity does :D

Answer 8

By the term "unit" I wasn't referring to atoms or molecules. It was a macroscopic unit and I was trying to analyze a part of the object independently from the rest.

And electromagnetic force cannot explain the observed spinning of planets (atleast as far as I can think)

Answer 9

i see your point.. but matter stays together because of electromagnetic force right?.. so the fundamental force should be electromagnetic itself shouldn't it?

but yea come to think of it, its gravity that holds such gigantic planets and stars together.. so i guess u are right then! ;)

Answer 10

The planets rotate due to the original accretion of material in preferred directions.

The atmosphere is carried along with the Earth's rotation due to shear forces at the surface, which produce momentum transfer up through the atmosphere (viscous and eddy diffusion). Atmospheric motion is complicated by Coriolis "force" and by pressure gradient force.

Answer 11

@Mashy
Yes, matter stays together because of electromagnetic force (Cold Welding might be the most beautiful phenomena to explain this). But we, generally, do not consider it while analyzing neutral macroscopic bodies (as its effect would be very weak).

@douglaswinslowcooper
Para 1
I guess, if we dwell deeper into the statement it will either lead to gravity or the history question (How it all begin?)

Para 2
Although it explains why two different units will not choose to rotate in opposite directions (clockwise and anti) but I cannot understand why my approach of imposing revolutionary motion (like that of a satellite) on Brownian motion was flawed.

@abdurrehmanlive
I'll admit that I and @Mashy (unethically? maybe :P ) hijacked your feed but I hope you got the answer to your question (and other follow-up questions).

Answer 12

no No mashy, I just enjoyed this discussion. And frankly speaking u have got more clearer concepts.

Answer 13

Brownian motion is due to unequal molecular impacts noticeable only on tiniest objects. Hard to put that into the context of rotation. Turbulent (eddy) diffusion of momentum from Earth's surface gets atmosphere to rotate with Earth. Large-scale, not molecular.