Earth is rotating around the sun?

[Hardik Batra]

Why the Earth is rotating around the sun?

I know the centripetal force is required for the rotation of Earth around the sun.

But initially there is required some force on Earth to rotate around the sun.

 

[Chronos]

Earth orbits the sun due to gravity and conservation of angular momentum. The angular momentum was provided by the accretion disc from which the Earth was formed.

 

[A.T.]

Why the Earth is rotating around the sun?

Watch this at time 1:05

https://www.youtube.com/watch?v=tmNXKqeUtJM

 

[Hardik Batra]

Earth orbits the sun due to gravity and conservation of angular momentum. The angular momentum was provided by the accretion disc from which the Earth was formed.

I actually don't get it what is accretion disc.

 

[A.T.]

I actually don't get it what is accretion disc.

Have you watched the video in post #3 ?

 

[sophiecentaur]

I actually don't get it what is accretion disc.

Did you try Google? I got a lot of hits when I tried it.

 

[mathman]

You should try to keep your terms for the Earth motion precise.

The Earth rotates around its axis.
The Earth revolves around the sun.

 

[dean barry]

Balancing act

As space is void of gases, motion of the stars and planets are not inhibited, so they can keep unpowered constant speed, this is the reason satellites are put into space.

Ive attached an (unfinished) layout of a star - planet - moon system, it will give you an idea of the layout and basic principles, you can treat the earth-moon system as one mass orbiting the sun.
Also attached are the basic equations for two body stable orbit.

Hope this is a help

Dean

 

[Hardik Batra]

You should try to keep your terms for the Earth motion precise.

The Earth rotates around its axis.
The Earth revolves around the sun.

The Earth is revolves around the sun. The centripetal force and conservation of angular momentum is used.

But the Earth is also rotating around its own axis. which force the Earth is gaining to rotate around its own axis?

 

[Nugatory]

The Earth is revolves around the sun. The centripetal force and conservation of angular momentum is used.

But the Earth is also rotating around its own axis. which force the Earth is gaining to rotate around its own axis?

angular momentum keeps it rotating, and the centripetal force is provided in part by the Earth's gravity and in part by the mechanical strength of the rock that makes up the earth.

 

[A.T.]

The Earth is revolves around the sun. The centripetal force and conservation of angular momentum is used.

But the Earth is also rotating around its own axis. which force the Earth is gaining to rotate around its own axis?

Centripetal force and conservation of angular momentum

 

[Master Sashin]

If you stand on a flat surface you will stand still however if you curve the fat surface you will fall over however if you are a ball like the Earth you will roll around the curvature. Massive boddies like the sun curve and warp the fabric of space and the Earth is forced to roll around it.

 

[voko]

If you stand on a flat surface you will stand still however if you curve the fat surface you will fall over however if you are a ball like the Earth you will roll around the curvature. Massive boddies like the sun curve and warp the fabric of space and the Earth is forced to roll around it.

This Pop-Sci statement is very crude and is best avoided. First, it is the spacetime, not necessarily space, that gets curved in General Relativity. The space in the vicinity of the orbit of the Earth is flat for any practical purpose.

Second, this has very little to do with the shape of the Earth. Almost anything, of any shape, as long as its mass is much less than the mass of the Sun, can revolve around the Sun exactly like the Earth does.

 

[A.T.]

This Pop-Sci statement is very crude and is best avoided.

Especially if someone asks about the spin of the Earth around it's own axis. It almost sounded like the rolling on the curved surface is responsible for the Earh's spin. Very misleading.

 

[Master Sashin]

This Pop-Sci statement is very crude and is best avoided. First, it is the spacetime, not necessarily space, that gets curved in General Relativity. The space in the vicinity of the orbit of the Earth is flat for any practical purpose.

Second, this has very little to do with the shape of the Earth. Almost anything, of any shape, as long as its mass is much less than the mass of the Sun, can revolve around the Sun exactly like the Earth does.

DUde i was using it as an example. If i said he started rolling around in circles it souldve confused him and he wouldve also have been confused about spece time

 

[voko]

DUde i was using it as an example.

The example was bad and misleading and it was physically wrong, too. There is no excuse for that. You just do not explain anything using such "examples".

 

[Drakkith]

DUde i was using it as an example. If i said he started rolling around in circles it souldve confused him and he wouldve also have been confused about spece time

I appreciate that you want to participate in discussions here at PF, and I don't intend any offense, but it was a poorly worded example. When giving explanations or examples it is important to be as clear, concise, and accurate as possible, otherwise you risk confusing others. Your explanation simply isn't accurate and is extremely vague. It's best to simply accept and learn from whatever criticism you get and to not let it get to you. Trust me, all of us here at PF have had to learn this lesson too. I don't know how many of my own posts have been corrected by others since joining.

 

[Student100]

As space is void of gases, motion of the stars and planets are not inhibited, so they can keep unpowered constant speed, this is the reason satellites are put into space.

This isn't quite true.

 

[Master Sashin]

Especially if someone asks about the spin of the Earth around it's own axis. It almost sounded like the rolling on the curved surface is responsible for the Earh's spin. Very misleading.

OKay fine, this is my explanation. Space or space time is like a trampoline. Place a few marbles on the trampoline and each of those marbles respresent a planet. If you stand in the centre of the trampoline, the marbles will move toward you because you curved the fabric of the trampolione. The marbles will not move to you in a straight line but will move in a circular motion.
SO now imagine yourself as the sun curving the fabric of space time and that curved space is pushin the Earth around the sun. I am not sure but i think its getting closer...(again, I am not 100 percent sure on my last sentance)

 

[A.T.]

OKay fine, this is my explanation.

Not really yours, rather a common flawed explanation of General Relativity, that you probably saw somewhere. Since the OP is already confused about classical Newtonian mechanics, I don't see the point of bringing up GR.

 

[voko]

Not really yours, rather a common flawed explanation of General Relativity, that you probably saw somewhere. Since the OP is already confused about classical Newtonian mechanics, I don't see the point of bringing up GR.

Sometimes GR (or, rather, some of its core ideas) explain things far more lucidly than non-relativistic mechanics. The equivalence principle is a particularly useful tool, which, I think, should be taught very early.

But not this kind of "fabric of space" fantasies, of course.

 

[Master Sashin]

In what way would the OP be confused about what I said?

 

[Student100]

In what way would the OP be confused about what I said?

Hey master, first it's a pop science description for the lay person, and it isn't an accurate way to to answer the OP's question. Like others have pointed out, it's best to avoid such devices here.