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truthseeker613
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5/3/2011 12:01:31 AM
Posted: 5 years ago
I once read that according to Einstein's theory of relativity or motion that the earth is not nickel revolving around the sun but rather it can be any location is any one fermiliar with this?
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Meatros
Posts: 1,075
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5/3/2011 7:38:03 AM
Posted: 5 years ago
At 5/3/2011 12:01:31 AM, truthseeker613 wrote:
I once read that according to Einstein's theory of relativity or motion that the earth is not nickel revolving around the sun but rather it can be any location is any one fermiliar with this?

I have no idea what you are referring to. The earth's orbit around the sun is elliptical. This was discovered by Newton, IIRC.

Relativity is about speed being relative to the observer - so, one of the consequences is there is no 'absolute' time or 'absolute' present.
Ore_Ele
Posts: 25,980
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5/3/2011 10:17:42 AM
Posted: 5 years ago
At 5/3/2011 12:01:31 AM, truthseeker613 wrote:
I once read that according to Einstein's theory of relativity or motion that the earth is not nickel revolving around the sun but rather it can be any location is any one fermiliar with this?

By using different frames (commonly done in special relativity to understand how things appear to different objects near the speed of light) you can make it appear that the Earth revolves around anything (though the physics will no longer add up).

One of the things I did in high school was use a different frame of reference to prove that the Earth rotated around a girl (she later married me).

Also, it was Copernicus, not Newton. Newton didn't do much with astronomy, just Physics and Math (mostly, though he did dabble in everything).
"Wanting Red Rhino Pill to have gender"
sal
Posts: 319
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5/3/2011 5:09:48 PM
Posted: 5 years ago
At 5/3/2011 12:01:31 AM, truthseeker613 wrote:
I once read that according to Einstein's theory of relativity or motion that the earth is not nickel revolving around the sun but rather it can be any location is any one fermiliar with this?

According to Einsteins theory of general relativity all reference frames are equal.
That means that you can pick any point in the universe as the center and all laws of physics apply to the motion of all bodies.

From my understanding it makes it stupid to argue whether the universe is heliocentric or geocentric its all relative.
Ore_Ele
Posts: 25,980
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5/3/2011 5:31:35 PM
Posted: 5 years ago
At 5/3/2011 5:09:48 PM, sal wrote:
At 5/3/2011 12:01:31 AM, truthseeker613 wrote:
I once read that according to Einstein's theory of relativity or motion that the earth is not nickel revolving around the sun but rather it can be any location is any one fermiliar with this?

According to Einsteins theory of general relativity all reference frames are equal.
That means that you can pick any point in the universe as the center and all laws of physics apply to the motion of all bodies.

From my understanding it makes it stupid to argue whether the universe is heliocentric or geocentric its all relative.

false.

The relative reference only applies to a reference frame which does not have any forces acting upon it (meaning that it is not accelerating). If you choose a reference frame that is accelerating (like the Earth, or the Sun) you run into some issues with the physics. We first discovered this with tracking the orbit of the planets via a geo-centric model.
"Wanting Red Rhino Pill to have gender"
Meatros
Posts: 1,075
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5/4/2011 7:48:02 AM
Posted: 5 years ago
At 5/3/2011 10:17:42 AM, OreEle wrote:

Also, it was Copernicus, not Newton. Newton didn't do much with astronomy, just Physics and Math (mostly, though he did dabble in everything).

From my (admittedly poor) understanding, Newton provided the mathematics for the orbits of the planets. This is what I was referring to.
Greyparrot
Posts: 14,337
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5/5/2011 1:00:37 PM
Posted: 5 years ago
At 5/3/2011 5:31:35 PM, OreEle wrote:
At 5/3/2011 5:09:48 PM, sal wrote:
At 5/3/2011 12:01:31 AM, truthseeker613 wrote:
I once read that according to Einstein's theory of relativity or motion that the earth is not nickel revolving around the sun but rather it can be any location is any one fermiliar with this?

According to Einsteins theory of general relativity all reference frames are equal.
That means that you can pick any point in the universe as the center and all laws of physics apply to the motion of all bodies.

From my understanding it makes it stupid to argue whether the universe is heliocentric or geocentric its all relative.

false.

The relative reference only applies to a reference frame which does not have any forces acting upon it (meaning that it is not accelerating). If you choose a reference frame that is accelerating (like the Earth, or the Sun) you run into some issues with the physics. We first discovered this with tracking the orbit of the planets via a geo-centric model.

You have to account for wind and drop, like a snipah!
sal
Posts: 319
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5/6/2011 10:48:32 AM
Posted: 5 years ago
At 5/3/2011 5:31:35 PM, OreEle wrote:
At 5/3/2011 5:09:48 PM, sal wrote:
At 5/3/2011 12:01:31 AM, truthseeker613 wrote:
I once read that according to Einstein's theory of relativity or motion that the earth is not nickel revolving around the sun but rather it can be any location is any one fermiliar with this?

According to Einsteins theory of general relativity all reference frames are equal.
That means that you can pick any point in the universe as the center and all laws of physics apply to the motion of all bodies.

From my understanding it makes it stupid to argue whether the universe is heliocentric or geocentric its all relative.

false.

The relative reference only applies to a reference frame which does not have any forces acting upon it (meaning that it is not accelerating). If you choose a reference frame that is accelerating (like the Earth, or the Sun) you run into some issues with the physics. We first discovered this with tracking the orbit of the planets via a geo-centric model.

Apparently you never studied the theory of general relativity.
There is no such thing as a reference frame which doesn't have some gravitational field.
There is no difference between an accelerated reference frame and a reference frame in a gravitational field. the equivalence principle.
Ore_Ele
Posts: 25,980
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5/6/2011 11:08:17 AM
Posted: 5 years ago
At 5/6/2011 10:48:32 AM, sal wrote:
At 5/3/2011 5:31:35 PM, OreEle wrote:
At 5/3/2011 5:09:48 PM, sal wrote:
At 5/3/2011 12:01:31 AM, truthseeker613 wrote:
I once read that according to Einstein's theory of relativity or motion that the earth is not nickel revolving around the sun but rather it can be any location is any one fermiliar with this?

According to Einsteins theory of general relativity all reference frames are equal.
That means that you can pick any point in the universe as the center and all laws of physics apply to the motion of all bodies.

From my understanding it makes it stupid to argue whether the universe is heliocentric or geocentric its all relative.

false.

The relative reference only applies to a reference frame which does not have any forces acting upon it (meaning that it is not accelerating). If you choose a reference frame that is accelerating (like the Earth, or the Sun) you run into some issues with the physics. We first discovered this with tracking the orbit of the planets via a geo-centric model.

Apparently you never studied the theory of general relativity.
There is no such thing as a reference frame which doesn't have some gravitational field.
There is no difference between an accelerated reference frame and a reference frame in a gravitational field. the equivalence principle.

You should really let this go.

" the equivalence principle refers to several related concepts dealing with the equivalence of gravitational and inertial mass, and to Albert Einstein's assertion that the gravitational "force" as experienced locally while standing on a massive body (such as the Earth) is actually the same as the pseudo-force experienced by an observer in a non-inertial (accelerated) frame of reference."

In case you didn't realize, "pseudo-forces" are not real. The fact that changing the reference frame (so that it is under an acceleration) can create a pseudo force, which is needed to balance out the physics, because without it they don't work.

i.e. not all reference frames are the same. This is most notable with centrifugal "force." If you are in the rotating object (like you are in a certrifuges), you experience a pseudo-force that is pushing you out (away from the center of rotation). However, when standing back from it, we know that the is no real force pushing back.
"Wanting Red Rhino Pill to have gender"
sal
Posts: 319
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5/7/2011 10:19:48 PM
Posted: 5 years ago
At 5/6/2011 11:08:17 AM, OreEle wrote:
At 5/6/2011 10:48:32 AM, sal wrote:
At 5/3/2011 5:31:35 PM, OreEle wrote:
At 5/3/2011 5:09:48 PM, sal wrote:
At 5/3/2011 12:01:31 AM, truthseeker613 wrote:
I once read that according to Einstein's theory of relativity or motion that the earth is not nickel revolving around the sun but rather it can be any location is any one fermiliar with this?

According to Einsteins theory of general relativity all reference frames are equal.
That means that you can pick any point in the universe as the center and all laws of physics apply to the motion of all bodies.

From my understanding it makes it stupid to argue whether the universe is heliocentric or geocentric its all relative.

false.

The relative reference only applies to a reference frame which does not have any forces acting upon it (meaning that it is not accelerating). If you choose a reference frame that is accelerating (like the Earth, or the Sun) you run into some issues with the physics. We first discovered this with tracking the orbit of the planets via a geo-centric model.

Apparently you never studied the theory of general relativity.
There is no such thing as a reference frame which doesn't have some gravitational field.
There is no difference between an accelerated reference frame and a reference frame in a gravitational field. the equivalence principle.

You should really let this go.

" the equivalence principle refers to several related concepts dealing with the equivalence of gravitational and inertial mass, and to Albert Einstein's assertion that the gravitational "force" as experienced locally while standing on a massive body (such as the Earth) is actually the same as the pseudo-force experienced by an observer in a non-inertial (accelerated) frame of reference."

It was from the equivalence principle that he derived the laws of general relativity.

In case you didn't realize, "pseudo-forces" are not real. The fact that changing the reference frame (so that it is under an acceleration) can create a pseudo force, which is needed to balance out the physics, because without it they don't work.

i.e. not all reference frames are the same. This is most notable with centrifugal "force." If you are in the rotating object (like you are in a certrifuges), you experience a pseudo-force that is pushing you out (away from the center of rotation). However, when standing back from it, we know that the is no real force pushing back.

Not really, here is were your mistake lies. There is no such thing as an inertial reference frame in our universe. A man standing on a rotating object will feel a force which he can say is gravity. He than has to use the formulas of tensor calculus to derive how all the bodies will move relative to him.
Ore_Ele
Posts: 25,980
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5/9/2011 11:50:31 AM
Posted: 5 years ago
At 5/7/2011 10:19:48 PM, sal wrote:
At 5/6/2011 11:08:17 AM, OreEle wrote:
At 5/6/2011 10:48:32 AM, sal wrote:
At 5/3/2011 5:31:35 PM, OreEle wrote:
At 5/3/2011 5:09:48 PM, sal wrote:
At 5/3/2011 12:01:31 AM, truthseeker613 wrote:
I once read that according to Einstein's theory of relativity or motion that the earth is not nickel revolving around the sun but rather it can be any location is any one fermiliar with this?

According to Einsteins theory of general relativity all reference frames are equal.
That means that you can pick any point in the universe as the center and all laws of physics apply to the motion of all bodies.

From my understanding it makes it stupid to argue whether the universe is heliocentric or geocentric its all relative.

false.

The relative reference only applies to a reference frame which does not have any forces acting upon it (meaning that it is not accelerating). If you choose a reference frame that is accelerating (like the Earth, or the Sun) you run into some issues with the physics. We first discovered this with tracking the orbit of the planets via a geo-centric model.

Apparently you never studied the theory of general relativity.
There is no such thing as a reference frame which doesn't have some gravitational field.
There is no difference between an accelerated reference frame and a reference frame in a gravitational field. the equivalence principle.

You should really let this go.

" the equivalence principle refers to several related concepts dealing with the equivalence of gravitational and inertial mass, and to Albert Einstein's assertion that the gravitational "force" as experienced locally while standing on a massive body (such as the Earth) is actually the same as the pseudo-force experienced by an observer in a non-inertial (accelerated) frame of reference."


It was from the equivalence principle that he derived the laws of general relativity.

In case you didn't realize, "pseudo-forces" are not real. The fact that changing the reference frame (so that it is under an acceleration) can create a pseudo force, which is needed to balance out the physics, because without it they don't work.

i.e. not all reference frames are the same. This is most notable with centrifugal "force." If you are in the rotating object (like you are in a certrifuges), you experience a pseudo-force that is pushing you out (away from the center of rotation). However, when standing back from it, we know that the is no real force pushing back.

Not really, here is were your mistake lies. There is no such thing as an inertial reference frame in our universe.

Yes there is, for the universe, it is the center of the universe. Whenever we deal with a group, we go with the center of that group. For the physics on Earth, we can look at just the Earth for the center. When we look at the solar system, we have to use the sun as the center. When we look at the galaxy, we have to use the center as the center. This is because, all external forces work on the entire system roughly equally (so they don't mess with the math).

When looking at our solar system, gravity from the rest of the galaxy does effect us, however, it effects every body approximately equally, so if we use a frame reference which is also effected the same, it nets out to zero.

If you use the Earth as your reference window, you cannot calculate the rotation of planets, and the sun, and everything else the same as you would if you used the Sun.

A man standing on a rotating object will feel a force which he can say is gravity. He than has to use the formulas of tensor calculus to derive how all the bodies will move relative to him.

They tried that with the Geo-centric model, that is how they concluded that the Earth was not the center of the solar system.
"Wanting Red Rhino Pill to have gender"
Greyparrot
Posts: 14,337
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5/9/2011 1:53:00 PM
Posted: 5 years ago
There no centre of the universe because there is no edge of the universe. In a finite universe, space is curved so that if you could travel billions of light years in a straight line you would eventually finish back where you started. It is also possible that our universe is infinite. In both examples, groups of galaxies completely fill the universe and are moving apart at all points making the universe expand.

Consider an example of a very small universe containing only 48 stars. A spaceship flying among these stars cannot find the edge of this universe. If the ship exits on one side of the universe it reemerges on the other side. The people in the spaceship see an infinite number of stars all around them. This universe has no boundary and no center.
Greyparrot
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5/9/2011 1:58:42 PM
Posted: 5 years ago
At 5/9/2011 11:50:31 AM, OreEle wrote:

Yes there is, for the universe, it is the center of the universe. Whenever we deal with a group, we go with the center of that group. For the physics on Earth, we can look at just the Earth for the center. When we look at the solar system, we have to use the sun as the center. When we look at the galaxy, we have to use the center as the center. This is because, all external forces work on the entire system roughly equally (so they don't mess with the math).


There is no centre of the expansion, the universe is simply expanding at all points. Observers in any galaxy see most of the other galaxies in the universe moving away from them.

The only answer to the question "Where did the Big Bang happen?" is that it occured everywhere in the Universe.
sal
Posts: 319
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5/11/2011 10:05:47 AM
Posted: 5 years ago
At 5/9/2011 11:50:31 AM, OreEle wrote:

Yes there is, for the universe, it is the center of the universe. Whenever we deal with a group, we go with the center of that group. For the physics on Earth, we can look at just the Earth for the center. When we look at the solar system, we have to use the sun as the center. When we look at the galaxy, we have to use the center as the center. This is because, all external forces work on the entire system roughly equally (so they don't mess with the math).

When looking at our solar system, gravity from the rest of the galaxy does effect us, however, it effects every body approximately equally, so if we use a frame reference which is also effected the same, it nets out to zero.

If you use the Earth as your reference window, you cannot calculate the rotation of planets, and the sun, and everything else the same as you would if you used the Sun.

Yes you can if you learn the right type of math.
You can use any reference frame using tensors.
Just because one reference frame has easier formulas doesn't make it superior.


A man standing on a rotating object will feel a force which he can say is gravity. He than has to use the formulas of tensor calculus to derive how all the bodies will move relative to him.

They tried that with the Geo-centric model, that is how they concluded that the Earth was not the center of the solar system.

That was because tensor calculus wan not yet understood.
Skeptical
Posts: 6
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5/15/2011 11:14:06 PM
Posted: 5 years ago
Wow, this thread got a little crazy.

At 5/3/2011 12:01:31 AM, truthseeker613 wrote:
I once read that according to Einstein's theory of relativity or motion that the earth is not nickel revolving around the sun but rather it can be any location is any one fermiliar with this?

I have no idea what you are referring to. The earth's orbit around the sun is elliptical. This was discovered by Newton, IIRC.

Relativity is about speed being relative to the observer - so, one of the consequences is there is no 'absolute' time or 'absolute' present.

In the early 1600's Kepler compared the astronomer Tycho Brahe's observations of the planets to various mathematical models and found that the equation for an ellipse matched up with their orbits. He didn't understand what kept the planets in their orbits, but the laws of planetary motion he developed from this discovery allowed astronomers to accurately predict the positions of the planets.

In the 1680's Newton developed his universal law of gravitation. All objects with mass attract all other objects with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. The universal law of gravitation provides an accurate approximation of the gravitational force between the planets and the sun. This explained the force behind Kepler's laws, but it doesn't actually show how gravity works.

Einstein's theory of general relativity explains that spacetime is 4-dimensional and is curved by whatever mass and radiation are present, showing how gravity is actually 'propagated.' Massive objects like the sun literally bend spacetime. Objects in orbit around the sun (or any other object) are 'falling' around it. Various experiments have shown that this curvature of space really does exist.
http://physicsworld.com...
Teash
Posts: 12
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5/16/2011 11:35:39 PM
Posted: 5 years ago
At this moment I don't believe we can claim where the center of the Universe is. There is no inclination of whether or not the earth orbits the sun. If you wake up in the morning and see the sun you know very well that it will be there the next morning, duh. When you read "duh" make it sound like charlie sheen is saying it in your head. "duh". Yes the Earth most definitely evolves around the sun, if it didn't, we would be a floating ball of darkness unable to survive. DUH!
RoyLatham
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5/27/2011 1:07:51 PM
Posted: 5 years ago
The universe has a center and an edge. The edge is at the distance determined by the speed of light traveling since the Big Bang. No one can get to the edge since that would require traveling faster than the speed of light.

The sun is the center of the solar system because the center of rotation of the solar system is located inside the sun. The Milky Way has a center, similarly defined as the center of rotation. It's often convenient to use the center of mass of an object in calculations.

The deal is that coordinate system defined by any "center" is not preferred by the laws of nature. All of the laws of nature work with respect to any reference frame. The math is simpler in some frames of reference than the others, but the math always works.
Greyparrot
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5/27/2011 7:02:36 PM
Posted: 5 years ago
At 5/27/2011 1:07:51 PM, RoyLatham wrote:
The universe has a center and an edge. The edge is at the distance determined by the speed of light traveling since the Big Bang. No one can get to the edge since that would require traveling faster than the speed of light.

The sun is the center of the solar system because the center of rotation of the solar system is located inside the sun. The Milky Way has a center, similarly defined as the center of rotation. It's often convenient to use the center of mass of an object in calculations.

The deal is that coordinate system defined by any "center" is not preferred by the laws of nature. All of the laws of nature work with respect to any reference frame. The math is simpler in some frames of reference than the others, but the math always works.

Are you aware of the physics required to have a center point of a big bang considering what the universe would have looked like at the time of that event?
Cliff.Stamp
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5/27/2011 7:50:50 PM
Posted: 5 years ago
At 5/27/2011 1:07:51 PM, RoyLatham wrote:

The sun is the center of the solar system because the center of rotation of the solar system is located inside the sun.

Roy,

You have already defined a co-ordinate system to even make that statement. You can easily define a co-ordinate system where the solar system is not rotating at all, or it is is oscillating or even doing the hardcore shuffle. In fact even when statements like "the universe is expanding" are made there is already a co-ordinate system defined and you can define one where it isn't.
RoyLatham
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5/28/2011 12:09:41 AM
Posted: 5 years ago
At 5/27/2011 7:02:36 PM, Greyparrot wrote:
Are you aware of the physics required to have a center point of a big bang considering what the universe would have looked like at the time of that event?

The universe did not exist at the time of the Big Bang. I guess modern theory would say that "our universe" did not exist, although an infinity of other universes existed as part of the multiverse. The theory is that the Big Bang created the matter and energy spontaneously. If one accepts the Big Bang theory, it can from a point, or at least a small volume, that defined the center.
RoyLatham
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5/28/2011 12:18:00 AM
Posted: 5 years ago
At 5/27/2011 7:50:50 PM, Cliff.Stamp wrote:

Roy,

You have already defined a co-ordinate system to even make that statement. You can easily define a co-ordinate system where the solar system is not rotating at all, or it is is oscillating or even doing the hardcore shuffle. In fact even when statements like "the universe is expanding" are made there is already a co-ordinate system defined and you can define one where it isn't.

Of course you can define a coordinate system in an way you want, and all the laws of physics work no matter how the coordinate system is defined. So what's your point? The equations are just easier to manipulate if one makes a good choice of coordinate system.

Does the solar system have a center of mass? How about a bicycle wheel -- does it have a center of mass?
Cliff.Stamp
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5/28/2011 10:18:15 PM
Posted: 5 years ago
At 5/28/2011 12:18:00 AM, RoyLatham wrote:

So what's your point?

The point is the actual question that this thread raised Roy which was that absolute motion characteristics are not a valid concept.

How about a bicycle wheel -- does it have a center of mass?

The co-ordinates of the center of mass of any object are simply co-ordinates, the values of said co-ordinate will obviously depend on the co-ordinate system being used to calculate said values. Now in many problems, it is useful to use CoM as axial intersections, and thus you simply define a co-ordinate system where the CoM is just 0,0,0. This again however has no absolute nature, you could just as easily defined the co-ordinate system where it was (-1,PI,e^2). The fact is Roy even the nature of a wheel as a wheel assumes a particular co-ordinate system, you can define one where the wheel is no longer even round. You can define one for example where the wheel is actually two parallel lines. Again, the point of the OP was to explore the nature of absolute statements regarding motion.
RoyLatham
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5/29/2011 11:28:14 AM
Posted: 5 years ago
The original question was, "Is the earth revolving around the sun?" The answer is, "Yes, because the Sun contains the center of mass of the solar system." A second part of the question was, "Does the Theory of Relativity change that?" The answer to that is, "No, the Theory of Relativity just says that the laws of nature can be applied independent of the coordinate system selected."

By contrast, for example, in a binary star system the stars revolve around a poin in space between them. Neither star is the center.

You seemingly could not bring yourself to say that the center of mass is a unique and well defined point, and not arbitrary. It is.
Cliff.Stamp
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5/31/2011 5:42:48 PM
Posted: 5 years ago
At 5/29/2011 11:28:14 AM, RoyLatham wrote:
The original question was, "Is the earth revolving around the sun?" The answer is, "Yes, because the Sun contains the center of mass of the solar system."

Roy do you think there is a big band around the solar system which constrains it to be some absolute dimensional body?

It is a completely arbitrary spacial distinction and anyone is free to define another one and corresponding co-ordinate system where any other motion they wish to observe is present including one where the earth is stationary, oscillates in place or spins backwards and fowards to the tune of Fridays.

By contrast, for example, in a binary star system the stars revolve around a poin in space between them. Neither star is the center.

In a particular co-ordinate system.

You seemingly could not bring yourself to say that the center of mass is a unique and well defined point, and not arbitrary. It is.

In a particular coordinate system.
RoyLatham
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6/1/2011 12:52:42 AM
Posted: 5 years ago
At 5/31/2011 5:42:48 PM, Cliff.Stamp wrote:
At 5/29/2011 11:28:14 AM, RoyLatham wrote:
The original question was, "Is the earth revolving around the sun?" The answer is, "Yes, because the Sun contains the center of mass of the solar system."

Roy do you think there is a big band around the solar system which constrains it to be some absolute dimensional body?

What is "an absolute dimensional body"? If you mean the size of the largest excursion of objects in the solar system, then that is not constrained. Comets may be in large orbits for example. That is of no relevance.

Areyou claiming that the location of the center of mass of the solar system, or any other object, is arbitrary? I claim the center of mass is a point independent of the coordinate system choice. It's a physical property, not a property of the coordinate system.

It is a completely arbitrary spacial distinction and anyone is free to define another one and corresponding co-ordinate system where any other motion they wish to observe is present including one where the earth is stationary, oscillates in place or spins backwards and fowards to the tune of Fridays.

So, you are saying the location of the center of mass is arbitrary?

By contrast, for example, in a binary star system the stars revolve around a poin in space between them. Neither star is the center.

In a particular co-ordinate system.

Ah, you're saying the location of the center of mass depends upon the arbitrary selection of coordinate system, right?

You seemingly could not bring yourself to say that the center of mass is a unique and well defined point, and not arbitrary. It is.

In a particular coordinate system.

So, would you like to affirm, "The location of the center of mass of an object depends upon the coordinate system selected for the calculation"? The location is the physical point in space. For example, you claim that whether the center of mass of the solar system is inside the sun or not depends upon the selection of the coordinate system, right? That would contradict all the engineering and physics textbooks.
Cliff.Stamp
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6/3/2011 12:02:06 PM
Posted: 5 years ago
At 6/1/2011 12:52:42 AM, RoyLatham wrote:

That would contradict all the engineering and physics textbooks.

No it would not, assuming you are reading something beyond the highschool level which allows for non-galilean transformations and clearly define what it means to be transformation invariant. This is trivial to demonstrate :

A) Take the 2D unit circle centered on 0,0 in the cartesian co-ordinate system R.

B) Take R' to be the co-ordinate system which has the following translation;x'=1/(x+ct) for all x>0, x'=x for all x<0, y'=y for all y. Use natural units where the speed of light (c) equals 1.

Now two questions :

1) what are the co-ordinate of the center of mass in R and R'.

2) what is the shape of the object in R'.

3) what are the co-ordinates of the center of mass in R' as t -> inf.

In regards to the solar system, the point is that you picked an arbitrary spacial bound, picked an arbitrary co-ordinate system and then described a motion. This motion is completely arbitrary by definition.
Justin_Chains
Posts: 623
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6/3/2011 4:50:05 PM
Posted: 5 years ago
At 6/3/2011 12:02:06 PM, Cliff.Stamp wrote:
At 6/1/2011 12:52:42 AM, RoyLatham wrote:

That would contradict all the engineering and physics textbooks.

No it would not, assuming you are reading something beyond the highschool level which allows for non-galilean transformations and clearly define what it means to be transformation invariant. This is trivial to demonstrate :

A) Take the 2D unit circle centered on 0,0 in the cartesian co-ordinate system R.

B) Take R' to be the co-ordinate system which has the following translation;x'=1/(x+ct) for all x>0, x'=x for all x<0, y'=y for all y. Use natural units where the speed of light (c) equals 1.

Now two questions :

1) what are the co-ordinate of the center of mass in R and R'.

2) what is the shape of the object in R'.

3) what are the co-ordinates of the center of mass in R' as t -> inf.

In regards to the solar system, the point is that you picked an arbitrary spacial bound, picked an arbitrary co-ordinate system and then described a motion. This motion is completely arbitrary by definition.

Perception is the key to understanding the answers to all of your questions. Gain the correct perception and your questions are answered without error.

Motion is one of the 3 aspects of the absolute.

Motion; Duration; Abstract Space; the 3 aspects of the absolute.

Motion is an aspect of the absolute, everything has the aspect of motion at all times.
Ogan
Posts: 407
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6/4/2011 8:26:30 AM
Posted: 5 years ago
Every sphere, be it microcosmic or macrocosmic, revolves upon it own axis around an invisible mathematical Point. God is everywhere of the circle whose Centre is everywhere and its Circumference nowhere.