Geocentrism 101, Part II: Basic Physics

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Mark,

Since this is being posted on a blog, let me make a couple of technical notes. I’m not trying to pick this apart, and I apologize if it looks like I am; what I am trying to do is point out some minor inaccuracies so that you can remove them and strengthen the presentation as a whole.
  1. The more common term is “coordinate transformation” rather than “coordinate transform.” A “transform” is usually something different–like a change from the time domain to the frequency domain in a Fourier transform.
  2. I had not heard of Pioneer 10 giving any results that differed from Newtonian gravity by 60 percent. Do you have a reference?
  3. Einstein’s general relativity theory actually states that massive objects distort the spacetime around them, not just the space. A neighboring body, as it travels through spacetime, follows a geodesic–the equivalent of a straight line on the curved “surface” and the curvature of this geodesic is the “gravitational attraction.” There is no need for a separate “rolling downhill;” what is happening is more like coasting through space-time.
  4. In the paragraph after the quote from Gron and Erikson, you say that “This is true from the perspective of a coordinate system fixed say on the north pole of the earth and rotating with the earth. In this case the cosmic masses are not rotating.” This is not so; if the coordinate system is “rotating with the earth”, then relative to that coordinate system the cosmos is indeed rotating.
I’ll deal with my substantive objections in another post.
  • Liberian
 
Mark,

I have read through your blog on “Geocentricism 101, Part II” and still have some areas of disagreement with it. Please bear with me as I try to explain them.

The first is the idea that a rotating coordinate system is as good (or as simple) as a non-rotating coordinate system. In a rotating coordinate system–by which I mean a coordinate system in which the “cosmos as a whole” rotates, you have to add the centripetal and Coriolis terms to the equations of motion. I call these terms fictitious forces; you call them the effect of the distant cosmos. Either way, they are in the equations, and either way, the equations of motion in a non-rotating coordinate system do not need them. So no matter what Einstein may have said, I submit to you that the universe does indeed have a preferred type of coordinate system to the extent that it should be non-rotating and non-accelerating. Regarding the position and (constant) velocity of its center, there is no preference, as Einstein correctly stated.

My second objection remains, what constitutes the earth? Just because something is undetectable does not mean that it does not exist. And to be a robust scientific theory, geocentricism needs to be able to handle realistic “what-if” scenarios–like “what if an asteroid the size of the planet Mars collided with the earth.” In that case, the effect on the rest of the universe would be very detectable.

Non-geocentric theories do not have this problem because they are not specifying that the earth must remain stationary. In an acentric theory, each atom that constitutes the earth moves along its own geodesic, affected by its collisions with its neighboring atoms and perhaps influenced by such things as electromagnetic fields. There is no statement similar to “the earth stands still,” and so the question of “what constitutes the earth” is not raised.

In the same way, the question of one part of the earth moving relative to another part of the earth is still unresolved in geocentric theory and is irrelevant to acentric theory. And these relative motions of the different parts of the earth are not only detectable, they have been measured.
  • Liberian
 
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Liberian:
Mark,

Since this is being posted on a blog, let me make a couple of technical notes. I’m not trying to pick this apart, and I apologize if it looks like I am; what I am trying to do is point out some minor inaccuracies so that you can remove them and strengthen the presentation as a whole.
  1. The more common term is “coordinate transformation” rather than “coordinate transform.” A “transform” is usually something different–like a change from the time domain to the frequency domain in a Fourier transform.
  2. I had not heard of Pioneer 10 giving any results that differed from Newtonian gravity by 60 percent. Do you have a reference?
  3. Einstein’s general relativity theory actually states that massive objects distort the spacetime around them, not just the space. A neighboring body, as it travels through spacetime, follows a geodesic–the equivalent of a straight line on the curved “surface” and the curvature of this geodesic is the “gravitational attraction.” There is no need for a separate “rolling downhill;” what is happening is more like coasting through space-time.
  4. In the paragraph after the quote from Gron and Erikson, you say that “This is true from the perspective of a coordinate system fixed say on the north pole of the earth and rotating with the earth. In this case the cosmic masses are not rotating.” This is not so; if the coordinate system is “rotating with the earth”, then relative to that coordinate system the cosmos is indeed rotating.
I’ll deal with my substantive objections in another post.
  • Liberian
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  1. This is true. I am thinking of the verb “to tranform a coordinate system” and just reversing it.
  2. I calculated the acceleration field from the sun at 45 AU, and this was 36% (round to 40%) of the anamoly, i.e., 60% difference. The anomoly is actually 2X the predicted acceleration!
  3. I meant to say space-time. I believe this is the term I use elsewhere.
  4. It should read “…fixed to the north pole with the earth rotating around it (or below it)”, i.e. approximately static space (ignoring the orbit).
Thanks for the proofread and comments.

Mark
www.veritas-catholic.blogspot.com
 
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Liberian:
Mark,

I have read through your blog on “Geocentricism 101, Part II” and still have some areas of disagreement with it. Please bear with me as I try to explain them.

The first is the idea that a rotating coordinate system is as good (or as simple) as a non-rotating coordinate system. In a rotating coordinate system–by which I mean a coordinate system in which the “cosmos as a whole” rotates, you have to add the centripetal and Coriolis terms to the equations of motion. I call these terms fictitious forces; you call them the effect of the distant cosmos. Either way, they are in the equations, and either way, the equations of motion in a non-rotating coordinate system do not need them. So no matter what Einstein may have said, I submit to you that the universe does indeed have a preferred type of coordinate system to the extent that it should be non-rotating and non-accelerating. Regarding the position and (constant) velocity of its center, there is no preference, as Einstein correctly stated.
Click to expand...
Let’s not mix up ideas.

“There are no preferred reference frames” means that one can choose any center. It has nothing to with, nor does it matter whether the coordinate system is rotating or not. This is a principle of GR.

Of course, if you are the guy who has to do the math, you will personally *prefer *a non-rotating frame. The math is easier. But this is not what is meant by preferred in “There are no preferred reference frames”. A rotating reference frame is just as valid as a non-rotating one. Inertial frames are easier to deal with, but not more valid.
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Liberian:
My second objection remains, what constitutes the earth? Just because something is undetectable does not mean that it does not exist. And to be a robust scientific theory, geocentricism needs to be able to handle realistic “what-if” scenarios–like “what if an asteroid the size of the planet Mars collided with the earth.” In that case, the effect on the rest of the universe would be very detectable.

Non-geocentric theories do not have this problem because they are not specifying that the earth must remain stationary. In an acentric theory, each atom that constitutes the earth moves along its own geodesic, affected by its collisions with its neighboring atoms and perhaps influenced by such things as electromagnetic fields. There is no statement similar to “the earth stands still,” and so the question of “what constitutes the earth” is not raised.

In the same way, the question of one part of the earth moving relative to another part of the earth is still unresolved in geocentric theory and is irrelevant to acentric theory. And these relative motions of the different parts of the earth are not only detectable, they have been measured.
  • Liberian
Click to expand...
Geocentric theory does not state that the earth cannot move. This is a principle upon which the theory is built, but in the case of the specific theories I talked about, the earth remaining stationary is a consequence of the universe doing everything in its power to maintain the stability of its center. And God happened to place the earth in that center. Now the Providence of God could be seen as part of keeping the earth in the center. If an object the size of the sun hit the earth at great relative velocity, the earth may no longer be in the center, and the universe will strive to maintain whatever is in the center stable.

Small things like asteroids hitting the earth, volcanic eruptions, earthquakes are no problem for the universe to absorb. Just like a 10 pound top perturbed momentaritly by a gnat, the universe will gyroscopically maintain its center.

Mark
www.veritas-catholic.blogspot.com
 
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Liberian:
Mark,

…
2. I had not heard of Pioneer 10 giving any results that differed from Newtonian gravity by 60 percent. Do you have a reference?

…
  • Liberian
Click to expand...
I have removed the statement. I checked my math, and was incorrect. The anomolous acceleration is more like 0.03% of the predicted- pretty small.

I accept your point that I need to be more careful before I post something.

Mark
www.veritas-catholic.blogspot.com
 
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trth_skr:
Let’s not mix up ideas.

“There are no preferred reference frames” means that one can choose any center. It has nothing to with, nor does it matter whether the coordinate system is rotating or not. This is a principle of GR.

Of course, if you are the guy who has to do the math, you will personally *prefer *a non-rotating frame. The math is easier. But this is not what is meant by preferred in “There are no preferred reference frames”. A rotating reference frame is just as valid as a non-rotating one. Inertial frames are easier to deal with, but not more valid.
Click to expand...
Mark,

I think you just put your finger on the reason for my preference: usually, when all is said and done, I’m the guy who has to do the math–if not in geocentricity problems, at least in other dynamics problems. I am straying from science into the philosophy of science, in which the simpler theory is to be preferred over the more complicated one. In this case, “simpler” means for me that it gives equations with fewer terms.
Geocentric theory does not state that the earth cannot move. This is a principle upon which the theory is built, but in the case of the specific theories I talked about, the earth remaining stationary is a consequence of the universe doing everything in its power to maintain the stability of its center.%between%
Click to expand...
Ahhh, I see. You are right, this is a completely different concept from the one that I was criticizing. If I understand you correctly, it’s not that the earth is stationary at the center of the universe, it’s that the earth is in a stable equilibrium at the center of the universe–that it is stable to (at least) a small perturbation. I will have to go back and dig through the equations all over again.
  • Liberian
 
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Liberian:
Mark,

I think you just put your finger on the reason for my preference: usually, when all is said and done, I’m the guy who has to do the math–if not in geocentricity problems, at least in other dynamics problems. I am straying from science into the philosophy of science, in which the simpler theory is to be preferred over the more complicated one. In this case, “simpler” means for me that it gives equations with fewer terms.
Click to expand...
Sure, in practical terms this is the case. But this does not speak to the possible reality of the earth being in the center.
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Liberian:
Ahhh, I see. You are right, this is a completely different concept from the one that I was criticizing. If I understand you correctly, it’s not that the earth is stationary at the center of the universe, it’s that the earth is in a stable equilibrium at the center of the universe–that it is stable to (at least) a small perturbation. I will have to go back and dig through the equations all over again.
  • Liberian
Click to expand...
Bingo! Even more to the point, the universe gyroscopically stabilizes its center and [as long as] the earth is in the center [it is] being stabilized by the universe. And it (the center, the earth) is stabilized by the universe to a pertubation ( up to some undetermined degree).

Mark
www.veritas-catholic.blogspot.com
 
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