[Halc]

If so, please advise them to look for a real theory of creation as Theory-D.

Your idea doesn't attempt to explain creation.  It starts out with something already there, just like the BBT.  Unlike the BBT, it violates many laws of physics from that initial state.

[Dave Lev (OP)]

The part that you quoted is about a "solid sphere of uniform density" not a "hollow sphere". Gravity varies linearly from the center of a solid sphere, whereas there is no net force at all inside of a hollow sphere.

I have just read the article which you have offered:

Shell theorem is normally used to describe gravity, but it should work here too because radiation intensity falls off at the exact same rate as gravitational strength does (the inverse square law): https://en.wikipedia.org/wiki/Shell_theorem

In the article they show clearly that from inside the sphere each point get's different force:
"The magnitude of the gravitational field that would pull a particle at point P in the x direction is the gravitational field multiplied by cos(theta) where theta is the angle adjacent to the x axis.  In this case, cos(theta)=p/sqrt(p^2+R^2)"
If we:
"Integrating the field due to each thin disc from x=-a to x=+a with respect to x, and after careful algebra, beautifully yields Newton's shell theorem."
Hence, by setting the integration on all of those different forces at different locations we get that Newton's shell theorem.
However, we are dealing with the different forces at different locations:
You actually claim that we can compare the gravity forces to radiation:"radiation intensity falls off at the exact same rate as gravitational strength does (the inverse square law)"
So, it is very clear that we should get different radiation if we won't stay at the center of this finite Universe "shell".
If you think differently - please prove it.

I can think of models where there is an edge and we are right at it, and the CMB still isotropic.

Is it real???
If we stay at the far edge of the Universe, while we see half of the sky full with galaxies and the other half without even one star, how can we still get that isotropic radiation?
I really can't understand why do you insist to claim that there is no meaning for that isotropic radiation?
I can also think on a model which proves that 1+1=0.
We can always band the reality.
But, what is our benefit with that?
Why do you totally reject the idea that the Universe is/could be infinite?
Why are you both so afraid from infinite Universe?
What is the big disaster if our Universe is Infinite?

[Kryptid]

In the article they show clearly that from inside the sphere each point get's different force:
"The magnitude of the gravitational field that would pull a particle at point P in the x direction is the gravitational field multiplied by cos(theta) where theta is the angle adjacent to the x axis.  In this case, cos(theta)=p/sqrt(p^2+R^2)"
If we:
"Integrating the field due to each thin disc from x=-a to x=+a with respect to x, and after careful algebra, beautifully yields Newton's shell theorem."
Hence, by setting the integration on all of those different forces at different locations we get that Newton's shell theorem.
However, we are dealing with the different forces at different locations:
You actually claim that we can compare the gravity forces to radiation:"radiation intensity falls off at the exact same rate as gravitational strength does (the inverse square law)"
So, it is very clear that we should get different radiation if we won't stay at the center of this finite Universe "shell".
If you think differently - please prove it.

You are still making reference to a solid sphere, not a hollow shell. If you go to the part that says "Inside a shell", then you will see what I am talking about. To quote the article, "the net gravitational forces acting on the point mass from the mass elements of the shell, outside the measurement point, cancel out."

This video reveals the same thing. Skip to 1:35 :

To quote the narrator, "So now, we have the second part of Newton's shell theorem. It states that a homogeneous spherically symmetric shell exerts no gravitational force on objects within the shell."

[Dave Lev (OP)]

To quote the narrator, "So now, we have the second part of Newton's shell theorem. It states that a homogeneous spherically symmetric shell exerts no gravitational force on objects within the shell."

Sure, I fully agree with that.
However, all it says that the sum of all the forces from all the directions is zero.
But they don't say that the forces from all the directions are the same.
They say that one direction cancel the force from the opposite direction.
So, if we take one line (left/right) we should find that the force from the left side cancel the force from the right side.
If we take another line (up/down), we should find that the force from upwards cancel the force from downwards.
However, they didn't say that the forces from Left/right are equal with the forces from up/down.
So, do you agree that there is no prove for isotropic forces in this example?
However, we discuss on isotropic radiation/forces from all directions.
Can you please prove that the gravity isn't isotropic?

If no, do you agree that at any size of finite universe with spherically symmetric shell there is no way to get isotropic radiation unless we are located at the center?
Therefore, as the chance to be at the center is virtually zero, do you finally accept the idea that our universe must be infinite in order to get that kind of isotropic CMB radiation?

[Halc]

I can think of models where there is an edge and we are right at it, and the CMB still isotropic.

Is it real???

No idea what you're asking here.  Yes, I gave an example of exactly such a model.  You edited it away.

If we stay at the far edge of the Universe, while we see half of the sky full with galaxies

That's a different model.  With the one I gave, we'd see isotropy on all sides, and that means you'd see galaxies in every direction.  That's what isotropy means.

Why do you totally reject the idea that the Universe is/could be infinite?

Where did I say this?

[Kryptid]

However, all it says that the sum of all the forces from all the directions is zero.
But they don't say that the forces from all the directions are the same.

That is exactly what it means. If the force from any one direction was greater than the force from another direction, then there would be a net force in one direction and thus shell theorem would be wrong.

So, if we take one line (left/right) we should find that the force from the left side cancel the force from the right side.
If we take another line (up/down), we should find that the force from upwards cancel the force from downwards.
However, they didn't say that the forces from Left/right are equal with the forces from up/down.

The forces from the left and right direction are zero and the forces from the up and down direction are zero. Zero is equal to zero, so they are equal.

[Dave Lev (OP)]

The forces from the left and right direction are zero and the forces from the up and down direction are zero. Zero is equal to zero, so they are equal.

Sure.
But the forces from left/right are not equal to the up down directions.
For example
If the gravity force form the left is F1 than the force from right must be also F1 (at the opposite direction)
However, the force from up could be F2 which is different from F1. However the force from down must be F2 in order to cancel the force from up.
So, if you add all the forces you get Zero.
But it is clear that from any direction we could get different forces.
Therefore, the forces are not isotropic.
Is it clear to you by now?

[Halc]

So, if we take one line (left/right) we should find that the force from the left side cancel the force from the right side.
If we take another line (up/down), we should find that the force from upwards cancel the force from downwards.
However, they didn't say that the forces from Left/right are equal with the forces from up/down.
So, do you agree that there is no prove for isotropic forces in this example?

I understand what you're asking.  Cancelling forces (net zero) does not imply isotropy.  It wasn't the purpose of the example to demonstrate isotropy.  But the same mathematics of the shell theorem can be used to demonstrate that the force/radiation is isotropic inside a shell, and you'd realize that if you understood how the proof works and didn't just focus on the words used in the conclusion.

[Dave Lev (OP)]

I understand what you're asking.  Cancelling forces (net zero) does not imply isotropy.  It wasn't the purpose of the example to demonstrate isotropy.  But the same mathematics of the shell theorem can be used to demonstrate that the force/radiation is isotropic inside a shell, and you'd realize that if you understood how the proof works and didn't just focus on the words used in the conclusion.

So, what do you want to say by that?
I hope that you accept my approval by Newton's shell theorem that our universe must be infinite in order to get that kind of isotropic CMB radiation.

Why do you totally reject the idea that the Universe is/could be infinite?

Where did I say this?

If you accept the idea that the universe is/could be infinite, then why do you continue to disapprove this idea?
What do you gain with that?

[Kryptid]

But the forces from left/right are not equal to the up down directions.

They have to be equal because you already posited a spherical Universe. There is nothing to cause the radiation coming from above you or below you to have a different intensity than the radiation coming at you from the sides.

If they weren't equal, then the microwave background would not look isotropic from any point in the Universe, not even in the middle. If the radiation coming from above you and below you was brighter than the radiation coming from your sides, this would be detectable anywhere. The fact that the radiation is observed to be isotropic means that this is not the case.

A hyperspherical universe or Big Bang universe would also explain an isotropic microwave background without having to rely on anything infinite in size. So your argument still does not work as proof.

[Halc]

the same mathematics of the shell theorem can be used to demonstrate that the force/radiation is isotropic inside a shell, and you'd realize that if you understood how the proof works and didn't just focus on the words used in the conclusion.

So, what do you want to say by that?

You seemed to ask if the shell theorem can be used to show that a shell of uniform radiation would be isotropic from anywhere inside the shell, so I answered that.

Why do you totally reject the idea that the Universe is/could be infinite?

Where did I say this?

If you accept the idea that the universe is/could be infinite, then why do you continue to disapprove this idea?

Please quote one place where I (or Kryptid) deny that the universe could be infinite.  I'm simply denying that it must be, as you assert.

[Dave Lev (OP)]

Please quote one place where I (or Kryptid) deny that the universe could be infinite.  I'm simply denying that it must be, as you assert.

So, you still do not want to accept the idea that the Universe IS INFINITE.
You prefer to set it under "Could be" infinite, (or: "We don't know"?).
Sorry, you must know the clear answer.
Is it infinite or not?
"Could be" is nice first step but it's not good enough
I have proved that in order to get isotropic CMB radiation the universe MUST BE infinite.
If you are still denying that it "must be" infinite, then please prove it.
Please show why in a finite Universe we can still get isotropic CMB radiation - based on "shell theorem" (and only on shell theorem theory)" .
If you can't do so, would you kindly and finally write clearly that you agree that the Universe IS/MUST BE infinite!

[Halc]

So, you still do not want to accept the idea that the Universe IS INFINITE.
You prefer to set it under "Could be" infinite, (or: "We don't know"?).

I have no choice.  There is as of yet no conclusive way to falsify one or the other idea.  The CMB thing doesn't work because there are very viable finite models (the hypersphere one in particular) with perfect isotropy.

I have proved that in order to get isotropic CMB radiation the universe MUST BE infinite.

You did no such thing.  As I said, the valid finite models predict isotropy, so the observed CMB is exactly as predicted.
Your model on the other hand (besides being a violation of several principles) doesn't predict one.  If the universe started out at one place (instead of everywhere) and spread out from there, it would be finite size after finite time (due to light speed limitation) and probably wouldn't have a CMB at all.

If you are still denying that it "must be" infinite, then please prove it.

We did. We showed a model that is finite and matches observations.  That counterexample proves that a non-infinite universe is a possibility.

Please show why in a finite Universe we can still get isotropic CMB radiation - based on "shell theorem" (and only on shell theorem theory)" .

I'll let Kryptid do that.  He brought it up.  The hypersphere model is isotropic due to symmetry and the shell theorem isn't a part of the argument.

[Dave Lev (OP)]

Your model on the other hand (besides being a violation of several principles) doesn't predict one.  If the universe started out at one place (instead of everywhere) and spread out from there, it would be finite size after finite time (due to light speed limitation) and probably wouldn't have a CMB at all.

My modeling/theory or any other theory (including the BBT) isn't relevant to the shape of the real Universe.
Somehow, it seems to me that you try to band the evidences in order to meet your BBT theory.
I don't think that I have more wisdom than any average scientist.
Therefore, it is quite clear to me that based on that discovery any scientist will agree that the universe must be infinite.
But you don't want to accept it as it might contradict the BBT theory.
Therefore, you prefer to set it under "could be" and look for some unrealistic modeling which proves the opposite.

Please be aware that the black body radiation in the CMB is also a clear indication for Infinity Universe.
However, I assume that any evidence that contradicts the wishful list should be rejected.
Therefore, I hope that I will not have to discuss about the black body radiation as the isotropic idea will be good enough to prove that our Universe is infinite.

I'll let Kryptid do that.  He brought it up.  The hypersphere model is isotropic due to symmetry and the shell theorem isn't a part of the argument.

Why do you claim that: "the shell theorem isn't a part of the argument."?
How can reject that kind of important law? (Is it just because it doesn't meet the requested wishful list?)

So, yes please.
Although Kryptid is in your side, I have full confidence that he will answer based on "shell theorem" real evidence and not based on wishful list.
So, I'm waiting for Kryptid to let us know if there is a possibility to get isotropic radiation at a finite Universe (at any size and at any location in the Universe) under the "shell theorem" theory

[Halc]

However, I assume that any evidence that contradicts the wishful list should be rejected.

Yes, I notice that you do that. It is very unscientific.

The hypersphere model is isotropic due to symmetry and the shell theorem isn't a part of the argument.

Why do you claim that: "the shell theorem isn't a part of the argument."?

Because 'due to symmentry' is 3 words and makes no reference to a shell theorem.  It doesn't mean I deny all theorems that are similarly unmentioned. I didn't use the pythagorean theorem either. 'Theorem' means that it has been proved, unlike a 'theory' that has been empirically tested.

So, I'm waiting for Kryptid to let us know if there is a possibility to get isotropic radiation at a finite Universe

Why?  I already did.  I showed a finite model with equal material and density on all sides from any point, and thus predicts isotropy. As usual, you totally reject this because it contradicts your wishful list, exactly as you say should be done above.
If you wish, you can complicate the description by dividing the universe into shells and then applying the shell theorem. That works fine with that model, but it is a needless complication from the 'due to symmentry' approach.

[Kryptid]

So, I'm waiting for Kryptid to let us know if there is a possibility to get isotropic radiation at a finite Universe (at any size and at any location in the Universe) under the "shell theorem" theory

I already did:

They have to be equal because you already posited a spherical Universe. There is nothing to cause the radiation coming from above you or below you to have a different intensity than the radiation coming at you from the sides.

If they weren't equal, then the microwave background would not look isotropic from any point in the Universe, not even in the middle. If the radiation coming from above you and below you was brighter than the radiation coming from your sides, this would be detectable anywhere. The fact that the radiation is observed to be isotropic means that this is not the case.

[Dave Lev (OP)]

They have to be equal because you already posited a spherical Universe. There is nothing to cause the radiation coming from above you or below you to have a different intensity than the radiation coming at you from the sides.

I disagree with you
We see clearly that the net forces are based on distances
So, if we are located at the center we have exactly the same distance to all directions.
In this case, it is clear that the forces are fully isotropic.
However, once we move from the center, there is no balance between the Up/Down distance to the Left/right distance. Therefore, it is clear that for one we might get F1 force while from the other line we can get F2.
So, I really can't understand why you insist on isotropic forces at the shell theorem.

If they weren't equal, then the microwave background would not look isotropic from any point in the Universe, not even in the middle. If the radiation coming from above you and below you was brighter than the radiation coming from your sides, this would be detectable anywhere. The fact that the radiation is observed to be isotropic means that this is not the case.

I agree with you.
They have to be equal. But that could be only if our universe is infinite or we are located at the center.
 
However, I'm not going to argue about it anymore.
Let's move to the radiation spectrum.
Our scientists have found that the CMB has the most perfect blackbody spectrum in nature ever observed.
They have also calculated a redshift of 1100 in the CMB.
Therefore, I wonder how could it be that we get the same spectrum and the same redshift from all directions while in one side we are closer to the edge (or even right at the edge) of the Universe while in the other side we are far away?
So, how do we get the same CMB spectrum, same black body radiation and the same redshift from all directions as we get closer to one edge of the finite Universe?

[Kryptid]

We see clearly that the net forces are based on distances

It isn't based only on distance, but also on the amount of mass present at those differing distances. It is the finding of shell theorem that those two factors always perfectly balance each other out inside of a uniform, spherical shell such that the forces in all directions always add up to zero. I don't know why this is so hard for you to understand.

Therefore, it is clear that for one we might get F1 force while from the other line we can get F2.

I addressed that right here:

If they weren't equal, then the microwave background would not look isotropic from any point in the Universe, not even in the middle. If the radiation coming from above you and below you was brighter than the radiation coming from your sides, this would be detectable anywhere. The fact that the radiation is observed to be isotropic means that this is not the case.

So, how do we get the same CMB spectrum, same black body radiation and the same redshift from all directions as we get closer to one edge of the finite Universe?

Space expanding in all directions would cause an equal redshift at all locations in the Universe.

[Dave Lev (OP)]

Space expanding in all directions would cause an equal redshift at all locations in the Universe.

https://en.wikipedia.org/wiki/Expansion_of_the_universe
"the expansion rate of the universe has been measured to be H0 = 73.24 ± 1.74 (km/s)/Mpc.[14] This means that for every million parsecs of distance from the observer, the light received from that distance is cosmologically redshifted by about 73 kilometres per second (160,000 mph)."
We see clearly that the local impact of the expansion is very minimal.
Hence:
1. If our distance to the near edge is R1 and the distance to the far edge is 1000R1, do you agree that the expansion impact of 1000R1 should be higher than R1 by 1000? If so, how could it be that we should get the same redshift in both directions?
2. If we are located only one Mpc from the edge, then the impact of the expansion is only 73Km/s. How that speed can set a redshift of 1100?

[Halc]

We see clearly that the local impact of the expansion is very minimal.
Hence:
1. If our distance to the near edge is R1 and the distance to the far edge is 1000R1, do you agree that the expansion impact of 1000R1 should be higher than R1 by 1000? If so, how could it be that we should get the same redshift in both directions?

The CMB is equidistant in all directions.  It is a shell centered on us.  Any CMB light that originated closer by has already passed by us.  Any further out hasn't got here yet.  Therefore the distance to the edge, in a model that has an edge at all, has zero effect on what is seen.

2. If we are located only one Mpc from the edge, then the impact of the expansion is only 73Km/s. How that speed can set a redshift of 1100?

1100 is approximately the ratio of the temperature at the decoupling event and what we measure from this distance, which has nothing to do with things one Mpc away now.  If we're currently one Mpc from 'the edge', then material at the edge would be moving away from us at 73Km/s.  What we see in such a model depends very much on the model.  The model I described in post 378 would result in no detectable anomaly in any direction regardless of how close we were to the edge.  That's a pretty far fetched model, but so is yours.  The hypersphere model doesn't have an edge.  The eternal inflation model has an edge under certain foliations, but no observer can be near it because the universe is too young there.  The latter two models are both viable finite universe models that predict CMB isotrophy.  The post-378 one predicts it as well, but it isn't a very viable model.  It asserts that there is a preferred location in space and we're not at that location.