[alancalverd]

Current physics thinks that via gravity potential energy which is set at infinity in a 0 gravity field.

Not as practised by current physicists.  We say that gravitational potential is zero in deep space and negative at any point in a nonzero gravitational field.

I've quoted my old navigation instructor many times in this forum, but once more won't hurt. In the immortal words of Charlie Kovac "always start from where you are, then you won't get lost before you take off".

[PmbPhy]

Pete - Then how can it be said that the frequency and therefore energy of a caesium atomic clock in a differing gravity potential is observer dependent?

There's nothing wrong with what I explained. I was describing the answer in terms of non-relativistic mechanics. You're speaking of general relativity. Atoms absorb and emit energy in the form of photons. In that sense they behave like ideal clocks. In GR the frequency measured by the observer of the clock depends on the difference of the gravitational potential where the clock is located and where the observer is located. What I explained above is sometimes explained (e.g. in Gravitation by Misner, Thorne and Wheeler as well  as Nightingale and Foster) in terms of the energy of a photon, its energy being all kinetic. As the photon climbs out of the g-field its kinetic energy decreases and its potential energy increases, the sum being constant.

For the derivation see: http://www.newenglandphysics.org/physics_world/gr/grav_red_shift.htm

[PmbPhy]

Current physics thinks that via gravity potential energy which is set at infinity in a 0 gravity field.

Not as practised by current physicists.  We say that gravitational potential is zero in deep space and negative at any point in a nonzero gravitational field.

I've quoted my old navigation instructor many times in this forum, but once more won't hurt. In the immortal words of Charlie Kovac "always start from where you are, then you won't get lost before you take off".

There are certain problems used as exercises where one sets the zero at an arbitrary location since in those problems the g-field doesn't go to zero at infinity. E.g. a infinitely long rod.

[timey]

Current physics thinks that via gravity potential energy which is set at infinity in a 0 gravity field.

Not as practised by current physicists.  We say that gravitational potential is zero in deep space and negative at any point in a nonzero gravitational field.

I've quoted my old navigation instructor many times in this forum, but once more won't hurt. In the immortal words of Charlie Kovac "always start from where you are, then you won't get lost before you take off".

As one gets further away from M, gravity potential increases.

So why do current physicists say that gravity potential is zero in a deep space gravity field?

Zero for what?
For mass in that gravity field?
Or for the gravity field itself?

And if you start out with a negative value from any point in a non zero gravity field for m, this negative value will still escalate, negatively, as kinetic energy escalates positively.

Such a wonderful system, so beautiful and logical, oh - apart from the fact that:

This is the cosmological constant problem, the worst problem of fine-tuning in physics: there is no known natural way to derive the tiny cosmological constant used in cosmology from particle physics.

https://en.m.wikipedia.org/wiki/Cosmological_constant

So - never mind where you are, you can always try the other runway...
It's about where it is you will end up, as well as where you start from.

[timey]

Pete - Then how can it be said that the frequency and therefore energy of a caesium atomic clock in a differing gravity potential is observer dependent?

There's nothing wrong with what I explained. I was describing the answer in terms of non-relativistic mechanics. You're speaking of general relativity. Atoms absorb and emit energy in the form of photons. In that sense they behave like ideal clocks. In GR the frequency measured by the observer of the clock depends on the difference of the gravitational potential where the clock is located and where the observer is located. What I explained above is sometimes explained (e.g. in Gravitation by Misner, Thorne and Wheeler as well  as Nightingale and Foster) in terms of the energy of a photon, its energy being all kinetic. As the photon climbs out of the g-field its kinetic energy decreases and its potential energy increases, the sum being constant.

For the derivation see: http://www.newenglandphysics.org/physics_world/gr/grav_red_shift.htm

I did not say you hadn't described anything correctly.

Yes - if an atom emits a photon in a differing gravity potential, then as an observer observing the photon that has been emitted in the differing gravity potential, one will view the photon as it is when it has 'arrived in' the observation reference frame one is observing from, and not as it was when it was emitted in the differing reference frame.
So yes light is observer dependent...

But the cession atomic clock, although it uses light as part of the clocks apparatus, is making a reading of the light apparatus in its own frame of reference, and it is that reading that is sent to the computer.

If the clock is only ticking faster as an observer dependent phenomenon, (this can also be applied to SR time dilation), then the widely reported (NASA, NIST) and scientifically accepted (?) concept of a person ageing in keeping with their time dilated clock is wrong.

So, as a photon climbs out of a gravity well it's kinetic energy decreases, and it's potential energy increases?

When a caesium atom is ticking at elevation in a higher gravity potential, does it's potential energy also increase?

[PmbPhy]

As one gets further away from M, gravity potential increases.

So why do current physicists say that gravity potential is zero in a deep space gravity field?

Because it starts out being negative when in the field and increases to zero outside the field. The potential for a spherical mass distribution outside the body is U = -GM/r
And if you start out with a negative value from any point in a non zero gravity field for m, this negative value will still escalate, negatively, as kinetic energy escalates positively.

Such a wonderful system, so beautiful and logical, oh - apart from the fact that:

Not trying to be rude whatsoever but it's not the theory that is flawed but your understanding of it. In this case things like the cosmological constant not being derived is no different than the fact that no theory in physics can be derived. They're all arrived at by things such as intuition.

This is the cosmological constant problem, the worst problem of fine-tuning in physics: there is no known natural way to derive the tiny cosmological constant used in cosmology from particle physics.

Fine tuning and the cosmological constant have little to do with each other. And you have no idea whether it can or can't be derived. All that can be said is that it hasn't been derived yet. And if it was the cosmological constant that drove inflation then it was very large at that time. That article was silly for saying that.

[PmbPhy]

I did not say you hadn't described anything correctly.

I didn't say you did. I was merely saying that what I said was correct. However your responses indicate that what I said is in error and that's what I responded to.

Yes - if an atom emits a photon in a differing gravity potential, then as an observer observing the photon that has been emitted in the differing gravity potential, one will view the photon as it is when it has 'arrived in' the observation reference frame one is observing from, and not as it was when it was emitted in the differing reference frame.

Its not clear to me what you mean when you use the term "frame." That term is usually used only in SR, i.e. inertial frames with no spacetime curvature.  one usually speaks in terms of coordinate systems, not frames.

If the clock is only ticking faster as an observer dependent phenomenon, (this can also be applied to SR time dilation), then the widely reported (NASA, NIST) and scientifically accepted (?) concept of a person ageing in keeping with their time dilated clock is wrong.

Not at all. I can't even see how you arrived at that conclusion.

So, as a photon climbs out of a gravity well it's kinetic energy decreases, and it's potential energy increases?

From these responses it appears to me that you didn't follow the derivation in the URL I posted. Is that correct? The reason I created those pages was to address these exact questions. I takes exact math to be precise and that's what I did on that page. I only assumed the reader knows basic algebra and physics.

If you'd prefer a textbook then read section 4.3 in A Short Course in General Relativity by James Foster,  J. D. Nightingale.
You can download the text from - http://bookzz.org/book/681818/a5c827

Note: When I spoke of the kinetic energy of a photon/light it refers to the "intrinsic" energy of the light, i.e. as measured at the same location as the light. If one uses the frequency as reckoned from one location only then you should know that such a frequency doesn't change. Eg the frequency of light as it moves through a gravitational field does not change as reckoned by a Schwarzschild observer, i.e. an observer far away from the body.

When a caesium atom is ticking at elevation in a higher gravity potential, does it's potential energy also increase?

That depends on the nature of the field that you're talking about. E.g. if the field is uniform then the potential energy increases without bound as one goes higher and higher in the field.

[timey]

As one gets further away from M, gravity potential increases.

So why do current physicists say that gravity potential is zero in a deep space gravity field?

Because it starts out being negative when in the field and increases to zero outside the field. The potential for a spherical mass distribution outside the body is U = -GM/r
And if you start out with a negative value from any point in a non zero gravity field for m, this negative value will still escalate, negatively, as kinetic energy escalates positively.

Such a wonderful system, so beautiful and logical, oh - apart from the fact that:

Not trying to be rude whatsoever but it's not the theory that is flawed but your understanding of it. In this case things like the cosmological constant not being derived is no different than the fact that no theory in physics can be derived. They're all arrived at by things such as intuition.

This is the cosmological constant problem, the worst problem of fine-tuning in physics: there is no known natural way to derive the tiny cosmological constant used in cosmology from particle physics.

Fine tuning and the cosmological constant have little to do with each other. And you have no idea whether it can or can't be derived. All that can be said is that it hasn't been derived yet. And if it was the cosmological constant that drove inflation then it was very large at that time. That article was silly for saying that.

Well Pete - In the case of arriving at a theory of everything, Wikapedia is not the only source by a long shot where I have read that the measured cosmological constant being many orders too small is a large problem that needs to be addressed.

And in stating that potential energy and kinetic energy escalate or diminish positively and negatively to each other to retain balance is repeating what I already said to Alan.

Leaving aside rudeness or not - to derive relativity one also needs to rely on unknowns that are necessary for this theories validity.  One of these unknowns is dark energy and this directly relates to the cosmological constant, and this isn't really all that intuitive.

But my interest and question is:
Does the caesium atom in a higher gravity potential experience an increase in potential energy, such as the photon does?

[timey]

I did not say you hadn't described anything correctly.

I didn't say you did. I was merely saying that what I said was correct. However your responses indicate that what I said is in error and that's what I responded to.

Yes - if an atom emits a photon in a differing gravity potential, then as an observer observing the photon that has been emitted in the differing gravity potential, one will view the photon as it is when it has 'arrived in' the observation reference frame one is observing from, and not as it was when it was emitted in the differing reference frame.

Its not clear to me what you mean when you use the term "frame." That term is usually used only in SR, i.e. inertial frames with no spacetime curvature.  one usually speaks in terms of coordinate systems, not frames.

If the clock is only ticking faster as an observer dependent phenomenon, (this can also be applied to SR time dilation), then the widely reported (NASA, NIST) and scientifically accepted (?) concept of a person ageing in keeping with their time dilated clock is wrong.

Not at all. I can't even see how you arrived at that conclusion.

So, as a photon climbs out of a gravity well it's kinetic energy decreases, and it's potential energy increases?

From these responses it appears to me that you didn't follow the derivation in the URL I posted. Is that correct? The reason I created those pages was to address these exact questions. I takes exact math to be precise and that's what I did on that page. I only assumed the reader knows basic algebra and physics.

If you'd prefer a textbook then read section 4.3 in A Short Course in General Relativity by James Foster,  J. D. Nightingale.
You can download the text from - http://bookzz.org/book/681818/a5c827

Note: When I spoke of the kinetic energy of a photon/light it refers to the "intrinsic" energy of the light, i.e. as measured at the same location as the light. If one uses the frequency as reckoned from one location only then you should know that such a frequency doesn't change. Eg the frequency of light as it moves through a gravitational field does not change as reckoned by a Schwarzschild observer, i.e. an observer far away from the body.

When a caesium atom is ticking at elevation in a higher gravity potential, does it's potential energy also increase?

That depends on the nature of the field that you're talking about. E.g. if the field is uniform then the potential energy increases without bound as one goes higher and higher in the field.

Which is why I corrected you, because I did not say that you ere in error.  That was your interpretation.

*

ie: If an atom is omitting a photon at 22 metres top of Harvard bell tower, then when it is observed at bottom of tower it has changed frequency.  The bottom of tower cannot observe the photon being emitted at top of tower, because it is not observable until it reaches the observer at bottom of tower.
Therefore light is observer dependent.

*

Because if the clock at elevation's frequency is observer dependent, then the caesium atom's frequency, when you place yourself with the clock will be the same as it was for the clock you were observing on the ground.
And if it's frequency is the same at elevation as it is on the ground, then the person with the elevated clock shall age no faster than the person on the ground.

*

I am well read in Relativity thank you...

You said in post 41:

As the photon climbs out of the g-field its kinetic energy decreases and its potential energy increases, the sum being constant.

I was directly quoting what you said, and didn't look at the link.

*

When you say uniform - do you mean unchanging. ie: not diminishing with the inverse square law with distance?
I am asking if the potential energy increases for the caesium atom when placed in elevation in a higher gravity potential than ground level earth.

[PmbPhy]

And in stating that potential energy and kinetic energy escalate or diminish positively and negatively to each other to retain balance is repeating what I already said to Alan.

I don't read all of the posts in threads since it'd take too long to post the answer to the question asked and it serves no purpose to me.

- to derive relativity ...

As I explained above one does not "derive" SR or any other theory. That's not possible, at not using deductive logic. One takes intuitive guesses and hints from other laws to arrive at postulates which are then used to form postulates which are then used for construct theories. That's what's known as "inductive" logic. See:
http://www.iep.utm.edu/ded-ind/

A deductive argument is an argument that is intended by the arguer to be (deductively) valid, that is, to provide a guarantee of the truth of the conclusion provided that the argument's premises (assumptions) are true. This point can be expressed also by saying that, in a deductive argument, the premises are intended to provide such strong support for the conclusion that, if the premises are true, then it would be impossible for the conclusion to be false. An argument in which the premises do succeed in guaranteeing the conclusion is called a (deductively) valid argument. If a valid argument has true premises, then the argument is said to be sound.
...
An inductive argument is an argument that is intended by the arguer merely to establish or increase the probability of its conclusion. In an inductive argument, the premises are intended only to be so strong that, if they were true, then it would be unlikely that the conclusion is false. There is no standard term for a successful inductive argument. But its success or strength is a matter of degree, unlike with deductive arguments. A deductive argument is valid or else invalid.

Please keep this in mind when you again claim that theories such as SR are "derived." It a theory could actually be derived then that would be proof a theory. But that's not how science works. A very good friend of mine, Alan Guth (inventor of the inflationary model of the universe) did several interviews for me where he addressed several common misconceptions in physics. He did one concerning the common misconception Physics Is About Proving Things. See:
http://www.newenglandphysics.org/common_misconceptions/Alan_Guth_04.mp4

one also needs to rely on unknowns that are necessary for this theories validity.  One of these unknowns is dark energy and this directly relates to the cosmological constant, and this isn't really all that intuitive.

I have no idea where you got the idea that ...one also needs to rely on unknowns that are necessary for this theories validity. Also, it's not necessarily true that dark energy relies on the cosmological constant. It's quite possible that dark energy is a result of negative pressure, i.e. stress.

Does the caesium atom in a higher gravity potential experience an increase in potential energy, such as the photon does?

Yes.

Note: Keep in mind that there is a difference between gravitational potential and gravitational potential energy.

It appears to me that not only that you didn't follow my derivation but that you have no intention of doing so. Perhaps you can't follow the algebra? I'll assume that's the case and no longer respond to your questions, especially since you keep repeating the same misconceptions over and over again regardless of my corrections to them. Good bye.

[PmbPhy]

Which is why I corrected you, because I did not say that you ere in error.  That was your interpretation.

So you claim, but you're wrong.

ie: If an atom is omitting a photon at 22 metres top of Harvard bell tower, then when it is observed at bottom of tower it has changed frequency.  The bottom of tower cannot observe the photon being emitted at top of tower, because it is not observable until it reaches the observer at bottom of tower.

Did you see me say "as observed"? No. You didn't. I said "reckoned" because that's what it is. I.e. its how its calculated. Not observed. However I can also rightly say that its also possible to be observed because there's nothing wrong with having more than one observer. This is done all the time in SR when one speaks of observers in two frames measuring things like speed, energy, etc.

Therefore light is observer dependent.

I never said otherwise, did I?

If you learned how to follow a derivation and/or reading the text I referred to then you'd learn this.

[timey]

And in stating that potential energy and kinetic energy escalate or diminish positively and negatively to each other to retain balance is repeating what I already said to Alan.

I don't read all of the posts in threads since it'd take too long to post the answer to the question asked and it serves no purpose to me.

- to derive relativity ...

As I explained above one does not "derive" SR or any other theory. That's not possible, at not using deductive logic. One takes intuitive guesses and hints from other laws to arrive at postulates which are then used to form postulates which are then used for construct theories. That's what's known as "inductive" logic. See:
http://www.iep.utm.edu/ded-ind/

A deductive argument is an argument that is intended by the arguer to be (deductively) valid, that is, to provide a guarantee of the truth of the conclusion provided that the argument's premises (assumptions) are true. This point can be expressed also by saying that, in a deductive argument, the premises are intended to provide such strong support for the conclusion that, if the premises are true, then it would be impossible for the conclusion to be false. An argument in which the premises do succeed in guaranteeing the conclusion is called a (deductively) valid argument. If a valid argument has true premises, then the argument is said to be sound.
...
An inductive argument is an argument that is intended by the arguer merely to establish or increase the probability of its conclusion. In an inductive argument, the premises are intended only to be so strong that, if they were true, then it would be unlikely that the conclusion is false. There is no standard term for a successful inductive argument. But its success or strength is a matter of degree, unlike with deductive arguments. A deductive argument is valid or else invalid.

Please keep this in mind when you again claim that theories such as SR are "derived." It a theory could actually be derived then that would be proof a theory. But that's not how science works. A very good friend of mine, Alan Guth (inventor of the inflationary model of the universe) did several interviews for me where he addressed several common misconceptions in physics. He did one concerning the common misconception Physics Is About Proving Things. See:
http://www.newenglandphysics.org/common_misconceptions/Alan_Guth_04.mp4

one also needs to rely on unknowns that are necessary for this theories validity.  One of these unknowns is dark energy and this directly relates to the cosmological constant, and this isn't really all that intuitive.

I have no idea where you got the idea that ...one also needs to rely on unknowns that are necessary for this theories validity. Also, it's not necessarily true that dark energy relies on the cosmological constant. It's quite possible that dark energy is a result of negative pressure, i.e. stress.

Does the caesium atom in a higher gravity potential experience an increase in potential energy, such as the photon does?

Yes.

Note: Keep in mind that there is a difference between gravitational potential and gravitational potential energy.

It appears to me that not only that you didn't follow my derivation but that you have no intention of doing so. Perhaps you can't follow the algebra? I'll assume that's the case and no longer respond to your questions, especially since you keep repeating the same misconceptions over and over again regardless of my corrections to them. Good bye.

You directly quoted this

Such a wonderful system, so beautiful and logical, oh - apart from

from the post I made to Alan in your post: 45, so you did indeed read my answer to Alan.

*

I think you are picking nits here Pete. But on the basis of a deductive argument, I see that it is deduced that Relativity requires unknowns to be a valid theory, that one of these unknowns is Dark Energy, and that Dark Energy 'can' be related to the cosmological constant.

*

If Dark Energy is negative stress, this still leaves particle physics in relation to relativity with a cosmological constant that is many orders too small.

*

Ah good, I see you have answered the question.  Thank you!  I know that your opinion is respected here and I shall quote you on that next time someone tells me that it doesn't.

*

Dear oh me - so touchy Pete.  Really there is no need.  You are quite correct, I have actually discussed with you on several occasions over the last few years that I am not much of a mathematician...
But the good news is Pete, that I'm getting a lot better at it than I was.
Good day to you... in Boston isn't it?
I will probably have a look at your maths, but it was the question that I was asking that was interesting me.

[timey]

Which is why I corrected you, because I did not say that you ere in error.  That was your interpretation.

So you claim, but you're wrong.

ie: If an atom is omitting a photon at 22 metres top of Harvard bell tower, then when it is observed at bottom of tower it has changed frequency.  The bottom of tower cannot observe the photon being emitted at top of tower, because it is not observable until it reaches the observer at bottom of tower.

Did you see me say "as observed"? No. You didn't. I said "reckoned" because that's what it is. I.e. its how its calculated. Not observed. However I can also rightly say that its also possible to be observed because there's nothing wrong with having more than one observer. This is done all the time in SR when one speaks of observers in two frames measuring things like speed, energy, etc.

Therefore light is observer dependent.

I never said otherwise, did I?

If you learned how to follow a derivation and/or reading the text I referred to then you'd learn this.

If it wasn't your interpretation then why did you mention it?

*

Clearly!  Any relativity book will tell you that.

*

No you didn't.  I was using the sentence to illustrate the difference between light and an atom.

*

I already know it and am the one who mentioned it first.

I'm sorry I just don't understand why you are so defensive.  I only asked you a question.
Sorry, won't do it again...

P.S. Btw, you do realise that you 'are' using the word derivation yourself?

[alancalverd]

As one gets further away from M, gravity potential increases.

Yes

So why do current physicists say that gravity potential is zero in a deep space gravity field?

"deep space" is somewhere that there is no net gravitational field, so "deep space gravity field" is meaningless, and if the field is zero then the potential is also zero.

Zero for what?
For mass in that gravity field?
Or for the gravity field itself?

if the field is zero, the potential is zero and the potential energy of any mass at that point is zero.

And if you start out with a negative value from any point in a non zero gravity field for m, this negative value will still escalate, negatively, as kinetic energy escalates positively.

you've got it!

The logic is that the sum of kinetic and potential energy is always zero for an object in free fall, so we can calculate the orbit of anything if we know the starting parameters.

You can use this approach to model the banking crisis. Banks were supposed to invest deposits (potential) in loans (kinetic) in order to make a profit. But they started selling loans to each other for profit until the notional value of the loans far exceeded the deposits, which was OK until a depositor asked for his money back. Not surprising that accountants have borrowed the "black hole" metaphor, and they seem to turn up wherever you thought there was a deposit!