At Rest with our Hubble view

[quantum_wave]

This isn't strictly true, in that you could place light-clocks in an equatorial plane around the Earth, and plot the readings. The lower clocks go slower, and your plot exhibits a curvature. You can observe this. That's what curved spacetime is. But it's a plot, a "map". Space isn't curved. There's a curvature in your plot of motion through space over time. Gravity is of course directly observable in that you can drop a pencil, or see that light curves when it skims the Sun. The issue is one of cause and effect. Markus is effectively saying the lower light clocks go slower because your plot of light-clock rates is curved. That's wrong. Those lower light-clocks go slower for a reason, but that isn't it. **

Einstein did say matter/energy "conditions the surrounding space". It alters its properties. It doesn't curve it.

Your definition of spacetime seems different from GR then. I think the GR notion is that natural motion through space follows the curvature of spacetime which is determined by matter/energy in accord with the EFEs; in GR there is a resulting natural geometry that determines the amount of curvature based on the amount of matter/energy that is influencing the body that is moving through the spacetime in that location.

When you say the presence of matter/energy alters the properties of space, you are referring to what GR refers to as curved spacetime, aren't you, but you are denying the natural geometric cause?

I'm on the spacetime side of the issue too, but I'm saying curved spacetime isn't curved space, it's just a curvature of your measurements of things moving through space. Using things like light-clocks. As for the mechanism, Einstein used the stress-energy-momentum tensor. See wiki. See the shear stress? The mechanism is essentially elastic. Like space is elastic. When you subject it to pressure you alter its properties. Note the energy-pressure diagonal. Imagine space is a big block of gin-clear ghostly elastic jelly. With some deft gedanken surgery you insert of sphere of jelly into the block. You've now got a pressure gradient all around the sphere.

Though you say you are on the spacetime side of the issue, you perspective of what Einstein's equations are defining is different, i.e. you refer to the elasticity of space instead of the curvature of spacetime. You see a difference between those two phrases.

I would say you aren't on the side of spacetime. You are on the side that says there is more to curved spacetime than just geometry; you are saying that the effect that your light clocks expose is caused by an effect that is readily observable, time dilation caused by the difference in the strength of gravity at different altitudes, gravitational time dilation. Isn't that what you mean, it is gravity that is affecting the elasticity of space?

I refer to that side of the issue as the "energy density of space due to the presence of gravitational energy density" side, instead of the "geometry of spacetime" side. That perspective is that all space contains energy density. That energy density is from a history of the motion of matter based on the gravitational energy that is a characteristic of the presence of matter. As matter moves it leaves behind the waning gravitational wave energy density that is expanding away from it at all times and that I think equates to the pressure that you refer to.

 

[Tach]

This isn't strictly true, in that you could place light-clocks in an equatorial plane around the Earth, and plot the readings. The lower clocks go slower, and your plot exhibits a curvature. You can observe this.

Actually this is also false, Duffield, like everything else that you pretend to know about science. All the clocks tick exactly at the same rate on the surface of the Earth.

That's what curved spacetime is.

Maybe in your mind, Duffield. In mainstream science, it isn't.

 

[PhysBang]

I've addressed the points raised.

This is an obvious lie. This is not merely an issue of your interpretation of whether or your replies are good answers, you must know that you have never given an example of how you're variable speed of light theory works and you have been asked.

Please, just show us how to calculate the perihelion shift of the orbit of Mercury or how to calculate a galaxy rotation curve. The first is a classic test of GR. The second is something that you have claimed that every astronomer and physicist has done wrong. Yet you have never answered questions asking for these details.

 

[OnlyMe]

This isn't strictly true, in that you could place light-clocks in an equatorial plane around the Earth, and plot the readings. The lower clocks go slower, and your plot exhibits a curvature. You can observe this.

Actually this is also false,... All the clocks tick exactly at the same rate on the surface of the Earth.

Tach, I don't agree with Farsight on most of his interpretation of Einstein's words. That said your response above seems deliberately misleading. Farsight, specifically mentioned lower clocks, establishing multiple clocks at different locations in the Earth's gravity well. You restrict your response to on the surface of the Earth, which if the surface represented a uniform location within the Earth's gravity well, would make the statement correct. Unfortunately the Earth's gravitational field varies even when measured at different locations on its surface.

Today's technology has already proven that clocks at different positions within a gravity well do record time at different rates. It is called time dilation.

The fact, of the affect that gravity has on clocks, which has been experimentally verified.., is not the same as the reason gravity affects clocks, which remains the subject of theory.

Farsight's reasons for observed fact are not consistent with modern scientific consensus. The fact is.., well.., fact.

 

[Tach]

Tach, I don't agree with Farsight on most of his interpretation of Einstein's words.

Based on your posts, I would say that you two agree most of the time.

That said your response above seems deliberately misleading. Farsight, specifically mentioned lower clocks, establishing multiple clocks at different locations in the Earth's gravity well.

No, he didn't, he talks about the clocks "in an equatorial plane around the Earth".

Unfortunately the Earth's gravitational field varies even when measured at different locations on its surface.

While this is true, all clocks tick at the same rate on the Earth surface, contrary to your fringe ideas.

 

[OnlyMe]

No, he didn't, he talks about the clocks "in an equatorial plane around the Earth".

Tach, he said equatorial plane, not on the equator.., and then he added the qualifier lower in "The lower clocks go slower..."

While this is true, all clocks tick at the same rate on the Earth surface, contrary to your fringe ideas.

Are you thinking before you post?

Tell me what happens to a pendulum clock when you move it from sea level to the top of a mountain? Both being on the surface of the Earth. As soon as you mention the Earth you cannot just assume that every location is the same, relative to the center of the Earth's gravity well. To answer the question, pendulum clocks are sensitive to both elevation and latitude... Or did you mean all clocks except some clocks?

Even for one clock to tick at the same rate everywhere on the Earth's surface, it would have to be recalibrated repeatedly as it is moved from location to another. The accuracy of most clocks is such that tick rate variations, resulting from changes in location, on the earth, are generally insignificant, but not absent.

 

[Tach]

Tach, he said equatorial plane, not on the equator.., and then he added the qualifier lower in "The lower clocks go slower..."

The above would be true for a non-rotating Earth. Last I checked, the Earth was rotating and the rotation effect , when combined with the gravitational time dilation, makes all clocks tick at the same rate everywhere on the Earth surface.
I am quite sure that you cannot follow this paper. Enough said, you and your "idol" , Farsight, are wrong.

 

[quantum_wave]

The above would be true for a non-rotating Earth. Last I checked, the Earth was rotating and the rotation effect , when combined with the gravitational time dilation, makes all clocks tick at the same rate everywhere on the Earth surface.
I am quite sure that you cannot follow this paper. Enough said, you and your "idol" , Farsight, are wrong.

This is absurd.

 

[Tach]

This is absurd.

Yes, for you, OnlyMe, Farsight, mainstream science is "absurd".

 

[quantum_wave]

Yes, for you, OnlyMe, Farsight, mainstream science is "absurd".

That is not at all true. Gravitational time dilation is observed on earth, and you saying mainstream science says otherwise is absurd.

 

[OnlyMe]

The above would be true for a non-rotating Earth. Last I checked, the Earth was rotating and the rotation effect , when combined with the gravitational time dilation, makes all clocks tick at the same rate everywhere on the Earth surface.
I am quite sure that you cannot follow this paper. Enough said, you and your "idol" , Farsight, are wrong.

Tach, the paper you cite addresses an ideal and unreal case. Yes the earth is rotating, but you have already admitted that its gravity is not uniform. The earth does not represent a mass of uniform density or shape. As I said for most common clocks the change in tick rate would be unmeasurable except over long time frames... But then most clocks are not as dependent on gravity as are pendulum clocks.

I specifically chose the pendulum clock, as example, because it is sensitive to changes in gravity and rotation, though you will not find it easy to locate data on the effect of the Earth's rotation, common sense should tell you that it will add mechanical stresses and friction to the mechanism where the pendulum is not allowed to swing completely free.

Even when moved from one sea level location to another, a pendulum clock must be adjusted, to keep accurate time. This does not even need experiment to confirm, it is a matter of practcal experience, to anyone familiar with pendulum clocks.

The part of your statement that I was challenging was, "all clocks".

 

[Tach]

Tach, the paper you cite addresses an ideal and unreal case.

Last ditch desperation approach. Sorry to puncture your delusional balloon but this is a paper published in American Journal of Physics. I can't help you if it disagrees with your misconceptions.

Yes the earth is rotating, but you have already admitted that its gravity is not uniform.

The math in the paper explains how the non uniform effects of both gravitation and centrifugal force balance each other. It is not my fault that you are unable to follow the math.

I specifically chose the pendulum clock, as example, because it is sensitive to changes in gravity and rotation,

This might surprise you but all clocks are sensitive to both changes in the strength of the gravitational field and in rotation, this is a direct consequence of GR solutions to EFE.

though you will not find it easy to locate data on the effect of the Earth's rotation, common sense should tell you that it will add mechanical stresses and friction to the mechanism where the pendulum is not allowed to swing completely free.

Even when moved from one sea level location to another, a pendulum clock must be adjusted, to keep accurate time. This does not even need experiment to confirm, it is a matter of practcal experience, to anyone familiar with pendulum clocks.

The part of your statement that I was challenging was, "all clocks".

Last I checked, NIST didn't use pendulum clocks, it uses atomic clocks. Can't help you if you are stuck in 16-th century technology.

 

[OnlyMe]

Last ditch desperation approach. Sorry to puncture your delusional balloon but this is a paper published in American Journal of Physics. I can't help you if it disagrees with your misconceptions.

The math in the paper explains how the non uniform effects of both gravitation and centrifugal force balance each other. It is not my fault that you are unable to follow the math.

This might surprise you but all clocks are sensitive to both changes in the strength of the gravitational field and in rotation, this is a direct consequence of GR solutions to EFE.

Last I checked, NIST didn't use pendulum clocks, it uses atomic clocks. Can't help you if you are stuck in 16-th century technology.

Tach, perhaps this has slipped past you but most scientific papers dealing with GR and SR deal with ideal and often unrealistic conditions. Especially where GR is concerned, attempting to deal with all of the real variables is an unrealistic endevor.

Yes theoretically all clocks are equally affected by gravity, something which has not been experimentally demonstrated. Again, take the pendulum clock and try to put it in a sattelite.., or for that matter show me anywhere that time dilation has been demonstrated with a spring wound clock! And yes, NIST does not use pendulum clocks, or spring wound clocks, but you said all clocks and then referenced a paper that, assumes sea level and does not take variations in local gravity into account.

As I mentioned before, the issue was your blanket statement that all clocks tick at the same rate. That is not true even theoretically, as I am sure you are not suggesting my wristwatch, a spring wound relic, ticks at the same rate as those the NIST rely on.

 

[Cheezle]

Tach, perhaps this has slipped past you but most scientific papers dealing with GR and SR deal with ideal and often unrealistic conditions. Especially where GR is concerned, attempting to deal with all of the real variables is an unrealistic endevor.

Yes theoretically all clocks are equally affected by gravity, something which has not been experimentally demonstrated. Again, take the pendulum clock and try to put it in a sattelite.., or for that matter show me anywhere that time dilation has been demonstrated with a spring wound clock! And yes, NIST does not use pendulum clocks, or spring wound clocks, but you said all clocks and then referenced a paper that, assumes sea level and does not take variations in local gravity into account.

As I mentioned before, the issue was your blanket statement that all clocks tick at the same rate. That is not true even theoretically, as I am sure you are not suggesting my wristwatch, a spring wound relic, ticks at the same rate as those the NIST rely on.

Please drop the annoying, "what about a pendulum" or "what about a mechanical wrist watch". It is obvious that Tach was talking about atomic clocks. All common household clocks are calibrated to varying accuracies. Your watch, if you opened it up, has an adjustment in it. Pendulums are calibrated. Quartz clocks are calibrated. Even common electric alarm clocks that run on 60 Hz synchronous motors use the mains power 60Hz which is calibrated at the power company. For applications such as being discussed here, atomic clocks are called for. Even they are calibrated but the accuracy is many orders of magnitude better. ALways use the right tool for the job. Please stop this ignorant argument for argument's sake line of "reasoning".

 

[Aqueous Id]

Yes theoretically all clocks are equally affected by gravity, something which has not been experimentally demonstrated.

You speak as if there is no science dealing with measurement and calibration.

In one set of experiments, scientists raised one of the clocks by jacking up the laser table to a height one-third of a meter (about a foot) above the second clock. Sure enough, the higher clock ran at a slightly faster rate than the lower clock, exactly as predicted.

​

http://www.nist.gov/public_affairs/releases/aluminum-atomic-clock_092310.cfm

 

[Markus Hanke]

I've addressed the points raised.

No you haven't.

I've explained this umpteen times via restatements of the fabulous post #158 which you have spectacularly failed to address.

Post 158 contains an animated GIF which has no relation to physical reality; it is just a pictorial representation of your erroneous assertions, all of which have been addressed to death.

describes elastic space

Wrong :
http://math.ucr.edu/home/baez/gr/stress.energy.html
http://www.nicadd.niu.edu/~bterzic/PHYS652/Lecture_03.pdf
http://www2.warwick.ac.uk/fac/sci/physics/current/teach/module_home/px436/notes/lecture6.pdf
MTW's Gravitation, Chapter 5.2

describes your measurements

Wrong again :
http://en.wikipedia.org/wiki/Einstein_tensor
http://math.ucr.edu/home/baez/einstein/node10.html
http://www.nicadd.niu.edu/~bterzic/PHYS652/Lecture_03.pdf
MTW's Gravitation, Page 40 onwards

But the seconds aren't the same, so two speeds aren't the same.

...which brings us back to the original problem - if the local speeds aren't the same across different regions of space, as in the vicinity of the sun, we would see frequency-dependent refraction effects along the global trajectory of a ray of light grazing past a massive body. Needless to say these aren't observed, so you are manifestly wrong. Thanks for pointing that out once again.

I've explained this umpteen times

Blatant lie. Not even once have you shown us exactly how the EFEs give us a relation for a varying speed of light. You have completely ignored the question.

I've blown away your straw-man which asserted that refraction in glass involves a variable c

What you have blown away is the illusion that you understand basic high school physics, such as Snell's law.

 

[Markus Hanke]

And again Farsight has not answered the question put to him; instead, just repetitions of the same old stuff which has long since been shown to be wrong.
This really is becoming a bit of a joke !

Talk about pompous.

Pompous is when someone who has never studied a subject matter in-depth asserts to be right, even though every single textbook on the matter says otherwise, including Einstein's very own; megalomania might be a better term, though.

 

[Markus Hanke]

Please, just show us how to calculate the perihelion shift of the orbit of Mercury or how to calculate a galaxy rotation curve. The first is a classic test of GR. The second is something that you have claimed that every astronomer and physicist has done wrong. Yet you have never answered questions asking for these details.

That is because he can't. And if he could he wouldn't do it, because it would show that a varying speed of light cannot produce the correct numbers, let alone explain why Mercury's orbit should precess at all.

 

[arfa brane]

Not even once have you shown us exactly how the EFEs give us a relation for a varying speed of light

This might be interesting then:

Journal of Modern Physics, 2012, *, **
doi:10.4236/jmp.2012.

Abstract

A variable Speed of Light is supported by the fact that all direct measurements of that speed are basically flawed, be-
cause the “meter per second” is proportional to the Speed of Light. Since it is impossible to measure the Speed of Light
directly, any variations of it can only be obtained in an indirect way. It will be shown that the recent Supernovae data
are in very good agreement with a universe that is slowly expanding exponentially with a Speed of Light that falls over
time, inversely proportionally to the expansion of the universe. It will be shown that the definition of the angular and
standard impulse momentum has to be modified to get a consistent expansion of the universe. And that all clocks run
inversely proportionally to the red-shift z+1. General Relativity remains valid even with a varying Speed of Light and
also Quantum Mechanics is unaffected.

http://www.google.co.nz/url?sa=t&rc...dvqxbvhVHFvU51g&bvm=bv.48705608,d.dGI&cad=rja

 

[Markus Hanke]

This might be interesting then:
http://www.google.co.nz/url?sa=t&rc...dvqxbvhVHFvU51g&bvm=bv.48705608,d.dGI&cad=rja

Interesting paper, but it deals with cosmological considerations as opposed to the very simple scenario of gravitational light deflection on massive bodies. Also, the paper does not deny space-time curvature, and does not assert that all gravitational phenomena are the result of varying speeds of light, as Farsight does. Thus, it does not give the answer to the question posed to Farsight, namely how the EFEs can give a relation for such variances in the vicinity of local bodies.