On Accelerated Surfaces

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A Troubled Man
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On Accelerated Surfaces

Post #1

Post by A Troubled Man »

Divine Insight wrote:
I have reason to be concerned.

Here you are starting an entire sub-forum on science and you believe that General Relativity is stating that the Earth Surface is accelerating outward at 9.8 m/s/s.

That is simple false. And if you go around teaching people that this is what General Relativity is saying then you are perpetuating false information.

General Relativity is NOT describing the Earth's surface to be accelerating up toward us.

Here you are starting a Science sub-forum and you don't even understand the basics of modern science.

You better get that squared away first.
I have gathered together my sources and citations that explain accelerated surfaces in General Relativity and placed them into one thread for Diving Insight to refute if he wishes. He has yet to provide any sources or citations showing his understanding is valid. His personal opinions show evidently he does not understand what he claims.

He can then feel free to apologize for his unnecessary concern and claims of propagating false information, which in fact is what he is doing.


"The key idea of general relativity, called the equivalence principle, is that gravity pulling in one direction is completely equivalent to an acceleration in the opposite direction. A car accelerating forwards feels just like sideways gravity pushing you back against your seat. An elevator accelerating upwards feels just like gravity pushing you into the floor."

http://www.pbs.org/wgbh/nova/physics/re ... osmos.html

"He proposed an experiment involving two elevators: one at rest on the ground on the Earth and another, far out in space away from any planet, moon, or star, accelerating upward with an acceleration equal to that of one Earth gravity (9.8 meters/second2). (Modern readers can substitute ``rocket ship'' for Einstein's elevator.)

http://www.astronomynotes.com/relativity/s3.htm

"The equivalence principle was Einstein's `Newton's apple' insight to gravitation. His thought experiment was the following, imagine two elevators, one at rest of the Earth's surface, one accelerating in space. To an observer inside the elevator (no windows) there is no physical experiment that he/she could perform to differentiate between the two scenarios.

The equivalence principle is a fundamental law of physics that states that gravitational and inertial forces are of a similar nature and often indistinguishable."

http://abyss.uoregon.edu/~js/21st_centu ... lec07.html

"In a gravitational field (of small spatial extension) things behave as they do in a space free of gravitation, if one introduces into it, in place of an “inertial system�, a frame of reference accelerated relative to the former.

Inertia and gravity are phenomena identical in nature. From this and from the special theory of relativity it follows necessarily that the symmetric fundamental [metric] tensor gmn determines the metric properties of space, the inertial behavior of bodies in this space, as well as the gravitational effects."

http://www.mathpages.com/home/kmath622/kmath622.htm[/quote]

If the ground wasn't there (e.g. all the Earth's mass was concentrated at the Earth's centre instead), then you'd free-fall towards the centre of the Earth. To stop that from happening, the ground exerts an upwards force on you.

Now, in general relativity, you need to realise that gravity is not a force. Gravity is just spacetime geometry. So, as you stand on the surface of the Earth,the only force acting on you is the ground pushing up. There's no "gravity pulling you down" force.

Newton's second law says F=ma . That is, you accelerate in the direction of the net force on you.* And when the only force is the ground pushing up, that means you must be accelerating upwards as you stand on the Earth's surface.
http://www.sciforums.com/showthread.php ... -s-surface

Here's another forum with working physicists that say the same thing...
In Newton's theory, a falling object is accelerating at 9.8 m/s2 in the "down" direction. In GR, the surface of the Earth is accelerating 9.8 m/s2 in the "up" direction
http://www.physicsforums.com/archive/in ... 60253.html


"The 1 g-force on an object sitting on the Earth's surface is caused by mechanical force exerted in the upward direction by the ground, keeping the object from going into free-fall. The upward force from the ground ensures that an object at rest on the Earth's surface is accelerating relative to the free-fall condition, which is the path that the object would follow when falling freely toward the Earth's center.

While acceleration is a vector quantity, g-force accelerations ("g-forces" for short) are often expressed as a scalar, with positive g-forces pointing upward (indicating upward acceleration), and negative g-forces pointing downward. Thus, a g-force is a vector acceleration. It is an acceleration that must be produced by a mechanical force, and cannot be produced by simple gravitation. Objects acted upon by only by gravitation, experience (or "feel") no g-force, and are weightless."

http://en.wikipedia.org/wiki/G-force

"The Principle of Equivalence says that we can base our calculation on the assumption that the Earth’s surface is accelerating upward...

http://www.alternativephysics.org/book/ ... tivity.htm

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Re: On Accelerated Surfaces

Post #2

Post by Divine Insight »

A Troubled Man wrote: "The Principle of Equivalence says that we can base our calculation on the assumption that the Earth’s surface is accelerating upward...
This is actually false.

The Principle of Equivalence is not a valid principle of General Relativity.

This Principle of Equivalence is only true in the calculus limit taken at a point.

It is not true arbitrarily, as A Troubled Man, has misunderstood it to mean.

In fact, many textbooks have this wrong, which is no doubt why A Troubled Man has misunderstood this. The problem with textbooks is that they don't consider taking things to the extreme. They actually assume that your power to conduct experiments is quite limited. And so they ignore what I'm about to explain in the following examples:

~~~~

To begin with it's false that no experiment can be done to differentiate between the two scenarios that have been proposed.

Consider the following scenario:

We have the two rooms as described. One sitting on Earth, the other accelerating through uniform space. But in these rooms we also have two clocks. One clock is on the ceiling marked "clock A" the other clock is on the floor marked "clock B".

We will be using these clocks to show that an experiment can indeed be done to distinguish between these two situations.


[center]Image[/center]


Actually before we do this, allow me to explain how this experiment has actually been done on the earth. We don't have a uniform field of spacetime to conduct the second experiment but it will become clear as we proceed why the second experiment must necessarily produce different results.

The Acceleration due to gravity is given by A = GM/r²

Where:

A is the acceleration in meters per second per second.
G is Newton's gravitational constant. (This remains constant in all our calculations).
M is the mass of the Earth in all our calculations.
r is the radius from the center of the Earth.

This radius is of utmost importance in these experiments.

What we realize from this equation is that the further from the center of the Earth we get the weaker the acceleration due to gravity becomes. This effect is of course very small over very small distance. And this is precisely why it is ignored in this Principle of Equivalence. It's practically irrelevant. In other words, it's irrelevant as a practical matter for most experiments.

However, experiments have been done to measure the difference between two clocks on earth that are sitting at two different heights (i.e. two different radii from the center of the earth). In fact, this difference in time dilation caused by these two different rates of acceleration have been measures for clocks separated as little as one meter from each other in terms of height from the center of the Earth.

See this article on Wikipedia:
Gravitational Time Dilation

Understanding this is the case, we can now easily see that even for rooms as small as only a meter high there will be a difference in the accelartion they experience here on Earth. Clock A on the ceiling of the room will run faster than clock B on the floor of the room. This difference in time dilation is due to the different rates of accelerations experience by the two clocks.

Obviously in the example of a room being accelerated through a uniform field of spacetime this will not be the case. Both clocks will be accelerating at precisely the same rate (i.e. whatever rate the entire room itself is accelerating at). Therefore there will be no time dilation difference between clock A on the ceiling of this room and clock B on the floor.

So we can tell these two situations apart by simply keeping track of the times on these two clocks. In the room on Earth the two clocks will run at different rates. In the room accelerating through a uniform field of spacetime there will be no reason for the two clocks to run at different rates since they are both experiencing precisely the same acceleration.

To bring this home we can simply expand these room and imagine them to be extremely tall.

Just to make the problem extremely easy to grasp, let's imagine that these rooms are as tall as the Earth's radius. Let's also imagine that the accelerating room is accelerating at precisely the acceleration experience at the surface of the Earth what do we then see in these two situations?

We see the following:

[center]Image[/center]


Clock B on the floor of the room on Earth keeps standard time at the surface of the Earth. However, clock A on the ceiling of the room on Earth (a room that is as tall as the Earth's radius) is running much faster. Why? Because it's experiencing far less acceleration. I'll let you do the math. You can either calculate this out using the formula for acceleration due to gravity I gave above.

Or you can simply recognize that the inverse square law requires that at twice the Earth's radius the acceleration would need to be 1/4 as much as that at the Earth's surface. So the clock on the ceiling of the room on Earth would be experiencing an acceleration of only 2.45 m/s/s. And thus that clock would run faster and get out of sync with the clock on the floor.

However, the two clocks in the room that is accerlating through a uniform spacetime field are still both experiencing precisely the same acceleration. They are both accelerating at 9.81 m/s/s, because this is what they room they are both attached to is accelerating at.

And thus we have performed an experiment that has proven the Principle of Equivalency to be false.

Or have we?

Well, not really. We've only proven it to be false is we ignore a basic assumption. And that is that these rooms are so small that these slight differences are negligible.

In the calculus limit they disappear. In other words, when we take the height of these rooms to zero and find the limit, then they are indeed equivalent. At least for the clocks on the floor. But only then.

In other words, clock B in the room on Earth is equivalent to clock B in the accelerating room example. However this is only true, because we have arbitrarily chosen to accelerate that room at 9.81 m/s/s.

If we take the calculus limits for the clocks on the ceilings of these rooms they won't be equivalent because clock A in the room on Earth in this example is only experience the effect of an acceleration of 2.45 m/s/s whilst clock A in the accelerating room is still experiencing an acceleration of 9.81 m/s/s.

So the equivalency principle doesn't hold true over extended space. It only holds true at a point. And thus it's actually false to show people these pictures and claim that there is no experiment that can be done to distinguish between them. It conveys a false idea.

This is obviously the fault of many textbook publishers. They should be more careful to point out these subtleties. It's actually false to claim that no experiment can be done in the actual graphics that they are displaying to tell them apart. That's actually false.

The Principle of Equivalency only holds true at a point, (i.e. in the calculus limit taken at a point). And this is often overlooked by far too many textbooks.

However, Einstein himself did not get this wrong. Einstein understood that it only holds true in the limit.

His finally crafted version of his Spacetime Field Equation clearly show this. It describes a warping of spacetime that is not uniform. Just as I had said from the very beginning.

Everything I have presented here is true, and in complete harmony with my position all along.

Gravity is the result of a warping of the very fabric of spacetime in the vicinity of mass. And Einstein's Spacetime Field Equation describes this very precisely.

The Earth's surface is not accelerating upward. Nor would that explanation even work, as the examples I gave above clearly show.

The forces we experience as gravity are not caused by the Earth's surface rushing outward toward us in an accelerated fashion. On the contrary, our bodies are trying to rush toward the surface. Our bodies are actually pushing down on the surface of the Earth, and this is due to the fact that we exist in a warped, or non-uniform field of spacetime.

So I hold to my original position. And I chastise the authors of textbooks for not making this more clear to their students.
A Troubled Man wrote: He can then feel free to apologize for his unnecessary concern and claims of propagating false information, which in fact is what he is doing.
The people who owe you an apology are the people who write and publish sloppy textbooks.

I can fully understand why you are confused, and I can hardly even blame you for being confused. Elementary textbooks are horrible for overlooking these important details. It requires a true understanding of General Relativity to realize these subtle nuances. Unfortunately even many physics students don't fully grasp the significance of this until their graduate years, if they make it that far.

I don't require an apology from you Troubled Man, as this was never an egotistical thing for me to begin with.

But I would appreciate an acknowledgement of comprehension. 8-)
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Re: On Accelerated Surfaces

Post #3

Post by A Troubled Man »

Divine Insight wrote:
A Troubled Man wrote: "The Principle of Equivalence says that we can base our calculation on the assumption that the Earth’s surface is accelerating upward...
This is actually false.

The Principle of Equivalence is not a valid principle of General Relativity.

This Principle of Equivalence is only true in the calculus limit taken at a point.

It is not true arbitrarily, as A Troubled Man, has misunderstood it to mean.

In fact, many textbooks have this wrong, which is no doubt why A Troubled Man has misunderstood this. The problem with textbooks is that they don't consider taking things to the extreme.
So, it would appear that Divine Insight is now claiming textbooks are wrong.

To begin with it's false that no experiment can be done to differentiate between the two scenarios that have been proposed.

Consider the following scenario:

We have the two rooms as described. One sitting on Earth, the other accelerating through uniform space. But in these rooms we also have two clocks. One clock is on the ceiling marked "clock A" the other clock is on the floor marked "clock B".

We will be using these clocks to show that an experiment can indeed be done to distinguish between these two situations.


[center]Image[/center]


Actually before we do this, allow me to explain how this experiment has actually been done on the earth. We don't have a uniform field of spacetime to conduct the second experiment but it will become clear as we proceed why the second experiment must necessarily produce different results.

The Acceleration due to gravity is given by A = GM/r²

Where:

A is the acceleration in meters per second per second.
G is Newton's gravitational constant. (This remains constant in all our calculations).
M is the mass of the Earth in all our calculations.
r is the radius from the center of the Earth.

This radius is of utmost importance in these experiments.

What we realize from this equation is that the further from the center of the Earth we get the weaker the acceleration due to gravity becomes. This effect is of course very small over very small distance. And this is precisely why it is ignored in this Principle of Equivalence. It's practically irrelevant. In other words, it's irrelevant as a practical matter for most experiments.
And, he is now claiming the Principle of Equivalence is "practically irrelevant".
However, experiments have been done to measure the difference between two clocks on earth that are sitting at two different heights (i.e. two different radii from the center of the earth). In fact, this difference in time dilation caused by these two different rates of acceleration have been measures for clocks separated as little as one meter from each other in terms of height from the center of the Earth.
What Divine Insight is referring to here is the inverse square law that states gravity is weaker proportional to the square of the distance away from the center of the object. Of course, gravities influence changes in various parts of the world depending on what altitude one is standing. The amounts are infinitesimally small and negligible for all intents and purposes.
Understanding this is the case, we can now easily see that even for rooms as small as only a meter high there will be a difference in the accelartion they experience here on Earth. Clock A on the ceiling of the room will run faster than clock B on the floor of the room. This difference in time dilation is due to the different rates of accelerations experience by the two clocks.

Obviously in the example of a room being accelerated through a uniform field of spacetime this will not be the case. Both clocks will be accelerating at precisely the same rate (i.e. whatever rate the entire room itself is accelerating at). Therefore there will be no time dilation difference between clock A on the ceiling of this room and clock B on the floor.

So we can tell these two situations apart by simply keeping track of the times on these two clocks. In the room on Earth the two clocks will run at different rates. In the room accelerating through a uniform field of spacetime there will be no reason for the two clocks to run at different rates since they are both experiencing precisely the same acceleration.

To bring this home we can simply expand these room and imagine them to be extremely tall.

Just to make the problem extremely easy to grasp, let's imagine that these rooms are as tall as the Earth's radius. Let's also imagine that the accelerating room is accelerating at precisely the acceleration experience at the surface of the Earth what do we then see in these two situations?

We see the following:

[center]Image[/center]


Clock B on the floor of the room on Earth keeps standard time at the surface of the Earth. However, clock A on the ceiling of the room on Earth (a room that is as tall as the Earth's radius) is running much faster. Why? Because it's experiencing far less acceleration. I'll let you do the math. You can either calculate this out using the formula for acceleration due to gravity I gave above.
Since, Divine Insight has now completely changed the entire premise and conditions for the Principle of Equivalence, it no longer applies.
And thus we have performed an experiment that has proven the Principle of Equivalency to be false.

Or have we?

Well, not really. We've only proven it to be false is we ignore a basic assumption. And that is that these rooms are so small that these slight differences are negligible.
No, what you've done is to change the conditions so that they no longer apply.
In the calculus limit they disappear. In other words, when we take the height of these rooms to zero and find the limit, then they are indeed equivalent. At least for the clocks on the floor. But only then.

In other words, clock B in the room on Earth is equivalent to clock B in the accelerating room example. However this is only true, because we have arbitrarily chosen to accelerate that room at 9.81 m/s/s.

If we take the calculus limits for the clocks on the ceilings of these rooms they won't be equivalent because clock A in the room on Earth in this example is only experience the effect of an acceleration of 2.45 m/s/s whilst clock A in the accelerating room is still experiencing an acceleration of 9.81 m/s/s.

So the equivalency principle doesn't hold true over extended space. It only holds true at a point. And thus it's actually false to show people these pictures and claim that there is no experiment that can be done to distinguish between them. It conveys a false idea.
The original conditions show the Principle to be sound, however Divine Insight is attempting to show it false by changing the conditions, which does not hold.
This is obviously the fault of many textbook publishers. They should be more careful to point out these subtleties. It's actually false to claim that no experiment can be done in the actual graphics that they are displaying to tell them apart. That's actually false.

The Principle of Equivalency only holds true at a point, (i.e. in the calculus limit taken at a point). And this is often overlooked by far too many textbooks.

However, Einstein himself did not get this wrong. Einstein understood that it only holds true in the limit.

His finally crafted version of his Spacetime Field Equation clearly show this. It describes a warping of spacetime that is not uniform. Just as I had said from the very beginning.

Everything I have presented here is true, and in complete harmony with my position all along.

Gravity is the result of a warping of the very fabric of spacetime in the vicinity of mass. And Einstein's Spacetime Field Equation describes this very precisely.

The Earth's surface is not accelerating upward. Nor would that explanation even work, as the examples I gave above clearly show.

The forces we experience as gravity are not caused by the Earth's surface rushing outward toward us in an accelerated fashion. On the contrary, our bodies are trying to rush toward the surface. Our bodies are actually pushing down on the surface of the Earth, and this is due to the fact that we exist in a warped, or non-uniform field of spacetime.

So I hold to my original position. And I chastise the authors of textbooks for not making this more clear to their students.
LOL. Hilarious. Divine Insight has now made himself the one true arbiter of General Relativity, telling us all that textbooks are wrong and he is right.
The people who owe you an apology are the people who write and publish sloppy textbooks.

I can fully understand why you are confused, and I can hardly even blame you for being confused. Elementary textbooks are horrible for overlooking these important details. It requires a true understanding of General Relativity to realize these subtle nuances. Unfortunately even many physics students don't fully grasp the significance of this until their graduate years, if they make it that far.

I don't require an apology from you Troubled Man, as this was never an egotistical thing for me to begin with.

But I would appreciate an acknowledgement of comprehension. 8-)
Notice that Divine Insight has once again ignored completely all the sources and citations I've provided.

Of course, Divine Insight is now claiming textbooks are wrong and he is right and that the Principle of Equivalence is irrelevant. :lol:

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Re: On Accelerated Surfaces

Post #4

Post by Divine Insight »

A Troubled Man wrote: Since, Divine Insight has now completely changed the entire premise and conditions for the Principle of Equivalence, it no longer applies.
It never did apply in the way that you have been using it.

It has always only applied at a point, and has never applied over an extended distance as depicted in many textbooks.

And yes, any textbook that shows a full-sized room like in the examples you've linked to and simultaneously claims there is no experiment that you can do to tell them apart is indeed wrong.

If they go into detail and say there is no "practical experiment" that you could perform with standard crude measuring instruments they'd be right. But if they state that there is no experiment that can be performed to tell these two graphical pictures apart they are wrong. Plain and simple.

If you read carefully, many of them will say something like, "There is no experiment you can perform in a local region of space". Meaning that if you keep these rooms sufficiently small enough the differences will be so negligible as to be unmeasurable as a practical matter.

But these examples have been around for many years, and modern technologies are becoming available now to make such experiments possible. So these textbook authors really need to start updating these publications and clarifying that there are experiments that can be done, it's just that they require highly precise measuring instruments to perform them.

Such experiments can be done, (and have been done) as I've demonstrated in my previous post.

I think it's pretty clear at this point that A Trouble Man is never going to concede that General Relativity is not stating that the Earth's surface is not rushing up toward us producing a "force" of gravity on us.

That was his original claim and argument. I offered to correct him on this misunderstanding and he has been taking exception to this ever since.

What I am saying about General Relativity is true and perfectly correct.

1. General Relativity is not saying that the Earth's surface is accelerating upward toward us.

2. General Relativity is actually stating that the fabric of spacetime near the earth is warped by the very pretense of the mass of the earth.

3. It is this warped fabric of spacetime that causes objects that exist within it to move, in fact to accelerate

4. Our bodies are literally being accelerated downward toward the stationary surface of the earth.

5. The cause of this acceleration is due to the fact that we exist in a warped, or non-uniform, field of spacetime.

6. Both space and time are warped across the extent of our bodies and this is what causes our bodies to accelerate toward the center of the Earth.

7. This is all described in the actual spacetime field equation of Albert Einstein's General Relativity.

8. The Equivalency Principle, is not a final statement of General Relativity. It was merely a guideline that gave birth to the theory.

9. The Equivalency Principle technically only applies at a point in the calculus limit and does not apply over extended tall rooms as depicted in many textbooks.

10. Textbooks are giving people wrong impressions by not pointing out this important detail.


A Troubled Man was shown a graphic of this Equivalency Principle and has concluded that it holds in all cases, and that this Equivalency Principle is the be all, and end all of General Relativity. This is simply not true.

General Relativity is actually described by Einstein's Field Equation shown below, and describes a warping of the fabric of spacetime around planet earth, also shown below using 3-dimension graphic to attempt to illustrate a 4-dimensional fabric.

This is Einstein's General Relativity Field Equation.

Image

This is a graphic of the equation that attempts to try to convey some idea of how the fabric of spacetime is actually warped. It's not the best graphic, better graphics may be available, but this gets the general idea across.

Image

This has been my position all along from the very moment this was brought up in the following post by A Troubled Man in another thread:
A Troubled Man wrote: GR works from reference frames under acceleration and basically demonstrates that acceleration and gravity are indistinguishable from each other. Since that is the case, we can see that gravity is not a "pulling force" and that we are all literally in free fall and it is the earths surface that is accelerating up towards us, given that gravity and acceleration are indistinguishable.
A Troubled Man seems to believe that The Principle of Equivalency is all there is to General Relativity, and he also believes that it needs to be taken to mean that these two things are precisely identical and indistinguishable in every way.

This is actually false. They are only indistinguishable in terms of effect, not in terms of what is causing the effect.

They are also only indistinguishable at a point (in the calculus limit) and not over extended space as is shown in the graphics that many text books use to illustrate the Principle of Equivalency. Those textbooks are actually wrong if they claim that no experiment could be done in those rooms to distinguish the two rooms apart. They fail to mention that this is only true at a POINT, and not over an extended space such as an entire room.

So it's understandable why A Troubled Man has the wrong idea. We can blame the textbook authors for that one. They give the wrong impression with their pictures. Although if you read the fine print in the actual text they will often make statements such as "in a LOCAL area of space", where they are attempting to acknowledge that this only works in the calculus limit or infinitesimally small "rooms".

Einstein knew that it only works in the calculus limit.

It's textbook authors who fail to make this clear.

And this causes people like ATM to get the wrong idea that General Relativity is proclaiming that the surface of the earth is accelerating upward toward us causing a force of gravity. That's simply not true.

Gravity is caused because the spacetime around the earth is warped, and our bodies are actually being forced to accelerate toward the center of the earth.

This is not unlike an electron that accelerates in a non-uniform electric field.

Think of our bodies as particles in a non-uniform field of spacetime and we are being pushed around by this field.

We are not being pushed upward by the surface of the earth accelerating upward towards us.

That's the wrong idea.

I hope this finally clarifies this issue once and for all.
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Re: On Accelerated Surfaces

Post #5

Post by A Troubled Man »

Divine Insight wrote:
It never did apply in the way that you have been using it.

It has always only applied at a point, and has never applied over an extended distance as depicted in many textbooks.
Again, you are confused. It doesn't depict or apply over an extended distance, ever, it ALWAYS applies to a point because it is at a point in which one would conduct an experiment. Where you get the notion that it should apply over a distance is baffling.
And yes, any textbook that shows a full-sized room like in the examples you've linked to and simultaneously claims there is no experiment that you can do to tell them apart is indeed wrong.
Your claim that textbooks are wrong merely shows you are confused and don't even understand the basic principles of conducting an experiment.
If they go into detail and say there is no "practical experiment" that you could perform with standard crude measuring instruments they'd be right. But if they state that there is no experiment that can be performed to tell these two graphical pictures apart they are wrong. Plain and simple.
No, it is YOU who are wrong, not them.
If you read carefully, many of them will say something like, "There is no experiment you can perform in a local region of space". Meaning that if you keep these rooms sufficiently small enough the differences will be so negligible as to be unmeasurable as a practical matter.
One does not conduct an experiment based on the size of a room, nor do they place clocks at various points in the room, that is sheer nonsense. ONE clock is placed at the point in which the experiment is conducted.
But these examples have been around for many years, and modern technologies are becoming available now to make such experiments possible. So these textbook authors really need to start updating these publications and clarifying that there are experiments that can be done, it's just that they require highly precise measuring instruments to perform them.

Such experiments can be done, (and have been done) as I've demonstrated in my previous post.
You have changed the conditions of how experiments are conducted and how clocks are positioned in any experiment. That is completely false, you are not conducting science.
I think it's pretty clear at this point that A Trouble Man is never going to concede that General Relativity is not stating that the Earth's surface is not rushing up toward us producing a "force" of gravity on us.

That was his original claim and argument. I offered to correct him on this misunderstanding and he has been taking exception to this ever since.
I NEVER said gravity was a 'force' acting on us.
What I am saying about General Relativity is true and perfectly correct.

1. General Relativity is not saying that the Earth's surface is accelerating upward toward us.


I have provided many sources that state the Earth's surface is indeed accelerating up towards us. You have ignore them all in favor of your personal opinions and your dishonesty of putting words in my mouth.
A Troubled Man was shown a graphic of this Equivalency Principle and has concluded that it holds in all cases, and that this Equivalency Principle is the be all, and end all of General Relativity. This is simply not true.
I never said that anything about be all and end all. That is simply not true.
General Relativity is actually described by Einstein's Field Equation shown below, and describes a warping of the fabric of spacetime around planet earth, also shown below using 3-dimension graphic to attempt to illustrate a 4-dimensional fabric.

This is Einstein's General Relativity Field Equation.

Image
Presenting the field equation here only serves to weaken your position, it is the energy-momentum tensor that describes an accelerated surface using g as the metric and Newton's 'G' as the constant.
This is a graphic of the equation that attempts to try to convey some idea of how the fabric of spacetime is actually warped. It's not the best graphic, better graphics may be available, but this gets the general idea across.

Image
Anyone who has studied GR knows that illustration is a very poor representation and only serves to confuse people. Obviously, it has confused you, too.
And this causes people like ATM to get the wrong idea that General Relativity is proclaiming that the surface of the earth is accelerating upward toward us causing a force of gravity. That's simply not true.
I never said anything about a 'force of gravity' acting upon us. We are in free fall and it is the geodesics, the straight lines we follow in free fall of spacetime that are being curved.
Gravity is caused because the spacetime around the earth is warped, and our bodies are actually being forced to accelerate toward the center of the earth.

This is not unlike an electron that accelerates in a non-uniform electric field.

Think of our bodies as particles in a non-uniform field of spacetime and we are being pushed around by this field.
Not true, the electron is also moving on a geodesic, and it is the geodesic that is being curved. The electron is not "being pushed around"
We are not being pushed upward by the surface of the earth accelerating upward towards us.

That's the wrong idea.

I hope this finally clarifies this issue once and for all.
Not at all, your personal misunderstandings are only cause for confusion.

You still have yet to answer to all the citations and sources I provided that agree with me. Funny, how you keep ignoring them. How many more sources would you like me to provide?

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Divine Insight
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Re: On Accelerated Surfaces

Post #6

Post by Divine Insight »

A Troubled Man wrote: You have changed the conditions of how experiments are conducted and how clocks are positioned in any experiment. That is completely false, you are not conducting science.
Now you are wrong on a totally different topic.

These textbooks show two entire rooms with a person inside the room, and then they state in the text that "No experiment can be done to tell these two situations apart"

That is false. There are experiments that you can perform in the rooms they portray in their graphics that can indeed tell the two rooms apart.

And where is it written that you are only allowed to use one clock in any given experiment? Scientists have already performed an experiment where they have measured the time passed by two different clocks, one only a meter higher than the other and that they shown that the higher clock runs faster.

So you are wrong here too Troubled Man. You most certain can use multiple clocks in experiments if you wish to test how time passes at two different locations.

You're just getting yourself in deeper and deeper. You're the one who is trying to place limitations on science that don't exist.
A Troubled Man wrote: I NEVER said gravity was a 'force' acting on us.
Sure you did. In fact you said:
A Troubled Man wrote: GR works from reference frames under acceleration and basically demonstrates that acceleration and gravity are indistinguishable from each other. Since that is the case, we can see that gravity is not a "pulling force" and that we are all literally in free fall and it is the earths surface that is accelerating up towards us, given that gravity and acceleration are indistinguishable.
In red you state that it is the Earth's surface that is accelerating up towards us. That is a false claim. General Relativity does not state that the Earth's surface is accelerating up toward us. And to suggest that this is the situation does indeed imply that the Earth's surface is a force acting on us, since you claim that this is the cause of gravity.

Also, what you said in blue above is also wrong. Gravity actually is a "Pulling Force" according to General Relativity. General Relativity states the the mass of the Earth causes the fabric of spacetime around it to warp, or become nonuniform. It is this non-uniform field of spacetime that cases any massive object within it to accelerate in the direction of the center of mass that is causing this warping of spacetime.

So yes General Relativity is indeed saying that there is force being exerted on your body to make it move toward the center of the earth in much the same way that an electric field is said to be a force acting on a charged particle to cause it to move in an electric field.

So General Relativity is indeed describing gravity as a "Pulling Force". Although, since you body is also a mass that creates it's own warped field of spacetime around it, you can also say that your body is pulling the Earth toward you. But the Earth is a far greater mass and therefore contribute to the warping of spacetime far more than you body does.

But you are wrong on both counts.

1. The Earth's surface is not accelerating upward toward us.
2. The Earth does generate a "Pulling Force" acting on us by warping the field of spacetime in which we reside.

So you're doubly wrong.
A Troubled Man wrote:
What I am saying about General Relativity is true and perfectly correct.

1. General Relativity is not saying that the Earth's surface is accelerating upward toward us.
I have provided many sources that state the Earth's surface is indeed accelerating up towards us. You have ignore them all in favor of your personal opinions and your dishonesty of putting words in my mouth.
I didn't read every source you've linked to, because you appear to keep linking to The Equivalency Principle. The Equivalency Principle is not saying that the Earth surface is accelerating up toward us. If any sources you've linked to make that claim that too are wrong.

The Equivalency Principle is NOT saying that the Earth's surface is accelerating up toward us. You are reading far too much into an analogy that isn't meant to imply that conclusion.
A Troubled Man wrote:
A Troubled Man was shown a graphic of this Equivalency Principle and has concluded that it holds in all cases, and that this Equivalency Principle is the be all, and end all of General Relativity. This is simply not true.
I never said that anything about be all and end all. That is simply not true.
Well, you're certainly acting like it should be. You keep pointing to The Equivalency Principle and acting like that single principle equates to General Relativity.
A Troubled Man wrote:
General Relativity is actually described by Einstein's Field Equation shown below, and describes a warping of the fabric of spacetime around planet earth, also shown below using 3-dimension graphic to attempt to illustrate a 4-dimensional fabric.

This is Einstein's General Relativity Field Equation.

Image
Presenting the field equation here only serves to weaken your position, it is the energy-momentum tensor that describes an accelerated surface using g as the metric and Newton's 'G' as the constant.
It describes the warping of spacetime itself which is precisely my position.

A Troubled Man wrote:
This is a graphic of the equation that attempts to try to convey some idea of how the fabric of spacetime is actually warped. It's not the best graphic, better graphics may be available, but this gets the general idea across.

Image
Anyone who has studied GR knows that illustration is a very poor representation and only serves to confuse people. Obviously, it has confused you, too.
Anyone who has studied GR knows that to continually refer to pictures of a room sitting on Earth and a room being accelerated through empty space is a very poor representation of GR.
A Troubled Man wrote:
And this causes people like ATM to get the wrong idea that General Relativity is proclaiming that the surface of the earth is accelerating upward toward us causing a force of gravity. That's simply not true.
I never said anything about a 'force of gravity' acting upon us. We are in free fall and it is the geodesics, the straight lines we follow in free fall of spacetime that are being curved.
And now you are finally starting to agree with my position. How ironic.

This is what I've been saying ALL ALONG.

What do you think causes are "free fall". Do you think it comes for FREE?

It is caused by the non-uniform field of spacetime in which we exist. And the it is the pretense of the mass of the Earth that is causing the fabric of spacetime to be warped.

Just as I have been saying from the very beginning.

You've been screaming all along that I've been wrong, and proclaiming that I have no understanding of General Relativity and now you're finally confessing that I've been right all along.

The Earth's surface is not accelerating up toward us. This should be obvious to anyone. The Earth isn't getting any bigger. The surface of the Earth isn't moving relative to the center of the Earth at all.

So gravity cannot be caused by the Earth's surface accelerating up toward us.

Why do you continue to argue that it is?

I have no choice but to conclude that you just don't know how to admit that you've been wrong about something.

But there's no way you're going to shove that off onto me. I've been prefectly right and correct about General Relativity all along.

Never has anything I've stated in any of our conversations about General Relativity been wrong.

You're accusations that I've been wrong about anything are unwarranted false slander.
A Troubled Man wrote:
Gravity is caused because the spacetime around the earth is warped, and our bodies are actually being forced to accelerate toward the center of the earth.

This is not unlike an electron that accelerates in a non-uniform electric field.

Think of our bodies as particles in a non-uniform field of spacetime and we are being pushed around by this field.
Not true, the electron is also moving on a geodesic, and it is the geodesic that is being curved. The electron is not "being pushed around"
Now you are really scraping the bottom of the barrel to try to save face.

Scientists always speak of electromagnetic fields as "FORCES"

In face they speak of Gravity as a FORCE too!

Are you aware of the "The Four Forces"?

The force of Gravity.
The force of Electromagnetism
The strong nuclear force
The weak nuclear force

Scientists consider gravity to be a force in precisely the same way that they think of electromagnetism to be a force.

And yes, it's true that objects travel along what we call geodesic curves within their respective fields. But it's also true that this alone does not cause a force. This is because you can travel along a geodesic curves at a constant velocity and therefore no forces are even required. It's only when they are accelerated that we need to speak in terms of force because of Newton's famous law F=ma.

Again, nothing you've said here defies my position. On the contrary everything that has been in any and all of our conversations to date have been in perfect harmony with my position all along.

I haven't been wrong about anything yet.
A Troubled Man wrote:
We are not being pushed upward by the surface of the earth accelerating upward towards us.

That's the wrong idea.

I hope this finally clarifies this issue once and for all.
Not at all, your personal misunderstandings are only cause for confusion.
So you are still claiming that we are being pushed upward by the earth's surface accelerating upward toward us?

Sorry Troubled Man, but that idea is a wrong idea. It's was wrong when you first claimed it, and it's still wrong today.

A Troubled Man wrote: You still have yet to answer to all the citations and sources I provided that agree with me. Funny, how you keep ignoring them. How many more sources would you like me to provide?


Baloney.

I'm not going to dance to your wild goose chases.

If you want to play that game post them ONE at a TIME.

Be very specific about WHERE in the particular article you are pointing to it claims that the Earth's surface is actually accelerating upward toward us.

I'll look into the matter. If the web site actually states that this is the case, I'll even contact that website and point out their error.

However, what is far more likely to be the case, is that they aren't really saying that.

And keep in mind too that anyone can create a website. Just because you are pointing to a web site doesn't mean they know what they are talking about.

You need to verify that the web site itself has respectable credentials.

Anyone who claims that gravity is being caused by the Earth's surface accelerating out toward us is going to also have the HUGE PROBLEM of explaining why the Earth isn't getting any bigger and has a constant radius.

:roll:


Nothing that I have ever said in any of our conversations on this matter has been wrong.

And the Earths surface isn't moving at all relative to the center of the Earth save for very minor fluctuations both up and down caused by the tidal forces of the Moon.
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A Troubled Man
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Re: On Accelerated Surfaces

Post #7

Post by A Troubled Man »

Divine Insight wrote:
Now you are wrong on a totally different topic.

These textbooks show two entire rooms with a person inside the room, and then they state in the text that "No experiment can be done to tell these two situations apart"

That is false. There are experiments that you can perform in the rooms they portray in their graphics that can indeed tell the two rooms apart.
Show us those experiments.
And where is it written that you are only allowed to use one clock in any given experiment?
Are you serious? Your profile states you are a "Retired Physicist - College Professor" yet you don't even know the reason for that? LOL. Obviously, your profile is complete bs.
Scientists have already performed an experiment where they have measured the time passed by two different clocks, one only a meter higher than the other and that they shown that the higher clock runs faster.
Of course, that is a specific experiment to show the difference in gravitational time dilation between two different heights. And, that is actually two experiments.
So you are wrong here too Troubled Man. You most certain can use multiple clocks in experiments if you wish to test how time passes at two different locations.
That's utterly ridiculous because the experiment is not being conducted at two different heights. You are no longer doing science here.
You're just getting yourself in deeper and deeper. You're the one who is trying to place limitations on science that don't exist.
You don't appear to know much about doing experiments.
A Troubled Man wrote: I NEVER said gravity was a 'force' acting on us.
Sure you did. In fact you said:
A Troubled Man wrote: GR works from reference frames under acceleration and basically demonstrates that acceleration and gravity are indistinguishable from each other. Since that is the case, we can see that gravity is not a "pulling force" and that we are all literally in free fall and it is the earths surface that is accelerating up towards us, given that gravity and acceleration are indistinguishable.
Everyone can easily see that nowhere did I say gravity is a 'force' acting on us. Why would lie about that when it's so blatantly obvious?
In red you state that it is the Earth's surface that is accelerating up towards us. That is a false claim. General Relativity does not state that the Earth's surface is accelerating up toward us. And to suggest that this is the situation does indeed imply that the Earth's surface is a force acting on us, since you claim that this is the cause of gravity.
Notice that Divine Insight is compelled to make up things in order to support his position. Pure dishonesty.
Also, what you said in blue above is also wrong. Gravity actually is a "Pulling Force" according to General Relativity. General Relativity states the the mass of the Earth causes the fabric of spacetime around it to warp, or become nonuniform. It is this non-uniform field of spacetime that cases any massive object within it to accelerate in the direction of the center of mass that is causing this warping of spacetime.

So yes General Relativity is indeed saying that there is force being exerted on your body to make it move toward the center of the earth in much the same way that an electric field is said to be a force acting on a charged particle to cause it to move in an electric field.

So General Relativity is indeed describing gravity as a "Pulling Force". Although, since you body is also a mass that creates it's own warped field of spacetime around it, you can also say that your body is pulling the Earth toward you. But the Earth is a far greater mass and therefore contribute to the warping of spacetime far more than you body does.
"In GR, gravitation is not viewed as a force, but rather, objects moving freely in gravitational fields travel under their own inertia in straight lines through curved space-time – defined as the shortest space-time path between two space-time events."

http://en.wikipedia.org/wiki/Force#Gravity

That is what I said. At this time, we can easily see you have an extremely poor understanding of General Relativity.
But you are wrong on both counts.

1. The Earth's surface is not accelerating upward toward us.
2. The Earth does generate a "Pulling Force" acting on us by warping the field of spacetime in which we reside.

So you're doubly wrong.
I have provided yet another source showing YOU to be wrong, again. Where are your sources that state gravity is force in GR?
I didn't read every source you've linked to, because you appear to keep linking to The Equivalency Principle.
I expected you didn't read them because they all agree with me.
The Equivalency Principle is not saying that the Earth surface is accelerating up toward us. If any sources you've linked to make that claim that too are wrong.

The Equivalency Principle is NOT saying that the Earth's surface is accelerating up toward us. You are reading far too much into an analogy that isn't meant to imply that conclusion.
Actually, they all show you have no idea what you're talking about.
Well, you're certainly acting like it should be. You keep pointing to The Equivalency Principle and acting like that single principle equates to General Relativity.
Acting? LOL. All you are doing is diminishing what's left of your credibility here, which is almost nil.
It describes the warping of spacetime itself which is precisely my position.
LOL. So obviously, you have no idea what I even explained to you.

A Troubled Man wrote:

Anyone who has studied GR knows that to continually refer to pictures of a room sitting on Earth and a room being accelerated through empty space is a very poor representation of GR.
It isn't, it is a representation of the Equivalence Principle.
And now you are finally starting to agree with my position. How ironic.

This is what I've been saying ALL ALONG.

What do you think causes are "free fall". Do you think it comes for FREE?

It is caused by the non-uniform field of spacetime in which we exist. And the it is the pretense of the mass of the Earth that is causing the fabric of spacetime to be warped.
LOL. Free fall is the state in which there are no external forces acting on an object, which has nothing to do with gravity.
You've been screaming all along that I've been wrong, and proclaiming that I have no understanding of General Relativity and now you're finally confessing that I've been right all along.
I have not been screaming nor have confessed anything of the sort.
The Earth's surface is not accelerating up toward us. This should be obvious to anyone. The Earth isn't getting any bigger. The surface of the Earth isn't moving relative to the center of the Earth at all.

So gravity cannot be caused by the Earth's surface accelerating up toward us.

Why do you continue to argue that it is?
Because, I understand GR and you obviously don't. All of the sources I've provided show that despite the fact you keep ignoring those sources.
I have no choice but to conclude that you just don't know how to admit that you've been wrong about something.
Yet, you've claimed textbooks are wrong and you are right. Hilarious.
You're accusations that I've been wrong about anything are unwarranted false slander.
No, they are accurate considering I keep providing sources that agree with me.
A Troubled Man wrote:
Now you are really scraping the bottom of the barrel to try to save face.

Scientists always speak of electromagnetic fields as "FORCES"

In face they speak of Gravity as a FORCE too!
Are you aware of the "The Four Forces"?

The force of Gravity.
The force of Electromagnetism
The strong nuclear force
The weak nuclear force

Scientists consider gravity to be a force in precisely the same way that they think of electromagnetism to be a force.
I have already provided a source that states gravity is not a force in GR and no scientist who understands GR would ever say it was.

The concept of gravity being a force is from Classical Newtonian physics, not GR.
Baloney.

I'm not going to dance to your wild goose chases.

If you want to play that game post them ONE at a TIME.

Be very specific about WHERE in the particular article you are pointing to it claims that the Earth's surface is actually accelerating upward toward us.

I'll look into the matter. If the web site actually states that this is the case, I'll even contact that website and point out their error.

However, what is far more likely to be the case, is that they aren't really saying that.

And keep in mind too that anyone can create a website. Just because you are pointing to a web site doesn't mean they know what they are talking about.

You need to verify that the web site itself has respectable credentials.

Anyone who claims that gravity is being caused by the Earth's surface accelerating out toward us is going to also have the HUGE PROBLEM of explaining why the Earth isn't getting any bigger and has a constant radius.
That was explained in one of my sources, it shows that those who believe the earth would get bigger don't have an understanding of GR. That would be you.

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Divine Insight
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Re: On Accelerated Surfaces

Post #8

Post by Divine Insight »

A Troubled Man wrote:
Divine Insight wrote: Now you are wrong on a totally different topic.

These textbooks show two entire rooms with a person inside the room, and then they state in the text that "No experiment can be done to tell these two situations apart"

That is false. There are experiments that you can perform in the rooms they portray in their graphics that can indeed tell the two rooms apart.
Show us those experiments.
I had already linked to a reference to them once:

Gravitational Time Dilation

I don't typically get my sources over the Internet, and I can't very well link you to my previous college courses.

I can tell you two things though:

1. The Bureau of Time Standards for the USA has done these experiments so that's a good place to check out.

2. Any book on General Relativity explains how gravity dilates time.

If you need for me to verify this for you then clearly you don't know the first thing about General Relativity and therefore you aren't in any position to even be discussing it much less telling someone else that they have no understanding of it.

A Troubled Man wrote:
And where is it written that you are only allowed to use one clock in any given experiment?
Are you serious? Your profile states you are a "Retired Physicist - College Professor" yet you don't even know the reason for that? LOL. Obviously, your profile is complete bs.
I honestly can't believe some of the things you say in our conversations.

Where do you get the idea that scientists must only use one clock per experiment?

If they were restricted to that criteria how could they ever do experiments that validate time dilation between two different clocks that experience two different physical situations?

Have you ever heard of the "Twin Brothers Paradox" used in Special Relativity to show how time dilation occurs due to motion?

Those Twin Brothers actually serve as two different biological clocks.

You can do the same experiment using physical clocks instead. Using Twin Brothers just makes it more intuitive. ;)

Clearly you are on a personal quest to slander my character.

And you're not succeeding.

On the contrary, you are just digging yourself in the hole deeper and deeper.


First you claim:

1. The surface of the Earth is accelerating upward toward us.

And now you're apparently trying to claim:

2. Scientists are only allowed to use one clock per experiment.

Both of these are wrong.



A Troubled Man wrote:
Scientists have already performed an experiment where they have measured the time passed by two different clocks, one only a meter higher than the other and that they shown that the higher clock runs faster.
Of course, that is a specific experiment to show the difference in gravitational time dilation between two different heights. And, that is actually two experiments.
Why do you call it two experiments?

This experiment would be totally meaningless if these two clocks weren't specifically linked together via an initial synchronization. They would also need to be shown to remain synchronized when simply sitting side-by-side over an extended period of time with nothing keeping them in sync other than their own individual precision.

Only then could they be separated and the relative difference in time between them be used to show that time dilation had indeed occurred.

So there's really no way that you could even call this "two different experiments'. It's one experiment that clearly uses two clocks.

Thus violating your own claim that it's non-scientific to use more than one clock per experiment.

You violate your own previous claim right here. A claim that you attempted to use to slander me.

In fact, your anxiousness to slander me shows that this isn't even about General Relativity or science at all. On the contrary all you are out to do is to attempt to discredit me.


Nothing I have stated has been wrong yet.

Yet you've been wrong at least twice already:

1. You claim the surface of the Earth is accelerating upward toward us.

That's false.

2. You claim that scientists are only allowed to use one clock per experiment.

That too is false.

A Troubled Man wrote:
You're just getting yourself in deeper and deeper. You're the one who is trying to place limitations on science that don't exist.
You don't appear to know much about doing experiments.

So far I've been right about everything and you've been wrong at least twice:

1. You claim the surface of the Earth is accelerating upward toward us.
2. You claim that scientists are only allowed to use one clock per experiment.

Both of these are false.

A Troubled Man wrote: Notice that Divine Insight is compelled to make up things in order to support his position. Pure dishonesty.
I don't need to make up anything Troubled Man.

On the contrary I'm not even out to discredit you on a personal level. That kind of personal vendetta appears to belong entirely to you.

You are the one who is constantly attempting to make an effort to discredit me on a personal level.

You are also the one who is attempting to distract from the original point of disagreement.

The original point of disagreement began because I attempted to offer you a better understanding of General Relativity after you had stated that General Relativity is saying that the earth's surface is accelerating up toward us.

That was the point of our original disagreement.

Now you are attempting to change the goalpost altogether by changing the original disagreement into whether or not Gravity should be considered to be a "force".

I'm not going there.

Physicists today clearly consider gravity to be one of the four main forces of nature.

They treat it as a force. They speak of it as a force. And even Einstein's General Relativity describes in detail the nature of a spacetime field that can be used to mathematically predict how this force of gravity will act upon any massive particle.

So if you want to argue with someone over whether or not gravity is a force, please feel free to start a thread on that. I'll be glad to offer my views on that notion in that separate thread.

In the meantime, the Earth's surface is not accelerating up toward us. Nor is there anything in General Relativity that suggests that this is the case.

You are also wrong to suggest that scientists are only permitted to use one clock per experiment. But that too is a totally different matter.

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Re: On Accelerated Surfaces

Post #9

Post by A Troubled Man »

Divine Insight wrote:
A Troubled Man wrote:
Divine Insight wrote: Now you are wrong on a totally different topic.

These textbooks show two entire rooms with a person inside the room, and then they state in the text that "No experiment can be done to tell these two situations apart"

That is false. There are experiments that you can perform in the rooms they portray in their graphics that can indeed tell the two rooms apart.
Show us those experiments.
I had already linked to a reference to them once:

Gravitational Time Dilation

I don't typically get my sources over the Internet, and I can't very well link you to my previous college courses.

I can tell you two things though:

1. The Bureau of Time Standards for the USA has done these experiments so that's a good place to check out.

2. Any book on General Relativity explains how gravity dilates time.

If you need for me to verify this for you then clearly you don't know the first thing about General Relativity and therefore you aren't in any position to even be discussing it much less telling someone else that they have no understanding of it.

A Troubled Man wrote:
And where is it written that you are only allowed to use one clock in any given experiment?
Are you serious? Your profile states you are a "Retired Physicist - College Professor" yet you don't even know the reason for that? LOL. Obviously, your profile is complete bs.
I honestly can't believe some of the things you say in our conversations.

Where do you get the idea that scientists must only use one clock per experiment?

If they were restricted to that criteria how could they ever do experiments that validate time dilation between two different clocks that experience two different physical situations?

Have you ever heard of the "Twin Brothers Paradox" used in Special Relativity to show how time dilation occurs due to motion?

Those Twin Brothers actually serve as two different biological clocks.

You can do the same experiment using physical clocks instead. Using Twin Brothers just makes it more intuitive. ;)

Clearly you are on a personal quest to slander my character.

And you're not succeeding.

On the contrary, you are just digging yourself in the hole deeper and deeper.


First you claim:

1. The surface of the Earth is accelerating upward toward us.

And now you're apparently trying to claim:

2. Scientists are only allowed to use one clock per experiment.

Both of these are wrong.



A Troubled Man wrote:
Scientists have already performed an experiment where they have measured the time passed by two different clocks, one only a meter higher than the other and that they shown that the higher clock runs faster.
Of course, that is a specific experiment to show the difference in gravitational time dilation between two different heights. And, that is actually two experiments.
Why do you call it two experiments?

This experiment would be totally meaningless if these two clocks weren't specifically linked together via an initial synchronization. They would also need to be shown to remain synchronized when simply sitting side-by-side over an extended period of time with nothing keeping them in sync other than their own individual precision.

Only then could they be separated and the relative difference in time between them be used to show that time dilation had indeed occurred.

So there's really no way that you could even call this "two different experiments'. It's one experiment that clearly uses two clocks.

Thus violating your own claim that it's non-scientific to use more than one clock per experiment.

You violate your own previous claim right here. A claim that you attempted to use to slander me.

In fact, your anxiousness to slander me shows that this isn't even about General Relativity or science at all. On the contrary all you are out to do is to attempt to discredit me.


Nothing I have stated has been wrong yet.

Yet you've been wrong at least twice already:

1. You claim the surface of the Earth is accelerating upward toward us.

That's false.

2. You claim that scientists are only allowed to use one clock per experiment.

That too is false.

A Troubled Man wrote:
You're just getting yourself in deeper and deeper. You're the one who is trying to place limitations on science that don't exist.
You don't appear to know much about doing experiments.

So far I've been right about everything and you've been wrong at least twice:

1. You claim the surface of the Earth is accelerating upward toward us.
2. You claim that scientists are only allowed to use one clock per experiment.

Both of these are false.

A Troubled Man wrote: Notice that Divine Insight is compelled to make up things in order to support his position. Pure dishonesty.
I don't need to make up anything Troubled Man.

On the contrary I'm not even out to discredit you on a personal level. That kind of personal vendetta appears to belong entirely to you.

You are the one who is constantly attempting to make an effort to discredit me on a personal level.

You are also the one who is attempting to distract from the original point of disagreement.

The original point of disagreement began because I attempted to offer you a better understanding of General Relativity after you had stated that General Relativity is saying that the earth's surface is accelerating up toward us.

That was the point of our original disagreement.

Now you are attempting to change the goalpost altogether by changing the original disagreement into whether or not Gravity should be considered to be a "force".

I'm not going there.

Physicists today clearly consider gravity to be one of the four main forces of nature.

They treat it as a force. They speak of it as a force. And even Einstein's General Relativity describes in detail the nature of a spacetime field that can be used to mathematically predict how this force of gravity will act upon any massive particle.

So if you want to argue with someone over whether or not gravity is a force, please feel free to start a thread on that. I'll be glad to offer my views on that notion in that separate thread.

In the meantime, the Earth's surface is not accelerating up toward us. Nor is there anything in General Relativity that suggests that this is the case.

You are also wrong to suggest that scientists are only permitted to use one clock per experiment. But that too is a totally different matter.
Since Divine Insight refuses to acknowledge sources and citations in favor of his misinformed opinions and dishonest tactics, no further discussion is required.

Topic is locked.

Locked