Dark energy was discovered by two international teams that included astronomers.The FE term "Dark Energy" is not to be confused with dark energy as defined within astronomy. While both refer to a largely unknown force, they are not one and the same.
Do you see where I'm getting with this?No. If you want to make a point, make it. We won't be trying to guess.
It’s only a problem if you are mistakenly under the impression that something is somehow prohibited from undergoing constant acceleration for an arbitrary length of time. Which would put you at odds with long established theory from some great scientific minds, but you’d be far from the first person to plant a flag on that hill just to die on it.I'm unsure as to why you think that I am mistaken. You have made a statement but failed to provide any evidence. What theory, what scientists? I'm honestly unsure as to whether this is authentic or a joke. The speed of light in a certain medium is a speed barrier that cannot be surpassed, numerous experiments have proved this. One such example is the phenomenon of Cherenkov radiation, which is the blue glow observed in nuclear coolant pools. Light travels much slower underwater than in a vacuum, so nuclear material can emit radiation that would be traveling faster than light in water. This cannot happen, and so the particles emit photons to release energy.
Okay, here's the thing.
According to the FE theory, the Earth moves upwards due to a constant acceleration caused by dark energy/the Davis plane.
I'm quite certain you can't demonstrate that you are right, because doing so would violate General Relativity, which I strongly suspect is the very theoretical framework you are referring to when you say nothing can travel faster than "the speed of light" (which you probably meant to call simply c, or the vacuum speed of light, but whatever it doesn't matter). The issue is that you are defining the speed of something either against some sort of a preferred FoR (which doesn't exist) or from some independent observer's FoR, which is necessarily going to be different than that of an observer standing on the surface of a constantly accelerating disc.It’s only a problem if you are mistakenly under the impression that something is somehow prohibited from undergoing constant acceleration for an arbitrary length of time. Which would put you at odds with long established theory from some great scientific minds, but you’d be far from the first person to plant a flag on that hill just to die on it.I'm unsure as to why you think that I am mistaken. You have made a statement but failed to provide any evidence. What theory, what scientists? I'm honestly unsure as to whether this is authentic or a joke. The speed of light in a certain medium is a speed barrier that cannot be surpassed, numerous experiments have proved this. One such example is the phenomenon of Cherenkov radiation, which is the blue glow observed in nuclear coolant pools. Light travels much slower underwater than in a vacuum, so nuclear material can emit radiation that would be traveling faster than light in water. This cannot happen, and so the particles emit photons to release energy.
If you are referring to linear acceleration, then I am right. An object is prohibited from undergoing linear acceleration for an arbitrary length of time. Acceleration is change of velocity. For a linearly accelerated flat earth to match empirical observations of gravity, the world would have to constantly increase it's velocity. At some point, in this case just under a year as I previously mentioned, the world would reach the speed of light. The idea of the speed of light then has to either be dispelled with, which contrasts with observations, or has to be somehow overcome. The acceleration cannot be changed, because that would result in a perceived change of gravity. The speed of the earth cannot be changed, because then everyone would smack into the ceiling at the speed of light (which would be quite a sight).
Then I fell down today. When I fell I DEFINITELY sensed acceleration which I had previously discussed. This, to me at least, shows that I am the one accelerating down because i'm unable to sense the acceleration of objects outside of my body.It sounds to me like you misunderstood what I said previously. You can certainly feel your own weight. Lie down on your back and you can feel your back pressing against the floor (and vice versa). Sit in an accelerating car* and you can feel the car seat press against your back. That's all that "feeling acceleration" is in everyday scenarios.
The same thing happened when I jumped off the diving board. I didn't sense that I was floating weightless. I sensed that I was accelerating down toward the water. I wonder how this observation is possible in the UA model.
you cannot tell the difference between yourself falling down and yourself being perfectly still in an ever-accelerating body of air.
However, Equivalence Theory is unrelated to either school of thought.This is untrue. The consequences of the physics behind EP are essential for either model to work. If you prove that it doesn't actually work, you've disproved RET.
It’s only a problem if you are mistakenly under the impression that something is somehow prohibited from undergoing constant acceleration for an arbitrary length of time. Which would put you at odds with long established theory from some great scientific minds, but you’d be far from the first person to plant a flag on that hill just to die on it.I'm unsure as to why you think that I am mistaken. You have made a statement but failed to provide any evidence. What theory, what scientists? I'm honestly unsure as to whether this is authentic or a joke. The speed of light in a certain medium is a speed barrier that cannot be surpassed, numerous experiments have proved this. One such example is the phenomenon of Cherenkov radiation, which is the blue glow observed in nuclear coolant pools. Light travels much slower underwater than in a vacuum, so nuclear material can emit radiation that would be traveling faster than light in water. This cannot happen, and so the particles emit photons to release energy.
If you are referring to linear acceleration, then I am right. An object is prohibited from undergoing linear acceleration for an arbitrary length of time. Acceleration is change of velocity. For a linearly accelerated flat earth to match empirical observations of gravity, the world would have to constantly increase it's velocity. At some point, in this case just under a year as I previously mentioned, the world would reach the speed of light. The idea of the speed of light then has to either be dispelled with, which contrasts with observations, or has to be somehow overcome. The acceleration cannot be changed, because that would result in a perceived change of gravity. The speed of the earth cannot be changed, because then everyone would smack into the ceiling at the speed of light (which would be quite a sight).
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If you are talking about centrifugal acceleration, on the other hand, there is quite another problem. Centrifugal acceleration is observably different from gravity. Just watch this amazing video by Tom Scott:
https://www.youtube.com/watch?v=bJ_seXo-Enc
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Before I go on, Dave, I am unsure as to what you are arguing. Your arguments seem to support a round earth, which is what I support. Are we beating a dead horse, because I am an RE supporter. We seem to be arguing the same point.No, you were arguing that an object cannot undergo constant acceleration indefinitely because it would eventually exceed c, therefore the Universal Acceleration model for FE is impossible.
There's only one way to test this, and that is to build a rocket, accelerate it upwards at around 3g until it reaches a velocity of a little over 11 km s-1 relative to the surface of the Earth. If the rocket escapes the Earth carries on into space with the same relative velocity then RE gravity is correct. If however, the Earth slams into the back of the rocket after some period of time since the Earth is accelerating, then FE Universal Acceleration is correct.This, once again, defies the equivalence principle or the definition of gravity under the FE model - it's hard to say which one because you provided very little information on your actual reasoning. Whenever you say that you've found a way to distinguish things that are indistinguishable by definition, you probably did a dumb.
In short: no, FET does not go against the idea of escape velocities.
Is there anything in the wiki on this?Yes, it's described in the "The Basics" paragraph of the UA page (https://wiki.tfes.org/Universal_Acceleration#The_Basics). Universal Acceleration is, well, universal. The main (but likely not only) reason for objects immediately above the Earth not being affected by it is that the Earth's mass shields us from the effect. Once you're sufficiently far away, you will have escaped the Earth's "gravitational" effect, or the nullification thereof.
Yes, it's described in the "The Basics" paragraph of the UA page (https://wiki.tfes.org/Universal_Acceleration#The_Basics). Universal Acceleration is, well, universal. The main (but likely not only) reason for objects immediately above the Earth not being affected by it is that the Earth's mass shields us from the effect. Once you're sufficiently far away, you will have escaped the Earth's "gravitational" effect, or the nullification thereof.
The FE term "Dark Energy" is not to be confused with dark energy as defined within astronomy. While both refer to a largely unknown force, they are not one and the same.
So would i be right in saying that when you reach a certain height above the Earth's surface, then you will start to feel the effects of universal acceleration?Yes, you would be right in repeating what I just said. But before you jump to your next "gotcha!", you might want to familiarise yourself with the resources I linked you to.
Then can you explain to me, with proof, as to what is 'dark energy' in the FE theory?No, I cannot explain to you what an unknown force is. If I could, it wouldn't be described as unknown.
It sounds to me like you misunderstood what I said previously. You can certainly feel your own weight. Lie down on your back and you can feel your back pressing against the floor (and vice versa). Sit in an accelerating car* and you can feel the car seat press against your back. That's all that "feeling acceleration" is in everyday scenarios.
What you felt when you fell was a brief experience of weightlessness/free-fall. This, too, can be colloquially described as "feeling acceleration", but it's a wholly distinct phenomenon. It sounds to me that by using an ambiguous term, you accidentally drew an equivalence between the two.
In the free-fall scenario, it follows from Einstein's Equivalence Principle that you cannot tell the difference between yourself falling down and yourself being perfectly still in an ever-accelerating body of air.
So would i be right in saying that when you reach a certain height above the Earth's surface, then you will start to feel the effects of universal acceleration?Yes, you would be right in repeating what I just said. But before you jump to your next "gotcha!", you might want to familiarise yourself with the resources I linked you to.Then can you explain to me, with proof, as to what is 'dark energy' in the FE theory?No, I cannot explain to you what an unknown force is. If I could, it wouldn't be described as unknown.
On a disc-shaped FE, the proof would be that things fall down. A force that makes things fall down on Earth exists. The shape of the Earth will put some parameters around what that force might be and how it might work.So would i be right in saying that when you reach a certain height above the Earth's surface, then you will start to feel the effects of universal acceleration?Yes, you would be right in repeating what I just said. But before you jump to your next "gotcha!", you might want to familiarise yourself with the resources I linked you to.Then can you explain to me, with proof, as to what is 'dark energy' in the FE theory?No, I cannot explain to you what an unknown force is. If I could, it wouldn't be described as unknown.
Okay, then can you submit proof that the said force exists?
This analogy is not appropriate. In order to correctly simulate this, you'd have to find a way to switch gravity/UA off and on on demand. Bungee cords, platforms, or any other form of suspension won't do it.
Unfortunately, it is you who will have to "contend" with physics to make your claim work. Namely, the Equivalence Principle. If you find a way to disprove this principle, you will have completely destroyed the foundations of the Round Earth Theory. Aside from being an own goal, I somehow doubt your chances of success.
Your anecdote on the inner ear makes things even more complicated. You're no longer just discussing free-fall (which was already too complex for you to appropriately work with), but you are now introducing additional momenta and rotation. If you want to rely on that particular sensation, you'll have to adjust your experiment to include those factors. Notably, this is another case of abusing ambiguous terms - falling over is not free-fall, but you chose to refer to both as "falling".
This discussion will be useless unless you choose a scenario and describe it accurately. Mixing them up, or picking and choosing from completely different scenarios, is not going to help you understand the physics here.
Note that none of this touches on FET, not yet. We're just discussing high school physics.
(...) It takes more force to roll a bowling ball across the floor than a marble. So it is curious how 'gravity' knows how to equalize the inertial resistance all bodies naturally exhibit when they are pulled or pushed through space so they fall at the same rate.
Really? Gravity cancels out exactly with inertial resistance by pulling harder for heavier objects?
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What about on another planet like the conventional Saturn where, assuming that it had a surface that you could stand on, g is stronger? The inertial resistance of a body stays the same throughout the universe (on Earth, in weightless space, on Saturn), but g can change.
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Why should the Earth be so special that gravity exactly cancels out with inertial resistance on Earth to a very high precision but not on any other planet or environment?
Sorry, can you clarify? You appear to be claiming that a body's inertial mass and inertial resistance changes when under different levels of gravity.
Can you clarify this? Why is the inertial force of a bullet or bowling ball approaching you the same in weightless space and on Earth? According to that logic inertial resistance should disappear in a weightless environment far from gravitational fields.
If a bowling ball is in vertical free fall towards the surface of Saturn, are you claiming that it would take more force to move it sideways horizontally during its downwards descent than on Earth, since the bowling ball now has a greater inertial mass? And if not, why should the force to move that object sideways horizontally be the same as on Earth or in weightless space?
However, Equivalence Theory is unrelated to either school of thought.This is untrue. The consequences of the physics behind EP are essential for either model to work. If you prove that it doesn't actually work, you've disproved RET.
I also have some doubts over the Universal accelerator. If the earth were really accelerating constantly at approximately 9.8 meters per second^2, then from a halt it would reach the speed of light in just under a year. Does this mean that FET denies the speed of light as a universal speed limit? I know that there is some disagreement in the community over this, but this is a problem that has to be avoided somehow.
Once you're sufficiently far away, you will have escaped the Earth's "gravitational" effect, or the nullification thereof.
Why would it disprove RET?Well, if you declare a central tenet of your model to be false, that necessarily requires you to decline the model in its current form. It's really not much more profound than that - if you conclude that RET is false, then you conclude that RET is false.
If there are any subtle flaws within the Equivalence PrincipleWe are not discussing "subtle flaws" here. The contention is whether or not the Equivalence Principle should be discarded. I propose that it shouldn't.
That's at odds with the fact that the flat surface we would be on is now travelling upwards at quite a fast speed (incredibly greater than the speed of light).Please complete your assertion by answering the following question: Relative to what frame of reference?
So how come we don't observe this?! in fact most of those smudges of light that we call galaxies are actually redshifted!
I'll say it again slowly. Equivalence Theory is not a central part of either model.It doesn't matter how slowly you type, you continue to be wrong. If you disprove EP, then you disprove the physics that directly concludes EP. In doing so, you disprove RET in its current form.
I find it odd that FET states that the effects of the universal accelerator begin to take effect as one gets further away from Earth.You are expected to develop an understanding of the basics before posting here. Please do so before continuing with the debate.
In FET all celestial bodies are accelerating at the same rateThis statement is false. Your issue stems from making poor assumptions.
Right, but you're using RET here to mean "the whole of physics". And yeah, it would fundamentally change our understanding of things. But I think Regicide is talking about RET in the more literal sense of the theory that the earth is round [shouldn't it really be GET, btw?]I'll say it again slowly. Equivalence Theory is not a central part of either model.It doesn't matter how slowly you type, you continue to be wrong. If you disprove EP, then you disprove the physics that directly concludes EP. In doing so, you disprove RET in its current form.
All celestial bodies (that we know) share UA, but UA is not the only contributing factor to their motion.
Right, but you're using RET here to mean "the whole of physics".More or less, yes. Does that affect the validity of my argument, in your mind?
So what are these other contributing factors to their motion?
You are expected to develop an understanding of the basics before posting here. Please do so before continuing with the debate.
In FET all celestial bodies are accelerating at the same rateThis statement is false. Your issue stems from making poor assumptions.
All celestial bodies (that we know) share UA, but UA is not the only contributing factor to their motion. If it was, we'd perceive all celestial bodies as stationary relative to one another. Surely you knew this is not the case, so why waste our time with something so poorly thought out?
The stars must be accelerating at the same rate in FET, don't you think?Given that the stars are in motion relative to an Earthbound observer, this is entirely impossible. I already told you that. Asking me again won't change this. If you disagree that we can observe stars moving relative to us, I can't really help you.
In FET the stars are in a layer just a few thousand km above the EarthI can't say I agree, but perhaps you're addressing a specific claim made by someone else. Nonetheless, your view that stars are motionless relative to the Earth is going to be a bit of a showstopper.
That's at odds with the fact that the flat surface we would be on is now travelling upwards at quite a fast speed (incredibly greater than the speed of light).Please complete your assertion by answering the following question: Relative to what frame of reference?
Once your assertion has been made complete and coherent, please explain: How have you concluded this?
Your understanding of redshift and blueshift also appears to be fundamentally flawed, though you haven't been forthcoming enough for it to be completely clear how/why. Somehow, you're trying to tie it to acceleration relative to an external inertial observer rather than objects moving apart/closer together. You're also discussing the speed of the light instead of its wavelength. It's quite messy.
The frame of reference is irrelevant.Incorrect. The frame of reference is absolutely crucial. If you believe it to be irrelevant, simply choose your favourite one. I'll give you a hint, there are three FoR's that are worth considering here: a local observer standing atop the Earth, a local observer located immediately above the Earth who is initally at rest relative to the Earth, and an external inertial observer.
If I'm accelerated in a direction and nothing is stopping me, I will acquire speed.Correct, but entirely irrelevant. The magnitude of that speed is the key point here, not the fact that it's increasing. Specifically, your claim that "the flat surface we would be on is now travelling upwards at quite a fast speed (incredibly greater than the speed of light)" contradicts basic physics. You cannot identify a frame of reference in which the Earth is moving faster than c without contradicting Special Relativity. As was the case previously, I suggest that throwing physics out the window is not the best way for you to defend RET.
because you're not in a different system S' but you are on SIf you're on S, your speed relative to S is 0m/s, and the speed of S relative to you is 0m/s. That's significantly lower than c.
Its not messy, I'm talking about redshift/blueshift for uniform acceleration which is part of EP and is used as evidence to back UA.So, here's the thing. I raised specific objections to what you're saying. Responding with nothing other than "it's not messy" is not going to cut it.
For example, if we have a rocket accelerating at 1g away from any gravitational field with two observers onboardThis is where you fail. The Doppler Effect is experienced when two bodies are in motion relative to one another. I already explained this to you, but you chose to ignore it. Two bodies accelerating upwards at the same rate and with no initial velocity will be stationary relative to one another. Thus, UA itself is not going to have any impact on the Doppler Effect.
The light from the stars directly above the Earth would be blueshifted and an observer on one of those stars would see the Earth being redshifted.This would be true if the stars were accelerating away from the Earth. As far as UA is concerned, they're not.
The frame of reference is absolutely crucial. If you believe it to be irrelevant, simply choose your favourite one. I'll give you a hint, there are three FoR's that are worth considering here: a local observer standing atop the Earth, a local observer located immediately above the Earth who is initally at rest relative to the Earth, and an external inertial observer.
If I'm accelerated in a direction and nothing is stopping me, I will acquire speed.Correct, but entirely irrelevant. The magnitude of that speed is the key point here, not the fact that it's increasing. Specifically, your claim that "the flat surface we would be on is now travelling upwards at quite a fast speed (incredibly greater than the speed of light)" contradicts basic physics. You cannot identify a frame of reference in which the Earth is moving faster than c without contradicting Special Relativity. As was the case previously, I suggest that throwing physics out the window is not the best way for you to defend RET.
because you're not in a different system S' but you are on SIf you're on S, your speed relative to S is 0m/s, and the speed of S relative to you is 0m/s. That's significantly lower than c.
What you felt when you fell was a brief experience of weightlessness/free-fall. This, too, can be colloquially described as "feeling acceleration", but it's a wholly distinct phenomenon. It sounds to me that by using an ambiguous term, you accidentally drew an equivalence between the two.
Special Relativiy is safe, because what you cannot do is *measure* a speed faster than light in any frame of reference. But a traveller on a spaceship that is constantly accelerating at g toward a, let's say ten light years afar, star will reach it quicker than the speed of light, according *on the spaceship clock*, so it's indirectly a travel faster than the speed of light.
But a traveller on a spaceship that is constantly accelerating at g toward a, let's say ten light years afar, star will reach it quicker than the speed of light, according *on the spaceship clock*, so it's indirectly a travel faster than the speed of light.That has nothing go do with speed, and everything to do with spacetime.
What would explain that? Yes, Einstein said acceleration and gravity produce the same effects but that does not come close to explaining why you can feel the acceleration.Didn't we already discuss this in the part you've quoted? The feeling you've described is created by your inner ear, and is not exclusively tied to acceleration.
For example, if we have a rocket accelerating at 1g away from any gravitational field with two observers onboardThis is where you fail. The Doppler Effect is experienced when two bodies are in motion relative to one another. I already explained this to you, but you chose to ignore it. Two bodies accelerating upwards at the same rate and with no initial velocity will be stationary relative to one another. Thus, UA itself is not going to have any impact on the Doppler Effect.
What would explain that? Yes, Einstein said acceleration and gravity produce the same effects but that does not come close to explaining why you can feel the acceleration.Didn't we already discuss this in the part you've quoted? The feeling you've described is created by your inner ear, and is not exclusively tied to acceleration.
You say that "the feeling of falling was very dramatic, and nothing at all like hovering while the ground rushed up", but you have no way of
contrasting the two. They are, as you've admitted, equivalent.
Two observers on a rocket accelerating at the same rateAt the same rate relative to what? In what direction? It's impossible to judge the correctness of your statement because it doesn't even come close to being complete. In the specific scenario you proposed (Earth and stars under UA), the Earth and stars are stationary relative to one another as far as UA is concerned. In other words, a=0.
What am I missing?The air. A car accelerating towards you doesn't cause your entire surroundings to start zooming around you. The sensation of falling does.
But a traveller on a spaceship that is constantly accelerating at g toward a, let's say ten light years afar, star will reach it quicker than the speed of light, according *on the spaceship clock*, so it's indirectly a travel faster than the speed of light.That has nothing go do with speed, and everything to do with spacetime.
What am I missing?The air. A car accelerating towards you doesn't cause your entire surroundings to start zooming around you. The sensation of falling does.
Two observers on a rocket accelerating at the same rateAt the same rate relative to what? In what direction? It's impossible to judge the correctness of your statement because it doesn't even come close to being complete. In the specific scenario you proposed (Earth and stars under UA), the Earth and stars are stationary relative to one another as far as UA is concerned. In other words, a=0.
Once again, you talk of speed, distance, and an individual photon (for which the concept of Doppler shifts is meaningless). You need to be talking about waves and wavelengths. Until you do so, you're not even discussing the Doppler effect in any meaningful fashion. There's a reason this failure is significant. As much as your upward acceleration will speed up the rate at which the waves hit you, the upward acceleration of the source will slow that rate down. If the two vectors are identical, the effect will cancel out. This is why the Doppler effect concerns the effect of the relative motion of two bodies on the wavelengths of the wave.
Two observers on a rocket accelerating at the same rateAt the same rate relative to what? In what direction? It's impossible to judge the correctness of your statement because it doesn't even come close to being complete. In the specific scenario you proposed (Earth and stars under UA), the Earth and stars are stationary relative to one another as far as UA is concerned. In other words, a=0.
Freefall at terminal is a very noisy place but there is no sensation of falling at all. Only pre terminal.Well, yes, once you stop accelerating, your inner ear stops perceiving the effects of the air's acceleration relative to you. What... what exactly is your objection here?
Like wise, we should be under the influence of UA, and we should experience a=0.Incorrect. Please, at the very least read the article describing UA before posting here.
On the same rocket but now accelerating at 1g in space away from any gravityOnce again, for those in the back: the stars are not a rocket, and they are not accelerating away from the Earth. They are not moving away from the Earth, or at least are not doing so due to UA. As far as UA is concerned, the height of the stars relative to the Earth's surface remains static.
Where is the accelerationa is 0. Therefore, . I'll let you crunch the numbers from there.
On the same rocket but now accelerating at 1g in space away from any gravityOnce again, for those in the back: the stars are not a rocket, and they are not accelerating away from the Earth. They are not moving away from the Earth, or at least are not doing so due to UA. As far as UA is concerned, the height of the stars relative to the Earth's surface remains static.
Your analogy would make some sense if you were to replace your source of gravity with an upward acceleration of a rocket. However, you're not doing that. You're adding more acceleration to the mix and acting surprised that your results have changed. That's not equivalence, now is it?Where is the accelerationa is 0. Therefore, . I'll let you crunch the numbers from there.
The Doppler effect occurs when two bodies are in motion relative to one another. Reference frames don't come into this. You can use one of the bodies as a frame of reference to help you simplify the task of drawing a diagram, but you can just as well do it from an external inertial FoR.
I would strongly suggest that you do this, even if just in your imagination. I'll borrow some diagrams from Wikipedia. Consider a source of waves like this:
(https://upload.wikimedia.org/wikipedia/commons/e/e3/Dopplereffectstationary.gif)
Now imagine it's moving away from you. Imagine the observer is located in the middle of the left-hand-side y axis. Whether the source accelerates or not is not important, since we're only discussing whether the effect is present at all, not its magnitude. The presence of relative motion will therefore be good enough.
(https://upload.wikimedia.org/wikipedia/commons/c/c9/Dopplereffectsourcemovingrightatmach0.7.gif)
You can, of course, see that a point on the left y axis would now observe a Doppler shift.
Finally, imagine that the point is not stationary on the y axis, but is rather moving in sync with the source. We can draw it from two perspectives. One of them uses the source as a frame of reference. That's just a repeat of the first diagram I've linked. But we can also draw it from an inertial perspective for your benefit.
(https://i.imgur.com/zoKGBbR.gif)
Even though the source is moving, so is the observer. Since their speeds are matched, the observer picks up the waves' peaks at the exact same rate as if both objects were stationary. Consequently, the wavelength is unchanged compared to the two objects being stationary within the inertial FoR.
The Doppler effect occurs when the source and observer are in motion relative to one another. The Equivalence Principle doesn't come into this. The two bodies are not in motion relative to one another (as far as UA is concerned), so there is no possible Doppler shift to be seen as a result of UA.
One can also see the role of the equivalence principle by considering a pulse of light emitted over a distance h along the axis of a spaceship in uniform acceleration g in outer space. The time taken for the light to reach the detector is t = h (we use units G = c = 1). The difference in velocity of the detector acquired during the light travel time is v = gt = gh, the Doppler shift z in the detected light. This experiment, carried out in the gravity-free environment of a spaceship whose rockets produce an acceleration g, must yield the same result for the energy shift of the photon in a uniform gravitational field f according to the equivalence principle. The Pound-Rebka-Snyder experiments can therefore be regarded as an experimental proof of the equivalence principle. ”
Pete, all those diagrams you have used above are Doppler shifts for 'sound waves', so are not relevant for this discussion as we are talking about light waves.The Doppler effect applies to all waves. It applies to sound waves, light waves, ripples in a disturbed body of water, vibrations of a piece of string - waves. If you believe that sound waves would behave differently in your scenario, you'll have to state why. If you believe that the diagrams do not apply to the perception of light, please feel free to provide ones of your own which illustrate the same scenario, and highlight any corrections that you believe are necessary.
I suppose the last diagram is a little bit more on the lines but its still sound waves and the source and observer are travelling at constant speed they are nor accelerating.I already explained why this is irrelevant. One: the bodies are stationary relative to one another - this will not change if you accelerate the entire system. Two: we are discussing the presence of a Doppler shift, not its magnitude over time. As such, we only need to concern ourselves with the relative motion of the two bodies (or lack thereof, as the case may be). The magnitudes of said (non-)motion are irrelevant. If you disagree, you will have to state why. Specifically, you will have to address my position.
It seems you are going against the Equivalence principle here Pete.Not at all. You made two errors:
The Pound-Rebka ExperimentI already explained this to you several times. You're taking an experiment which concerns a gravity-free environment, thwacking it into an environment that is not gravity-free, and pondering super hard about why your results are not working out for you. You'd have to remove gravity/UA from your scenario to obtain reasonable results.
I suppose the last diagram is a little bit more on the lines but its still sound waves and the source and observer are travelling at constant speed they are nor accelerating.I already explained why this is irrelevant. One: the bodies are stationary relative to one another - this will not change if you accelerate the entire system. Two: we are discussing the presence of a Doppler shift, not its magnitude over time. As such, we only need to concern ourselves with the relative motion of the two bodies (or lack thereof, as the case may be). The magnitudes of said (non-)motion are irrelevant. If you disagree, you will have to state why. Specifically, you will have to address my position.It seems you are going against the Equivalence principle here Pete.Not at all. You made two errors:
- You chose one two scenarios which are not equivalent: gravity, and gravity plus acceleration. This is incorrect. For EP to apply, the gravitational element would have to be absent in the second scenario.
- You assumed that the Doppler effect will occur between two bodies who are stationary to each other, as long as they're in motion relative to some other observer. This is a complete misunderstanding of the Doppler effect.
I will try to explain (again) how we can see Doppler shifts when two observers are stationary relative to one another in a uniform accelerating frame.You don't need to keep re-explaining it. You need to fix the errors in your claims. I even provided you with a handy list. Are you going to get started, or are we done here?
I suppose the last diagram is a little bit more on the lines but its still sound waves and the source and observer are travelling at constant speed they are nor accelerating.I already explained why this is irrelevant. One: the bodies are stationary relative to one another - this will not change if you accelerate the entire system. Two: we are discussing the presence of a Doppler shift, not its magnitude over time. As such, we only need to concern ourselves with the relative motion of the two bodies (or lack thereof, as the case may be). The magnitudes of said (non-)motion are irrelevant. If you disagree, you will have to state why. Specifically, you will have to address my position.It seems you are going against the Equivalence principle here Pete.Not at all. You made two errors:
- You chose one two scenarios which are not equivalent: gravity, and gravity plus acceleration. This is incorrect. For EP to apply, the gravitational element would have to be absent in the second scenario.
- You assumed that the Doppler effect will occur between two bodies who are stationary to each other, as long as they're in motion relative to some other observer. This is a complete misunderstanding of the Doppler effect.
I will try to explain (again) how we can see Doppler shifts when two observers are stationary relative to one another in a uniform accelerating frame.
Einstein's elevator, have a look at this:
(https://i.imgur.com/mk5Ty4T.png)
(https://i.imgur.com/1vgswde.png)
If the Pound-Rebka experiment was carried out on the accelerating elevator away from any gravity then according to Einstein they would've had the same results with a Doppler shift z of
Using the Doppler shift formula in my earlier post you can see that the expected value for a Doppler shift in an accelerating frame where both observer are 22.6 m apart and do not move relative to one another is:
plug in the values to give
Not only would both observers see Doppler shifts, they would also see the effects of time dilation, the clock at the top of the elevator will tick faster that the one at the bottom one, which is same effects in gravity close to the surface of the Earth.
Are you winding me up Pete or what? ;)
link for the diagram: http://www.astro.ucla.edu/~wright/relatvty.htm
Not at all. You made two errors:
- You chose one two scenarios which are not equivalent: gravity, and gravity plus acceleration. This is incorrect. For EP to apply, the gravitational element would have to be absent in the second scenario.
- You assumed that the Doppler effect will occur between two bodies who are stationary to each other, as long as they're in motion relative to some other observer. This is a complete misunderstanding of the Doppler effect.
There is one more failure that I raised early on (https://forum.tfes.org/index.php?topic=16458.msg214157#msg214157), which I don't want you to forget just yet:
- You assume that UA is the only source of motion/acceleration of the stars relative to the Earth.
Once you've tidied up your messy claims, resolving this failure will finally eliminate all outstanding contradictions.
Where did i say gravity plus acceleration?Every time you describe "a rocket accelerating away from any gravity". In other words: all the time, everywhere, without respite.
Pete, two observers that are stationary to each other in an accelerating frame, away from any gravity, really do see the Doppler effect.Right, but that's not the signifciant factor in the shift you're observing from the stars. I pointed this out very early on, so there's no way you could possibly still be rambling about that. You're talking about the shift that supposedly contradicts observation. Hint: it doesn't, and as soon as you've tidied up your mess, that much will be obvious.
Lets forget about the stars for now and just concentrate on the Earth.No, let's not. I'm not interested in your excuses and diversions. Fix your messy claims. If you do not want to take responsibility for your failures, then stop wasting our time.
Lets forget about the stars for now and just concentrate on the Earth.No, let's not. I'm not interested in your excuses and diversions. Fix your messy claims. If you do not want to take responsibility for your failures, then stop wasting our time.
We don't need to use the starsNo, no, let's not change your claims. Let's simply correct the errors within. You were provided with a list. Get on with it.
If the Pound-Rebka experiment was carried out in an accelerating frame (without gravity) such as a rocket or in this case the Earth accelerating upwards (UA), then the results would be somewhat different. This is due to the 'blueshift drift' effect for accelerating frames. The formula for the expected z values is given by: which is time dependent.
The plot below shows blueshift (z) against time, if the same experiment was carried out in gravity (red line) and an accelerating frame such as UA (blue line). For the accelerating frame, we have blueshift drift, and for gravity no blueshift drift would be detected. The time axis is in seconds and goes to six months.
Using the Equivalence Principle as evidence to support UA is fine for things like how objects fall, projectile motion etc... but when it comes to the nature of light and how we observe its Doppler shifts over periods of time then it no longer holds. This flaw within the Equivalence Principle is a way to distinguish between an accelerating frame and gravity.
Hmm, but I thought the idea of the EP, was that there was no local experiment you can do which differentiated between free fall and an accelerating frame relative to some observer who is not accelerating or experiencing free fall