[roosh]

Originally Posted by 18AD

As an aside: If we stay within the remit of phenomenology (which I'm trying to do) the experience of walking and the ground moving are experientially distinct phenomena. When I walk I am propelling myself, my senses tell me this. When the ground moves I have to adjust my balance, my senses tell me this (but I probably do it automatically). Regardless of experimental verifiability.

Whether either of us is absolutely moving or at rest is beyond the scope of this analysis.

Apologies, I had started replying to the post before you added this part.

I don't think the question of whether either of us is absolutely moving, or at rest, is beyond the scope of the analysis. I would say that we cannot determine which of us (us or the ground) is absolutely moving, but we can deduce that, at least one of us has to be.

As you mention, the experience of us walking and the ground moving are, at the very least, deductively different; I'm not sure if they are necessarily experientially different, because if we take the example of where the earth is always behaving as a treadmill, and you are being carried around with it, then you wouldn't be able to tell the difference; you're walking then would feel like normal walking; however, we can still deduce that they are different.


The question then becomes, what is "absolute motion"; "absolute" as I understand it means something which can be viewed without relation to other things i.e. something that is true, in and of itself. So absolute motion would be a state of motion which cna be viewed without relation to other things.

It would be a simple "yes or no", "either, or" question.

E.g. "Is X moving?" or "Is Y moving?", or "Is X or Y moving?"

On a more personal level it would be the question "Am I moving?", "am I moving, or is it the ground?", or "is our train moving, or is it the other train?".


Boil it down
I think we can boil it down to the following:

A and B start off at rest, relative to each other.

A and B start moving relative to each other.

A labels B as moving relative to A, while B labels A as moving relative to B; which is perfectly valid.

However, in order for relative motion to manifest between A and B, either A had to actually move, or B had to actually move; A and B can be you and the road as outlined above - this represents two different scenarios, with the same result.

However, we cannot determine whether it was A or B that actually moved.

We can deduce that it was either A or B, or both.

[18AD]

Originally Posted by roosh

Boil it down
I think we can boil it down to the following:

A and B start off at rest, relative to each other.

A and B start moving relative to each other.

A labels B as moving relative to A, while B labels A as moving relative to B; which is perfectly valid.

However, in order for relative motion to manifest between A and B, either A had to actually move, or B had to actually move; A and B can be you and the road as outlined above - this represents two different scenarios, with the same result.

However, we cannot determine whether it was A or B that actually moved.

We can deduce that it was either A or B, or both.

To look at the experience, yes, one has to actually move. If you are on the train you will only be able to tell either:

Your train has moved. You can't tell if the other one has.
Your train has not moved. You can tell if the other one has.

So if A moves, B is indeterminate.
If not A then B moves.

[roosh]

Originally Posted by 18AD

To look at the experience, yes, one has to actually move. If you are on the train you will only be able to tell either:

You're train has moved. You can't tell if the other one has.
You're train has not moved. You can tell if the other one has.

So if A moves, B is indeterminate.
If not A then B moves.

I would slightly amend that, to reflect scientific principles, perhaps:

if you are on a train and relative motion arises;

You can't tell if your train has moved
You can't tell if the other train has moved

You can tell that either your train or the other train has moved.

[18AD]

Originally Posted by roosh

I would slightly amend that, to reflect scientific principles, perhaps:

if you are on a train and relative motion arises;

You can't tell if your train has moved
You can't tell if the other train has moved

You can tell that either your train or the other train has moved.

Well that makes you a bad phenomenologist.

[Morbert]

Originally Posted by roosh

Ok, I think I see where the issue lies; I'm not sure if I'll be able to illucidate it fully but hopefully, with some patience, on both our parts, I will be.

First, it is necessary to highlight that the implication of a preferred reference frame implied by the statement "John is travelling at 60mph", is not in dispute. I entirely agree that it is possible to define a reference frame which labels John as traveling at 60mph, as it is to define one where he is "at rest", just as one can be defined where his relative motion is that between him and the centre of the galaxy.

What is in dispute is the statement "John is moving", and whether or not this makes sense without reference to a reference frame; the contention is that, without this reference to a reference frame, the statement is a statement about John's absolute motion, precisely because it is a statement about John's motion without reference to a reference frame i.e. it is a statement about his state of motion, not what he is moving relative to.

The intention here isn't to try to find a way to recover presentism from relativity; this is entirely independent of the concept of presentism, and I'm not even sure if this concept of absolute motion will result in the conclusion of presentism. I personally think the universe is presentist, but that isn't something which plays a role in examining the relative motion between two bodies. This is simply a question of trying to develop a more accurate view of the world; this entails developing an understanding of what existing scientific theories say about the world and subjecting them to critical questioning.

The crux
The crux of the issue isn't so much whether there is a preferred reference frame, it's about what logical deductions we can make from about those reference frames. I see no issue with the idea of equally valid reference frames, so long as it is qualified with the idea that an observers instruments might be contracted by an amount unknown to themselves.

It comes down to something which doesn't seem to be illucidated by mathematical reference frames - that an observers instruments are contracted by an amount unknown to themselves is one such issue - to borrow 18ADs term, it comes down to a phenomenological description of the cause of the relative motion between two bodies.

Where there is relative motion between me and the street, either the earth has to be behaving like a giant treadmill, or spinning log as you mentioned elsewhere, or the earth is passive while I am actively "doing the moving", and my walking is propelling me forward.

The Earth can be moving relative to any other object in the universe, and us along with it, but the subsequent relative motion between us and the street has to be accounted for by one, or both, of the scenarios above. This offers three possible explanations as to how/why relative motion occurs between us and the street, one of which has to be correct. We can still define equally valid reference frames which label either as moving, but the three scenarios outlined have deductive consequences.

If I understand this correctly, you are saying the existence of a preferred reference frame (i.e. a reference frame that reflects the "true" motion of an object). The problem is you are begging the question. To reiterate, your line of reasoning is:

1) Two observers are moving, relative to each other.
2) Therefore at least one of the observers must have an absolute velocity, and one of their reference frames, on a metaphysical level, must be incorrect.
3) Therefore absolute velocities exist.

I am saying 2) does not follow from 1) unless you assume 3). You are implicitly assuming the very thing you are trying to show. Instead, relativity only permits us to say

1) Two observers are moving, relative to each other.
2) Therefore there is absolutely motion between the two observers.

To say/deduce anything else requires more assumptions.

Did you not mention in the other thread that the state of absolute rest is perfectly compatible with relativity; you can either have it, or not have it?

I did indeed. Which is why I said "is not supported" rather than "contradicted". You are not merely saying "absolute motion, in the sense of an absolute velocity, may or may not exist". You are saying it can be shown to necessarily exist, based on our current understanding of motion. I am saying our current understanding of motion does not support the notion of an absolute velocity.

I think this point, though, indicates a critical issue; the contention is that my "problem with [...] understanding motion" is that what I am saying doesn't agree with relativity, implying that, if it doesn't agree with relativity it can't be right; it almost seems like a conditioned attachment to "what relativity says" is the only way. The conditioning or training seems to be triggered at the first mention of "actually moving" or "absolute motion".

This isn't necessarily a negative thing, it's an entirely natural aspect of the human condition, but it can prevent us from looking at things more objectively. Of course, the same could be said for a belief in presentism, but both would depend on the level of sub-conscious attachment.

In the other thread, you make the argument that relativity implicitly assumes absolute motion, and I figured you were doing the same thing here. Can I assume you no longer believe relativity says absolute motion, in the sense of absolute velocity, exists?

The answer to "am I moving [full stop]?" is "I don't know, but I'm either moving [full stop] or I'm not [full stop]."

I assume by "moving" you mean absolute motion. If this is the case, "I am not [full stop]" has two interpretations. It means either I have an absolute velocity of 0, or it means absolute velocity, and hence absolute motion, does not exist.

<snipped redundant exchanges>

[roosh]

Originally Posted by Morbert

If I understand this correctly, you are saying the existence of a preferred reference frame (i.e. a reference frame that reflects the "true" motion of an object). The problem is you are begging the question. To reiterate, your line of reasoning is:

1) Two observers are moving, relative to each other.
2) Therefore at least one of the observers must have an absolute velocity, and one of their reference frames, on a metaphysical level, must be incorrect.
3) Therefore absolute velocities exist.

I am saying 2) does not follow from 1) unless you assume 3). You are implicitly assuming the very thing you are trying to show. Instead, relativity only permits us to say

1) Two observers are moving, relative to each other.
2) Therefore there is absolutely motion between the two observers.

To say/deduce anything else requires more assumptions.

OK; I think this is probably where the confusion lies. The contention isn't necessarily that there exists a preferred frame of reference, which reflects the true motion of objects. The contention is that we can deduce that at least one of two relatively moving bodies must be in absolute motion.

The existence of an absolute reference frame isn't a necessary assumption, because we are talking about the underlying physical process which the mathemeatical reference frames attempt to describe. We are talking about the nature of motion, as opposed to it's measurement.

The problem probably lies in the historical concept of what "absolute motion" means; it was taken to mean motion relative to an absolute reference frame; but that, of course, would be a contradiction in terms; because what is absolute is not, by definition, relative. So there is no necessity for an absolute reference frame to exist.

"Absolute motion" is a statement about the nature of motion of an object, which is not necessarily a measurable quantity, but it does have deductive consequences. "Absolute motion" is a "yes or no", "either, or" question:
"Is X moving?"
"Is Y moving?"
"Is X or Y moving?"

It is also unqualified statements such as "I am moving" or "I am not moving".

Physical processes
Absolute motion is probably easier to interpret using contextual examples; like the example of the observer walking along the earth. As you mentioned in another thread, the observer cannot determine if it is they that is moving, or if the earth is behaving like a spinning log. Here we have two deductively different scenarios which both account for the relative motion between an observer and the road - actually we have three, where the earth is behaving like a spinning log and the observer is walking at a pace that doesn't exactly offset the rotation of the log.

In all cases, the nature of motion ascribed to each object is different, but all result in the same relative motion. We cannot determine which of the three scenarios is the true one, but we can deduce that one of them has to be, because otherwise there would be no relative motion.

Just to reiterate, absolute motion is not relative i.e. it is not necessarily motion relative to an absolute rest frame, so such an assumption isn't necessary.

Originally Posted by Morbert

I did indeed. Which is why I said "is not supported" rather than "contradicted". You are not merely saying "absolute motion, in the sense of an absolute velocity, may or may not exist". You are saying it can be shown to necessarily exist, based on our current understanding of motion. I am saying our current understanding of motion does not support the notion of an absolute velocity.

I'm not necessarily saying that there exists an absolute velocity, because that would imply some measurable quantity; and measurement, by its very nature, is relative, not absolute.

I'm not so sure that I would say that absolute motion can be deduced from our current understanding of motion, becaues the idea of "our current understanding of motion" is somewhat vague; what is being said is that based on the observation of relative motion - not necessarily contemporary interpretation of that observation - we can deduce, in general, three different scenarios that can account for the relative motion between bodies; each of these scenarios, necessarily, distinguish between the nature of motion of the bodies involved, that is, they make reference to the motion of the body in a manner that isn't necessarily relative i.e. in an absolute manner.

We cannot determine which of the three scenarios is the true one, but we can deduce that one of them has to be, and therefore that at least one of the bodies must absolutely be in motion.

Originally Posted by Morbert

In the other thread, you make the argument that relativity implicitly assumes absolute motion, and I figured you were doing the same thing here. Can I assume you no longer believe relativity says absolute motion, in the sense of absolute velocity, exists?

No, I would still maintain that.

Originally Posted by Morbert

I assume by "moving" you mean absolute motion. If this is the case, "I am not [full stop]" has two interpretations. It means either I have an absolute velocity of 0, or it means absolute velocity, and hence absolute motion, does not exist.

Again though, we can outline three general scenarios to account for the relative motion between two bodies, each of which makes reference to the absolute motion of one or the other bodies i.e. by making a statement about the movement of the body, that isn't necessarily relative. So this determines that absolute motion does exist.

There might be some confusion being caused by the conflation of absolute velocity with absolute motion, where the former referes to a measurable quanity, while the latter refers to the nature of motion, which isn't necessarily measurable.

So, absolute velocity doesn't necessarily exist, because it implies some measurable quantity, and measurement is by nature relative, not absolute. Theoretically, if we could determine an absolute reference frame we could possibly perform a measurement which we could label "absolute velocity", even though it would technically be velocity relative to a body at absolute rest; but we cannot determine whether or not a body is at absolute rest or not.

Absolute rest
The issue of absolute rest is somewhat different, and you would be right in saying that it is possible that an absolute rest frame doesn't exist, but this in itself would have two interpretations; firstly, that mathematically constructed reference frames don't have phyiscal existence; and secondly, that an absolute rest frame doesn't exist because there is no object in the universe that is at absolute rest; that is, everything in the universe is absolutely in motion.

[roosh]

Originally Posted by 18AD

Well that makes you a bad phenomenologist.

I should probably have looked up the meaning of the word first

[Morbert]

Originally Posted by roosh

OK; I think this is probably where the confusion lies. The contention isn't necessarily that there exists a preferred frame of reference, which reflects the true motion of objects. The contention is that we can deduce that at least one of two relatively moving bodies must be in absolute motion.

The existence of an absolute reference frame isn't a necessary assumption, because we are talking about the underlying physical process which the mathemeatical reference frames attempt to describe. We are talking about the nature of motion, as opposed to it's measurement.

The problem probably lies in the historical concept of what "absolute motion" means; it was taken to mean motion relative to an absolute reference frame; but that, of course, would be a contradiction in terms; because what is absolute is not, by definition, relative. So there is no necessity for an absolute reference frame to exist.

"Absolute motion" is a statement about the nature of motion of an object, which is not necessarily a measurable quantity, but it does have deductive consequences. "Absolute motion" is a "yes or no", "either, or" question:
"Is X moving?"
"Is Y moving?"
"Is X or Y moving?"

It is also unqualified statements such as "I am moving" or "I am not moving".

Physical processes
Absolute motion is probably easier to interpret using contextual examples; like the example of the observer walking along the earth. As you mentioned in another thread, the observer cannot determine if it is they that is moving, or if the earth is behaving like a spinning log. Here we have two deductively different scenarios which both account for the relative motion between an observer and the road - actually we have three, where the earth is behaving like a spinning log and the observer is walking at a pace that doesn't exactly offset the rotation of the log.

In all cases, the nature of motion ascribed to each object is different, but all result in the same relative motion. We cannot determine which of the three scenarios is the true one, but we can deduce that one of them has to be, because otherwise there would be no relative motion.

Just to reiterate, absolute motion is not relative i.e. it is not necessarily motion relative to an absolute rest frame, so such an assumption isn't necessary.


I'm not necessarily saying that there exists an absolute velocity, because that would imply some measurable quantity; and measurement, by its very nature, is relative, not absolute.

I'm not so sure that I would say that absolute motion can be deduced from our current understanding of motion, becaues the idea of "our current understanding of motion" is somewhat vague; what is being said is that based on the observation of relative motion - not necessarily contemporary interpretation of that observation - we can deduce, in general, three different scenarios that can account for the relative motion between bodies; each of these scenarios, necessarily, distinguish between the nature of motion of the bodies involved, that is, they make reference to the motion of the body in a manner that isn't necessarily relative i.e. in an absolute manner.

We cannot determine which of the three scenarios is the true one, but we can deduce that one of them has to be, and therefore that at least one of the bodies must absolutely be in motion.


No, I would still maintain that.



Again though, we can outline three general scenarios to account for the relative motion between two bodies, each of which makes reference to the absolute motion of one or the other bodies i.e. by making a statement about the movement of the body, that isn't necessarily relative. So this determines that absolute motion does exist.

There might be some confusion being caused by the conflation of absolute velocity with absolute motion, where the former referes to a measurable quanity, while the latter refers to the nature of motion, which isn't necessarily measurable.

So, absolute velocity doesn't necessarily exist, because it implies some measurable quantity, and measurement is by nature relative, not absolute. Theoretically, if we could determine an absolute reference frame we could possibly perform a measurement which we could label "absolute velocity", even though it would technically be velocity relative to a body at absolute rest; but we cannot determine whether or not a body is at absolute rest or not.

Absolute rest
The issue of absolute rest is somewhat different, and you would be right in saying that it is possible that an absolute rest frame doesn't exist, but this in itself would have two interpretations; firstly, that mathematically constructed reference frames don't have phyiscal existence; and secondly, that an absolute rest frame doesn't exist because there is no object in the universe that is at absolute rest; that is, everything in the universe is absolutely in motion.

This thread is beginning to repeat what has already been said in the other thread. My response to this would be the same as my response here.

Namely, the motion of an object is reference frame dependent. If two objects are in motion with respect to each other, then there is no reference frame that labels both as at rest (Though each has a reference frame where they are at rest, as you acknowledge in your post above). This does not establish any form of "intrinsic" motion independent of reference frames.

To put it another way:

Originally Posted by roosh

In all cases, the nature of motion ascribed to each object is different, but all result in the same relative motion. We cannot determine which of the three scenarios is the true one, but we can deduce that one of them has to be, because otherwise there would be no relative motion.

Relativity says all three scenarios are true.

[roosh]

Originally Posted by Morbert

This thread is beginning to repeat what has already been said in the other thread. My response to this would be the same as my response here.

Namely, the motion of an object is reference frame dependent. If two objects are in motion with respect to each other, then there is no reference frame that labels both as at rest (Though each has a reference frame where they are at rest, as you acknowledge in your post above). This does not establish any form of "intrinsic" motion independent of reference frames.

Indeed, we are repeating ourselves, and the point raised above has been addressed several times in this thread alone. The measurement of relative motion is frame dependent; the nature of motion isn't.

When you talk about motion being frame dependent, you are talking about relative motion, not absolute motion; absolute motion pertains to the nature of motion of an object, and isn't necessarily a measurable quantity, and hence doesn't require a reference frame to define it. As said before, it is a "yes or no", "either, or" question.

The observation of relative motion, as opposed to the measurement of relative velocity, allows us to determine three physically distinct scenarios which all ascribe the nature of motion to the relatively moving objects, in deductively different ways.

In each scenario, the implication is that the "intrinsic" motion of each object is different from the other scenarios.

Originally Posted by Morbert

To put it another way:

Relativity says all three scenarios are true.

The three scenarios are physically different, with different deductive consequences; they can't all be simultaneously true.

[Morbert]

Originally Posted by roosh

Indeed, we are repeating ourselves, and the point raised above has been addressed several times in this thread alone. The measurement of relative motion is frame dependent; the nature of motion isn't.

And as I have responded, the nature of motion that is absolute is the relation between objects that persist in all reference frames, and not some notion of intrinsic absolute velocity.

When you talk about motion being frame dependent, you are talking about relative motion, not absolute motion; absolute motion pertains to the nature of motion of an object, and isn't necessarily a measurable quantity, and hence doesn't require a reference frame to define it. As said before, it is a "yes or no", "either, or" question.

"Am I moving?" Is frame-dependent. What ever frame-independent questions you can construct, that question will always be frame-dependent.

The observation of relative motion, as opposed to the measurement of relative velocity, allows us to determine three physically distinct scenarios which all ascribe the nature of motion to the relatively moving objects, in deductively different ways.

In each scenario, the implication is that the "intrinsic" motion of each object is different from the other scenarios.

The three scenarios are physically different, with different deductive consequences; they can't all be simultaneously true.

These scenarios are physically identical. That is the entire revelation of relativity: The physical indistinguishability of reference frames. Perhaps you mean metaphysically distinct. Again, this is only true if you tacitly assume frame-dependent statements are actually "absolute" statements.

[roosh]

Originally Posted by Morbert

And as I have responded, the nature of motion that is absolute is the relation between objects that persist in all reference frames, and not some notion of intrinsic absolute velocity.

The problem is you are conflating absolute statements, about the relative motion between two objects, with statements about the absolute nature of motion of an object.

"I am moving relative to X" is an absolute statement about the relative motion between two objects; while, "I am moving" is an absolute statement about the intrinsic motion of an object.

Originally Posted by Morbert

"Am I moving?" Is frame-dependent. What ever frame-independent questions you can construct, that question will always be frame-dependent.

We can see how the question "Am I moving?" pertains to the intrinsic motion of an object, by considering the example of the two trains at rest, relative to each other in a train station, when the trains start moving relative to each other.

The question "am I, or is our train, moving; or is it the other train that is moving?" clearly pertains to a question of absolute motion; the reason being, there is absolute no doubt whatsoever about the fact that both trains are moving relative to each other, nor is there any doubt that the observer is at rest relative to their train.

The question is asking, which train is actually moving i.e. the intrinsic motion of which train changes?

Originally Posted by Morbert

These scenarios are physically identical. That is the entire revelation of relativity: The physical indistinguishability of reference frames. Perhaps you mean metaphysically distinct. Again, this is only true if you tacitly assume frame-dependent statements are actually "absolute" statements.

I think you might mean that they are mathematically identical, which of course doesn't mean that they are physically identical. I am talking about physical scenarios, which are deductively different from each other. I'm not sure which term best applies, but whatever it is, I'm talking about the physical world, not mathematical reference frames.

[Donnielighto]

Light moves in absolute terms under certain conditions and can be used as reference for everything else. Stuff moves in relative terms but also in absolute terms, it just takes more effort ti figure out the numbers.

[Morbert]

Originally Posted by roosh

The problem is you are conflating absolute statements, about the relative motion between two objects, with statements about the absolute nature of motion of an object.

I have been saying that such a conflation is the problem. I.e. You have been showing that it is logically true that one object must be moving relative to the other. You have been arguing for absolute statements about relative motion. But you then confuse absolute statements about relative motion with statements about "absolute motion".

"I am moving relative to X" is an absolute statement about the relative motion between two objects; while, "I am moving" is an absolute statement about the intrinsic motion of an object.

And you must show that intrinsic motion is a logical necessity. I am saying it is not a logical necessity. We are perfectly consistent in stating that absolute motion, in the sense of "I am moving" is meaningless, and only "I am moving, relative to X" is needed.

We can see how the question "Am I moving?" pertains to the intrinsic motion of an object, by considering the example of the two trains at rest, relative to each other in a train station, when the trains start moving relative to each other.

The question "am I, or is our train, moving; or is it the other train that is moving?" clearly pertains to a question of absolute motion; the reason being, there is absolute no doubt whatsoever about the fact that both trains are moving relative to each other, nor is there any doubt that the observer is at rest relative to their train.

"My train is moving." and "The other train is moving." are both correct answers, provided the appropriate frame is referenced. You are saying one must be less correct, due to intrinsic motion, but you have not established intrinsic motion.

I think you might mean that they are mathematically identical, which of course doesn't mean that they are physically identical. I am talking about physical scenarios, which are deductively different from each other. I'm not sure which term best applies, but whatever it is, I'm talking about the physical world, not mathematical reference frames.

They are mathematically different. They are physically identical. If they were not, we could tell them apart by looking at their physics. You yourself have acknowledged this point.

[roosh]

Originally Posted by Morbert

I have been saying that such a conflation is the problem. I.e. You have been showing that it is logically true that one object must be moving relative to the other. You have been arguing for absolute statements about relative motion. But you then confuse absolute statements about relative motion with statements about "absolute motion".

Indeed it is the probelm.

You are conflating an absolute statement about the relative motion between objects - "I am moving relative to X" - with a statement about the absolute nature of motion, of an object - "I am moving".

"I am moving" is a statement distinct from "I am moving relative to X"; and it is a statement about the absolute nature of motion, precisely because it doesn't relate the motion to anything else; it is a statement about the intrinsic motion of an object.

3 scenarios
The three scenarios outlined, are three distinct cases, where the intrinsic motion of the objects is ascribed differently; in each scenario, the object that is "doing the moving" is different, and hence, the statement about the absolute nature of motion, in each case is different i.e. "I am moving" doesn't apply to all three scenarios, it only applies to two.

On the other hand, the absolute statement about the relative motion of the objects applies in all three cases.

Originally Posted by Morbert

And you must show that intrinsic motion is a logical necessity. I am saying it is not a logical necessity. We are perfectly consistent in stating that absolute motion, in the sense of "I am moving" is meaningless, and only "I am moving, relative to X" is needed.

This is precisely what the three scenarios do; they provide the three distinct scenarios that can account for the relative motion; each one is deductively different, and each one carries different implications about the absolute nature of motion of the objects involved.

While we cannot determine which of the three scenarios are true, it is a logical necessity that one of them must be, otherwise there would be no relative motion to account for.

The logical necessity of one of the scenarios means we can deduce that the nature of motion must be absolute, or that the objects must have some intrinsic motion.

Originally Posted by Morbert

"My train is moving." and "The other train is moving." are both correct answers, provided the appropriate frame is referenced. You are saying one must be less correct, due to intrinsic motion, but you have not established intrinsic motion.

Again, the logical necessity of one of the three scenarios, to account for the observation of relative motion, establishes intrinsic motion; because one of them has to be correct.

But, "my train is moving" is a statement about the intrinsic motion of the train, because it doesn't make reference to any relatively moving object. The same applies for the statement "the other train is moving". They don't require a reference frame to define the movement, because they are statements about what object is "doing the moving".


You are saying that "my train is moving" and "the other train is moving" are both correct answers, provided the appropriate frame is referenced; what this is effectively saying is that "my train is moving relative to the other train" - appropriate frame is referenced - and "the other train is moving relative to my train" - appropriate frame is referenced; this of course is true, but these are absolute statements about the relative motion of two objects.

You are effectively just repeating what has been said before, that "I am moving" is not a valid statement without saying "relative to X"; but this is conflating absolute statements about relative motion with statements about the absolute nature of motion of an object - of which, "I am moving" is one.

Again, the three scenarios distinguish between the intrinsic motion of the objects, and by logical necessity, one of the three scenarios must be true, because otherwise there would be no relative motion.

Originally Posted by Morbert

They are mathematically different. They are physically identical. If they were not, we could tell them apart by looking at their physics. You yourself have acknowledged this point.

I think this is where the confusion lies; the erroneous conclusion that all three must be the same, because we cannot distinguish between them by means of a scientific experiment; I think this more highlights the limitation of experiments in determining absolute properties, than it does anything about the absolute nature of objects.

Of course, while we may not be able to distinguish between them experimentally, we can deduce that they each carry different logical implications; and thus, we can determine that they must be physically different.

Essentially, it is a question of, is there a physical difference between walking on a treadmill and walking down the road?

[Morbert]

Originally Posted by roosh

Indeed it is the probelm.

You are conflating an absolute statement about the relative motion between objects - "I am moving relative to X" - with a statement about the absolute nature of motion, of an object - "I am moving".

"I am moving" is a statement distinct from "I am moving relative to X"; and it is a statement about the absolute nature of motion, precisely because it doesn't relate the motion to anything else; it is a statement about the intrinsic motion of an object.

3 scenarios
The three scenarios outlined, are three distinct cases, where the intrinsic motion of the objects is ascribed differently; in each scenario, the object that is "doing the moving" is different, and hence, the statement about the absolute nature of motion, in each case is different i.e. "I am moving" doesn't apply to all three scenarios, it only applies to two.

On the other hand, the absolute statement about the relative motion of the objects applies in all three cases.

This is precisely what the three scenarios do; they provide the three distinct scenarios that can account for the relative motion; each one is deductively different, and each one carries different implications about the absolute nature of motion of the objects involved.

While we cannot determine which of the three scenarios are true, it is a logical necessity that one of them must be, otherwise there would be no relative motion to account for.

The logical necessity of one of the scenarios means we can deduce that the nature of motion must be absolute, or that the objects must have some intrinsic motion.

Again, the logical necessity of one of the three scenarios, to account for the observation of relative motion, establishes intrinsic motion; because one of them has to be correct.

But, "my train is moving" is a statement about the intrinsic motion of the train, because it doesn't make reference to any relatively moving object. The same applies for the statement "the other train is moving". They don't require a reference frame to define the movement, because they are statements about what object is "doing the moving".

Again, the three scenarios distinguish between the intrinsic motion of the objects, and by logical necessity, one of the three scenarios must be true, because otherwise there would be no relative motion.

You are implicitly assuming intrinsic motion to argue that the three scenarios are different. You are then arguing that intrinsic motion is a logical necessity because the three scenarios are different. This is circular reasoning.

Relativity says the three scenarios are just different ways of labelling the same scenario.

You are saying that "my train is moving" and "the other train is moving" are both correct answers, provided the appropriate frame is referenced; what this is effectively saying is that "my train is moving relative to the other train" - appropriate frame is referenced - and "the other train is moving relative to my train" - appropriate frame is referenced; this of course is true, but these are absolute statements about the relative motion of two objects.

You are effectively just repeating what has been said before, that "I am moving" is not a valid statement without saying "relative to X"; but this is conflating absolute statements about relative motion with statements about the absolute nature of motion of an object - of which, "I am moving" is one.

I am not conflating anything. I have been very precise about what I mean. "I am moving, relative to X." is an absolute statement. "I have an absolute velocity/intrinsic motion." is a metaphysical statement, an untestable assumption, and in no way logically necessary.

I think this is where the confusion lies; the erroneous conclusion that all three must be the same, because we cannot distinguish between them by means of a scientific experiment; I think this more highlights the limitation of experiments in determining absolute properties, than it does anything about the absolute nature of objects.

Of course, while we may not be able to distinguish between them experimentally, we can deduce that they each carry different logical implications; and thus, we can determine that they must be physically different.

That intrinsic motion exists a priori in nature is an assumption that is in no way supported by relativity. Again, you must show that intrinsic motion is a logical necessity. So far, all you have shown is absolute statements about relative motion can be made.

Essentially, it is a question of, is there a physical difference between walking on a treadmill and walking down the road?[/QUOTE]