Question on Lorentz transforms and relativity of simultaneity

roosh

Morbert wrote: »

You are deeply frustrating. It is like arguing with a man who insists the sky is green because he has been living in a forest all his life.

How Albert's brain orders physical stimuli is frame dependent. Everything you said in red is false. It is wrong. It is incorrect. It is not true on any physical or metaphysical level.



No. I have told you over and over and over and over and over and over and over that the statement in blue is a frame dependent statement. It is true according to S. It is not true according to S'. According to S', the retinas are struck non-simultaneously, but due to the hyperbolic structure of spacetime, the same structure responsible for the universal speed of light, the signal travels through one wire in a more dilated manner than the other. This description is absolutely frame dependent. No argument there. But it is no more or less frame dependent than Albert's description of events. We have two descriptions of the interactions between light, retinas, wires, and a cpu. You cannot say one is more physical than the other.

You cannot say one description is more indicative of reality than the other. No you cannot.




But he would. Henry could push one button first, then the other, triggering the lasers to fire non-simultaneously, and would strike Albert's retinas non simultaneously. He could do so in such a way that Albert would experience the flashes as simultaneous. Who is wrong in this case?

In case you are tempted to blame the discrepancy on the signalling from the button pushes to the rods, let's embed the rods alongside the track, such that the wires are perpendicular to the track, and parallel to each other.

Relativity says that if Albert, or you, are standing on the embankment with metre stick and clock in hand, as far as you are concerned, the metre stick is not contracted and time is not dilated; this goes for your brain too. So, when a photon makes physical contact with your eyes, while you are standing on an embankment, that is how your body will process it, as though length is not contracted and time is not dilated. This is under parabolic geometry also.

If photons make physical contact with your eyes in the order of one first, then the other, then your body will process them in that order and your brain will generate an ordered experience.

Morbert wrote: »

The question presupposes a frame, but you do not specify which frame. For example, is this a frame in which I am stationary? Or is this a frame in which I am tumbling very fast through space on a rotating rock? You cannot make a frame-dependent statement without tendering the frame.

You are standing on an embankment, at rest relative to it, where there is relative motion between you and a train, and whatever other objects you like to insert. The statements you make above are statements about the absolute nature of motion of the objects in question, not absolute statements about relative motion. They are also, apparently, just different ways of artificially labeling the same physical scenario; the artificial labels should have no bearing on the physical behaviour at a fundamental level; just as the the process of pouring tea into a cup shouldn't be affected differently by saying "the tea is poured into the cup" and making the equivalent statement in a different language; where the different languages represent different ways of artificially labeling the same physical process.

Morbert

roosh wrote: »

Relativity says that if Albert, or you, are standing on the embankment with metre stick and clock in hand, as far as you are concerned, the metre stick is not contracted and time is not dilated; this goes for your brain too. So, when a photon makes physical contact with your eyes, while you are standing on an embankment, that is how your body will process it, as though length is not contracted and time is not dilated. This is under parabolic geometry also.

If photons make physical contact with your eyes in the order of one first, then the other, then your body will process them in that order and your brain will generate an ordered experience.

This is correct as far as Albert is concerned. As far as someone else is concerned, it is not correct. And since relativity says no perspective is preferred, you cannot say Albert's perspective is more correct.

Again, according to Albert, the photons that strike Albert simultaneously will be perceived simultaneously. But according to Henry, the photons strike Albert in the order of one fist then the other and will be perceived by Albert simultaneously.

You are standing on an embankment, at rest relative to it, where there is relative motion between you and a train, and whatever other objects you like to insert. The statements you make above are statements about the absolute nature of motion of the objects in question, not absolute statements about relative motion. They are also, apparently, just different ways of artificially labeling the same physical scenario; the artificial labels should have no bearing on the physical behaviour at a fundamental level; just as the the process of pouring tea into a cup shouldn't be affected differently by saying "the tea is poured into the cup" and making the equivalent statement in a different language; where the different languages represent different ways of artificially labeling the same physical process.

You have made serveral mistakes above. I will ignore the irrelevant mistakes and address the relevant ones: All frames agree that you are at rest relative to the embankment. All frames agree that there is relative motion between you and the train. Therefore you have not specified the frame you are referring to. And since you have not specified the frame you are referring to, I cannot interpret your premise in a non-ambiguous manner. Is this a frame, for example, where I and the embankment are at rest? Is this a frame where I and the embankment are orbiting the sun at a phenomenal rate? Is this a frame where I am orbiting the galaxy at an even more phenomenal rate? Is this a frame where the galaxy I am in is itself flying through our local cluster?

roosh

Morbert wrote: »

This is correct as far as Albert is concerned. As far as someone else is concerned, it is not correct. And since relativity says no perspective is preferred, you cannot say Albert's perspective is more correct.

Again, according to Albert, the photons that strike Albert simultaneously will be perceived simultaneously. But according to Henry, the photons strike Albert in the order of one fist then the other and will be perceived by Albert simultaneously.

So, as far as Albert is concerned, photons which make physical contact with his retinae will be processed in the order they make physical contact; such that, if photons make physical contact with his retinae in the order of one first, then the other, while he is standing on the embankment, his brain will generate an ordered experience.

According to relativity, photons make physical contact with Albert's retinae, while he is standing on the embankment, in the order of one first, then the other as well as not in that order; with both scenarios being equally true; therefore, Albert's brain should generate discordant experiences. Anything else is superfluous to the point.


It might be tempting to say that the photons don't strike Albert's retinae in the order of one first, then the other, as far as Albert is concerned, but anything which makes physical contact with Albert concerns him, while the physicality of the ordering doesn't matter, given that Henry's brain will generate an ordered experience despite the fact that the ordering of the events isn't physical.

Morbert wrote: »

You have made serveral mistakes above. I will ignore the irrelevant mistakes and address the relevant ones: All frames agree that you are at rest relative to the embankment. All frames agree that there is relative motion between you and the train. Therefore you have not specified the frame you are referring to. And since you have not specified the frame you are referring to, I cannot interpret your premise in a non-ambiguous manner. Is this a frame, for example, where I and the embankment are at rest? Is this a frame where I and the embankment are orbiting the sun at a phenomenal rate? Is this a frame where I am orbiting the galaxy at an even more phenomenal rate? Is this a frame where the galaxy I am in is itself flying through our local cluster?

Again, there are a number of issues with the statements above, all of which are relevant.

The questions you raise above, are are just different ways of artificially labeling the same physical scenario, according to yourself; how a physical scenario is artificially labeled should have no bearing at the fundamental, physical level; otherwise you are making a statement about the absolute motion of you and the embankment.

In the physical scenario, and in every reference frame, you are moving relative to the sun and at rest relative to the embankment. Throw in any other physical object you please and it won't change that.


By the way, when you say a frame where you and the embankment are at rest, relative to what other physical object do you mean?

Morbert

roosh wrote: »

So, as far as Albert is concerned, photons which make physical contact with his retinae will be processed in the order they make physical contact; such that, if photons make physical contact with his retinae in the order of one first, then the other, while he is standing on the embankment, his brain will generate an ordered experience.

According to relativity, photons make physical contact with Albert's retinae, while he is standing on the embankment, in the order of one first, then the other as well as not in that order; with both scenarios being equally true; therefore, Albert's brain should generate discordant experiences. Anything else is superfluous to the point.


It might be tempting to say that the photons don't strike Albert's retinae in the order of one first, then the other, as far as Albert is concerned, but anything which makes physical contact with Albert concerns him, while the physicality of the ordering doesn't matter, given that Henry's brain will generate an ordered experience despite the fact that the ordering of the events isn't physical.

And as far as Henry is concerned, if photons strike Albert's retinas in the order of one first and then the other, Albert will experience the strikes as simultaneous. And no reference is privileged, so Henry is no more or less correct than Albert.

Again, there are a number of issues with the statements above, all of which are relevant.

The questions you raise above, are are just different ways of artificially labeling the same physical scenario, according to yourself; how a physical scenario is artificially labeled should have no bearing at the fundamental, physical level; otherwise you are making a statement about the absolute motion of you and the embankment.

In the physical scenario, and in every reference frame, you are moving relative to the sun and at rest relative to the embankment. Throw in any other physical object you please and it won't change that.

Again, it is clear that you have absolutely no idea what you are talking about. You are tendering a physically ambiguous scenario. It is a physically ambiguous scenario because you yourself are tendering an artificial label, a coordinate statement ("one first then the other"), without specifying the coordinate frame you are using. So unless you specify the frame, your scenario is incoherent. It is not a matter of fundamental physics. It is a matter of you not making a meaningful statement, because you are making a coordinate statement without referencing a coordinate system.

By the way, when you say a frame where you and the embankment are at rest, relative to what other physical object do you mean?

Relative to a hypothetical set of perfect clocks and rulers which would provide a specific reference.

roosh

Morbert wrote: »

And as far as Henry is concerned, if photons strike Albert's retinas in the order of one first and then the other, Albert will experience the strikes as simultaneous. And no reference is privileged, so Henry is no more or less correct than Albert.




Again, it is clear that you have absolutely no idea what you are talking about. You are tendering a physically ambiguous scenario. It is a physically ambiguous scenario because you yourself are tendering an artificial label, a coordinate statement ("one first then the other"), without specifying the coordinate frame you are using. So unless you specify the frame, your scenario is incoherent. It is not a matter of fundamental physics. It is a matter of you not making a meaningful statement, because you are making a coordinate statement without referencing a coordinate system.



Relative to a hypothetical set of perfect clocks and rulers which would provide a specific reference.

It can essentially be boiled down to this:

As far as you are concerned, your body will process all photons which make physical contact with your retinae, while you are standing in your front garden; and it will process all photons which make physical contact, in the same manner; that is, in the order they make physical contact, while you are standing in your front garden. Your brain will generate an experience which corresponds to the order in which the photons make physical contact with your retinae; where the physicality of the ordering is irrelevant, and with it, which frame specifies which order - the important pieces of information are whether or not they make physical contact and the fact that the order, in which they make physical contact, is different.

Supposedly, photons make physical contact with your retinae in two different orders, while you are standing in your front garden, therefore, your brain should generate two different, discordant, experiences; as far as you are concerned.

Morbert

roosh wrote: »

It can essentially be boiled down to this:

As far as you are concerned, your body will process all photons which make physical contact with your retinae, while you are standing in your front garden; and it will process all photons which make physical contact, in the same manner; that is, in the order they make physical contact, while you are standing in your front garden. Your brain will generate an experience which corresponds to the order in which the photons make physical contact with your retinae; where the physicality of the ordering is irrelevant, and with it, which frame specifies which order - the important pieces of information are whether or not they make physical contact and the fact that the order, in which they make physical contact, is different.

Supposedly, photons make physical contact with your retinae in two different orders, while you are standing in your front garden, therefore, your brain should generate two different, discordant, experiences; as far as you are concerned.

You are treating frames of references inconsistently, as you refuse, somewhat suspiciously, to apply the Lorentz transformations to relate measures used by myself and Henry. As far as I am concerned, the photons strike my retinas simultaneously and I experience blindness in both eyes simultaneously. As far as Henry is concerned, the photons strike my retinas in the order of one first, then the other, and I experience blindness simultaneously. You cannot use Henry's coordinates to label the events, and then carry those labels to my coordinate system without the relevant Lorentz transformations. That is why you are predicting discordant experiences.

[edit]- Note, your phrase "as far as X is concerned" is only valid if it is interpreted as "according to the reference frame which measures X as at rest". If you mean something else, then your premise can be dismissed out of hand as inconsistent.

roosh

Morbert wrote: »

You are treating frames of references inconsistently, as you refuse, somewhat suspiciously, to apply the Lorentz transformations to relate measures used by myself and Henry. As far as I am concerned, the photons strike my retinas simultaneously and I experience blindness in both eyes simultaneously. As far as Henry is concerned, the photons strike my retinas in the order of one first, then the other, and I experience blindness simultaneously. You cannot use Henry's coordinates to label the events, and then carry those labels to my coordinate system without the relevant Lorentz transformations. That is why you are predicting discordant experiences.

[edit]- Note, your phrase "as far as X is concerned" is only valid if it is interpreted as "according to the reference frame which measures X as at rest". If you mean something else, then your premise can be dismissed out of hand as inconsistent.

That can be dismissed out of hand because it is inconsistent, as it relies on a statement about the absolute nature of motion of X. You should be saying "according to the reference frame which measures X as at rest relative to the hypothetical measuring instruments", but, of course, every reference frame measures X as being at rest relative to those.

But maybe we've been looking at this the wrong way, by focusing solely on light; if we amend the original thought experiment such that there is a device on each pole which emits a sound when the lightning makes physical contact with it.

If we use dlouth's (was it dlouth's?) device with the light, where the light only switches on if it struck simultaneously, and amend it so that the light only switches on if the sound waves strike it simultaneously.

Here, the differing order of the events should give rise to a paradox, shouldn't it, where the light switches on according to one reference frame but not the other.


We make the proviso, of course, that Albert (or the light device) and the rods are at rest relative to the medium through which the sound waves travel; we can put him in a dome or something like that, if necessary.

citrus burst

This thread has become a bit farcical. Roosh I don't know where you get your assumed authority in this field against the back drop of over 400 years of physics. Time and time again you refuse to listen to what people have said to you. Ignored basic comments out of hand, responded with at best vague or wordy answers and refused outright to accept the ideas of what people have been rather patiently trying to explain to you.

Special relativity is in no way fully correct. It doesn't take into account many things, such as forces. However, it does make extremely accurate predictions and is a good approximation for most things. It is totally self consistent, which cannot be said for what you are trying to argue. It correctly predicts electrodynamics, which pretty much by itself should be enough proof for anyone. Electrodynamics being the corner stone of modern physics, for relativity to be consistent with it, without any alterations or as you call them "mathematical tricks" is a huge success for the theory.

roosh wrote: »

That can be dismissed out of hand because it is inconsistent, as it relies on a statement about the absolute nature of motion of X. You should be saying "according to the reference frame which measures X as at rest relative to the hypothetical measuring instruments", but, of course, every reference frame measures X as being at rest relative to those.

What is inconsistent with what Morbert said? How can you just dismiss it? You've just given a hand waving argument that doesn't really answer or say anything?

roosh wrote: »

absolute nature of motion of X

What is absolute about motion? No object is in any way "absolutely" moving. Prove to me this notion of absoluteness that motion apparently has.

roosh wrote: »

You should be saying "according to the reference frame which measures X as at rest relative to the hypothetical measuring instruments",

Again this is just a way you have developed to get out of something, that at this stage even you know, albeit are unwilling to admit, answering a question or actually having to engage and think about.

When we say something is at rest, we mean its not moving relative to something. As I sit here writing I am at rest relative to the earth, my house etc. I am not at rest relative to an airplane flying over head, neither is my house or the earth. We call these objects that are at rest relative to each other reference frames. Basically anything that is moving at a constant velocity can be considered a reference frame and anything that is moving a the same velocity as reference frame can be considered at rest, relative to it. That is the people on the airplane are at rest with airplane (assuming there are not moving up and down it). Every reference frame has an associated coordinate system that is different then every other reference frame. These coordinate systems can extend for most intents and purposes to infinity. So the airplane has a coordinate system, that says the passengers don't move relative to it, but the entire rest of the earth does.

This is an important point, to sum it up means that pretty much any object can be considered a rest frame. But as you pointed out there are inconsistencies when we deal with two or more reference frames, or objects moving relative to each other. If someone on the airplane dropped something, according to everyone on the plane, it would fall down in a straight line, relative to the plane. Someone at rest relative to the earth might say that it fell in some sort of parabolic curve. These inconsistencies are dealt with by applying some sort of transformation. This is what all relativity tries to achieve. Classical mechanics sorted it out years ago, for relatively slow moving and moderately sized objects.

Relativity is pointless if you don't consider two or more objects. If the airplane was all that existed in the universe, you wouldn't need to do any of this. You have been talking about how an outside observers measurements influence another measurement and should in fact send the whole physical world into chaos. But every time you say it, you say we don't care what the other observer measures. In this case you don't need to invoke relativity, you've basically answered your own question.

roosh wrote: »

But maybe we've been looking at this the wrong way, by focusing solely on light; if we amend the original thought experiment such that there is a device on each pole which emits a sound when the lightning makes physical contact with it.

The reason we focus on light is because special relativity is essentially a theory on light. By doing this experiment we are taking a step back, to the world of classical mechanics.

roosh wrote: »

If we use dlouth's (was it dlouth's?) device with the light, where the light only switches on if it struck simultaneously, and amend it so that the light only switches on if the sound waves strike it simultaneously.

roosh wrote: »

Here, the differing order of the events should give rise to a paradox, shouldn't it, where the light switches on according to one reference frame but not the other.

Nope, let me explain why. You have made an assumption about the light and its device, while only considering one reference frame, the one where you are at rest. In it you have set up an operation system, the light only turns on when it receives two signals at the same time according to someone at rest to the set up.

Lets jump the gun a bit. Two observers, one at rest relative to the set up and one moving relative to it at 0.5c no nothing about how the light operates. Both see the light turn on and try to figure out the mechanics of the light. Both agree that the light turns on when it receives two signals. However the guy at rest says it turns on when the two signals arrive at the same time, but the guy moving relative says it turns on when the two signals arrive at some time interval. Both start testing around and confirm that the light only turns on when the time interval is the same as when if first turned on, t=0 for the guy at rest and t=t for the guy moving relative. So as we would expect causality is not affected.

The problem arose with your initial assumption about the operation of the light.

Morbert

roosh wrote: »

That can be dismissed out of hand because it is inconsistent, as it relies on a statement about the absolute nature of motion of X. You should be saying "according to the reference frame which measures X as at rest relative to the hypothetical measuring instruments", but, of course, every reference frame measures X as being at rest relative to those.

The above is completely unrelated to anything I said.

But maybe we've been looking at this the wrong way, by focusing solely on light; if we amend the original thought experiment such that there is a device on each pole which emits a sound when the lightning makes physical contact with it.

If we use dlouth's (was it dlouth's?) device with the light, where the light only switches on if it struck simultaneously, and amend it so that the light only switches on if the sound waves strike it simultaneously.

Here, the differing order of the events should give rise to a paradox, shouldn't it, where the light switches on according to one reference frame but not the other.


We make the proviso, of course, that Albert (or the light device) and the rods are at rest relative to the medium through which the sound waves travel; we can put him in a dome or something like that, if necessary.

So does this mean you accept that no contradiction is evident in your previous thought experiment?

In your new thought experiment, the light switches on according to all observers. Just as, in the previous thought experiment, with photons instead of sound, the light switched off according to all observers.

roosh

citrus burst wrote: »

What is inconsistent with what Morbert said? How can you just dismiss it? You've just given a hand waving argument that doesn't really answer or say anything? What is absolute about motion? No object is in any way "absolutely" moving. Prove to me this notion of absoluteness that motion apparently has.

This goes back to a discussion myself and Morbert were having in a different thread, about "statements absolute motion" and "absolute statements of relative motion". Morbert was saying that the former is not something we can make, we can only make statements of the latter variety; however, his statement was a statement about the absolute motion of X because it didn't specify relative to what X was at rest.

citrus burst wrote: »

Again this is just a way you have developed to get out of something, that at this stage even you know, albeit are unwilling to admit, answering a question or actually having to engage and think about.

If I was pursuing the same line of reasoning I would address it, but it appears to be fruitless; because the line of reasoning has changed, there isn't too much need to pursue it much further.

citrus burst wrote: »

When we say something is at rest, we mean its not moving relative to something. As I sit here writing I am at rest relative to the earth, my house etc. I am not at rest relative to an airplane flying over head, neither is my house or the earth. We call these objects that are at rest relative to each other reference frames. Basically anything that is moving at a constant velocity can be considered a reference frame and anything that is moving a the same velocity as reference frame can be considered at rest, relative to it. That is the people on the airplane are at rest with airplane (assuming there are not moving up and down it). Every reference frame has an associated coordinate system that is different then every other reference frame. These coordinate systems can extend for most intents and purposes to infinity. So the airplane has a coordinate system, that says the passengers don't move relative to it, but the entire rest of the earth does.

This is an important point, to sum it up means that pretty much any object can be considered a rest frame. But as you pointed out there are inconsistencies when we deal with two or more reference frames, or objects moving relative to each other. If someone on the airplane dropped something, according to everyone on the plane, it would fall down in a straight line, relative to the plane. Someone at rest relative to the earth might say that it fell in some sort of parabolic curve. These inconsistencies are dealt with by applying some sort of transformation. This is what all relativity tries to achieve. Classical mechanics sorted it out years ago, for relatively slow moving and moderately sized objects.

Relativity is pointless if you don't consider two or more objects. If the airplane was all that existed in the universe, you wouldn't need to do any of this. You have been talking about how an outside observers measurements influence another measurement and should in fact send the whole physical world into chaos. But every time you say it, you say we don't care what the other observer measures. In this case you don't need to invoke relativity, you've basically answered your own question.

This isn't in dispute; Morebert specified the interpretation of "according to X" which was, supposedly, required; but this was inconsistent with points made in our previous discussions.

citrus burst wrote: »

The reason we focus on light is because special relativity is essentially a theory on light. By doing this experiment we are taking a step back, to the world of classical mechanics.

So relativity is true for light but not for sound?

citrus burst wrote: »

Nope, let me explain why. You have made an assumption about the light and its device, while only considering one reference frame, the one where you are at rest. In it you have set up an operation system, the light only turns on when it receives two signals at the same time according to someone at rest to the set up.

Lets jump the gun a bit. Two observers, one at rest relative to the set up and one moving relative to it at 0.5c no nothing about how the light operates. Both see the light turn on and try to figure out the mechanics of the light. Both agree that the light turns on when it receives two signals. However the guy at rest says it turns on when the two signals arrive at the same time, but the guy moving relative says it turns on when the two signals arrive at some time interval. Both start testing around and confirm that the light only turns on when the time interval is the same as when if first turned on, t=0 for the guy at rest and t=t for the guy moving relative. So as we would expect causality is not affected.

The problem arose with your initial assumption about the operation of the light.

The assumption about the light device was one which dlouth (I think it was) introduced previously; it's the same light device. Morbert has stated previously that we are free to introduce such hypothetical devices.

I don't think it matters though because we can presumably exploit the disagreement over the simultaneity of events which occur at the same location in space and time, according to one reference frame, in other ways.

roosh

Morbert wrote: »

The above is completely unrelated to anything I said.


So does this mean you accept that no contradiction is evident in your previous thought experiment?

No, just that the other thought occurred to me, so I decided to pursue it instead.

Morbert wrote: »

In your new thought experiment, the light switches on according to all observers. Just as, in the previous thought experiment, with photons instead of sound, the light switched off according to all observers.

How is that? If the speed of sound is constant relative to the medium through which it travels, then shouldn't the sound waves arrive at the midpoint simultaneously in one reference frame but not in the other?

citrus burst

roosh wrote: »

The assumption about the light device was one which dlouth (I think it was) introduced previously; it's the same light device. Morbert has stated previously that we are free to introduce such hypothetical devices.

I don't think it matters though because we can presumably exploit the disagreement over the simultaneity of events which occur at the same location in space and time, according to one reference frame, in other ways.

The assumption you made is that the light only turns on if all relatively moving observers agreed that the signal (sound or light) arrived simultaneously. This is not true.

Morbert

roosh wrote: »

How is that? If the speed of sound is constant relative to the medium through which it travels, then shouldn't the sound waves arrive at the midpoint simultaneously in one reference frame but not in the other?

First, I should make clear that there was a typo in my previous post. I meant to type "on", not "off". I.e. Both versions of the thought experiment have a light switching on.

Second, there is no point in me entertaining a wild goose chase. So unless you can sort out your misunderstanding with the previous thought experiment, there is no point moving onto another. Especially since the mistake you are making is more or less the same.

roosh

citrus burst wrote: »

The assumption you made is that the light only turns on if all relatively moving observers agreed that the signal (sound or light) arrived simultaneously. This is not true.

It isn't an assumption, its a prescription; we are perfectly entitled to prescribe such a light system, as dlouth, I think it was, prescribed earlier.

Morbert

roosh wrote: »

his statement was a statement about the absolute motion of X because it didn't specify relative to what X was at rest.

That is a ridiculous inference not shared by anyone. You continue to misunderstand even the most elementary properties of reference frames.

roosh

Morbert wrote: »

First, I should make clear that there was a typo in my previous post. I meant to type "on", not "off". I.e. Both versions of the thought experiment have a light switching on.

Second, there is no point in me entertaining a wild goose chase. So unless you can sort out your misunderstanding with the previous thought experiment, there is no point moving onto another. Especially since the mistake you are making is more or less the same.

There is a fundamental difference between the propagation of light and sound, making the two cases quite different.

It might be easier just to answer one question: is the speed of sound constant relative to the medium through which it travels?

Morbert

roosh wrote: »

It isn't an assumption, its a prescription; we are perfectly entitled to prescribe such a light system, as dlouth, I think it was, prescribed earlier.

It is a frame-dependent prescription. As I have explained before: According to some frames, the light will activate if the retinas are struck simultaneously. According to other frames, the light will activate if the retinas are struck in a specific order.

roosh

Morbert wrote: »

It is a frame-dependent prescription. As I have explained before: According to some frames, the light will activate if the retinas are struck simultaneously. According to other frames, the light will activate if the retinas are struck in a specific order.

No, this is quite different. The point you were making before is that all frames agree that the signal reaches the CPU, or the point that is midway between the rods, simultaneously; here, the sound signals don't reach that point simultaneously according to relatively moving frames.

We can prescribe a light system, as dlouth did, where the light only works if it is struck simultaneously; only this time by the sound waves.

Morbert

roosh wrote: »

No, this is quite different. The point you were making before is that all frames agree that the signal reaches the CPU, or the point that is midway between the rods, simultaneously; here, the sound signals don't reach that point simultaneously according to relatively moving frames.

We can prescribe a light system, as dlouth did, where the light only works if it is struck simultaneously; only this time by the sound waves.

I have told you over and over and over and over that all observers agree on all co-incident events (events that occur at the same place and time). So all frames agree that the sound signals reach the centre point, (cpu or light).

roosh

Morbert wrote: »

I have told you over and over and over and over that all observers agree on all co-incident events (events that occur at the same place and time). So all frames agree that the sound signals reach the centre point, (cpu or light).

The speed of sound is constant in the medium through which it travels, isn't it; or, it's constant relative to the medium it travels through.

Given this fact we, can we not deduce that only simultaneous lightning strikes, which trigger the sound emitters, could possibly result in the simultaneous meeting of the sound waves at a location midway between the emitters; where the emitters and the midpoint are at rest relative to the air through which the sound travels?

Morbert

roosh wrote: »

The speed of sound is constant in the medium through which it travels, isn't it; or, it's constant relative to the medium it travels through.

Given this fact we, can we not deduce that only simultaneous lightning strikes, which trigger the sound emitters, could possibly result in the simultaneous meeting of the sound waves at a location midway between the emitters; where the emitters and the midpoint are at rest relative to the air through which the sound travels?

This has already been answered by myself previously. Remember what I said about the signals travelling through the wire? Remember how I asked you to do the Lorentz transformations to see how signals travelling at less than the speed of light (like sound) behave in a relativistic setting?

If you have difficulty with the Lorentz transformations, say so. I will gladly help you.

roosh

Morbert wrote: »

This has already been answered by myself previously. Remember what I said about the signals travelling through the wire? Remember how I asked you to do the Lorentz transformations to see how signals travelling at less than the speed of light (like sound) behave in a relativistic setting?

If you have difficulty with the Lorentz transformations, say so. I will gladly help you.

Aaah, my apologies; I was taking the speed of the signals from the retinae to the CPU to be the speed of light, for the sake of convenience. If you don't mind and have the time, I would be interested in seeing how the LTs work for the case in hand, of the propagation of the sound waves.

Also, is the speed of sound not constant relative to the medium through which it travels; that is, is the speed of sound in air a constant?

roosh

On the previous point, about the discordant experiences with light; essentially, the issue as I see it is, the physical process that is my body processing photons, which make physical contact with my retinae, and my brain generating the resultant experiences, remains unchanged; it is the same for all photons which make physical contact with my retinae; even if relatively moving observers disagree over how the body processes them, they will agree that the body processes all photons, which make physical contact with my retinae, the same. Therefore, if photons make physical contact with my retinae in two different orders it should, physically, result in my brain generating two different experiences.

Essentially, stimuli making physical contact with the body in two different orders, should result in the body physically generating two different experiences; given that the physicality of the ordering doesn't matter. The relatively moving observers would still disagree over how the body processes them.

The time, as given by clocks, shouldn't matter either; if the photons make physical contact in two different orders, it should result in the body physically generating two different experiences.


EDIT: it might be helpful to look at the issue in the following way, by posing the question, will Albert's brain functioning change depending on his physical location; that is, will the physical processes of his body and brain, while he is standing on the platform, be different from what they would if he was located on the train?

The reason being, if Albert were located on the train and photons made physical contact with his retinae in the order of one first, then the other, his brain would generate an ordered experience.

Morbert

roosh wrote: »

On the previous point, about the discordant experiences with light; essentially, the issue as I see it is, the physical process that is my body processing photons, which make physical contact with my retinae, and my brain generating the resultant experiences, remains unchanged; it is the same for all photons which make physical contact with my retinae; even if relatively moving observers disagree over how the body processes them, they will agree that the body processes all photons, which make physical contact with my retinae, the same. Therefore, if photons make physical contact with my retinae in two different orders it should, physically, result in my brain generating two different experiences.

Essentially, stimuli making physical contact with the body in two different orders, should result in the body physically generating two different experiences; given that the physicality of the ordering doesn't matter. The relatively moving observers would still disagree over how the body processes them.

The time, as given by clocks, shouldn't matter either; if the photons make physical contact in two different orders, it should result in the body physically generating two different experiences.


EDIT: it might be helpful to look at the issue in the following way, by posing the question, will Albert's brain functioning change depending on his physical location; that is, will the physical processes of his body and brain, while he is standing on the platform, be different from what they would if he was located on the train?

The reason being, if Albert were located on the train and photons made physical contact with his retinae in the order of one first, then the other, his brain would generate an ordered experience.

The core problem I see is you are not starting your train of thought with the Lorentz transformations. By trying to intuitively construct what is going on with thought experiments and intuition, errors will repeatedly slip in, because no matter how diligent you think you are, the fact that relativity posits relationships between observers that are completely alien to common sense means your intuition will betray you. Maybe smaller steps need to be taken, and built upon.

Currently, we have a complicated measurement apparatus (retinas and a cpu, or retinas and a light, or retinas and a complex biological brain belonging to Albert). Let's replace this complicated apparatus with a simpler one: Two clocks where the retinas used to be. When they are struck, they stop ticking. So a measure of simultaneity that used to be "Do the retinas send a signal processed by a complex brain that generates the experience of simultaneous blindness" is replaced by "Do the clocks stop with the same reading on their faces". If the clocks stop with the same time reported on each clock, the system will report simultaneous strikes. If the clocks don't, then non-simultaneous strikes.

Here is my question to you: Do you accept that, even though different observers will disagree over whether or not the clocks were struck at the same time, all observers will agree with what the clock apparatus reports. I.e. if one observer sees that both clocks report the same time, all observers will agree. To stress it even further: Even though different observers disagree over simultaneity, all observers agree with what is reported by that particular system.

This is not a trick question, I am genuinely trying to see where we can start from.

I would be interested in seeing how the LTs work for the case in hand, of the propagation of the sound waves

Sure. I will throw the results up when I get a chance (probably later this evening). They will answer your question about whether or not the speed of sound, relative to the medium, is isotropic in all reference frames (the answer is no, due to time dilation effects across different paths).

dlouth15

roosh wrote: »

Aaah, my apologies; I was taking the speed of the signals from the retinae to the CPU to be the speed of light, for the sake of convenience. If you don't mind and have the time, I would be interested in seeing how the LTs work for the case in hand, of the propagation of the sound waves.

Let the speed of sound be [latex]v[/latex]. It doesn't matter what the speed is really. The same calculations apply to electrical signals. The important thing is that the speed is the same from either detector is the same.

Frame [latex]S[/latex]:

If you imagine that we have the two detectors in the rest frame [latex]S[/latex] at positions [latex]$x_{L}=-x$[/latex] and [latex]$x_R=x$[/latex] either side of the CPU which is at the origin in that frame. The speed of the signal is [latex]v \le c[/latex]. So at time [latex]t=0[/latex], signals travel at respective velocities [latex]v_L=v[/latex] and [latex]v_R=-v[/latex] and arrive at the CPU at [latex]t_C=x/v[/latex].

So we essentially have three spacetime events: [latex]E_{L}=\left(-x,\,0\right) [/latex], [latex]E_{R}=\left(x,\,0\right) [/latex] and [latex]E_{C}=\left(0,\, x/v\right)[/latex].

Frame [latex]S^\prime[/latex].

Frame [latex]S^\prime[/latex] is moving at speed [latex]-V[/latex] relative to frame [latex]S[/latex]. [edit: changed direction of V]

Applying the Lorentz transformation, the three events in [latex]S^{\prime}[/latex] are then [latex]E_{L}^{\prime}=\left(-\gamma x,\,-\gamma x/v\right)[/latex], [latex]E_{R}^{\prime}=\left(\gamma x,\,\gamma x/v\right)[/latex] and [latex]E_{C}^{\prime}=\left(-\gamma Vx/v,\,\gamma x/v\right)[/latex]. Note that the time coordinates for [latex]E_{L}^{\prime}[/latex] and [latex]E_{R}^{\prime}[/latex] are different: [latex]-\gamma x/v\neq\gamma x/v[/latex]. In frame [latex]S^{\prime}[/latex] the signals are detected at different times at the light detectors.

So the question is how is it that they reach the point [latex]x_C^{\prime}=-\gamma Vx/v[/latex] at the same time [latex]t_C^{\prime}=\gamma x/v[/latex]?

The key thing is that velocities are also transformed. Signals travel from detectors towards CPU at [latex]v_{L}^{\prime}=\left(V+v\right)/\left(1+vV/c^{2}\right)[/latex]and [latex]v_{L}^{\prime}=\left(V-v\right)/\left(1-vV/c^{2}\right).[/latex]Note that the absolute values of these velocities are different. The signals do not travel at the same speeds towards the CPU.

The signal is detected by the left detector at time [latex]t_{L}^{\prime}=-\gamma x/v[/latex]. It travels at [latex]v_{L}^{'}[/latex] velocity a distance of [latex]x_{C}^{'}-x_{L}^{\prime}[/latex]. Therefore the time at which it reaches the CPU is [latex]t_{C}^{\prime}=t_{L}^{\prime}+\left(x_{C}^{'}-x_{L}^{\prime}\right)/v_{L}^{'}[/latex]. If we do the algebra we find that [latex]t_{C}^{\prime}=\gamma x/v[/latex], which is exactly what was predicted by the Lorentz transformation applied to [latex]E_{C}[/latex]. We can do the same thing for the other detector on the right hand side: [latex]t_{C}^{\prime}=t_{R}^{\prime}+\left(x_{C}^{'}-x_{R}^{\prime}\right)/v_{R}^{'}[/latex] and again we get the same result: [latex]t_{C}^{\prime}=\gamma x/v[/latex]. Thus signals arrive simultaneously at the CPU even though they are detected by the detectors at different times in frame [latex]S^\prime[/latex].

---

Some general observations: Every thing predicted by special relativity is predicted mathematically. If you are trying to establish an inconsistency about special relativity the inconsistency must arise from the mathematics since it is a mathematical theory.

For example if it were shown that in frame [latex]S^\prime[/latex] the signals arrived at the CPU at two different times then we would have found an inconsistency in the theory since this would have indicated the CPU firing in one frame but not firing in the other.

What does not demonstrate an inconstancy is you saying that although the mathematics says one thing, "physically" something else should be happening according to your intuition of the situation. This is false reasoning because your intuition about what should be the case is not something predicted by special relativity in the first place. In fact a lot of commonsense notions have to be abandoned in order for special relativity to work. Yet it solves a very fundamental problem of reconciling electromagnetism with other branches of physics and has withstood all experimental tests within its limits to date.

roosh

Morbert wrote: »

The core problem I see is you are not starting your train of thought with the Lorentz transformations. By trying to intuitively construct what is going on with thought experiments and intuition, errors will repeatedly slip in, because no matter how diligent you think you are, the fact that relativity posits relationships between observers that are completely alien to common sense means your intuition will betray you. Maybe smaller steps need to be taken, and built upon.

Currently, we have a complicated measurement apparatus (retinas and a cpu, or retinas and a light, or retinas and a complex biological brain belonging to Albert).

We can essentially take the complexity out of it by considering whether or not the physical functioning of the brain will be the same regardless of it's physical location. If it will physically function the same, regardless of where it is located, then the complexity doesn't matter.

I'm working on the presumption that Albert's brain physically functions the same, regardless of whether he is on the platform or on the train; that is to say that the underlying physical processes are unaffected by how they are labeled.

The issue, then, is that if Albert were on board the train and photons made physical contact with his eyes in the order of one first, then the other, his body would process them and his brain would generate an ordered experience. However, the contention is that this will not be the case for photons which make physical contact with his retinae, in the same order while he is standing on the embankment.

This is where the physical photons which make physical contact with his retinae come from the same physical lightning strikes, and where the physical ordering of the events doesn't matter.

The only piece of intuition there is that Albert's brain will physically function the same on the train as on the embankment; if that is incorrect, then relativity must suggest that his brain will function differently depending on its physical location.

Morbert wrote: »

Let's replace this complicated apparatus with a simpler one: Two clocks where the retinas used to be. When they are struck, they stop ticking. So a measure of simultaneity that used to be "Do the retinas send a signal processed by a complex brain that generates the experience of simultaneous blindness" is replaced by "Do the clocks stop with the same reading on their faces". If the clocks stop with the same time reported on each clock, the system will report simultaneous strikes. If the clocks don't, then non-simultaneous strikes.

Here is my question to you: Do you accept that, even though different observers will disagree over whether or not the clocks were struck at the same time, all observers will agree with what the clock apparatus reports. I.e. if one observer sees that both clocks report the same time, all observers will agree. To stress it even further: Even though different observers disagree over simultaneity, all observers agree with what is reported by that particular system.

This is not a trick question, I am genuinely trying to see where we can start from.

I do agree that, according to relativity, the observers will agree on the time shown by each clock; but, I don't agree with the contention that the same time reading on a clock implies simultaneity, because this would only be true for synchronised clocks; the same time reading on clocks which are not synchronised implies non-simmultaneity.

Morbert wrote: »

Sure. I will throw the results up when I get a chance (probably later this evening). They will answer your question about whether or not the speed of sound, relative to the medium, is isotropic in all reference frames (the answer is no, due to time dilation effects across different paths).

Cheers.

Morbert

I had no idea boards supported LaTex?!

dlouth15 wrote: »

Frame [latex]S^\prime[/latex].

Frame [latex]S^\prime[/latex] is moving at speed [latex]V[/latex] relative to frame [latex]S[/latex].

Applying the Lorentz transformation, the three events in [latex]S^{\prime}[/latex] are then [latex]E_{L}^{\prime}=\left(-\gamma x,\,-\gamma x/v\right)[/latex], [latex]E_{R}^{\prime}=\left(\gamma x,\,\gamma x/v\right)[/latex] and [latex]E_{C}^{\prime}=\left(-\gamma Vx/v,\,\gamma x/v\right)[/latex]

I think these should be

[latex]E'_L = \left(-\gamma x,\gamma Vx\right)[/latex]
[latex]E'_R = \left(\gamma x,-\gamma Vx\right) [/latex]
[latex]E'_C = \left(-\gamma V x/v ,\gamma x/v\right)[/latex]

dlouth15

Morbert wrote: »

I had no idea boards supported LaTex?!



I think these should be

[latex]E'_L = \left(-\gamma x,\gamma Vx\right)[/latex]
[latex]E'_R = \left(\gamma x,-\gamma Vx\right) [/latex]
[latex]E'_C = \left(-\gamma V x/v ,\gamma x/v\right)[/latex]

Yeah, I tend to think of the moving frame as the one with the stuff to be measured and one from which the observations are made as being at rest. I've changed my post so that [latex]-V[/latex] has been substituted for [latex]V[/latex] and I think it now works.

dlouth15

Roosh, would you agree that regardless of the complexity of Albert's brain, the assumption has to be made that we're dealing with a physical object with observable characteristics that can be modeled and measured by observers moving with velocities relative to the brain?

If so, what then is the simplest setup that can be imagined that can demonstrate the alleged inconsistencies?

If not, why do you think that Albert's brain might be different to an observable physical system?

roosh

dlouth15 wrote: »

Roosh, would you agree that regardless of the complexity of Albert's brain, the assumption has to be made that we're dealing with a physical object with observable characteristics that can be modeled and measured by observers moving with velocities relative to the brain?

If so, what then is the simplest setup that can be imagined that can demonstrate the alleged inconsistencies?

If not, why do you think that Albert's brain might be different to an observable physical system?

I would agree that we are dealing with a physical object which could, theoretically, be modeled by different observers.

We can negate the issue of complexity simply by addressing the question of whether or not the physical processes, of the system, will operate the same, regardless of its physical location; that is, will Albert's brain physically function differently on the train than it will on the platform? In this manner we can hypothesise the most complex possible system, or the least complex possible system, as that should be sufficient for addressing our question.

If Albert were located on the train and the photons made physical contact with his eyes, in the order of one first then the other, his body, or brain, would generate an ordered experience. However, when photons make physical contact with his retinae, while he is standing on the embankment, in the order of one first then the other, his brain will not generate an ordered experience. This would seem to suggest that the physical operations of Albert's brain, or his body as a whole, functions differently depending on his physical location.

dlouth15

roosh wrote: »

I would agree that we are dealing with a physical object which could, theoretically, be modeled by different observers.

We can negate the issue of complexity simply by addressing the question of whether or not the physical processes, of the system, will operate the same, regardless of its physical location; that is, will Albert's brain physically function differently on the train than it will on the platform? In this manner we can hypothesise the most complex possible system, or the least complex possible system, as that should be sufficient for addressing our question.

If Albert were located on the train and the photons made physical contact with his eyes, in the order of one first then the other, his body, or brain, would generate an ordered experience. However, when photons make physical contact with his retinae, while he is standing on the embankment, in the order of one first then the other, his brain will not generate an ordered experience. This would seem to suggest that the physical operations of Albert's brain, or his body as a whole, functions differently depending on his physical location.

SR suggests that the physical location of the system should not make any difference. The difference arises when spacetime events as measured by one frame are measured by another.

However is conscious experience a spacetime event? It is only available to the system having the experience itself? Does it even mean anything to talk about conscious experience in conjunction with different reference frames?

This is why I tried to introduce the simpler system of the two light detectors and a CPU in the middle which flashes when signals from the light detectors occur simultaneously. Why is this not sufficient to demonstrate the inconsistency you believe occurs?

What is your basis for believing that Albert's brain might function in a fundamentally different way?

Morbert

dlouth15 wrote: »

Yeah, I tend to think of the moving frame as the one with the stuff to be measured and one from which the observations are made as being at rest. I've changed my post so that [latex]-V[/latex] has been substituted for [latex]V[/latex] and I think it now works.

The problem isn't specifically with V, it's how you're transforming the time coordinate. [latex]E'_C[/latex] and [latex]E'_R[/latex] are separated by a timelike interval, but you've transformed them so that they are now separated by a spacelike interval. I.e. In S', you have the two events occurring at the same time ([latex]\gamma x/v[/latex]) which would be impossible under the Lorentz transformations.

dlouth15

Thanks Morbert. You are right. Didn't notice that. I'm going to have another go when I have a bit of time.

roosh

dlouth15 wrote: »

SR suggests that the physical location of the system should not make any difference. The difference arises when spacetime events as measured by one frame are measured by another.

However is conscious experience a spacetime event? It is only available to the system having the experience itself? Does it even mean anything to talk about conscious experience in conjunction with different reference frames?

There appears to be two schools of thought when it comes to conscious experience; one, the materialist paradigm, suggests that conscious experience is nothing more than a by-product of the machinations of the brain; in this sense, conscious experience wouldn't be reducible to a single spacetime event, but would be reducible to a number of spacetime events. The other school of thought appears to be that consciousness is "metaphysical".


For the point in question, however, I don't think it matters whether or not conscious experience is a spacetime event; the point being made was that, when we take what relativity says about the physical world, and apply it to the physical world, that it gives rise to a paradox; that might be a physical paradox as opposed to a mathematical one. It isn't necessarily being said that relativity, as a closed system, is paradoxical or self-contradictory, in a mathematical sense, but rather, when it is applied to the physical world it would appear to suggest a paradox should arise.

Would you agree that if Albert's brain generates an ordered experience on the train, when photons make physical contact with his retinae in the order of one first, then the other, that his brain should generate a similar experience on the platform, if photons make physical contact with his eyes in the order of one first then the other; if there is no difference in how his brain functions between different physical locations and there is no difference in the physicality of the photons which strike his retinae?

dlouth15 wrote: »

This is why I tried to introduce the simpler system of the two light detectors and a CPU in the middle which flashes when signals from the light detectors occur simultaneously. Why is this not sufficient to demonstrate the inconsistency you believe occurs?

You may have answered your own question above, by suggesting the issue lies in the consciousness of the system.

dlouth15 wrote: »

What is your basis for believing that Albert's brain might function in a fundamentally different way?

I'm not suggesting it does, I'm asking if relativity says it does. If photons which make physical contact with Albert's retinae in the order of one first then the other lead to Albert's brain generating an ordered experience, on the train, then unless Albert's brain functions differently, photons which make physical contact in a given order on the platform should also lead to his brain generating an ordered experience. If that isn't the case, then it suggests that Albert's brian physically functions differently, depending on its physical location.

Morbert

roosh wrote: »

I do agree that, according to relativity, the observers will agree on the time shown by each clock; but, I don't agree with the contention that the same time reading on a clock implies simultaneity, because this would only be true for synchronised clocks; the same time reading on clocks which are not synchronised implies non-simmultaneity.

So, to clarify, we have a physical system which receives input in the form of two photons striking it, and reports "yes" or "no" the the question of "Did the physical strikes occur simultaneously?". And you accept that just because different observers disagree over whether or not the physical strikes are simultaneous doesn't mean the system in question should paradoxically produce two mutually exclusive reports?

roosh

Morbert wrote: »

So, to clarify, we have a physical system which receives input in the form of two photons striking it, and reports "yes" or "no" the the question of "Did the physical strikes occur simultaneously?". And you accept that just because different observers disagree over whether or not the physical strikes are simultaneous doesn't mean the system in question should paradoxically produce two mutually exclusive reports?

The system doesn't report "yes" or "no", the times on the clocks are what is reported; only if the clocks are synchronised does it imply that the events are simultaneous.

To refer to the illustration of the point above; if Albert were located on the train and the photons, from the lightning strikes, struck his retinae in the order of one first then the other, his body would process them and his brain would generate an ordered experience; if Albert's brain functions the same on the platform as it does on the train, then if the photons, from the same lightning strikes, strike his retinae in the order of one first, then the other is brain should generate an ordered experience.

However, the contention appears to be that this isn't the case.

Morbert

roosh wrote: »

The system doesn't report "yes" or "no", the times on the clocks are what is reported; only if the clocks are synchronised does it imply that the events are simultaneous.

So you are saying the system isn't necessarily reporting any real simultaneity, because whether or not the system reports the photon strikes as simultaneous depends on whether or not the clocks are synchronised?

dlouth15

roosh wrote: »

Would you agree that if Albert's brain generates an ordered experience on the train, when photons make physical contact with his retinae in the order of one first, then the other, that his brain should generate a similar experience on the platform, if photons make physical contact with his eyes in the order of one first then the other; if there is no difference in how his brain functions between different physical locations and there is no difference in the physicality of the photons which strike his retinae?

There should be no difference, I agree.
However we need to recognise the implicit frames of reference involved in your statement. The first is a frame of reference in which the train is at rest (or a frame moving with the train). The second is a frame of reference in which the platform is at rest. We're really talking about two separate scenarios involving frames in which Albert is at rest and we can expect things to happen in the same way in both these frames.

Can you point out the paradox?

dlouth15

roosh wrote: »

To refer to the illustration of the point above; if Albert were located on the train and the photons, from the lightning strikes, struck his retinae in the order of one first then the other, his body would process them and his brain would generate an ordered experience; if Albert's brain functions the same on the platform as it does on the train, then if the photons, from the same lightning strikes, strike his retinae in the order of one first, then the other is brain should generate an ordered experience.

However, the contention appears to be that this isn't the case.

I don't think anyone would contend that Albert's brain on the train functions differently to how it would function on the platform. Who is contending that?

All SR deals with is how measurements are made of the same system in different reference frames. In the example you have given we have two identical physical systems, clones of Albert, and each has their own implicit reference frame. SR only comes into play when one of these Alberts makes observations of what is happening with the other.

You could also have a single Albert who starts off on the platform and then gets on the train. Will his brain function the same in both cases as far as Albert is concerned? Yes, because when he's on the platform there's an implicit frame associated with him in which he's at rest. When he is on the train there's another implicit frame in which he's also at rest and the earlier one ceases to be relevant. SR is only involved when we have two or more frames from which measurements are made on the same system.

roosh

Morbert wrote: »

So you are saying the system isn't necessarily reporting any real simultaneity, because whether or not the system reports the photon strikes as simultaneous depends on whether or not the clocks are synchronised?

Is this not what relativity says when it says that the relativity of simultaneity is not physical?

I'm not sure if the system reports "real" simultaneity; the physicality of the ordering would be a separate debate; as would the question of whether or not lightning strikes can occur without an implicit physical ordering, such that the detection of photons from those strikes has to have a physical ordering. But, as mentioned, that would be a separate debate.

What we do know is that Alber's brain generates real experiences based on physical stimuli which make contact with his sensory organs. If he were on the train and photons struck his retinae in the order of one first, then the other then his brain would generate an ordered experience. If the physical functioning of his brain doesn't change depending on it's physical location, then photons which strike his retinae in the order [of one first then the other] should also lead to his brain generating an ordered experienece. Would you agree?

roosh

dlouth15 wrote: »

There should be no difference, I agree.
However we need to recognise the implicit frames of reference involved in your statement. The first is a frame of reference in which the train is at rest (or a frame moving with the train). The second is a frame of reference in which the platform is at rest. We're really talking about two separate scenarios involving frames in which Albert is at rest and we can expect things to happen in the same way in both these frames.

Can you point out the paradox?

If we can expect things to happen in the same way, then we should expect Albert's brain to generate an ordered experience when photons make physical contact with his retinae in the order of one first then the other, while he is standing on the platform, as it does when he is on the train; if it doesn't, then it implies that things don't happen in the same way.

If things do happen in the same way then Albert's brian should generate discordant experiences, which would be paradoxical.

dlouth15 wrote: »

I don't think anyone would contend that Albert's brain on the train functions differently to how it would function on the platform. Who is contending that?

All SR deals with is how measurements are made of the same system in different reference frames. In the example you have given we have two identical physical systems, clones of Albert, and each has their own implicit reference frame. SR only comes into play when one of these Alberts makes observations of what is happening with the other.

You could also have a single Albert who starts off on the platform and then gets on the train. Will his brain function the same in both cases as far as Albert is concerned? Yes, because when he's on the platform there's an implicit frame associated with him in which he's at rest. When he is on the train there's another implicit frame in which he's also at rest and the earlier one ceases to be relevant. SR is only involved when we have two or more frames from which measurements are made on the same system.

It sounds a bit like "if a tree falls in the woods..."; if lightning strikes happen at the poles and the relatively moving observers don't bother to measure them, are they simultaneous?

What we have is Albert and his clone in two different physical locations, where the physical brains in each of their skulls functions the exact same way, physically. The brain of Albert's clone [on the train] will physically process the sensory infromation received and generate an ordered experience, when photons make physical contact in the order of one first then the other. If Albert's brain [on the platform] physically functions the same, then his brain should also generate an ordered experience when photons make physical contact in the order of one first then the other.


Presumably both Albert and his clone will agree that their brains physically function the same way; otherwise we would have the scenario where Albert says, when he is on the platform, at rest relative to it and the hypothetical measuring instruments [that are his reference frame], that his brain operates in a certain manner that is different to how his clone's brain physically functions.

Then, when he is on the train with his clone, and both are moving relative to the platform and the hypothetical measuring instruments, that his brain physically functions the same as his clone, which was different to how his brain functioned when he was at rest relative to the platform and the hypothetical instruments; meaning that his brain functions differently depending on it's physical location and it's motion relative to the platform and hypothetical measuring instruments.

dlouth15

roosh wrote: »

If we can expect things to happen in the same way, then we should expect Albert's brain to generate an ordered experience when photons make physical contact with his retinae in the order of one first then the other, while he is standing on the platform, as it does when he is on the train; if it doesn't, then it implies that things don't happen in the same way.

However what I said was that if the photons strike the retinae in the order of one first then the other, it does produce an ordered experience (assuming an implicit frame of reference in which Albert is at rest). This is true whether he's on the train or the platform.

If things do happen in the same way then Albert's brian should generate discordant experiences, which would be paradoxical.

Why? On the train the photons strike in the order of one first and then the other and Albert has the ordered experience. On the platform the photons strike in the order of one first and then the other and Albert has the ordered experience. No paradox here as far as I can see.

The reason this works is that there's an implicit frame of reference associated with the first scenario where Albert is on the train and another for the scenario where Albert is on the platform. In each scenario we're only dealing with one Albert and one frame in which he's at rest. Therefore things like the Lorentz transformation don't need to be used.

It sounds a bit like "if a tree falls in the woods..."; if lightning strikes happen at the poles and the relatively moving observers don't bother to measure them, are they simultaneous?

What we have is Albert and his clone in two different physical locations, where the physical brains in each of their skulls functions the exact same way, physically. The brain of Albert's clone [on the train] will physically process the sensory infromation received and generate an ordered experience, when photons make physical contact in the order of one first then the other. If Albert's brain [on the platform] physically functions the same, then his brain should also generate an ordered experience when photons make physical contact in the order of one first then the other.

Yes, I agree with this.

Presumably both Albert and his clone will agree that their brains physically function the same way; otherwise we would have the scenario where Albert says, when he is on the platform, at rest relative to it and the hypothetical measuring instruments [that are his reference frame], that his brain operates in a certain manner that is different to how his clone's brain physically functions.

Yes, I think this is reasonable.

Then, when he is on the train with his clone, and both are moving relative to the platform and the hypothetical measuring instruments, that his brain physically functions the same as his clone, which was different to how his brain functioned when he was at rest relative to the platform and the hypothetical instruments; meaning that his brain functions differently depending on it's physical location and it's motion relative to the platform and hypothetical measuring instruments.

OK, here we've got a situation where there's two relevant frames: one associated with the two Alberts on the trains, S', and one associated with the measuring equipment on the platform, S.

In this scenario it is possible that the Alberts on the train process an ordered experience even though the measuring equipment on the platform measure simultaneous flashes.

But to the two Alberts everything is normal. They experience an ordered sequence of events and any measuring equipment on the train backs them up.

Back on the platform the measuring equipment sees simultaneous events and if the equipment is very sophisticated will also measure the neuronal signals as they pass through the two Alberts brains. The velocities of these signals as well as the spacial separation of the neurons will be different to those measured by equipment on the train. However someone with sufficiently advanced knowledge of neuroscience will be able to predict that the two Alberts will experience an ordered experience even though the light (when measured from the platform) strikes simultaneously.

No paradox as far as I can see. Yes counterintuitive but not paradoxical.

I think the important thing here is to acknowledge the implicit frame of reference associated with Albert when he experiences something. In normal language and thought we don't do this. This is because we've evolved in an environment where velocities are negligible compared to the speed of light. Forgetting to acknoledge this implicit frame then leads to confusion when we're dealing with relativistic effects.

When you say "first strikes one retina and then the other" you must specify the frame of reference for which this is true. I've noticed you tend to avoid this. You don't need to do this in ordinary language but it becomes necessary in SR. Something that is ordered in one frame may not be in another.

citrus burst

dlouth15 wrote: »

However what I said was that if the photons strike the retinae in the order of one first then the other, it does produce an ordered experience (assuming an implicit frame of reference in which Albert is at rest). This is true whether he's on the train or the platform.
If things do happen in the same way then Albert's brian should generate discordant experiences, which would be paradoxical.It sounds a bit like "if a tree falls in the woods..."; if lightning strikes happen at the poles and the relatively moving observers don't bother to measure them, are they simultaneous?

What we have is Albert and his clone in two different physical locations, where the physical brains in each of their skulls functions the exact same way, physically. The brain of Albert's clone [on the train] will physically process the sensory infromation received and generate an ordered experience, when photons make physical contact in the order of one first then the other. If Albert's brain [on the platform] physically functions the same, then his brain should also generate an ordered experience when photons make physical contact in the order of one first then the other.Yes, I agree with this.
Yes, I think this is reasonable.
OK, here we've got a situation where there's two relevant frames: one associated with the two Alberts on the trains, S', and one associated with the measuring equipment on the platform, S.

In this scenario it is possible that the Alberts on the train process an ordered experience even though the measuring equipment on the platform measure simultaneous flashes.

But to the two Alberts everything is normal. They experience an ordered sequence of events and any measuring equipment on the train backs them up.

Back on the platform the measuring equipment sees simultaneous events and if the equipment is very sophisticated will also measure the neuronal signals as they pass through the two Alberts brains. The velocities of these signals as well as the spacial separation of the neurons will be different to those measured by equipment on the train. However someone with sufficiently advanced knowledge of neuroscience will be able to predict that the two Alberts will experience an ordered experience even though the light (when measured from the platform) strikes simultaneously.

No paradox as far as I can see. Yes counterintuitive but not paradoxical.

I think the important thing here is to acknowledge the implicit frame of reference associated with Albert when he experiences something. In normal language and thought we don't do this. This is because we've evolved in an environment where velocities are negligible compared to the speed of light. Forgetting to acknoledge this implicit frame then leads to confusion when we're dealing with relativistic effects.

When you say "first strikes one retina and then the other" you must specify the frame of reference for which this is true. I've noticed you tend to avoid this. You don't need to do this in ordinary language but it becomes necessary in SR. Something that is ordered in one frame may not be in another.

Thanks dlouth15 for saying everything in a much more sophisticated and simpler way then I ever could! I think you've really summed it up in this post.

The more I've studied physics, the less intuitive it has become. Feynmann phrased it "Anyone who thinks they understand quantum mechanics, doesn't really understand it." And although we aren't talking about QM, the same can be said for relativity. Humans aren't designed for it. Evolution seems to be quite fickle in what it chooses and since our natural predators/prey didn't move at 15000000 m/s, it didn't think it was a good idea to evolve a sense to interpret this data.

I can see where you are coming from Roosh (I hope). If we have two identical cpu's/brains, then they should interpret data in the exact same way. One first, then the other?* I think we all agree on that. But this isn't the problem (again, I hope), the problem is what happens when these two identical cpu's/brains are in different reference frames (in other words, both moving relative to each other).

If each lived in isolation from the other, then there would be no problem. The old Newtonian approximation would still stand (I assume you don't disagree with Newtonian physics?). A nice, but bad **,way of checking would be to "magically" move one of the cpu's/brains to the other reference frame and test the two of them (I'll get back to this "magic", its important). I'd like to know you're opinion on this Roosh.

If each cpu/brain didn't live in isolation, then would things be different? Essentially all we have to do is bring the two reference frames*** closer together. I can't see why this would change the laws of physics, can you? So by this logic, as long as you agree, we can then "magically" move one cpu/brain to the other reference frame and test it against the other cpu/brain. All I've really done here is mess around with the other thought experiments discussed throughout.

As you have said, both cpu's/brains should disagree, if we do what I just described above and I'd be inclined to agree with you, except for the "magic".

So what's the magic? It seems fundamentally important, if it makes the two of us disagree. Well its a force.

In the first example I gave above, with the two reference frames isolated from each other, I didn't really need to say what it was, other then a theoretical idea. However if I didn't apply a force, the cpu's/brains would have to disagree. Each reference frame can assume its at rest relative to the other, no problem here? So essentially I need to speed a cpu/brain up or slow one down in order for it to bored another train. This speeding up/slowing/applying a force has the knock on effect of changing the reference frame of an object. Its the only way it can be done.

Lets go to the second example I gave. The more realistic one. Lets not apply a force/magic and try and bored a train; for arguments sake, and take a measurement. So since no forces are applied, how can I get my cpu on the train? Well actually I can't, but lets go through it. I throw my cpu at the train (pretty crude) and it goes through the window. So now its "on" the train, it should inherit all the properties of the train (same speed etc)? Short answer, no. Assuming the train is wide enough, (or fast enough) the cpu should fly out the open window at the back of the train. This by the way is why I agreed with you above.

Before the cpu leaves the train, we have a bizarre situation. One cpu is at rest relative to the train, the other is at rest relative to something else, but not the train, however both are on the train. If both cpu's decided to take measurements, they would get different results. So although, both cpu's are in the same, roughly speaking, space, they are not in the same reference frame. We need a force. This, I think is why you believe there should be two different memories between two identical things. One cpu is flying out the back of the train, the other is sitting there. You alluded to it earlier; about moving one Albert to another reference frame, whilst keeping his old reference frame, instead of inheriting a new reference frame. If you don't change his reference frame, to suit his speed, he should fall out the back of the train, while his twin looks on, if that makes sense, instead of having discordant memories.

To sum up I guess, if you change reference frame, you need to change coordinate system, or else you'll fall out the back of the reference frame. To do this you need a force.

I should also mention what I mean by a force. A force, in this context is something that causes the velocity of something to change instantaneously, at one instant it has velocity [Latex]v[/Latex], at the next it has velocity [Latex]vdv[/Latex]. This is to distinguish from General Relativity, something I know next to nothing about, other then to keep away from it.

Anyway, this was probably a bit of a tangent, from what we were discussing, but I thought I'd try and hopefully clarify why two identical cpu's/brains might disagree, when you would think they should agree. Basically you need a force to change the reference frame of an object.


*(The question mark is more for that we agree on that's how the data is interpreted, if it arrives sequentially, then questioning if that is how the data arrives)

**This only works in the theoretical world, that's why its bad

***Don't get hung up on the term reference frame. Its just an easier way of saying two objects (trains for example) moving relative to each other

roosh

dlouth15 wrote: »

However what I said was that if the photons strike the retinae in the order of one first then the other, it does produce an ordered experience (assuming an implicit frame of reference in which Albert is at rest). This is true whether he's on the train or the platform. Why? On the train the photons strike in the order of one first and then the other and Albert has the ordered experience. On the platform the photons strike in the order of one first and then the other and Albert has the ordered experience. No paradox here as far as I can see.

Assuming a frame of reference in which Albert is at rest relative to what? You must mean at rest relative to the platform and hypothetical measuring instruments which are extended throughout the universe that constitute Albert's reference frame; but all reference frames will measure Albert to be at rest relative to these physical objects.

If we look at what is said, according to the reference frame S'; it says that if photons strike Albert's retinae in the order of one first then the other when he is on the train, at rest relative to it and the hypothetical measuring instruments that constitute S', that his brain will generate an ordered experience; however, if he is on the platform, at rest relative to it and the hypothetical measuring instruments that constitute S, and photons strike in the order of one first then the other, his brain will generate a simultaneous experience. This implies that the physical functioning of his brain must be different while at rest relative to the platform and the measuring instruments that constitute S.

Although, I'm sure there are examples of where S' says that Albert's brain will generate an ordered experience when photons strike his retinae in the order of one first, then the other when is on the platform also. What would the reason for that be?

dlouth15 wrote: »

The reason this works is that there's an implicit frame of reference associated with the first scenario where Albert is on the train and another for the scenario where Albert is on the platform. In each scenario we're only dealing with one Albert and one frame in which he's at rest. Therefore things like the Lorentz transformation don't need to be used.

Again "in which he is at rest", relative to what?

As we have seen S' seems to suggest that Albert's brain functions differently depending on his physical location, or his motion relative the platform or the train; is there something in his motion relative to either that causes his brain to physically function differently?

dlouth15 wrote: »

OK, here we've got a situation where there's two relevant frames: one associated with the two Alberts on the trains, S', and one associated with the measuring equipment on the platform, S.

In this scenario it is possible that the Alberts on the train process an ordered experience even though the measuring equipment on the platform measure simultaneous flashes.

But to the two Alberts everything is normal. They experience an ordered sequence of events and any measuring equipment on the train backs them up.

Back on the platform the measuring equipment sees simultaneous events and if the equipment is very sophisticated will also measure the neuronal signals as they pass through the two Alberts brains. The velocities of these signals as well as the spacial separation of the neurons will be different to those measured by equipment on the train. However someone with sufficiently advanced knowledge of neuroscience will be able to predict that the two Alberts will experience an ordered experience even though the light (when measured from the platform) strikes simultaneously.

No paradox as far as I can see. Yes counterintuitive but not paradoxical.

I think the important thing here is to acknowledge the implicit frame of reference associated with Albert when he experiences something. In normal language and thought we don't do this. This is because we've evolved in an environment where velocities are negligible compared to the speed of light. Forgetting to acknoledge this implicit frame then leads to confusion when we're dealing with relativistic effects.

When you say "first strikes one retina and then the other" you must specify the frame of reference for which this is true. I've noticed you tend to avoid this. You don't need to do this in ordinary language but it becomes necessary in SR. Something that is ordered in one frame may not be in another.

When you say things like, there is a frame of reference associated with the platform and a different one associated with the train, or that the equipment on the platform measures simultaneous flashes, it seems as though you are suggesting that one frame of reference is more correct than the other, when it comes to describing an observers experiences; this is something Morbert was quite categorically against.

Every physical object is associated with every reference frame, because every reference frame can be used to represent every physical object, and the measuring equipment doesn't necessarily measure simultaneous flashes, according to relativity. You've mentioned implicit frames of reference where an observer is "at rest", without specifying relative to what he is at rest.


We can take the reference frame S', however, and see that it says Albert's brain functions one way when he is at rest relative to the train and another when he is at rest relative to the platform, and the hypothetical instruments each is respectively at rest to.

roosh

citrus burst wrote: »

Thanks dlouth15 for saying everything in a much more sophisticated and simpler way then I ever could! I think you've really summed it up in this post.

The more I've studied physics, the less intuitive it has become. Feynmann phrased it "Anyone who thinks they understand quantum mechanics, doesn't really understand it." And although we aren't talking about QM, the same can be said for relativity. Humans aren't designed for it. Evolution seems to be quite fickle in what it chooses and since our natural predators/prey didn't move at 15000000 m/s, it didn't think it was a good idea to evolve a sense to interpret this data.

I can see where you are coming from Roosh (I hope). If we have two identical cpu's/brains, then they should interpret data in the exact same way. One first, then the other?* I think we all agree on that. But this isn't the problem (again, I hope), the problem is what happens when these two identical cpu's/brains are in different reference frames (in other words, both moving relative to each other).

If each lived in isolation from the other, then there would be no problem. The old Newtonian approximation would still stand (I assume you don't disagree with Newtonian physics?). A nice, but bad **,way of checking would be to "magically" move one of the cpu's/brains to the other reference frame and test the two of them (I'll get back to this "magic", its important). I'd like to know you're opinion on this Roosh.

If each cpu/brain didn't live in isolation, then would things be different? Essentially all we have to do is bring the two reference frames*** closer together. I can't see why this would change the laws of physics, can you? So by this logic, as long as you agree, we can then "magically" move one cpu/brain to the other reference frame and test it against the other cpu/brain. All I've really done here is mess around with the other thought experiments discussed throughout.

As you have said, both cpu's/brains should disagree, if we do what I just described above and I'd be inclined to agree with you, except for the "magic".

So what's the magic? It seems fundamentally important, if it makes the two of us disagree. Well its a force.

In the first example I gave above, with the two reference frames isolated from each other, I didn't really need to say what it was, other then a theoretical idea. However if I didn't apply a force, the cpu's/brains would have to disagree. Each reference frame can assume its at rest relative to the other, no problem here? So essentially I need to speed a cpu/brain up or slow one down in order for it to bored another train. This speeding up/slowing/applying a force has the knock on effect of changing the reference frame of an object. Its the only way it can be done.

Lets go to the second example I gave. The more realistic one. Lets not apply a force/magic and try and bored a train; for arguments sake, and take a measurement. So since no forces are applied, how can I get my cpu on the train? Well actually I can't, but lets go through it. I throw my cpu at the train (pretty crude) and it goes through the window. So now its "on" the train, it should inherit all the properties of the train (same speed etc)? Short answer, no. Assuming the train is wide enough, (or fast enough) the cpu should fly out the open window at the back of the train. This by the way is why I agreed with you above.

Before the cpu leaves the train, we have a bizarre situation. One cpu is at rest relative to the train, the other is at rest relative to something else, but not the train, however both are on the train. If both cpu's decided to take measurements, they would get different results. So although, both cpu's are in the same, roughly speaking, space, they are not in the same reference frame. We need a force. This, I think is why you believe there should be two different memories between two identical things. One cpu is flying out the back of the train, the other is sitting there. You alluded to it earlier; about moving one Albert to another reference frame, whilst keeping his old reference frame, instead of inheriting a new reference frame. If you don't change his reference frame, to suit his speed, he should fall out the back of the train, while his twin looks on, if that makes sense, instead of having discordant memories.

To sum up I guess, if you change reference frame, you need to change coordinate system, or else you'll fall out the back of the reference frame. To do this you need a force.

I should also mention what I mean by a force. A force, in this context is something that causes the velocity of something to change instantaneously, at one instant it has velocity [Latex]v[/Latex], at the next it has velocity [Latex]vdv[/Latex]. This is to distinguish from General Relativity, something I know next to nothing about, other then to keep away from it.

Anyway, this was probably a bit of a tangent, from what we were discussing, but I thought I'd try and hopefully clarify why two identical cpu's/brains might disagree, when you would think they should agree. Basically you need a force to change the reference frame of an object.


*(The question mark is more for that we agree on that's how the data is interpreted, if it arrives sequentially, then questioning if that is how the data arrives)

**This only works in the theoretical world, that's why its bad

***Don't get hung up on the term reference frame. Its just an easier way of saying two objects (trains for example) moving relative to each other

We don't need to go through the process of throwing the cpu onto the train, we can reason abstractly based on imagining Albert in one location or the other; we can see what the reference frames say about how his brain would operate in one location or the other. S', for example, says Albert's brain will generate an ordered experience on the train but a simultaneous experience on the platform, if photons make physical contact with his retinae, in the order of one first, then the other.

Morbert

roosh wrote: »

Is this not what relativity says when it says that the relativity of simultaneity is not physical?

I'm not sure if the system reports "real" simultaneity; the physicality of the ordering would be a separate debate; as would the question of whether or not lightning strikes can occur without an implicit physical ordering, such that the detection of photons from those strikes has to have a physical ordering. But, as mentioned, that would be a separate debate.

This is all correct. Your interpretation is consistent so far.

We have an apparatus, X, consisting of two clocks that receive photons as input. Different observers disagree over the ordering of the photons, but all observers agree with the final state of X (two clock faces with the same time reading). Hence, there is no paradox

Now for the next step: The generalisation of X. I put it to you that, for any apparatus X, whether it is two clocks, or a biological brain, or a cpu attached to retinas, or a pre-industrial revolutionary council, the above conclusion holds. Different observers disagree over the ordering of the photons, but all observers agree with the final state of X. Hence, there is no paradox.

If you disagree, then I would ask you to tender, what you feel, is the fundamental difference between the various possible systems.

roosh

Morbert wrote: »

This is all correct. Your interpretation is consistent so far.

We have an apparatus, X, consisting of two clocks that receive photons as input. Different observers disagree over the ordering of the photons, but all observers agree with the final state of X (two clock faces with the same time reading). Hence, there is no paradox

Now for the next step: The generalisation of X. I put it to you that, for any apparatus X, whether it is two clocks, or a biological brain, or a cpu attached to retinas, or a pre-industrial revolutionary council, the above conclusion holds. Different observers disagree over the ordering of the photons, but all observers agree with the final state of X. Hence, there is no paradox.

If you disagree, then I would ask you to tender, what you feel, is the fundamental difference between the various possible systems.

The issue appears to arise when we introduce conscious experience. While the clocks may have the same readings they would represent noticeably different experiences [for an idealised observer]. In one case the same time readings would correspond to flashes of light being seen in a given order, while in the other case the flashes would occur together.

Morbert

roosh wrote: »

The issue appears to arise when we introduce conscious experience. While the clocks may have the same readings they would represent noticeably different experiences [for an idealised observer]. In one case the same time readings would correspond to flashes of light being seen in a given order, while in the other case the flashes would occur together.

We have been assuming a materialistic understanding of consciousness. The experience of a stimulus is defined by the state of the brain. Thus, if both observers agree with the state of the brain that results, both observers will agree with what should be experienced.

roosh

Morbert wrote: »

We have been assuming a materialistic understanding of consciousness. The experience of a stimulus is defined by the state of the brain. Thus, if both observers agree with the state of the brain that results, both observers will agree with what should be experienced.

There is somewhat of a disconnect between the readings on two clocks and the experience produced by the brain, because the same reading on two clocks implies different things depending on the reference frame it is viewed from.

Part of the issue is that S' says that when the strikes occur in order on the train, they result in an ordered experience, however, when they occur in order on the platform, they give rise to a simultaneous experience. This would seem to suggest that the physical functioning of the brain is affected.

Morbert

roosh wrote: »

There is somewhat of a disconnect between the readings on two clocks and the experience produced by the brain, because the same reading on two clocks implies different things depending on the reference frame it is viewed from.

Part of the issue is that S' says that when the strikes occur in order on the train, they result in an ordered experience, however, when they occur in order on the platform, they give rise to a simultaneous experience. This would seem to suggest that the physical functioning of the brain is affected.

S' would say this is because the the brain on the platform is moving, and hence will process events differently.