Question on Lorentz transforms and relativity of simultaneity

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.

roosh

Morbert wrote: »

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

So the physical processes of the brain are affected?

Morbert

roosh wrote: »

So the physical processes of the brain are affected?

Yes, but only in the usual relativistic, "kinematic" sense. We could bring the conversation back to the kinematic vs. dynamic debate, but I believe the purpose of this thread was to determine whether or not there was a contradiction in the Einsteinian interpretation of events. So even if you still don't like the idea of spacetime, you should at least accept that there is no contradiction or true paradox.

roosh

Morbert wrote: »

Yes, but only in the usual relativistic, "kinematic" sense. We could bring the conversation back to the kinematic vs. dynamic debate, but I believe the purpose of this thread was to determine whether or not there was a contradiction in the Einsteinian interpretation of events. So even if you still don't like the idea of spacetime, you should at least accept that there is no contradiction or true paradox.

Is that the usual kinematic sense in which contractions aren't physical and physical processes aren't affected?

Morbert

roosh wrote: »

Is that the usual kinematic sense in which contractions aren't physical and physical processes aren't affected?

The geometry of spacetime does have observable physical effects. A twin returning on a spaceship will be much younger than the twin staying at home. Clocks at different locations in a uniform gravitational field will tick at different rates. Relativity predicts all of these effects. What you are objecting to is the idea that the underlying kinematics of these effects, rather than some set of physical dynamics, is more fundamental, because that contradicts presentism.

roosh

Morbert wrote: »

The geometry of spacetime does have observable physical effects. A twin returning on a spaceship will be much younger than the twin staying at home. Clocks at different locations in a uniform gravitational field will tick at different rates. Relativity predicts all of these effects. What you are objecting to is the idea that the underlying kinematics of these effects, rather than some set of physical dynamics, is more fundamental, because that contradicts presentism.

The asymmetry between the reference frames is what is used to account for the twin "paradox", but asymmetry isn't a factor here. The issue is that the apparent implication is that an inertially moving brain will behave in two physically different ways. According to S' if the retinae are stimulated in a given order, the brain will produce an unordered experience for the observer on the platform [in this particular case], however, if the retinae are stimulated in the same order, for the observer on the train, then the brain will generate an ordered experience.

While S' says that a non-ordered experience will be produced from ordered retinae stimulation, for the observer on the platform, S would say that the brain would produce an ordered experience from ordered retinae stimulation [in this particular scenario].

Morbert

roosh wrote: »

The asymmetry between the reference frames is what is used to account for the twin "paradox", but asymmetry isn't a factor here. The issue is that the apparent implication is that an inertially moving brain will behave in two physically different ways. According to S' if the retinae are stimulated in a given order, the brain will produce an unordered experience for the observer on the platform [in this particular case], however, if the retinae are stimulated in the same order, for the observer on the train, then the brain will generate an ordered experience.

While S' says that a non-ordered experience will be produced from ordered retinae stimulation, for the observer on the platform, S would say that the brain would produce an ordered experience from ordered retinae stimulation [in this particular scenario].

That is not true in the general sense that you are implying. Observer S' will say that observer S experiences certain non-simultaneous events as simultaneous, but similarly, observer S says observer S' will experience certain non-simultaneous events as simultaneous. Relativity says neither S nor S' is more physically correct than the other.

To phrase it generally. For a given reference frame X, an observer that X labels as stationary will experience events that X labels simultaneous as simultaneous. An observer that X labels as moving will experience events that X labels simultaneous as non-simultaneous.

There is no consequential difference between the twin paradox and this. Simply consider the cases when the person on the train jumps to the ground, or the person on the platform jumps onto the train. Or the the case where the twin never returns to earth. In fact, in the same way that the equivalence principle (acceleration and gravity are locally equivalent) solves the twin paradox without the need to resort to asymmetry, it can solve your problem without the need to resort to asymmetry.

Also, again, there is no consequential difference between a brain modelled as a sophisticated set of neurons, and a brain modelled as two clocks. So if you accept one model as consistent, you are logically compelled to accept the other as consistent as well.

roosh

Morbert wrote: »

That is not true in the general sense that you are implying. Observer S' will say that observer S experiences certain non-simultaneous events as simultaneous, but similarly, observer S says observer S' will experience certain non-simultaneous events as simultaneous. Relativity says neither S nor S' is more physically correct than the other.

To phrase it generally. For a given reference frame X, an observer that X labels as stationary will experience events that X labels simultaneous as simultaneous. An observer that X labels as moving will experience events that X labels simultaneous as non-simultaneous.

There is no consequential difference between the twin paradox and this. Simply consider the cases when the person on the train jumps to the ground, or the person on the platform jumps onto the train. Or the the case where the twin never returns to earth. In fact, in the same way that the equivalence principle (acceleration and gravity are locally equivalent) solves the twin paradox without the need to resort to asymmetry, it can solve your problem without the need to resort to asymmetry.

Also, again, there is no consequential difference between a brain modelled as a sophisticated set of neurons, and a brain modelled as two clocks. So if you accept one model as consistent, you are logically compelled to accept the other as consistent as well.

The issue isn't resolved by saying that in certain situations each says the same thing about the other.

The issue is that the reference frames imply that inertially moving brains, in a region of space where gravity is equal for relatively moving observers - such that the equivalence principle doesn't apply - will physically process stimuli in two different ways. In the given example, S' says that the brain of the observer on the platform will process stimuli, received in a given order, as an unordered experience, while S says that, for the observer on the platform, all stimuli received in a given order will result in an ordered experience. So ordered stimuli will result in the brain physically producing two mutually exclusive experiences.

S' also says that for the observer on the train, if the stimuli are received in the given order, they will result in an ordered experience, unlike the observer on the platform. This suggests that the physical operation of the brain is different on the platform than on the train, where neither asymmetry or the equivalence principle apply.

Morbert

roosh wrote: »

The issue isn't resolved by saying that in certain situations each says the same thing about the other.

The issue is that the reference frames imply that inertially moving brains, in a region of space where gravity is equal for relatively moving observers - such that the equivalence principle doesn't apply - will physically process stimuli in two different ways. In the given example, S' says that the brain of the observer on the platform will process stimuli, received in a given order, as an unordered experience, while S says that, for the observer on the platform, all stimuli received in a given order will result in an ordered experience. So ordered stimuli will result in the brain physically producing two mutually exclusive experiences.

S' also says that for the observer on the train, if the stimuli are received in the given order, they will result in an ordered experience, unlike the observer on the platform. This suggests that the physical operation of the brain is different on the platform than on the train, where neither asymmetry or the equivalence principle apply.

Again (and again) relativity says brains moving relative to each other will not process events the same way. That is not the issue. The issue is your baseless insistence that this is due to mysterious dynamics, rather than the geometry of spacetime.

roosh

Morbert wrote: »

Again (and again) relativity says brains moving relative to each other will not process events the same way. That is not the issue. The issue is your baseless insistence that this is due to mysterious dynamics, rather than the geometry of spacetime.

What it says is that the same physical brain will physically process ordered stimuli in two different ways; according to one reference frame the brain will physically process ordered stimuli to produce an unordered experience. The other reference frame says that the same brain will produce an ordered experience from ordered stimuli.

Morbert

roosh wrote: »

What it says is that the same physical brain will physically process ordered stimuli in two different ways; according to one reference frame the brain will physically process ordered stimuli to produce an unordered experience. The other reference frame says that the same brain will produce an ordered experience from ordered stimuli.

Yes. For a given reference frame X, an observer that X labels as stationary will experience events that X labels simultaneous as simultaneous. An observer that X labels as moving will experience events that X labels simultaneous as non-simultaneous.

roosh

Morbert wrote: »

Yes. For a given reference frame X, an observer that X labels as stationary will experience events that X labels simultaneous as simultaneous. An observer that X labels as moving will experience events that X labels simultaneous as non-simultaneous.

S': A physical brain which receives ordered stimuli will produce an unordered experience.

S: The same physical brain which receives ordered stimuli will produce an ordered experience, for any of the infinite permutations of ordered stimuli.


The same brain produces two different experiences from ordered stimuli.

Morbert

roosh wrote: »

S': A physical brain which receives ordered stimuli will produce an unordered experience.

S: The same physical brain which receives ordered stimuli will produce an ordered experience, for any of the infinite permutations of ordered stimuli.


The same brain produces two different experiences from ordered stimuli.
The same brain produces one experience from the stimulus. The description of the stimulus is frame-dependent.

Fixed.

roosh

Morbert wrote: »

Fixed.

The same brain produces an unordered experience from ordered stimuli and unordered stimuli.

Morbert

roosh wrote: »

The same brain produces an unordered experience from ordered stimuli and unordered stimuli.

Yup. Hence, "relativity of simultaneity".

roosh

Morbert wrote: »

Yup. Hence, "relativity of simultaneity".

So, while an observer is standing in a given location his brain physically functions in two different ways, inside his skull.

citrus burst

roosh wrote: »

S': A physical brain which receives ordered stimuli will produce an unordered experience.

S: The same physical brain which receives ordered stimuli will produce an ordered experience, for any of the infinite permutations of ordered stimuli.


The same brain produces two different experiences from ordered stimuli.

Can you expand on this a little more? Do you mean one brain in two physical locations? (for example on a train S and simultaneously on the platform S'?)

Or do you mean two identical brains in two different locations as above?

roosh

citrus burst wrote: »

Can you expand on this a little more? Do you mean one brain in two physical locations? (for example on a train S and simultaneously on the platform S'?)

Or do you mean two identical brains in two different locations as above?

The same brain, in the same physical location, physically operating in two different ways.

One reference frame (S) says that, for the the observer on the platform, the infinite permutations of ordered stimuli will cause the brain to produce an ordered experience.

S' says that, for the same brain in the same location, ordered stimuli will cause the brain to produce and unordered experience.


The physicality of the ordering doesn't matter, because we can see that if the same brain were located on the train, it would generate an ordered experience despite the fact that the ordering isn't physical.

citrus burst

roosh wrote: »

The same brain, in the same physical location, physically operating in two different ways.

Why would one brain operate in two or more ways? (Unless its designed to do so) Does your brain do this? Mine doesn't.

roosh wrote: »

One reference frame (S) says that, for the the observer on the platform, the infinite permutations of ordered stimuli will cause the brain to produce an ordered experience.

Well is the brain here?

roosh wrote: »

S' says that, for the same brain in the same location, ordered stimuli will cause the brain to produce and unordered experience.

Or here?
Can't be both places.

roosh wrote: »

One reference frame (S) says that, for the the observer on the platform, the infinite permutations of ordered stimuli will cause the brain to produce an ordered experience.

S' says that, for the same brain in the same location, ordered stimuli will cause the brain to produce and unordered experience.

Whats the difference between an ordered and an unordered experience?

roosh wrote: »

The physicality of the ordering doesn't matter, because we can see that if the same brain were located on the train, it would generate an ordered experience despite the fact that the ordering isn't physical.

So you agree that the ordering of events is a relative thing?

Slow down the speed of light for a second, to 3 m/s (or alternatively make the distances really big) and have a think about this. You are sitting in your car at a cross road. The traffic lights are red. The lights that are closer to you will turn green before the lights that are further away. Cars further away from the lights will have a longer time interval before the lights change for them. The lights will turn green simultaneous only for someone equidistant from both lights. All others will have a differently ordered experience.

Do you agree with this?

roosh

citrus burst wrote: »

Why would one brain operate in two or more ways? (Unless its designed to do so) Does your brain do this? Mine doesn't.

According to relativity it should.

citrus burst wrote: »

Well is the brain here?

Or here?
Can't be both places.

The brain is in the skull of the observer on the platform; the location on the platform is described by both S and S'.

citrus burst wrote: »

Whats the difference between an ordered and an unordered experience?

Ordered experience is where you see one light flash first and then the other, unordered is where there is no ordering of the light flashes, they occur together.

citrus burst wrote: »

So you agree that the ordering of events is a relative thing?

I'm saying that the physicality of the ordering doesn't, apparently, matter.

citrus burst wrote: »

Slow down the speed of light for a second, to 3 m/s (or alternatively make the distances really big) and have a think about this. You are sitting in your car at a cross road. The traffic lights are red. The lights that are closer to you will turn green before the lights that are further away. Cars further away from the lights will have a longer time interval before the lights change for them. The lights will turn green simultaneous only for someone equidistant from both lights. All others will have a differently ordered experience.

Do you agree with this?

I would agree with that, but it doesn't represent the issue.

There are two traffic lights, either side; you are located equidistant from both lights; the lights turn green in the given order, one first then the other; the light from each green light reaches your retinae in that order; what experience would you expect to have?

dlouth15

roosh wrote: »

There are two traffic lights, either side; you are located equidistant from both lights; the lights turn green in the given order, one first then the other; the light from each green light reaches your retinae in that order; what experience would you expect to have?

It depends on the motion of the observer making the measurement. Under certain circumstances, an observer might measure non-simultaneous changes in the lights, yet I have an experience of simultaneous change. Strange, but if special relativity is correct, true.

If the observer, on the other hand, is not moving relative to me then, his measurements will correspond to my experience. In everyday life, of course, our motions are generally so slow compared to the speed of light that it really doesn't make a difference, and both the observer and I will agree on the simultaneity/non-simultaneity of events for practical purposes.