Question on Lorentz transforms and relativity of simultaneity

roosh

Morbert wrote: »

I can't make sense of this. Nobody is saying Albert's brain processes Albert's experiences by viewing itself from a relatively moving train.
That you would think anyone is saying this seriously suggests you do not understand the responses you are getting.

Applying the LTs to Albert's brain activity gives us the perspective of the observer in the relatively moving train. That isn't how Albert's brain processes Albert's experience, from its perspective on the embankment.

Morbert wrote: »

For one thing, it doesn't even make sense to say the brain processes experiences. Instead, the brain generates experience, based on stimulus.

Now you're just playing semantics.

Albert's brain processes stimuli to generate Albert's experiences; the generation of Albert's experiences is itself a process carried out by the brain.

Morbert wrote: »

You can repeat this falsehood as often as you want. I will continue to correct you.

And I will continue to point out the rudimentary facts about the physical world, which you are consistently trying to ignore.

Morbert wrote: »

1) The simultaneity of events is a frame-dependent observation, and not a physical or absolute characteristics of events.

Photons physically strike observers' retinae, in the physical world; an observer's brain processes the stimuli from the photons to generate what they see as a "flash of light". Observers experience ordered experiences of such things as flashes of light; this means that they see one flash first and another flash second. The reason they see one flash first and another flash second is because the photons from one flash physically strike their retinae first, while the photons from the second flash, physically strike their retinae second.

Morbert wrote: »

2) There are no contradictions or paradoxes, as explicitly shown in my diagrams, as all observers agree on what events are co-incident, even if they don't agree on ordering of events separated by a spacelike interval.

The reference frame S' "says" that the photons physically strike Albert's retinae in the order of one first, then the other, while Albert is physically standing on the embankment.

If the photons physically strike Albert's retinae in the given order, while he is physically standing on the embankment, then his brain will generate an ordered experience.

If S' doesn't say that the photons don't physically strike Albert's retinae in that order, then S' doesn't correspond to the physical world.

Morbert wrote: »

Now.... Do you know what I mean by 1) and 2)

Do you know what I mean by my replies?

Morbert

roosh wrote: »

They disagree on the order in which the photons physically strike Albert's retinae, while he is physically standing on the embankment.

This, together with how Albert's brain processes Albert's experiences; or more pointedly, how his brain processes photons which physically strike his retinae, to produce his experiences, from its location on the embankment, at rest relative to it, the paradox arises.

I will ask you again. Do understanding my posts? This is not a rhetorical question. I genuinely feel that you do not understand my posts. For example, when I say the ordering of events separated by a space-like interval is unphysical, just as time dilation and length contraction are unphysical, do you know what I mean by space-like? When I say the causal structure is invariant under transformation, which means no paradox exists, do you understand?

Morbert

And I will continue to point out the rudimentary facts about the physical world, which you are consistently trying to ignore.

Roosh, I am not going to let you get away with this. Your posts actually have the potential to be quite damaging to anyone reading this who is unfamiliar with relativity. What you say about what is and isn't physical is categorically untrue, and categorically contrary to relativity.

http://en.wikipedia.org/wiki/Relativity_of_simultaneity
"In physics, the relativity of simultaneity is the concept that simultaneity–whether two events occur at the same time–is not absolute, but depends on the observer's reference frame."

http://en.wikipedia.org/wiki/General_covariance
"The essential idea is that coordinates do not exist a priori in nature, but are only artifices used in describing nature, and hence should play no role in the formulation of fundamental physical laws."

These are the facts. These are what you ignore.

The physical relation between events is characterised by a structure that is not frame-dependent.

Simultaneity is frame-dependent. Therefore, simultaneity is not part of the physical relation between events.

The causality of events is frame-independent, and is therefore physical.

Therefore, we can conclude two important facts:

1) What S or S' says about the simultaneity of brain activity is not physical. Neither S nor S' is more correct when it comes to the simultaneity of brain activity.

2) What S or S' say about the causal structure of brain activity is physical. Both agree exactly with the causal structure of brain activity. I.e. They agree with what events are causally connected to other events. And they agree with what experiences the stimulus in question will produce.

Therefore, we can conclude one even more important fact:

There is no paradox.

The physics, as mentioned in the above link, is invariant across all observers. What physically happens is agreed upon by all observers. If they disagree over some quality (I.e. Length, time dilation, or the simultaneity of retina strikes), then that quality is unphysical.

roosh

Morbert wrote: »

I will ask you again. Do understanding my posts? This is not a rhetorical question. I genuinely feel that you do not understand my posts. For example, when I say the ordering of events separated by a space-like interval is unphysical, just as time dilation and length contraction are unphysical, do you know what I mean by space-like? When I say the causal structure is invariant under transformation, which means no paradox exists, do you understand?

Likewise, I would like to know if you understand what I mean.

When you say space-like, I take it to mean two events which are spatially separated, where the events don't have a causal influence on each other.

When you say the causal structure is invariant under transfromation I take it to mean that the transformation of the mathematical co-ordinates don't lead to a violation of causlity.

Morbert

roosh wrote: »

Likewise, I would like to know if you understand what I mean.

When you say space-like, I take it to mean two events which are spatially separated, where the events don't have a causal influence on each other.

When you say the causal structure is invariant under transfromation I take it to mean that the transformation of the mathematical co-ordinates don't lead to a violation of causlity.

Close. It means all observers will agree with the causal structure of events. This means that, even if two observers disagree over frame-dependent qualities like simultaneity, they will not disagree over what physically happens as a result of events.

Morbert

I might have identified the problem. Another question: Do you understand what I mean when I say all observers will agree with what events are co-incidental with other events (I.e. If two events occur at the same place and at the same time, all observers will agree that they do so)?

So, for example, using the toy model dlouth introduced: Do you accept that, regardless of the simultaneity of the retina strikes, both S and S' agree that the signals from the retinas strike the central processing unit at the same time. (I.e. One does does not reach the central processing unit before the other)?

roosh

Morbert wrote: »

Roosh, I am not going to let you get away with this. Your posts actually have the potential to be quite damaging to anyone reading this who is unfamiliar with relativity. What you say about what is and isn't physical is categorically untrue, and categorically contrary to relativity.

http://en.wikipedia.org/wiki/Relativity_of_simultaneity
"In physics, the relativity of simultaneity is the concept that simultaneity–whether two events occur at the same time–is not absolute, but depends on the observer's reference frame."

http://en.wikipedia.org/wiki/General_covariance
"The essential idea is that coordinates do not exist a priori in nature, but are only artifices used in describing nature, and hence should play no role in the formulation of fundamental physical laws."

What I'm saying about what is an isn't physical is simply a matter of simple deduction; whether or not it is categorically contrary to relativity is immaterial, not least because relativity is, apparently, being questioned. Thus far your argument has simply been "relativity says that isn't true"; but given that relativity is being questioned, that isn't sufficient.

Again, I will state some basic facts about the physical world, if you care to challenge those facts then we might get somewhere, but if you continue to reply with "relativity says it isn't true", then the points will remain, because the points, apparently, are a challenge of "what relativity says".

Basic facts
- photons physically strike Albert's retinae in the physical world

- Albert's brain processes photons which physically strike his retinae, to generate his experience of flashes of light.

- Albert, in the past, has experiences two flashes of light in the sequence of one flash first, the other flash second; or in the order of one first, then the other.

- The reason Albert saw the flahses of light in the first place, was because the photons physically struck his retinae.


What we want to know is why he saw the flashes in the order of one first then the other?

Morbert wrote: »

These are the facts. These are what you ignore.

I could say ditto, but I've posed a question which you might be able to answer.

Morbert wrote: »

The physical relation between events is characterised by a structure that is not frame-dependent.

Simultaneity is frame-dependent. Therefore, simultaneity is not part of the physical relation between events.

The causality of events is frame-independent, and is therefore physical.

The question above speaks directly to these points, I think.

Morbert wrote: »

Therefore, we can conclude two important facts:

1) What S or S' says about the simultaneity of brain activity is not physical. Neither S nor S' is more correct when it comes to the simultaneity of brain activity.

What we can say is that human brains operate in the physical world; they don't operate according to mathematical descriptions of them; when Albert's brain produces Albert's experiences, it does so from it's own perspective and so doesn't apply the LTs to itself.

Morbert wrote: »

2) What S or S' say about the causal structure of brain activity is physical. Both agree exactly with the causal structure of brain activity. I.e. They agree with what events are causally connected to other events. And they agree with what experiences the stimulus in question will produce.

In the physical world, Albert's brain processes all photons which physically strike his retinae in the order they physically strike; with it taking the same time for the signal to reach the processing centre from each retina.

Morbert wrote: »

Therefore, we can conclude one even more important fact:

There is no paradox.

The physics, as mentioned in the above link, is invariant across all observers. What physically happens is agreed upon by all observers. If they disagree over some quality (I.e. Length, time dilation, or the simultaneity of retina strikes), then that quality is unphysical.

Relativity says there is no paradox, but the physical world would seem to disagree.

roosh

Morbert wrote: »

Close. It means all observers will agree with the causal structure of events.

Same difference.

Morbert wrote: »

This means that, even if two observers disagree over frame-dependent qualities like simultaneity, they will not disagree over what physically happens as a result of events.

Indeed, this is what relativity says.

roosh

Morbert wrote: »

I might have identified the problem. Another question: Do you understand what I mean when I say all observers will agree with what events are co-incidental with other events (I.e. If two events occur at the same place and at the same time, all observers will agree that they do so)?

So, for example, using the toy model dlouth introduced: Do you accept that, regardless of the simultaneity of the retina strikes, both S and S' agree that the signals from the retinas strike the central processing unit at the same time. (I.e. One does does not reach the central processing unit before the other)?

This is just the same point again. I do agree that mathematical representations that are S and S', say that they will reach the processing centre at the same time; but Albert's brain which operates in the physical world doesn't.

The issue in the above lies in the philosophical assumptions that relativity tacitly makes about time and how clocks measure it. The relatively moving observer will agree that the timestamp on the two imaginary retinae clocks, in Albert's eyes, will record the same time for the striking events; however, he will still say that they struck the retinae in the order of one first, then the other. This allows us to demonstrate the difference between the simultaneity as determined by a clock and physical order in which photons strike an observers retinae.

If they physically strike Albert's retinae in the order of one first, then the other, then this is how Albert's brain will process them to produce Albert's experience.

Morbert

roosh wrote: »

What we can say is that human brains operate in the physical world; they don't operate according to mathematical descriptions of them; when Albert's brain produces Albert's experiences, it does so from it's own perspective and so doesn't apply the LTs to itself.

In the physical world, Albert's brain processes all photons which physically strike his retinae in the order they physically strike; with it taking the same time for the signal to reach the processing centre from each retina.

You are contradicting yourself here. First, you say humans brains do not operate according to mathematical descriptions of them. However, the simultaneity of events is a mathematical, frame-dependent, description, yet you assume it is physical.

This is just the same point again. I do agree that mathematical representations that are S and S', say that they will reach the processing centre at the same time; but Albert's brain which operates in the physical world doesn't.

The issue in the above lies in the philosophical assumptions that relativity tacitly makes about time and how clocks measure it. The relatively moving observer will agree that the timestamp on the two imaginary retinae clocks, in Albert's eyes, will record the same time for the striking events; however, he will still say that they struck the retinae in the order of one first, then the other. This allows us to demonstrate the difference between the simultaneity as determined by a clock and physical order in which photons strike an observers retinae.

If they physically strike Albert's retinae in the order of one first, then the other, then this is how Albert's brain will process them to produce Albert's experience.

Before I go any further with this, do you, at the very least, accept the fact that relativity is self-consistent. If you start with the postulates of relativity, and carefully apply them, no paradox arises? The above implies you do.

Morbert

Here is what confuses me: In post #31, you are clearly attempting to identify an inconsistency in the theory of relativity.

Now, you seem to have retreated to your old position of "relativity makes tacit assumptions". Does this mean you now understand how relativity is consistent? Do you accept that there is no inconsistency in the theory?

roosh

Morbert wrote: »

You are contradicting yourself here. First, you say humans brains do not operate according to mathematical descriptions of them. However, the simultaneity of events is a mathematical, frame-dependent, description, yet you assume it is physical.

Brains don't operate according to mathematical descriptions of them; the order in which photons physically strike an observers retinae is a matter of physicality; that is, photons can physically strike an observers retinae in sequential order, or together, "tied for first place".

I don't assume that the mathematical, frame-dependent, description, of simultaneity is phyiscal, I ask if it corresponds to the physical world; if it does, then it implies that the photons physically strike Albert's retinae in the order of one first, then the other; if they do physically strike in this order, then his brain will process them in that order.

Morbert wrote: »

Before I go any further with this, do you, at the very least, accept the fact that relativity is self-consistent. If you start with the postulates of relativity, and carefully apply them, no paradox arises? The above implies you do.

That depends on whether or no relativity claims to represent events which occur in the physical world; mathematically, I would say there are no paradoxes, phyiscally, I would say there is.

roosh

Morbert wrote: »

Here is what confuses me: In post #31, you are clearly attempting to identify an inconsistency in the theory of relativity.

Now, you seem to have retreated to your old position of "relativity makes tacit assumptions". Does this mean you now understand how relativity is consistent? Do you accept that there is no inconsistency in the theory?

As mentioned in my last, post which, in fairness I was writing whiel you were typing this; it depends on what the theory of relativity says, with regard to how it corresponds to the physical world. Mathematically I would say it is self-consistent, but when we apply it to the physical world, then it seems that a paradox arises.

roosh

Right, I'm going to hit the hay; it's 2am here, so it's getting (or has already gotten) late.

No doubt we will continue this discussion; I mightn't get the chance to reply til sunday or monday, but I look forward to it, eitherway.

Take care.

Morbert

roosh wrote: »

Brains don't operate according to mathematical descriptions of them; the order in which photons physically strike an observers retinae is a matter of physicality;

Here you are assuming a mathematical, frame-dependent description is physical.

I don't assume that the mathematical, frame-dependent, description, of simultaneity is phyiscal, I ask if it corresponds to the physical world; if it does, then it implies that the photons physically strike Albert's retinae in the order of one first, then the other; if they do physically strike in this order, then his brain will process them in that order.

The answer, is no, it does not. By this, I mean if a reference frame, for example, says two events are simultaneous, that does not correspond to reality. Another frame, which says they are not simultaneous, is no more or less correct. Instead, it is an arbitrary description. Similar to the way a frame might describe the set-up as stationary, or moving at some velocity.

That depends on whether or no relativity claims to represent events which occur in the physical world; mathematically, I would say there are no paradoxes, phyiscally, I would say there is.

And we were so close.

ceejay

At this stage I'm prepared to accept the possibility that roosh is actually just trolling us all

However, just in case you're not -

To state my understanding of your assertion of the paradox, it's the following:

Based on these key assumptions:
- Relativity says that different reference frames result in different descriptions of when the photons hit each retina
- these different descriptions are equally valid descriptions of the order of the real physical events of photons hitting the retinas
- The order of the events at the retinas equals Albert's experience of the order of the events for all descriptions of the sequence of events

This produces the following deduction:
- That the difference descriptions of the order of the events create multiple conflicting experiences in Albert's brain of the same two events

However, Albert clearly doesn't have that kind of experience, he only has one memory of the experience. Hence a paradox arises.

I believe you would agree that the paradox arises because the deduction is false, i.e. people don't have multiple conflicting experiences of the same events, and you are searching for the reason why the deduction is false.

For the deduction to be false one or more of the assumptions must be false:

- The theory of special relativity is incorrect
- The descriptions are not equally valid descriptions of the order of real physical events
- Albert's experience of the order of the events does not equal the order of the events at the retinas for all descriptions of the sequence of the events

Your posts have been questioning the validity of the second assumption mainly, and also now the first assumption. You consistently assert the third assumption as being true without questioning the validity of that assumption.

If we take the first two assumptions to be true and apply the theory of special relativity rigorously, we find that we have to adjust our common sense view of how Albert's experience of the sequence of events is connected to the sequence of events at his retinas for all descriptions of the sequence of events, and we find that the third assumption is not valid. The way Albert's experience of the sequence events is connected to the sequence of events at the retinas is dependent on which description of the events we are considering.

Based on revising the third assumption we can find what happens to the original deduction:
- In all of the descriptions of the real physical events Albert's experience is that the flashes of light were simultaneous, even though in most of the descriptions the light flashes started at different times, and hit his retinas at different times. In one particular description the light flashes started at the same time, and hit his retinas at the same time.

The revised deduction is that there is only one experience of the events for Albert, and since that matches with our own experiences we can therefore say that there is no longer a paradox.

The paradox is resolved by reassessing the assumption that the sequence of events at Albert's retinas is equal to his experience of the sequence of events in every description of the sequence of events. This is consistent with the theory of special relativity which has been rigorously tested in many experiments, and applying that theory consistently to the whole scenario resolves the paradox.

The very simplified scenario posted originally by Morbert shows this mathematically. The very specific graphs of the scenario posted by Morbert also are not mere illustrative sketches but accurate mathematical graphs of the actual events and show exactly that the perception of the events are simultaneous in both reference frames.

Now, are you trolling us or what?

roosh

Morbert wrote: »

Here you are assuming a mathematical, frame-dependent description is physical.

No, here we are deducing that if an observer sees two flashes of light in sequence, then the photons from those flashes must have physically struck his retinae in sequence, because his brain processes photons which physically strike his retinae, to generate his experience of flashes of light.

Morbert wrote: »

The answer, is no, it does not. By this, I mean if a reference frame, for example, says two events are simultaneous, that does not correspond to reality. Another frame, which says they are not simultaneous, is no more or less correct. Instead, it is an arbitrary description. Similar to the way a frame might describe the set-up as stationary, or moving at some velocity.

In the physical world, Albert's brain generates Albert's experiences by processing stimuli which hit his sensory organs; in the physical world, photons physically strike Albert's retinae; in the physical world, Albert's brain processes sequential experiences of such things as flashes of light; how does Albert's brain generate these sequential experiences of flashes of light, with explicit reference to photons stiking Albert's retinae?

Morbert wrote: »

And we were so close.

So close, yet so far away.

roosh

ceejay wrote: »

At this stage I'm prepared to accept the possibility that roosh is actually just trolling us all
...
Now, are you trolling us or what?

Ah, ya got me! I'm just trolling!

I'm not really though.

ceejay wrote: »

However, just in case you're not -

To state my understanding of your assertion of the paradox, it's the following:

Based on these key assumptions:
- Relativity says that different reference frames result in different descriptions of when the photons hit each retina
- these different descriptions are equally valid descriptions of the order of the real physical events of photons hitting the retinas
- The order of the events at the retinas equals Albert's experience of the order of the events for all descriptions of the sequence of events

I'm not sure about the third one; I would be more inclined to say that the order in which photons physically strike Albert's retinae, while he is on the embankment, dictates the sequence of his experience, of light flashes. Not necessarily his experience of the order of events, for all descriptions of the sequence of events - because I'm not entirely sure what that means, to be honest. If you believe it's the same, then we should be able to proceed with how I've stated it, because, I think, it is a little less wordy and a little easier to understand.

If the different descriptions are a valid representation of the order in which the photons physically strike the retinae, then Albert's brain will process them and generate the corresponding sequential experience.
This produces the following deduction:
- That the difference descriptions of the order of the events create multiple conflicting experiences in Albert's brain of the same two events

ceejay wrote: »

However, Albert clearly doesn't have that kind of experience, he only has one memory of the experience. Hence a paradox arises.

I believe you would agree that the paradox arises because the deduction is false, i.e. people don't have multiple conflicting experiences of the same events, and you are searching for the reason why the deduction is false.

The issue is that we are dealing with an idealised observer in Albert; he's had a prosthetic visual network surgically implanted; this removes any issue of the fallibility of our senses. We can also have a light connected to the "processing centre" of Albert's brain such that it switches on only if the signals from his retinae don't arrive in the order of one first, then the other - this was something dlouth suggested.

So, it's not so much that the deduction is false, such that "we don't have this experience, why don't we have it?" - perhaps our brains just rationalise this away so that we can operate more effectively in the physical world; it's that, given this idealised system, which are are entitled to postulate, a paradox should arise.

ceejay wrote: »

For the deduction to be false one or more of the assumptions must be false:

- The theory of special relativity is incorrect
- The descriptions are not equally valid descriptions of the order of real physical events
- Albert's experience of the order of the events does not equal the order of the events at the retinas for all descriptions of the sequence of the events

There is nothing special about mathemical rerfence frames, I'm sure you will agree; that is, they shouldn't - indeed can't - influence how physical systems operate; they can attempt to offer descriptions of how they operate, but physical systems don't operate according how they are described mathematically. What is of primary importance is how physical systems operate in the physical world.

Albert's experiences of events does equal the order of events at the retinae, in the physical world, not necessarily as they are described; because Albert's brain processes photons which physically strike his retinae, in the physical world, not on the basis of how they are described mathematically.

If the mathematical descriptions correspond to physical events, then it means the photons physically strike in the oder of one first, then the other, and Albert's brain will process them in that order.

ceejay wrote: »

Your posts have been questioning the validity of the second assumption mainly, and also now the first assumption. You consistently assert the third assumption as being true without questioning the validity of that assumption.

If we take the first two assumptions to be true and apply the theory of special relativity rigorously, we find that we have to adjust our common sense view of how Albert's experience of the sequence of events is connected to the sequence of events at his retinas for all descriptions of the sequence of events, and we find that the third assumption is not valid. The way Albert's experience of the sequence events is connected to the sequence of events at the retinas is dependent on which description of the events we are considering.

As outlined above, that wasn't necessarily the assumption; Albert's experience of the sequence of events is connected to the physical events, not necessarily to the descriptions of the events. The mathematical descriptions of the events, of course, aren't physically connected to the events they describe, because the descriptions are abstract; but if the descriptions accurately represent the events they purport to describe, then photons physically strike Albert's retinae in the order of one first, then the other, while he is located on the embankment, if this happens then his brain will generate a sequential experience.

ceejay wrote: »

Based on revising the third assumption we can find what happens to the original deduction:
- In all of the descriptions of the real physical events Albert's experience is that the flashes of light were simultaneous, even though in most of the descriptions the light flashes started at different times, and hit his retinas at different times. In one particular description the light flashes started at the same time, and hit his retinas at the same time.

The revised deduction is that there is only one experience of the events for Albert, and since that matches with our own experiences we can therefore say that there is no longer a paradox.

The assumption you were working off was:
Albert's experience of the order of the events does not equal the order of the events at the retinas for all descriptions of the sequence of the events

This isn't a correct formulation of the assumption though; as mentioned, Albert's experience of the order of events does equal the order of the events at the retinae, in the physical world, not necessarily the order in which they are mathematically described.

ceejay wrote: »

The paradox is resolved by reassessing the assumption that the sequence of events at Albert's retinas is equal to his experience of the sequence of events in every description of the sequence of events. This is consistent with the theory of special relativity which has been rigorously tested in many experiments, and applying that theory consistently to the whole scenario resolves the paradox.

But taking the correct assumption, that the sequence of events at Albert's retinae, in the physical world, does equal the sequence of his experience, not the sequence as described mathematically, the paradox arises again; if, and only if, the mathematical description of the physical events is valid, and corresponds to physical events.

Bear in mind, the assumption, that the processing time of signals from each retinae, to the central processing centre, is the same for both retinae, as far as Albert's brain is concerned, is an assumption taken directly from relativity. This is an important point, because Albert's experiences are generated by Albert's brain, from its own perspective.

The issue arises when we apply this to what we know about what Albert's brain processes in the physical world, namely, photons which physically strike his retinae, while he is standing on the embankment.

There would be no issue except that S' makes a statement about the order in which photons physically strike Albert's retinae.

ceejay wrote: »

The very simplified scenario posted originally by Morbert shows this mathematically. The very specific graphs of the scenario posted by Morbert also are not mere illustrative sketches but accurate mathematical graphs of the actual events and show exactly that the perception of the events are simultaneous in both reference frames.

Indeed, they represent "what relativity says"; but we are taking into account "what the physical world" says also.

Relativity should apply at all points throughout the process, not just certain convenient points.

Morbert

roosh wrote: »

No, here we are deducing that if an observer sees two flashes of light in sequence, then the photons from those flashes must have physically struck his retinae in sequence, because his brain processes photons which physically strike his retinae, to generate his experience of flashes of light.

That is an incorrect deduction. Just because Albert experiences blindness in both eyes simultaneously does not mean his eyes were struck simultaneously.

im invisible

He could have been struck on the back of the head

citrus burst

roosh wrote: »

Using reference frames doesn't necessarily cloud our reasoning; what clouds our reasoning is how we tacitly treat reference frames. S and S' are constituted of mathematical co-ordinates, which don't physically exist, and as such "mahtematical things" physical events cannot happen "in" them; physical events can be described "by" them, but events do not hapen "in" them. When we don't make this expressly clear, then our reasoning can become clouded because both statements means very different things.

If it doesn't cloud our reasoning, then why say it? Retract your statement and make a completely different point?

I agree the coordinates don't exist, but the reference frames do exist. An experiment can be done in a reference frame. You can live in a reference frame. So things can and do happen "in" them. What happen's in them is described by the arbitrarily chosen coordinate system. I could mess around with the coordinate system all I want; change their origin, orientation, even what type of coordinates I want, with out changing how the event actually happened. We usually choose the coordinates that most easily describe the situation, not to say that this is the correct approach.

roosh wrote: »

The physical observer Albert, and his retinae, are represented in S' prime using a set of mathematical co-ordinates; his location on the embankment, at rest relative to it, is represented using a set of mathematical co-ordinates; the physical striking of his retinae, by the photons, while he is standing on the embankment, is represented by mathematical co-ordinates.

I'm not sure I agree with you here. Are you saying that Albert is represented by one reference frame S', with one set of coordinates, call them C. That his location on the embankment, is represented by a different set of coordinates, call them C'. And that the photons hitting his eyes are represented by another coordinate system C''? Or do the coordinates system C represent all of the above in S'?

I really feel you should clarify this as it is of utmost importance.

roosh wrote: »

S' "says" that the photons strike Albert's retinae in the order of one first then the other; if S' corresponds to the physical world, then S' implies that Albert's retinae get struck in the order of one first, then the other.

Ok. You have said this many times.

roosh wrote: »

The ambulance is physical, agreed; the observer standing on the embankment, and the embankment are physical, agreed. But "the ambulance" isn't a representation of the measurements of the relatively moving observer, just as the embankment isn't a representation of the measurements that Albert will, supposedly make; that is the mathematical reference frames S' and S, respectively; S' is not physical, and neither is S.

But the measurements each make are frame dependent. You agree with this?

roosh wrote: »

Why the inverted commas around "physically" and "outside"; this could be misconstrued to mean "not really physically" and "not really outside", but that probably isn't what you meant, but I thought it would be worth hearing a clarifiction.

What I meant was that the person was actually in a different frame, to put emphasis on it.

roosh wrote: »

As you say, "different variables and different consequences"; it is precisely the idea that the actual speed of light is constant, as opposed to just the measured speed, which leads to the conclusion that simultaneity is relative, or that, according to an oberver moving relative to Albert, the photons physically strike Albert's retinae in the order of one first, then the other.

Are you trying to put forward the idea that the actual speed of light is different then the measured speed of light? If it were, this theory and a man called Albert Einstein would never have been heard of.

roosh wrote: »

People seem to be fond of making the analogy to sound, even though the two examples are materially different to the extent that they are not analgous in every way, and certainly not in the manner we are discussing. If we were talking about the colour of light seen by the observers, the analogy might, perhaps, be valid, but we're talking about the order in which photons physically strike an observers retinae, and the order in which the resulting flashes of light are seen by the observer. Alternatively, if the analogy factored in the order in which the eardrums of the observer are stimulated, it might also be valid.

It could be because they are both waves? It could be because they are both different enough that analogies can be drawn from them? It could be that they are both frame dependent? It could simply be that it makes a good every day example of a difficult situation to imagine, such as the loudness of a radio being relative to distance, or the frequency of a siren being relative to velocity. Who knows? In my case I used it to show that the relative velocity of sound to its observer affects the measured frequency of its siren. I used this to show how things can be different for different reference frames. I don't see any issue with this.

roosh wrote: »

Again, it's not the reference frames themselves, per se, which cause the issue to become muddled, it is the use of certain statements about the reference frames which attribute physical characteristics to what are, in essence, non-physical.

What certain statements are these?

roosh wrote: »

Indeed, it is helpful to make the distinction between physical frames of reference and mathematical reference frames, which is what I have endeavoured to do in this discussion, by speaking about physical locations in the physical world and the mathematical representation of the same.

This is the first I've heard of this endeavor. Pretty much up to this point, your fall back argument has been that they are not real. I don't think you have made the connection between physical locations and reference frames. The Earth being one large reference frame, with an associated "unreal" coordinate system known as longitude and latitude.

roosh wrote: »

The emboldened bit is the critical piece of information; they will disagree about which eye physically gets struck first, while Albert is standing on the embankment. Some will say that the photons physically strike the retinae in the order of one first, then the other, while he is standing on the embankment; another observer would say they physically strike in the opposite order, while he is physically standing on the embankment; another observer would say that they physically strike such that they are "tied for first place", on the embankment.

Why is the emboldened part the critical piece of information? I mean if we have 3 reference frames, S, S' and S''. S is the rest frame and S' and S'' are moving relative to S but in opposite directions, then they should disagree what eye got hit first.

You don't seem to have any issue with when I mentioned that if Albert was hit in S non simultaneously then there could be a reference frame that says the light did in fact hit him simultaneously.

roosh wrote: »

As you mention above, relativity says that, despite the disagreement between the observers, that all their measurements correspond to the physical world; that is, the following statements are both true:

They do correspond to the physical world.

roosh wrote: »

- while Albert is standing on the embankment, photons physically strike his retinae in the order of one first, then the other.

For most references frames, moving relative to Albert and the embankment

roosh wrote: »

- while Albert is standing on the embankment, the photons don't physically strike his retinae in the order of one first, then the other, they strike such that they are "tied for first place".

Only for Albert, standing on the embankment, and all others standing on the embankment or at rest relative to the embankment.

roosh wrote: »

Knowing how Albert's brain processes photons which physically strike his retinae, to produce his experiences, while he is standing on the embankment, this leads to the paradoxical situation where he should have discordant experiences of what are supposed to be the same events.

No. Like you have said, Albert's brain doesn't care about what others say about it, only the information it receives.

roosh wrote: »

Of course, if relativity doesn't say that the photons physically strike his retinae in the order of one first, then the other, while he is standing on the embankment, then the description of events given by S' do not correspond to the physical world, where Albert is standing on the embankment and photons physically strike his retinae.

So what you are saying here is that all things observed by moving things aren't physical. That when I get into my car and start driving the events I see do not correspond to the physical world.

roosh wrote: »

Just to reiterate what we are interested in; we're intersted in:
- how Albert's brain operates in the physical world, to produce Albert's experiences

Ok

roosh wrote: »

- how Albert's brain processes photons which physically strike Albert's retinae, while he is standing on the embankment.

Ok this is the same as the previous, just more elaborate. Presumably we also care about when he is not standing on the embankment, ie anywhere else in the universe.

roosh wrote: »

- the physicality of the retinae striking events, as described by both S and S'

By S and S' we mean to relatively moving objects, one of which Albert resides in

roosh wrote: »

Given this information we can make deductions about Albert's experiences, particularly when we idealise Albert and give him a prosthetic visual network which is as infallible as any inanimate system.

ok

roosh wrote: »

We are interested in whether or not the measurements of the relatively moving observer, which lead him to conclude that the photons physically strike Albert's retinae in the order of one first, then the other, while Albert is standing on the embankment are accurate; that is, do the photons physically strike Albert's retinae in the order of one first, then the other, while Albert is standing on the embankment.

I think the physically standing on the embankment is what is causing a lot of issue but I will get to that later.

roosh wrote: »

With that information we can make deductions about Albert's experience, because we know how Albert's brain processes Albert's experiences.

ok

roosh wrote: »

When you say "in Albert's reference frame" do you mean for anyone "standing on the embankment" or, more precisely, "anyone in the physical world who is not physically moving relative to the embankment"?

Yes, perhaps I should have called it Earth's reference frame, S. Where 99.999999% of people have spent all their time. If you aren't moving relative to something, you are in the same reference frame as it.

If you didn't know this, then you truly do not understand reference frames.

roosh wrote: »

Remember that S' is the set of mathematical co-ordinates used to describe events in the physical world; S' =/= the train, becuase the train is physical the co-ordinates aren't; S' is a set of co-ordinates used to describe events as they would supposedly be measured from the train; S' also describes Albert's location on the embankment, at rest relative to it; it describes the events which are the photons physically striking Albert's retinae, and it describes them as physically striking his retinae in the order of one first, then the other.

S and S' are tags we have given to distinguish the coordinates systems of two relatively moving objects. I agree that S' =/= the train, it could be anything really. S' does describe Albert's location, but you have to remember that Albert's location is constantly moving in S'. Similarly the train is constantly moving in S. The seats however are not constantly moving in S'. Similarly the embankment is not moving in S.

roosh wrote: »

However, it's a little more rigorous than that isn't it; relativity says that his measurements lead him to the conclusion that the photons physically strike Albert's retinae in the order of one first, then the other, while Albert is standing on the embankment.

Yes if he is moving relative to Albert, no if he isn't.

roosh wrote: »

If these measurements are accurate, and the photons do physically strike Albert's retinae in the order of one first, then the other, then we know how his brain will process them.

According to a relatively moving observer, not Albert

roosh wrote: »

The measurement of the order depends on the relative motion of the observer, in the physical world; but the measurements supposedly correspond to the physical world; the observer on the train will supposedly make measurements which imply that the photons physically strike Albert's retinae in the given order, while he is standing on the embankment.

Yes, so in Albert's case he isn't moving relative to the set up, he and the set up are in the same reference frame S. So Albert's memories correspond to his measurements.

Remember the other observer is at rest in S' and moving relative to S. Or as you like it, he is sitting on the train, moving relative to Albert and the setup on the embankment. For Albert at rest relative to the set up, the light hits his eyes and his memories are structured accordingly. Everyone else in S will agree. For the other observer, I should also mention that some light is reflected off Albert's eyes, moving relative to the set up and some time after Albert has done his measurement, light arrives at the train and the observer there makes his measurement.

Its as equal as Albert's and corresponds the same as Albert's to the physical world, but it is different then Albert's measurement. It doesn't affect Albert's memories. My memories don't affect yours, yours don't affect mine etc. Albert can use the Lorentz transforms to figure out how separate the two light strikes are for the observer. The observer can use the Lorentz transforms in reverse to figure out how separate the two light strikes are for Albert (in this case he finds they are equal).

The only way the situation could arise were Albert has conflicting memories, is if he is physically in two places at once. That is he is the observer on the train and on the embankment. Since this does not occur in nature there is no paradox in the physical world.

roosh wrote: »

When Albert's brain is processing Albert's experiences, from its location on the embankment, at rest relative to it, it doesn't need to apply the LT to itself.

He does, it just so happens that 0/c = 0 and the square root of 1 is one and you are left with the Newtonian approximation t=t.

roosh wrote: »

We can try and boil it down to a few simple questions, because there are certain things you don't seem to be disputing, and it is directly from those, apparently, undisputes points that our deduction follows. Maybe we can isolate the point of disagreement, a little more specifically.

ok

roosh wrote: »

Do you agree with the the following?

- Albert is physially located on the embankment, at rest relative to it.

Yes we call this S.

roosh wrote: »

- photons physically strike Albert's retinae while he is standing on the embankment.

Yes

roosh wrote: »

- Albert's brain processes all photons which physically strike his retinae, while he is standing on the embankment.

No, but for the sake of this argument I will say yes. His eyes only process visible light, but I am being pedantic.

roosh wrote: »

- if two photons physically strike Albert's retinae in the order of one first, then the other, while he is standing on the embankment, his brain will process an ordered experience that corresponds to the order in which the photons physically strike his retinae.

Yes

roosh wrote: »

- S' "says" that the photons physically strike Albert's retinae in the order of one first, then the other, while he is standing on the embankment.

An observer in s' will say this. I don't know why you need to include the standing on the embankment part.

If we replace Albert with a light bulb. That is if the light from the same two lasers arrives at the same time, the light bulb will turn on, all observers will agree that the bulb turned on, they just won't agree why.

roosh

citrus burst wrote: »

If it doesn't cloud our reasoning, then why say it? Retract your statement and make a completely different point?

It's not the reference frames per se, it's the statements make about the reference frames; so I will retract whatever statement about reference frames was made, that wasn't this, and put this in its stead. One such statement is the statement "in a reference frame", because, as we will discuss below, it seems to conflate the mathematical co-ordinate reference framw, with the physical object that we might refer to as a frame of reference.

citrus burst wrote: »

I agree the coordinates don't exist, but the reference frames do exist. An experiment can be done in a reference frame. You can live in a reference frame. So things can and do happen "in" them. What happen's in them is described by the arbitrarily chosen coordinate system. I could mess around with the coordinate system all I want; change their origin, orientation, even what type of coordinates I want, with out changing how the event actually happened. We usually choose the coordinates that most easily describe the situation, not to say that this is the correct approach.

The mathematical reference frame and the physical reference frame, the trian say, are not the same thing. The mathematical co-ordinates extend beyond the train and "cover" the entire universe, the trian does not. Experiments can be conducted on the train, using it as a frame of reference, but experiments cannot be conducted in mathematical reference frames; the mathematical co-ordinates are used to describe the experiments that take place on the physical train.

citrus burst wrote: »

I'm not sure I agree with you here. Are you saying that Albert is represented by one reference frame S', with one set of coordinates, call them C. That his location on the embankment, is represented by a different set of coordinates, call them C'. And that the photons hitting his eyes are represented by another coordinate system C''? Or do the coordinates system C represent all of the above in S'?

I really feel you should clarify this as it is of utmost importance.

No, all of the above are represented by the co-ordinates of S'; Albert's head will have different co-ordinates to his feet.

citrus burst wrote: »

But the measurements each make are frame dependent. You agree with this?

That depends on what you mean by "frame"; if you mean they are dependent on the set of mathematical co-ordinates which describe them, then no, I don't agree; if you mean are dependent on their location in the physical world, then I do.

citrus burst wrote: »

What I meant was that the person was actually in a different frame, to put emphasis on it.

Ah, OK; for future reference it's probably better to use bold type, or italics for emphasis; inverted commas can suggest that it is being used in a manner that is different to its commonly understood manner, or that the word isn't actually meant - or something to that effect.

citrus burst wrote: »

Are you trying to put forward the idea that the actual speed of light is different then the measured speed of light? If it were, this theory and a man called Albert Einstein would never have been heard of.

LET postulates that the measured speed and the actual speed are different, as far as I know.

citrus burst wrote: »

It could be because they are both waves? It could be because they are both different enough that analogies can be drawn from them? It could be that they are both frame dependent? It could simply be that it makes a good every day example of a difficult situation to imagine, such as the loudness of a radio being relative to distance, or the frequency of a siren being relative to velocity. Who knows? In my case I used it to show that the relative velocity of sound to its observer affects the measured frequency of its siren. I used this to show how things can be different for different reference frames. I don't see any issue with this.

That's all fair enough, but it is obviously limited in its use, and doesn't really address the overall problem we are discussing, of which the point was a part.

citrus burst wrote: »

What certain statements are these?

"Experiments are done in a reference frame", because it can conflate the mathematical set of co-ordinates with the physical location.

citrus burst wrote: »

This is the first I've heard of this endeavor. Pretty much up to this point, your fall back argument has been that they are not real. I don't think you have made the connection between physical locations and reference frames. The Earth being one large reference frame, with an associated "unreal" coordinate system known as longitude and latitude.

I think I've tried to make the distinction between the physical location of an observer e.g. "on the embankment" and the mathematical co-ordinates "used to describe physical events".

The difference between the mathematical co-ordinates and the physical earht is that the mathematical co-ordinates extend beyond the earth.

citrus burst wrote: »

Why is the emboldened part the critical piece of information? I mean if we have 3 reference frames, S, S' and S''. S is the rest frame and S' and S'' are moving relative to S but in opposite directions, then they should disagree what eye got hit first.

The emboldened is the critical piece of information because the observers disagree on which eye physically gets struck first; and we know how Albert's brain processes Albert's experiences; based on how photons, or visible light, physically strike his retinae; adding S'' just compounds the issue.

citrus burst wrote: »

You don't seem to have any issue with when I mentioned that if Albert was hit in S non simultaneously then there could be a reference frame that says the light did in fact hit him simultaneously.

The same issue arises.

citrus burst wrote: »

They do correspond to the physical world.

Then Albert's retinae get struck in the order of one first, then the other, while he is standing on the embankment, and his brain should process an ordered experience from its location on the embankment.

citrus burst wrote: »

For most references frames, moving relative to Albert and the embankment

What do you mean "for most reference frames here"; if we flesh it out to a clearer statement we find that it means that most relatively moving observers will make measurement which imply that Albert's retinae get physically struck by photons, in the order of one first then the other, while he is standing on the embankment.

We add this to what we know about how Albert's brain produces Albert's experiences, for Albert, and our issue arises.

citrus burst wrote: »

Only for Albert, standing on the embankment, and all others standing on the embankment or at rest relative to the embankment.

Different side of the same coin above.

citrus burst wrote: »

No. Like you have said, Albert's brain doesn't care about what others say about it, only the information it receives.

And it receives information from photons which physically strike his retinae; and apparently, photons physically strike his retinae in the order of one first, then the other, while he is standing on the embankment; this is according to the measurements of relatively moving observers, whose measurements are accurate and correspond to the physical world.

citrus burst wrote: »

So what you are saying here is that all things observed by moving things aren't physical. That when I get into my car and start driving the events I see do not correspond to the physical world.

No, I'm saying that, if the photons physicallly strike his retinae in the order of one first, then the other, then his brain will process an ordered experience.

Only if they don't physically strike in that order, will his brain not produce an ordered experience; if they don't physically strike in that order, then the description of S' doesn't correspond to the physical world.

citrus burst wrote: »

Ok this is the same as the previous, just more elaborate. Presumably we also care about when he is not standing on the embankment, ie anywhere else in the universe.

Indeed, but regardless of where he is standing on in the universe, his brain will process his experiences in the same manner; we can even relocate Albert from his location on the embankment and put him on the train which is moving relative to the embankment, and his brain will still process photons in the order they are received, with it taking the same time for signals to reach the processing centre from both retinae; from the perspective of Albert's brain, which is the perspective it produces his experiences from.

citrus burst wrote: »

By S and S' we mean to relatively moving objects, one of which Albert resides in

This is the crux of the issue, the co-ordinate reference frames extend beyond the embankment and are applied to relatively moving objects; they can also be used to represent his meaurements; the embankment, the trees he is at rest relative to, the shop down the road don't represent his measurements.

citrus burst wrote: »

Yes, perhaps I should have called it Earth's reference frame, S. Where 99.999999% of people have spent all their time. If you aren't moving relative to something, you are in the same reference frame as it.

If you didn't know this, then you truly do not understand reference frames.

I do indeed know that, but I also know you can't move relative to mathematical co-ordinates, so here again lies the distinction between the two.

citrus burst wrote: »

S and S' are tags we have given to distinguish the coordinates systems of two relatively moving objects. I agree that S' =/= the train, it could be anything really. S' does describe Albert's location, but you have to remember that Albert's location is constantly moving in S'. Similarly the train is constantly moving in S. The seats however are not constantly moving in S'. Similarly the embankment is not moving in S.

Above, however, you say that S and S' are relatively moving objects, one of which Albert resides in, so there does appear to be a conflation of the mathematical with the physical; which I think causes some problems and can cloud our reasoning.

citrus burst wrote: »

Yes if he is moving relative to Albert, no if he isn't.
...
According to a relatively moving observer, not Albert

But again, this just means that a relatively moving observers measurements imply that photons physically strike Albert's retinae in the order of one first, then the other, while he is standing on the embankment, and the measurements of an observer standing on the emabankment imply that they don't physically strike in that order.

This just gives rise to the issue, knowing what we know about how Albert's brain processes Albert's experiences - from its own perspective; that is, how it processes photons which physically strike his retinae, to generate his experiences, from his own perspective; which is how all his experiences are formed.

citrus burst wrote: »

Yes, so in Albert's case he isn't moving relative to the set up, he and the set up are in the same reference frame S. So Albert's memories correspond to his measurements.

Remember the other observer is at rest in S' and moving relative to S. Or as you like it, he is sitting on the train, moving relative to Albert and the setup on the embankment. For Albert at rest relative to the set up, the light hits his eyes and his memories are structured accordingly. Everyone else in S will agree. For the other observer, I should also mention that some light is reflected off Albert's eyes, moving relative to the set up and some time after Albert has done his measurement, light arrives at the train and the observer there makes his measurement.

Its as equal as Albert's and corresponds the same as Albert's to the physical world, but it is different then Albert's measurement. It doesn't affect Albert's memories. My memories don't affect yours, yours don't affect mine etc. Albert can use the Lorentz transforms to figure out how separate the two light strikes are for the observer. The observer can use the Lorentz transforms in reverse to figure out how separate the two light strikes are for Albert (in this case he finds they are equal).

The only way the situation could arise were Albert has conflicting memories, is if he is physically in two places at once. That is he is the observer on the train and on the embankment. Since this does not occur in nature there is no paradox in the physical world.

What affects Albert's memories are the physical stimuli which enter through his sensory organs, such as light; if light enters through one eye first and then the other, Albert's brain will process an ordered experience. According to the measurements of the relatively moving observer, which are valid and accurate, this is what happens; so Albert's brain should process an ordered experience.

citrus burst wrote: »

He does, it just so happens that 0/c = 0 and the square root of 1 is one and you are left with the Newtonian approximation t=t.

OK, so, this is how his brain processes his experiences when it applies the LT.

citrus burst wrote: »

Yes we call this S.

Again, there appears to be some conflation of the mathematical with the physical here; bear in mind, the mathematical co-ordinates are not the same as the physical location; the mathematical co-ordinates can be used to make calculations and predictions, the physical location cannot; at least, not in the same way.

citrus burst wrote: »

No, but for the sake of this argument I will say yes. His eyes only process visible light, but I am being pedantic.

I think we can substitute in the "blinding laser" there, if there's an issue.

citrus burst wrote: »

An observer in s' will say this. I don't know why you need to include the standing on the embankment part.

The "on the embankment" part is included because this is where the events occur; it's to distinguish it from the relatively moving observer who also has photons strike his retinae in the order of one first, then the other, while he is on the train.

citrus burst wrote: »

If we replace Albert with a light bulb. That is if the light from the same two lasers arrives at the same time, the light bulb will turn on, all observers will agree that the bulb turned on, they just won't agree why.

Yes, but when we include two photoreceptors a distance from the light bulb, and consider how the system process the signals - which it always does from its own perspective - then the order in which the photons physically strike the photoreceptors determines whether or not the buld switches on.

ceejay

Roosh,

Is your question fundamentally about how physically real are the timing of the events from the perspective of relatively moving observers?

Can I ask you to consider a different scenario:

Albert is standing on the embankment using some equipment to measure the frequency of two distant pulsars. Albert selects two pulsars such that their frequencies are equal and their pulses are in sync when he measures them on the embankment.

Next Albert goes into space and travels at a large fraction of the speed of light and measures the same two pulsars. He finds that their frequencies are now different, and they are no longer in sync.

He returns to Earth and repeats his experiments just to be sure, and the pulsars are back in sync with the same frequency.

He wants to be sure that the pulsars aren't changing while he's in space, so he asks his colleague Brian to go into space and measure the pulsars while Albert remains on Earth. Albert's measurements remain the same, they stay in sync and at the same frequency. Brian gets the same results as Albert did when Albert went into space, the pulsars change frequency and go out of sync.

So, are any of the measurements more or less physically real than any of the others?

roosh

ceejay wrote: »

Roosh,

Is your question fundamentally about how physically real are the timing of the events from the perspective of relatively moving observers?

Can I ask you to consider a different scenario:

Albert is standing on the embankment using some equipment to measure the frequency of two distant pulsars. Albert selects two pulsars such that their frequencies are equal and their pulses are in sync when he measures them on the embankment.

Next Albert goes into space and travels at a large fraction of the speed of light and measures the same two pulsars. He finds that their frequencies are now different, and they are no longer in sync.

He returns to Earth and repeats his experiments just to be sure, and the pulsars are back in sync with the same frequency.

He wants to be sure that the pulsars aren't changing while he's in space, so he asks his colleague Brian to go into space and measure the pulsars while Albert remains on Earth. Albert's measurements remain the same, they stay in sync and at the same frequency. Brian gets the same results as Albert did when Albert went into space, the pulsars change frequency and go out of sync.

So, are any of the measurements more or less physically real than any of the others?

Just trying to get a better picture of the scenario; where are the pulsars located with respect to Albert on Earth, are they separated like the rods A and B?

roosh

Morbert wrote: »

Here you are assuming a mathematical, frame-dependent description is physical.

Just plugging the point from the other thread in here, we can say that Albert's brain process photons which physically strike his retinae, while he is standing on the embankment, and it processes them in the order that they strike, without necessarily implying that the order is physical.

S' says that the photons physically strike Albert's retinae while he is standing on the embankment, and that they strike in the order of one first, then the other; so his brain should process an ordered experience.

dlouth15

Roosh, I think at this point if you want to show an inconsistency in special relativity you have to start getting in to the mathematics of it. It is a mathematical theory to start with so any inconsistency will show up mathematically.
For example if you want to show that on the platform we have a situation where Albert (or a simplified model of Albert) both perceives simultaneous and non-simultaneous flashes, then this will be a result of the Lorentz transformation giving two different results for the timing of events happening in the same place.

The problem with using verbal reasoning as you are doing is that you can be led astray easily. A lot of this stuff is counter intuitive initially and the mathematics keeps you on track (if you'll pardon the pun). I outlined how this might be done in another thread and the same applies here.

My recommendation would be to start with the simplified model of Albert i.e. with two light detectors an the processing unit at a point at the centre. In this simplified scenario you need to show that for a given frame, the Lorentz transformation shows that the signals arrive a) at the same time and b) at two different times.

If you can show that you have uncovered a fatal flaw in special relativity.

You may argue that, yes, for this simple system there is no paradox. The paradox arises when you add complexity. What you need to do then is add more processing units. You need to remember, though, that signals must travel at <= c.

You then apply the Lorentz transformation again and see what happens. Remember that you also need to transform the signals as they travel from one processing unit to the others. Do you now get inconsistent results? Keep adding them if necessary until you get an inconsistency. If you do then you have again uncovered a flaw in special relativity and a Nobel prize is surely yours.

Personally I would love to see some inconsistency in a fundamental theory like SR, but I think I would want to see it done in a mathematically rigorous way, especially given the degree to which SR has been tested.

What wouldn't work would be someone verbally stating that it simply can't be the case since it violates their intuition about what should be happening. They might be right but the more likely situation their intuition is wrong and they can't be bothered to do the calculations.

roosh

dlouth15 wrote: »

Roosh, I think at this point if you want to show an inconsistency in special relativity you have to start getting in to the mathematics of it. It is a mathematical theory to start with so any inconsistency will show up mathematically.
For example if you want to show that on the platform we have a situation where Albert (or a simplified model of Albert) both perceives simultaneous and non-simultaneous flashes, then this will be a result of the Lorentz transformation giving two different results for the timing of events happening in the same place.

The problem with using verbal reasoning as you are doing is that you can be led astray easily. A lot of this stuff is counter intuitive initially and the mathematics keeps you on track (if you'll pardon the pun). I outlined how this might be done in another thread and the same applies here.

My recommendation would be to start with the simplified model of Albert i.e. with two light detectors an the processing unit at a point at the centre. In this simplified scenario you need to show that for a given frame, the Lorentz transformation shows that the signals arrive a) at the same time and b) at two different times.

If you can show that you have uncovered a fatal flaw in special relativity.

You may argue that, yes, for this simple system there is no paradox. The paradox arises when you add complexity. What you need to do then is add more processing units. You need to remember, though, that signals must travel at <= c.

You then apply the Lorentz transformation again and see what happens. Remember that you also need to transform the signals as they travel from one processing unit to the others. Do you now get inconsistent results? Keep adding them if necessary until you get an inconsistency. If you do then you have again uncovered a flaw in special relativity and a Nobel prize is surely yours.

Personally I would love to see some inconsistency in a fundamental theory like SR, but I think I would want to see it done in a mathematically rigorous way, especially given the degree to which SR has been tested.

What wouldn't work would be someone verbally stating that it simply can't be the case since it violates their intuition about what should be happening. They might be right but the more likely situation their intuition is wrong and they can't be bothered to do the calculations.

dlouth, this is just the exact same point that has been made all along, which we have been discussing.

Bear in mind that we were using the simplified model of Albert that you suggested, we amalgamated the simplified model with Albert in the form of a prosthetic visual system; we added the light to the top of his head also. You essentially agreed that there was a paradox but you attributed this to the idea that we were choosing a preferred frame for the processing of Albert's experiences. We weren't, however, we were simply stating what we know about how Albert's brain processes Albert's experiences. There was also the implication that there was a paradox for conscious systems, but possibly not for non-conscious systems; but this wasn't established, as the same reasoning holds for the simple system. you suggested, when it was used as Albert's prosthesis as when it was used on its own.


I understand the point that you, and others, have made, about what the mathematics of relativity say; I'm not disputing what the mathematics of relativity say, or the idea that relativity does actually say that a relatively moving observer will measure Albert's brain activity such that the signals converge simultaneously; what I'm saying is that we're not interested in the meaurement of Albert's brain activity by a relatively moving observer, we're interested in how Albert's brain processes Albert's experiences.

We know that Albert's brain processes photons which physically strike his retinae, while he is standing on the embankment; we know that his brain processes them in the order that the physical strikes occur; we know this because Albert has ordered experiences, while he is standing on the platform.

S' says that the photons physically strike Albert's retinae and that the physical strikes occur in the order of one first, then the other; if they do, then Albert's brain will process the physical strikes in the order that the physical strikes occur.

dlouth15

roosh wrote: »

S' says that the photons physically strike Albert's retinae and that the physical strikes occur in the order of one first, then the other; if they do, then Albert's brain will process the physical strikes in the order that the physical strikes occur.

No, and this point has been made several times on this thread.

It is not the order in which the photons strike the receptors that is important but rather the order in which the signals from those receptors reach the central processing unit that determines whether or not the central processing unit detects simultaneity? This is the more fundamental statement.

Do you agree with this?

roosh

dlouth15 wrote: »

No, and this point has been made several times on this thread.

It is not the order in which the photons strike the receptors that is important but rather the order in which the signals from those receptors reach the central processing unit that determines whether or not the central processing unit detects simultaneity? This is the more fundamental statement.

Do you agree with this?

From the perspective of Albert's brain, which is the perspective it processes Albert's expriences from, the distance to the centre is the same for each retina, and the speed that each signal travels at is the same; so, the order in which the physical strikes occur, determines the order in which they reach the centre; that is, according to Albert's brain as it processes photons which physically strike his retinae, while he is standing on the embankment, to generate Albert's experience.

Essentially what you are saying is "the experience a relatively moving observer has, of Albert's brain process...."; what that gives us is the relatively moving observers experience, not Albert's; we want Albert's experience; and Albert's experience is generated by his brain which processes stimuli which physically "strike" his sensory organs; and it processes them in the order the physical strikes occur.

If we say that the photons which strike Albert's retinae, while he is standing on the embankment, and which occur in the given order, is the experience of the relatively moving observer, not of Albert, then the implication is that the photons do not physically strike Albert's retinae while he is standing on the embankment, or that the physical strikes do not occur in the given order, while he is standing on the embankment; because, if they satisfied both of those conditions then they would be part of Albert's experience as an ordered pair of flashes.

dlouth15

You are throwing in a lot of unnecessary stuff here. It is very simple really.

roosh wrote: »

[...]

Ignore frames of reference and Albert's brain and all that other complexity for the moment. You will note that I don't mention any of this in my question. Forget you ever heard about special relativity, Lorenz transformations and everything else. We will bring the complexity back later.

Now: the question basically was that the central processing unit determines simultaneity based on the arrival of signals from detectors. If the signals arrive simultaneously then the light goes on.

Very simply do you agree with that?