How the standard spacetime model relates to reality

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Did I make claims incompatible with the standard interpretation?
Well, a bit worse than that. Your claim is not even well defined. Your claim involved the word "simultaneously" repeatedly. Simultaneity is a frame-dependent concept, so whenever you use the term you must specify the reference frame.
I didn't realise that in the block universe interpretation of the mathematics, that there was a distinction made between what I was experiencing while you were experiencing what you were experiencing and simultaneity. Such that event A being simultaneous to event B does not imply that a witness of event A, located at the location of event A, would have of experienced event A while a witness of event B, located at the location of event B would have of experienced event B. Though if that is the case, then perhaps the physicists could use the term "experimental simultaneity" to avoid people misunderstanding what they were suggesting, and maybe even being mislead (perhaps thinking it implied atheism, and that free will didn't exist).

At different points
a(τ) along your worldline you have different past light cones. This accounts for your perception of changing experience.
I don't understand how this accounts for my perception of changing experience in the block universe interpretation. I don't mean that it doesn't account for perception at all, I'll overlook that. What I mean is that I don't understand how it suggests my experience will change, rather than suggesting I equally exist at different points along the curve, and that at each of these points I am having a different static perception. The reason is that I'm not sure what is moving along my worldline in the block universe interpretation, and so explains what is having the changing experience. As I pointed out, I am not a single point on my worldline, nor all the points on the worldline.
 
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  • #27
PeterDonis
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perhaps the physicists could use the term "experimental simultaneity"
You're missing the point: there is no such thing as "experimental simultaneity". Simultaneity is a convention, not something "real". When you say that two events A and B (say the event of you seeing your watch read noon December 22nd, and the event of me seeing my watch read noon December 22nd) are "simultaneous", you're not saying anything about our experience or anything "real"; all you're saying is that you've picked coordinates in which both of those events have the same value of "t", the time coordinate. That's a convention you've adopted, not anything physically "real".

I don't understand how it suggests my experience will change, rather than suggesting I equally exist at different points along the curve, and that at each of these points I am having a different static perception.
It doesn't suggest the one "rather" than the other; it suggests that both of these are different ways of describing the same thing. Having different "static perceptions" at different points along your worldline is having a changing experience. The only difference between the two is the words you use; there is no difference in the physics, both sets of words are describing the same physics.
 
  • #28
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So that there could be a series of claims (by different observers) that amounted to a claim that simultaneously to you experiencing all of the points during that 10 second period it was true that I was experiencing the 3 second point.
The conclusion you should be drawing instead is that "simultaneous", when applied to spatially separated events, is not as useful a concept as your intuition is tempting you to believe. All "simultaneous" means is that the two events have the same t coordinate in whatever coordinate system we're using; and we're free to use whatever coordinate system we use. Interestingly though, no matter what coordinate system we use, we will find that for any event the future light cone region, the past light light cone region, and the neither light cone region comes out the same. That makes the light cones a much more useful concept than "happened at the same time".

If I find events A and B to be simultaneous (that is, I subtract the light travel time from the time when I see them and find that they both happened at the same time), and you moving relative to me find that events B and C are simultaneous.... It does not not follow that either of us will find events A and C simultaneous. There will be some third observer who does find A and C to be simultaneous - but that observer will find neither A and B nor B and C to be simultaneous.

So let us consider a whole bunch of observers. They all have watches that tick once every time their heart beats, and because they're all preternaturally calm and in astoundingly good aerobic health, their heart rates, metabolic processes, brain function, and perception of time are all unaffected by the excitement of space flight. We start them together at the same place at the same time, they set them all their watches to zero, and send them off in various directions at various relativistic speeds. Each one experiences the present ("My heart beat a moment ago, it's doing another beat right now, and because I like living I hope it will keep it up and beat again in a moment") just as if they were at rest and had never seen a spacetime diagram.

So now one of these observers may find that his watch read five ticks at the same time that your watch read three ticks; and another of these observers may find that his watch read five ticks at at the same time that your watch read four ticks - but how does this series of claims amount to saying you were experiencing your three-tick and four-tick moment at the same time? Their five-tick moments are not happening at the same time according to any of the three of you.
 
  • #29
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You're missing the point: there is no such thing as "experimental simultaneity". Simultaneity is a convention, not something "real". When you say that two events A and B (say the event of you seeing your watch read noon December 22nd, and the event of me seeing my watch read noon December 22nd) are "simultaneous", you're not saying anything about our experience or anything "real"; all you're saying is that you've picked coordinates in which both of those events have the same value of "t", the time coordinate. That's a convention you've adopted, not anything physically "real".
Are you suggesting that in the block universe interpretation of the mathematics, that there is a distinction between what I was experiencing while you were experiencing what you were experiencing and simultaneity? Such that event A being simultaneous to event B does not imply that a witness of event A, located at the location of event A, would have of experienced event A while a witness of event B, located at the location of event B would have of experienced event B.

It doesn't suggest the one "rather" than the other; it suggests that both of these are different ways of describing the same thing. Having different "static perceptions" at different points along your worldline is having a changing experience. The only difference between the two is the words you use; there is no difference in the physics, both sets of words are describing the same physics.
The discussion is about the interpretation, not the maths. And the interpretation being discussed is the block universe interpretation. I don't see how having different "static perceptions" at different points along your worldline is having a changing experience, unless somehow you move along the points, and you seemed to missed out the point that I was making which is that the interpretation seems to me to suggest that the human I experience being exists equally at all the points on the world line. So what am "I" reflected as in the interpretation, the human existing at a single coordinate on the line or the whole line, or something else? In the block universe model I thought, what exists at a coordinate, remains in existence at that coordinate, permanently.
 
  • #30
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The conclusion you should be drawing instead is that "simultaneous", when applied to spatially separated events, is not as useful a concept as your intuition is tempting you to believe. All "simultaneous" means is that the two events have the same t coordinate in whatever coordinate system we're using; and we're free to use whatever coordinate system we use. Interestingly though, no matter what coordinate system we use, we will find that for any event the future light cone region, the past light light cone region, and the neither light cone region comes out the same. That makes the light cones a much more useful concept than "happened at the same time".

If I find events A and B to be simultaneous (that is, I subtract the light travel time from the time when I see them and find that they both happened at the same time), and you moving relative to me find that events B and C are simultaneous.... It does not not follow that either of us will find events A and C simultaneous. There will be some third observer who does find A and C to be simultaneous - but that observer will find neither A and B nor B and C to be simultaneous.

So let us consider a whole bunch of observers. They all have watches that tick once every time their heart beats, and because they're all preternaturally calm and in astoundingly good aerobic health, their heart rates, metabolic processes, brain function, and perception of time are all unaffected by the excitement of space flight. We start them together at the same place at the same time, they set them all their watches to zero, and send them off in various directions at various relativistic speeds. Each one experiences the present ("My heart beat a moment ago, it's doing another beat right now, and because I like living I hope it will keep it up and beat again in a moment") just as if they were at rest and had never seen a spacetime diagram.

So now one of these observers may find that his watch read five ticks at the same time that your watch read three ticks; and another of these observers may find that his watch read five ticks at at the same time that your watch read four ticks - but how does this series of claims amount to saying you were experiencing your three-tick and four-tick moment at the same time? Their five-tick moments are not happening at the same time according to any of the three of you.
Are you suggesting that in the block universe interpretation of the mathematics, that there is a distinction between what I was experiencing while you were experiencing what you were experiencing and simultaneity? Such that event A being simultaneous to event B does not imply that a witness of event A, located at the location of event A, would have of experienced event A while a witness of event B, located at the location of event B would have of experienced event B.
 
  • #31
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Are you suggesting that in the block universe interpretation of the mathematics, that there is a distinction between what I was experiencing while you were experiencing what you were experiencing and simultaneity? Such that event A being simultaneous to event B does not imply that a witness of event A, located at the location of event A, would have of experienced event A while a witness of event B, located at the location of event B would have of experienced event B.
I don't know any way of answering that question until you can provide a definition of that word "while" that I've bolded above.
 
  • #32
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Are you suggesting that in the block universe interpretation of the mathematics, that there is a distinction between what I was experiencing while you were experiencing what you were experiencing and simultaneity? Such that event A being simultaneous to event B does not imply that a witness of event A, located at the location of event A, would have of experienced event A while a witness of event B, located at the location of event B would have of experienced event B.
I don't know any way of answering that question until you can provide a definition of that word "while" that I've bolded above.
If you are asking for a definition of how you could tell experimentally what I was experiencing while you are experiencing then the answer is I'm not sure that one exists. But in both cases I used it, I was assuming that the experience of each person was changing, and was considering what the one person's experience was as the other was at a certain point of their changing experience, or during a certain period of their changing experience. They don't have to be experiencing clocks or if they were what they experienced the clocks doing doesn't come into it. It is related to the idea that other people are experiencing change in parallel to your experiencing change, that corresponding to your experience of change, other people are experiencing change and so on. I presume these aren't exactly alien concepts to you, so if you aren't able to understand, perhaps you could highlight what is causing you confusion? If you think you can understand, then you should be ok to answer.
 
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  • #33
PeterDonis
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If you are asking for a definition of how you could tell experimentally what I was experiencing while you are experiencing then the answer is I'm not sure that one exists.
Such a definition does not exist; there is no such experimental method because, as I said, "simultaneity" is not a physical thing; it's a convention.

The discussion is about the interpretation, not the maths.
Then it's off topic here. We discuss physics here, not "interpretations" that make no difference to experimental predictions.

I don't see how having different "static perceptions" at different points along your worldline is having a changing experience
It is because the model says it is; that is how "changing experience" is modeled in SR.
 
  • #34
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Since discussion of interpretations is off topic here, this thread is closed.
 

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