Post by: Ethos on 05/04/2009 18:57:01
If one could hitch a ride on a photon, present theory suggests they would experience absolutely no passage of time. If I'm correct in this understanding, starting with the Big Bang, and progressing forward in time until the theorized heat death of the universe, how would the rider view the total experience? Would I be correct in saying; Because no time had elapsed for this passenger, the Big Bang and the Heat Death of the universe would be a single event with absolutely no time occuring in between. And with such a perspective, would the passenger have, from their position, already arrived at the Heat Death?
If this assumption is correct, then the future is already determined and it can't be changed...........................Ethos
Post by: yor_on on 05/04/2009 22:13:06
If you were able to 'live' like a photon and not 'interact', then 'time' would not be and neither would any universe. Distance wouldn't exist either. From that point of view nothing would happen. As i see it a photon only 'experience' anything when it interact with 'spacetime', otherwise it may be 'enlightened' :) But it sure as he** won't be able to think. Thinking takes place in 'time' but the photon?
And that is a result of 'frames of reference', then again, what is the photons 'frame of reference' as it travels. We see it as belonging to our definitions of distance and time, and it does, from our frame of reference.
Post by: Ethos on 05/04/2009 22:21:59
Its a question about 'time' and 'distance', is it not:)Actually, the question is about determinism. Because the photon's experience, has the future and the past all rolled up into oneness. In essence, the photon has already completed it's journey into the future, therefore, the future is fixed and cannot be changed.
Post by: Vern on 05/04/2009 23:27:27
Post by: lyner on 06/04/2009 00:06:07
I don't think that necessarily follows. You can look at a page of random numbers (they can be truly random - not just a pseudo random sequence which a computer can produce). You (playing the part of the photon) can see all of the numbers at once. But if you read each number at a time (playing the part of you and me) there is nothing about the third number which determines the fourth number (and so on) so you are experiencing a sequence which is not predetermined. That is the equivalent of living our lives - in time - when a photon will 'experience' its life - without time.Its a question about 'time' and 'distance', is it not:)Actually, the question is about determinism. Because the photon's experience, has the future and the past all rolled up into oneness. In essence, the photon has already completed it's journey into the future, therefore, the future is fixed and cannot be changed.
Post by: Ethos on 06/04/2009 02:07:53
I don't think that necessarily follows. You can look at a page of random numbers (they can be truly random - not just a pseudo random sequence which a computer can produce).The key word here is "random".
What determines the state of randomness?
I personally don't believe in randomness. I know there are those who will argue that quantum interactions are the best case scenario in support of the state of randomness. I believe however, that science has yet to uncover all the information necessary to unravel the cause and effect connection responsible for these phenomenon. The deeper we dig, and the more information we collect, I believe, will eventually find the causes and we will abandon this notion of randomness.........Ethos
Post by: lightarrow on 06/04/2009 18:01:14
I'm going to suggest a hypothetical circumstance which is quite impossible, nevertheless, it has raised a question in my mind which has many possible interpretations.Can we talk about very very fast moving starships, instead of photons? Moving so near c that you can't much say the difference? Ok, then, nothing changes in the sense that time still exist, space still exist. What changes is the values of distances (spatial or temporal) between events, as measured in 2 different frames of references. Example: how do you know that our visible universe is not already moving at ~ light speed with respect to a greater universe outside our visible one? Are we without time or without space? Consider a photon: it moves at c with respect to us, ok? So, aren't we all moving at c with respect it? But we are still experiencing space, time......
If one could hitch a ride on a photon, present theory suggests they would experience absolutely no passage of time. If I'm correct in this understanding, starting with the Big Bang, and progressing forward in time until the theorized heat death of the universe, how would the rider view the total experience? Would I be correct in saying; Because no time had elapsed for this passenger, the Big Bang and the Heat Death of the universe would be a single event with absolutely no time occuring in between. And with such a perspective, would the passenger have, from their position, already arrived at the Heat Death?
If this assumption is correct, then the future is already determined and it can't be changed...........................Ethos
Post by: LeeE on 06/04/2009 20:02:48
For any degree of time-dilation where the rate of time is > 0 events will occur in an order, one before the other, and so on, but where the rate of time drops to zero there is no scope for order, so all events would appear to be simultaneous. However, with no time, the events couldn't really be regarded as events at all, because they would neither start or end. Instead, anything that existed in different states, during the course of it's lifetime in it's own frame of reference, would have to be seen as existing in a single super-position of all it's states.
This would also seem to apply to the act of observation itself; if no time is to pass, the observation can neither be started or ended, so if it is to exist/happen at all it must be in the form of one of a super-position of actions, the observation being both endlessly performed and not performed.
If there's really any problem here, I think it's more because the question is contradictory; it asks about the concept of 'future' in a context where time has no meaning. The answer then, is that the concept of 'future' is meaningless in a context where there is no time.
Post by: lyner on 06/04/2009 20:55:35
Post by: Ethos on 06/04/2009 21:16:40
Excellent point LeeE, and to eveyone who contributed to this thread, Vern, lightarrow, sophie, and yor_on, you have cleared this question up for me,............Thanks
If there's really any problem here, I think it's more because the question is contradictory; it asks about the concept of 'future' in a context where time has no meaning. The answer then, is that the concept of 'future' is meaningless in a context where there is no time.
Post by: lightarrow on 06/04/2009 21:26:16
For any degree of time-dilation where the rate of time is > 0 events will occur in an order, one before the other, and so on,No. If two spatially separated events A and B occur in an order (A first and then B), they can occur in the reverse order (B first and then A) in another frame of reference moving with respect to the first.
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but where the rate of time drops to zero there is no scope for order, so all events would appear to be simultaneous.In my starship travelling at ~ c I experience time in the same way as before the travel.
Post by: yor_on on 07/04/2009 03:46:53
Lovely idea :)
Although a photon is a boson and your spaceship is made of fermions.
There seems to be a very strict division between those two states as I understands it, so when traveling we won't ever have that same 'no time' experience as the bosons (photons) does, would you agree to that? That's what makes photons so strange to me. They interact with us in time and space, but never sharing the 'equivalence' I sort of expect.
Post by: LeeE on 07/04/2009 21:58:33
For any degree of time-dilation where the rate of time is > 0 events will occur in an order, one before the other, and so on,No. If two spatially separated events A and B occur in [a temporal] order (A first and then B), they can occur in the reverse [temporal] order (B first and then A) in another frame of reference moving with respect to the first.
My emphasis.
This is logically correct, but the other frame of reference must be one where the direction of movement along the temporal axis is in the opposite direction to ours when it seems that within our spacetime environment everything moves along the temporal axis in the same direction. That is, unless it is stationary, of course. This isn't to say that this alternate frame of reference is impossible, but for us to be able to experience it would seem to require movement along a single axis in opposite directions, simultaneously. While there's no problem with moving along several different axis in different directions and at different rates, which is how we move through space, when we're referring to the same and single temporal axis, then we can move either one way or the other, but not both.
Quote
Quotebut where the rate of time drops to zero there is no scope for order, so all events would appear to be simultaneous.In my starship travelling at ~ c I experience time in the same way as before the travel.
Yes, you would experience time normally, but if you could reach 'c' so that no time passes, you will just experience what happens in zero time i.e. nothing.
Post by: yor_on on 08/04/2009 01:49:35
Post by: Ethos on 08/04/2009 04:36:20
Now I'm really getting confused. Could you plese clear this up for me?
Yes, you would experience time normally, but if you could reach 'c' so that no time passes, you will just experience what happens in zero time i.e. nothing.
If we consider a photon created at the Big Bang traveling unobstructed thru space until the present, from it's frame of reference, no time has elapsed. And looking into the future, choosing one of these photons that is fortunate enough to make it to the theorized heat death of the universe, it should have also experienced no passage of time.
If this scenario is correct, then for this photon at least, the future was predetermined at it's creation. And if we can agree upon that premise, all photon futures must be therefore, predetermined.
This is the point I'm trying to examine within this thread. If, with the creation of light, it's future is also determined, then likewise, all of history is. For without light, we would have no means to observe the passage of this history. For the photon, the past and the future are inextricably connected. And we as observers are held captive by the information light gives us. And that information was determined at it's creation..........................Ethos
Post by: lightarrow on 08/04/2009 09:11:01
For any degree of time-dilation where the rate of time is > 0 events will occur in an order, one before the other, and so on,No. If two spatially separated events A and B occur in [a temporal] order (A first and then B), they can occur in the reverse [temporal] order (B first and then A) in another frame of reference moving with respect to the first.
My emphasis.
This is logically correct, but the other frame of reference must be one where the direction of movement along the temporal axis is in the opposite direction to ours when it seems that within our spacetime environment everything moves along the temporal axis in the same direction.
Maybe I haven't explained myself well. I'm not talking about going back in the time, but normally travelling in space. If you are in a starship A and you are observing your friend in another equal starship B approaching you from left and going to right faster than you, both starships going to right (so the starships' "heads" are on the right, and the "tails" on the left) then in the frame of reference of your starship you see these events in this temporal order (HA = head of A; TB = tail of B, ecc):
1. HBTA --> TBTA --> HBHA
Instead, from his frame of reference:
2. HBTA --> HBHA --> TBTA.
As you see, the events coloured in blue and red are in reversal temporal order.
This is due to the fact that, for Lorentz contraction, you see your friend's starship shorter than your, and he sees the opposite.
Edit. I assumed it as obvious, but in case it's not: HBTA means "the head of starship B is next to the tail of starship A", ecc.
Post by: Vern on 08/04/2009 13:31:40
Quote from: Ethos
This is the point I'm trying to examine within this thread. If, with the creation of light, it's future is also determined, then likewise, all of history is. For without light, we would have no means to observe the passage of this history. For the photon, the past and the future are inextricably connected. And we as observers are held captive by the information light gives us. And that information was determined at it's creation..........................EthosI don't think it is a given that the information in a photon of light was determined at the instant of its creation. The question may be more in the way we think about it. A photon-entity would sense distance as we sense time. So, instead sensing the passage of time, as we do while occupying an inertial frame, the photon would sense the passage of inertial frames while occupying time.
Post by: lightarrow on 08/04/2009 15:43:35
In my starship travelling at ~ c I experience time in the same way as before the travel.
Yes, you would experience time normally, but if you could reach 'c' so that no time passes, you will just experience what happens in zero time i.e. nothing.
But that is true only in the hypothesis that our universe had a finite time of existence, because a finite number (universe time of existence) multiplied zero (Lorentz factor) is zero (time elapsed for the photon); but if the universe has an infinite time of existence (and, sincerely, neither me, nor you can know it) then infinite multiplied zero is undetermined (which means that it could be zero, a finite number or an infinite number).
Post by: Ethos on 08/04/2009 16:23:55
I don't think it is a given that the information in a photon of light was determined at the instant of its creation.Let's examine this statement;
If we accept the notion that the photon experiences no passage of time while traveling at c, we must also accept the notion that the photon's state of being has not changed. The only value we have to recognize the passage of time is change. If then, the photon has not changed it's character in any fashion, it remains the same as when it was created.
Let's perform a thought experiment:
We all recognize the sun is approx. 8 minutes away in light time. If we follow the course of photon X from it's source, the sun, to a location on earth, it will take 8 minutes our time to travel the distance. However, for the photon, this travel time was achieved in less than an instant. The photon will be absorbed by a patch of earth approx. 134 miles to the west of the initial straight line location. Photon X will change it's state of being upon being absorbed by this location, which in the photon's frame of reference happened instantly. Now; let's try and manipulate the outcome of this process.
Starting at zero minutes, the photon leaves the sun and the earth is rotating at it's regular pace, and 4 minutes later we decide to stop it's rotation. Will photon X still hit the same spot 134 miles to the west or, will it hit a spot on earth 67 miles to the west instead. According to our logic, it should hit the spot 67 miles to the west which is in straight line location with it's trajectory. And ofcourse, we all should recognize that the latter would be the case. However, photon X must have had prior information because it's final impact will occur 67 miles short of the previous estimate. From it's frame of reference, it's final destination was determined before we stopped the earth's rotation.
First question: Was our choice to stop the rotation predetermined?
Second question: Do we really have a choice or is history already cast in stone and we only have the delusion of free will?
.......................Ethos
Post by: Vern on 08/04/2009 17:14:50
Quote from: Ethos
If we accept the notion that the photon experiences no passage of time while travelling at c, we must also accept the notion that the photon's state of being has not changed. The only value we have to recognize the passage of time is change. If then, the photon has not changed it's character in any fashion, it remains the same as when it was created.
I think this is the notion that is causing our confusion. We assign an identity to an abstract function, photon. Then we say that abstract function, since it travels at c can experience no passage of time. But the wave-function concept is just a tool for thinking about a photon. I feel no compunction that this way of thinking about a photon must apply more globally.
QM avoids determinism by reducing everything to probability functions. I'm not sure how your deterministic photon could fit into QM theory. [:)]
Post by: LeeE on 08/04/2009 22:09:38
If this scenario is correct, then for this photon at least, the future was predetermined at it's creation. And if we can agree upon that premise, all photon futures must be therefore, predetermined.
You've gone back to referring to a time based property i.e. 'future' in a context where the duration of time = 0. Within it's frame of reference, the photon would appear to have no future because it has no time context (but remember, this is all based on the assumption that non-matter items i.e. photons, have the same properties as matter items i.e. er... matter, and personally, I'm not sure that this is a safe assumption to make, the two types of item being intrinsically different in just about every other respect we can think of. For example, non-matter items always travel at 'c' but matter items can never do this. Non-matter items have no rest mass, but matter items always do, and so on...).
Post by: LeeE on 08/04/2009 22:37:15
For any degree of time-dilation where the rate of time is > 0 events will occur in an order, one before the other, and so on,No. If two spatially separated events A and B occur in [a temporal] order (A first and then B), they can occur in the reverse [temporal] order (B first and then A) in another frame of reference moving with respect to the first.
My emphasis.
This is logically correct, but the other frame of reference must be one where the direction of movement along the temporal axis is in the opposite direction to ours when it seems that within our spacetime environment everything moves along the temporal axis in the same direction.
Maybe I haven't explained myself well. I'm not talking about going back in the time, but normally travelling in space. If you are in a starship A and you are observing your friend in another equal starship B approaching you from left and going to right faster than you, both starships going to right (so the starships' "heads" are on the right, and the "tails" on the left) then in the frame of reference of your starship you see these events in this temporal order (HA = head of A; TB = tail of B, ecc):
1. HBTA --> TBTA --> HBHA
Instead, from his frame of reference:
2. HBTA --> HBHA --> TBTA.
As you see, the events coloured in blue and red are in reversal temporal order.
This is due to the fact that, for Lorentz contraction, you see your friend's starship shorter than your, and he sees the opposite.
Edit. I assumed it as obvious, but in case it's not: HBTA means "the head of starship B is next to the tail of starship A", ecc.
Sorry lightarrow, I misunderstood what you meant.
That's a good illustration but I think that what you're really pointing out is that there isn't an absolute frame of reference. While each observer may see things happening in a different order, they will always see it in that order and the order will remain consistent within that frame of reference. Neither craft could see a different order from their respective frames of reference.
Post by: LeeE on 08/04/2009 22:53:17
In my starship travelling at ~ c I experience time in the same way as before the travel.
Yes, you would experience time normally, but if you could reach 'c' so that no time passes, you will just experience what happens in zero time i.e. nothing.
But that is true only in the hypothesis that our universe had a finite time of existence, because a finite number (universe time of existence) multiplied zero (Lorentz factor) is zero (time elapsed for the photon); but if the universe has an infinite time of existence (and, sincerely, neither me, nor you can know it) then infinite multiplied zero is undetermined (which means that it could be zero, a finite number or an infinite number).
If we accept the BB hypothesis, only a finite amount of time can have elapsed for the universe up to this point in time. Whether the universe goes on to exist for an infinite amount of time or not is open to debate, but for any specific time in the future only a finite amount of time can have elapsed.
While trying to do maths with ∞ doesn't give meaningful answers anyway, I have to disagree that ∞ * 0 is indeterminable; it will still be 0.
Post by: yor_on on 09/04/2009 01:03:42
As for the discussion going on here I think I'll just will read up on you, for now.
Though I'm sure I'll have one (opinion) soon enough :)
I seem to have a lot of them ::))
Post by: lightarrow on 09/04/2009 08:55:10
If you are in a starship travelling at c you have lived zero time from the BB up to know, but since you live in a different time, you keep going ahead, till the end of the universe, so don't know how your consideration applies here.
But that is true only in the hypothesis that our universe had a finite time of existence, because a finite number (universe time of existence) multiplied zero (Lorentz factor) is zero (time elapsed for the photon); but if the universe has an infinite time of existence (and, sincerely, neither me, nor you can know it) then infinite multiplied zero is undetermined (which means that it could be zero, a finite number or an infinite number).
If we accept the BB hypothesis, only a finite amount of time can have elapsed for the universe up to this point in time. Whether the universe goes on to exist for an infinite amount of time or not is open to debate, but for any specific time in the future only a finite amount of time can have elapsed.
Quote
While trying to do maths with ∞ doesn't give meaningful answers anyway, I have to disagree that ∞ * 0 is indeterminable; it will still be 0.Did you study mathematics?
Post by: Mr. Scientist on 09/04/2009 22:19:11
I'm going to suggest a hypothetical circumstance which is quite impossible, nevertheless, it has raised a question in my mind which has many possible interpretations.
If one could hitch a ride on a photon, present theory suggests they would experience absolutely no passage of time. If I'm correct in this understanding, starting with the Big Bang, and progressing forward in time until the theorized heat death of the universe, how would the rider view the total experience? Would I be correct in saying; Because no time had elapsed for this passenger, the Big Bang and the Heat Death of the universe would be a single event with absolutely no time occuring in between. And with such a perspective, would the passenger have, from their position, already arrived at the Heat Death?
If this assumption is correct, then the future is already determined and it can't be changed...........................Ethos
You kind of answered your own question, but a good question at that. Let me go through it for you:
''If one could hitch a ride on a photon, present theory suggests they would experience absolutely no passage of time. If I'm correct in this understanding,''
Yes you are right, from a photons point of view, it experiences no time because space is stretched into infinity
''starting with the Big Bang, and progressing forward in time until the theorized heat death of the universe, how would the rider view the total experience?
Going back to the original assumption, correct at that which you made, the photon would actually experience no time passing, so even from big bang to heat death, or even big rip to big crunch, it would never know, because it never lived for a single chronon, or a single Planck Time which stands at around
of a second.and thus your final remarks
''Would I be correct in saying; Because no time had elapsed for this passenger, the Big Bang and the Heat Death of the universe would be a single event with absolutely no time occuring in between. And with such a perspective, would the passenger have, from their position, already arrived at the Heat Death?''
Are absolutely sound :)
Post by: lightarrow on 10/04/2009 00:15:19
...
and thus your final remarks
''Would I be correct in saying; Because no time had elapsed for this passenger, the Big Bang and the Heat Death of the universe would be a single event with absolutely no time occuring in between. And with such a perspective, would the passenger have, from their position, already arrived at the Heat Death?''
Are absolutely sound :)
Actually, it's nonsense saying "the passenger have, from their position, already arrived at the Heat Death". If you want to relate events in our frame of reference with events in his frame of reference then he *is not* arrived there, he's arrived exactly where we are in this moment. Nonetheless it's true that he will experience just a few instants to go in our far future.
Post by: LeeE on 10/04/2009 21:06:27
If you are in a starship travelling at c you have lived zero time from the BB up to know, but since you live in a different time, you keep going ahead, till the end of the universe, so don't know how your consideration applies here.
But that is true only in the hypothesis that our universe had a finite time of existence, because a finite number (universe time of existence) multiplied zero (Lorentz factor) is zero (time elapsed for the photon); but if the universe has an infinite time of existence (and, sincerely, neither me, nor you can know it) then infinite multiplied zero is undetermined (which means that it could be zero, a finite number or an infinite number).
If we accept the BB hypothesis, only a finite amount of time can have elapsed for the universe up to this point in time. Whether the universe goes on to exist for an infinite amount of time or not is open to debate, but for any specific time in the future only a finite amount of time can have elapsed.
If you've lived zero time up until now, you're not living in a 'different' time; you've lived, as you said, zero time. With time being absent as a factor in your frame of reference, you don't keep going because you aren't doing anything. Nothing can happen and there is no scope for change to occur because there is nowhere else for a different state to exist.
Post by: lightarrow on 11/04/2009 09:01:19
If you've lived zero time up until now, you're not living in a 'different' time; you've lived, as you said, zero time. With time being absent as a factor in your frame of reference, you don't keep going because you aren't doing anything. Nothing can happen and there is no scope for change to occur because there is nowhere else for a different state to exist.That I have coloured is wrong.
Post by: amrit on 11/04/2009 09:43:02
I'm going to suggest a hypothetical circumstance which is quite impossible, nevertheless, it has raised a question in my mind which has many possible interpretations.
If one could hitch a ride on a photon, present theory suggests they would experience absolutely no passage of time. If I'm correct in this understanding, starting with the Big Bang, and progressing forward in time until the theorized heat death of the universe, how would the rider view the total experience? Would I be correct in saying; Because no time had elapsed for this passenger, the Big Bang and the Heat Death of the universe would be a single event with absolutely no time occuring in between. And with such a perspective, would the passenger have, from their position, already arrived at the Heat Death?
If this assumption is correct, then the future is already determined and it can't be changed...........................Ethos
photon moves in atemporal space only and not in time
time is a clock run that measure photon speed
you can not move woth photon speed, so your question has no answer
Post by: Mr. Scientist on 12/04/2009 02:51:54
...
and thus your final remarks
''Would I be correct in saying; Because no time had elapsed for this passenger, the Big Bang and the Heat Death of the universe would be a single event with absolutely no time occuring in between. And with such a perspective, would the passenger have, from their position, already arrived at the Heat Death?''
Are absolutely sound :)
Actually, it's nonsense saying "the passenger have, from their position, already arrived at the Heat Death". If you want to relate events in our frame of reference with events in his frame of reference then he *is not* arrived there, he's arrived exactly where we are in this moment. Nonetheless it's true that he will experience just a few instants to go in our far future.
Actually, to every beginning there is an end. If you want to get technical about this, then the photon never really existed at all, because it has no beginning of existence in time (this is why we say if the photon really has any kind of birth, it would simultaneously be its death also). This is why, as soon as big bang imploded, and photon where released - the very basic building energy tools of all matter - from ''their point of perspective,'' not a single bit of time passes, so any symmetry in time (such as a big crunch where the time direction has flipped due to gravity), from their point of perspective, there existence accounts to nothing, so it has experiences nothing, but can be said to have a birth and death (the beginning and end) which cancel out entirely.
Post by: Ethos on 12/04/2009 03:01:57
And this exposes a contradiction in terms because; If the photon never really existed within it's own time, why did it exist in ours? My own take on this is that the photon experiences it's birth and it's death even though these are crowded into a singular event.
Actually, to every beginning there is an end. If you want to get technical about this, then the photon never really existed at all,
Post by: LeeE on 12/04/2009 19:43:54
If you've lived zero time up until now, you're not living in a 'different' time; you've lived, as you said, zero time. With time being absent as a factor in your frame of reference, you don't keep going because you aren't doing anything. Nothing can happen and there is no scope for change to occur because there is nowhere else for a different state to exist.That I have coloured is wrong.
What you have coloured is correct.
Post by: lightarrow on 12/04/2009 21:21:52
Then we're on a loop...If you've lived zero time up until now, you're not living in a 'different' time; you've lived, as you said, zero time. With time being absent as a factor in your frame of reference, you don't keep going because you aren't doing anything. Nothing can happen and there is no scope for change to occur because there is nowhere else for a different state to exist.That I have coloured is wrong.
What you have coloured is correct.
Post by: yor_on on 13/04/2009 13:14:40
---
But this is when discussing bosons like photons. They don't obey the rules of fermions, even thought they seem, as from our frame of reference, to obey both gravity and time. Fermions won't get up to 'c' as I understand it, if ever matter was at 'c' it would have a infinite amount of everything, from momentum to energy to 'mass' to??? As Lightarrow say, if fermions was at 'c' what he describes should be true. So, I think there are a collision of 'frames' here:)
To test the idea of time slows down 'internally' should be possible, the question here is not so much if an accelerated frame is 'slower' in all it does as compared to an unaccelerated frame. The question is rather if 'thinking' would stop at 'c' for us. The first question is defined by a comparison between frames, but with two truths to it, depending on your frame of reference.The other question is a question about what 'internal experience' you might have while traveling at 'c' and that can only be described from the 'internal' frame of reference. There I believe Lightarrow to be right, as time for 'fermions' never stops.
Post by: Mr. Scientist on 13/04/2009 13:37:55
And this exposes a contradiction in terms because; If the photon never really existed within it's own time, why did it exist in ours? My own take on this is that the photon experiences it's birth and it's death even though these are crowded into a singular event.
Actually, to every beginning there is an end. If you want to get technical about this, then the photon never really existed at all,
Shhh... :) That is where relativity comes in. Our frame of reference does not effect our ability to notice the distortions of spacetime themselves, even if there are photons and gluon ect ect all moving at speeds which defy their own existence. But this has to do with ''frame of references'' and it depends on what frame of reference you take.
You could say the photon is absolutely and utterly meaningless and utterly non-energetic, if there was no reference frame to destinguish it at all. Remember, the photon, is just a wave of possibilities, and the probability of finding that particle depends on some kind of decoherence due to observation.
It may seem contradictory, but relativity explains it quite well, and if my explanation is not good enough, i will try again.
Post by: Mr. Scientist on 13/04/2009 13:40:56
And this exposes a contradiction in terms because; If the photon never really existed within it's own time, why did it exist in ours? My own take on this is that the photon experiences it's birth and it's death even though these are crowded into a singular event.
Actually, to every beginning there is an end. If you want to get technical about this, then the photon never really existed at all,
Shhh... :) That is where relativity comes in. Our frame of reference does not effect our ability to notice the distortions of spacetime themselves, even if there are photons and gluon ect ect all moving at speeds which defy their own existence. But this has to do with ''frame of references'' and it depends on what frame of reference you take.
You could say the photon is absolutely and utterly meaningless and utterly non-energetic, if there was no reference frame to destinguish it at all. Remember, the photon, is just a wave of possibilities, and the probability of finding that particle depends on some kind of decoherence due to observation.
It may seem contradictory, but relativity explains it quite well, and if my explanation is not good enough, i will try again.
I will also add, since i mentioned the birth of photon, so-to-say, at the big bang, their goal must be evident and plain. It must be as plain as:
1) They desired to become rest matter
2) They desired to experience time under a rest matter's frame of existence
Without these ''desires'', then the world as we know it would just be a ghostly apparition of photons, if it would exist [at all].
Post by: Ethos on 14/04/2009 01:50:36
It may seem contradictory, but relativity explains it quite well,Yes, I understand. The only disagreement I have with this rationale is this: I believe the photon's experience, from birth to death, is crowded into a single moment. I don't accept the argument that this moment never existed within the photon's frame of reference.
Some will argue that a moment of time can't equal zero, and I would agree. For this moment I propose one attosecond. One unit of Plank time equal to: (10^-18) seconds.....................Ethos
Post by: yor_on on 14/04/2009 23:46:23
How long can the interaction of a photon in spacetime be.
The light I mean, from one photon.
Post by: Ethos on 14/04/2009 23:53:25
It's a nice question Ethos. We should have it on record. Ah, possibly :)From it's frame of reference or that of an observer?
How long can the interaction of a photon in spacetime be.
The light I mean, from one photon.
Post by: LeeE on 15/04/2009 01:03:13
Then we're on a loop...If you've lived zero time up until now, you're not living in a 'different' time; you've lived, as you said, zero time. With time being absent as a factor in your frame of reference, you don't keep going because you aren't doing anything. Nothing can happen and there is no scope for change to occur because there is nowhere else for a different state to exist.That I have coloured is wrong.
What you have coloured is correct.
You have acknowledged that that zero time has passed in that frame of reference, so how can it be a factor if it's value is zero? How can this be incorrect?
Just high-lighting a bit of text and saying it's incorrect without explaining why is worthless.
Post by: yor_on on 15/04/2009 09:09:22
Post by: lightarrow on 15/04/2009 11:28:48
Because I have already explained it, and sincerely I don't know how to explain it in a different way.Then we're on a loop...If you've lived zero time up until now, you're not living in a 'different' time; you've lived, as you said, zero time. With time being absent as a factor in your frame of reference, you don't keep going because you aren't doing anything. Nothing can happen and there is no scope for change to occur because there is nowhere else for a different state to exist.That I have coloured is wrong.
What you have coloured is correct.
You have acknowledged that that zero time has passed in that frame of reference, so how can it be a factor if it's value is zero? How can this be incorrect?
Just high-lighting a bit of text and saying it's incorrect without explaining why is worthless.
Post by: LeeE on 15/04/2009 20:19:21
Post by: lyner on 15/04/2009 23:55:52
Too much concrete thinking, I feel.
Post by: lightarrow on 16/04/2009 00:50:08
How can you guys get so airated[???]
Quote
about something which can't have any meaning? If time doesn't exist in a particular model then what is the point of discussing things as if it did?What do you mean? I was discussing about time in a very fast starship (because, as already said tens of times, the photon's frame of reference doesn't exist).
Too much concrete thinking, I feel.
Post by: amrit on 23/04/2009 10:12:46
Post by: yor_on on 03/10/2010 06:45:08
We have two possible effects.
1. If a photon would be shown to possess a mass.
Can it then be regarded as intrinsically timeless?
And what kind of Boson would it be then?
After all, we can 'make' them in a Bose Einstein condensate?
2. What are the actual proofs for it being intrinsically timeless?
I started to look for that but I can't seem to find them?
My own reasoning would possibly be, assuming that light propagates, that we need this as a definition for explaining how it conserves its energy, considering the 'distances' it covers, as well as the 'time' we notice it to have.
On the other hand. Without a clock, how can it propagate?
Not easily, if we assume distance needing a clock?
Also, it is often referred to it being a direct consequence of it being at 'c' but how do you prove that relationship? We talk about it as being a boson, and therefore having those properties, but I would still like to see the causality-chain clearer, leading to the conclusion.
You can say that as the equations prove that matter can't reach 'c' as the slope gets infinitely steep there is a clear difference between what we call bosons and fermions, but the idea of a photon possessing a mass would in my eyes degrade it from being 'time-less' if so?
So, anyone that can show me the proofs?
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The clock on this server is slightly weird :)
It says ten minutes before my correction 'intrinsically' came to be :)
Hmm, it's relativistic :)
Post by: yor_on on 03/10/2010 09:01:49
But assume that it would be found to have an ever so slight 'restmass'?
Could we then say with certainty that nothing can move faster?
And what would that do this axiom?
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In a way this idea seems sort of circular, as it build on the premise that light is as fast as anything can be and from there reasons that if we assume that we normally have a motion through both space and time, then with a faster motion you will have a lesser motion through time, all the way up to a photons 'no-time'.
If we go back and look at the theory of relativity, it builds on the idea that light will have the same velocity no matter what frame you measure it from, right? So if I use this definition of world-lines and assume that I send a light-corn from a speeding rocket near light-speed I will still measure it to be 'c' but what have I done to its worldline? Nothing it seems, as it already was as fast as can be? But I must have done something? The photon will see the exact same plane in both cases, that is, nothing.
So how do it do it, seeing nothing, but interacting with us?
Because it do interact, and have a speed as measured by us.
You can relate that to your 'invariant frame' as in your frame time never change, only the 'relations' do.
Post by: JP on 03/10/2010 09:06:01
1) A photon is massless, in which case it always moves at c, the cosmic speed limit, and it's probably a meaningless question to ask what it experiences, since we, as objects with mass, can't ever see what it "sees," nor can we measure it, since our detectors also have mass.
2) A photon has mass, in which case we would have to rename the cosmic speed limit something other than "the speed of light"! Special relativity should still hold, although now photons are like all particles with mass and can't reach that fastest possible speed. There are probably other tiny fixes that need to be made in various theories. But, since we know a lot of theories do hold to a high degree of accuracy, and various tests have been made looking for photon mass, the maximum allowable photon mass has to be very tiny, if it is non-zero.
Post by: yor_on on 03/10/2010 09:29:41
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Ahhaa :) But that's where we don't agree JP. I don't find it meaningless to look at from a photons frame. The only way that would be meaningless would be if they didn't exist for us. But they do, and therefore I will guess :)
And no, I assume that the reason we exist is our arrow of time, aka a 'clock', and I also assume that the reason we can measure that light to have a velocity is that same 'clock' ticking for us. And then I assume that without a clock you can't discuss a distance, and I don't have to discuss it from the frame of a photon to reach that conclusion.
But applied to that frame you either have to define how the photon can 'propagate' or ..
Well, as I see it :)
=
Tachyons though :)
That's another parcel of fish.
Post by: JP on 03/10/2010 11:24:01
Ahhaa :) But that's where we don't agree JP. I don't find it meaningless to look at from a photons frame. The only way that would be meaningless would be if they didn't exist for us. But they do, and therefore I will guess :)
Meaningless might be a strong word, but how would we go about explaining what a photon experiences (if it is massless, that is)? No theory covers this, so some new description would be required. Something beyond special relativity, at least.
Post by: lightarrow on 03/10/2010 12:07:50
I don't find it meaningless to look at from a photons frame. The only way that would be meaningless would be if they didn't exist for us.No, the only way in which such a frame could exist would be if photon's mass were not zero. Maybe you have not totally clear what a frame of reference is: not a simply abstract mathematical description, but a system of synchronized clocks put in all points of space (at steady intervals), or the possibility to really do it *physically*. You *can't* do this with massless particles.
Post by: yor_on on 03/10/2010 14:57:01
Am I wrong there?
Post by: yor_on on 03/10/2010 23:06:24
If a photon was found to have a restmass it seems to me that it could be considered to intersect? According to this definition..
"One of the most basic geometrical ideas is intersection. In relativity, we expect that even if different observers disagree about many things, they agree about intersections of world-lines. Either the particles collided or they didn't. The arrow either hit the bull's-eye or it didn't. So although general relativity is far more permissive than Newtonian mechanics about changes of coordinates, there is a restriction that they should be smooth, one-to-one functions. If there was something like a Lorentz transformation for v=c, it wouldn't be one-to-one, so it wouldn't be mathematically compatible with the structure of relativity. (An easy way to see that it can't be one-to-one is that the length contraction would reduce a finite distance to a point.)"
Am I right there?
Post by: JP on 04/10/2010 06:07:11
I think the quote above about world lines intersecting is getting at the point that all observers should agree on whether an event happens or not, no matter how fast they're moving. They might measure things differently, but the event itself should still happen. It would be nonsensical, for example, if you could make two asteroids miss each other or collide with each other simply by moving faster or slower as you viewed them. The above quote seems to be claiming that there is no theory compatible with special relativity that would give photons this property as they "viewed" the universe.
If photons are shown to have rest masses, then their point of view is described by special relativity, just as our point of view is.
Post by: yor_on on 04/10/2010 15:20:32
So how about an accelerating observer?
Accelerating non-linearly?
Will that frame give another speed for light?
Post by: yor_on on 04/10/2010 21:43:29
Post by: JP on 05/10/2010 01:39:58
Yep, I agree JP, but this whole excursion is just to ring in what proof we have for that a photon really have to be that 'massless' 'timeless' 'point' of no displacement in SpaceTime. So all ways we can think up to ring in why it have to be that way is good to me. And if there was some way proving it to be different I would be very interested. And, as you say "one of the postulates was that the speed of light is constant for all inertial observers."
So how about an accelerating observer?
Accelerating non-linearly?
Still constant. You'd see the light getting Doppler shifted, though.
Post by: JP on 05/10/2010 01:43:35
GoodElf wrote an interesting answer to a similar question of mine on another place. It it he comments that "The speed of light actually appears to be the thing keeping stuff apart and making all that space and energy out there in our universe." which I found to be rather worth thinking over. What he was talking about here was the invariance of that speed as measured from all 'inertial frames'. So what would happen if a photon would be found to have a restmass, as seen from this definition? Could you use this as a 'proof' why we don't expect a restmass?
I'm not sure I understand what he's getting at. The speed of light has to do with the expansion of the universe, I guess, in the sense that its a cosmic speed limit and that somewhat determines how general and special relativity work, but I don't see how it directly does what he claims. If light has a rest mass, then this speed limit still appears to exist (experiments involving things other than light seem to verify it).
Post by: CPT ArkAngel on 05/10/2010 05:46:33
What Ethos wrote is interesting because a photon is simply a quantum of electromagnetic wave and electromagnetic wave seems to be the ultimate carrier of information for our brain perception... our perception of reality.
Post by: yor_on on 05/10/2010 05:58:48
We had no problems with beams before relativity came :)
But we have now :)
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CPT "special relativity is a matter of perception and not reality."
You don't trust the separate 'frames' reality then?
(And no JP, GE was speculating there. It was me getting stuck on the formulation I'm afraid.
It had such a nice ring to it.)
Post by: yor_on on 05/10/2010 06:18:35
But there is still that example in which a attacking Andromeda space-fleet will attack before or after, depending on which one of two persons you are, and depending on the direction of their walks as they cross each others path. That is, to one it haven't happened at all, being in that ones future world-line, whilst in the other pedestrians world-line the space-fleet already have left Andromeda.. I can look it up if you're interested. Got to admit that it made no sense to me, even if true it becomes weird to think of.
Post by: CPT ArkAngel on 05/10/2010 06:56:54
http://www.phys.ncku.edu.tw/mirrors/physicsfaq/Relativity/SR/acceleration.html
Post by: lightarrow on 05/10/2010 13:04:32
Like i said in another post, special relativity is a matter of perception and not reality,What does this phrase mean?
Post by: yor_on on 05/10/2010 14:12:14
And that's also why I asked about lights invariance in a accelerated non-linear frame. Because I see it that way too, assuming that we're discussing 'black box scenarios'. There is just one thing more, assume a uniformly moving rocket, defined as being close to light as seen against Earth (inertial frame:). Will they too observe a Doppler shift? And it's a 'black box' scenario, not using any stars, or light, outside the ship. Forgot to mention that before.
Post by: CPT ArkAngel on 05/10/2010 16:10:17
Like i said in another post, special relativity is a matter of perception and not reality,What does this phrase mean?
I should have said special relativity using only inertial frames of reference.
See the "Twins paradox". If you only use inertial frames for calculations, you don't make any distinction on who is moving relative to the other. In this way, if two people are moving relative to each other, they should both think that the other is aging at a slower rate. It is paradoxical... Which one has the truth? You need to take account of acceleration and synchronized clocks to really knows what is happening...
Post by: lightarrow on 05/10/2010 16:32:11
I should have said special relativity using only inertial frames of reference.Let's imagine that I am in an inertial frame even if I don't know it, and my sibling goes to Proxima Centauri and come back, but we don't know this, we only know that we are in a relative motion and that our distance starts to zero, increases to a maximum then decreases to zero again. During our relative motion he sends me light pulses every second of his time and I send him light pulses every second of my time.
See the "Twins paradox". If you only use inertial frames for calculations, you don't make any distinction on who is moving relative to the other.
Do you think that I'm not able to make the correct computation according to SR and to conclude that I'm in an inertial frame and he is in an accelerating frame?
Post by: Ron Hughes on 05/10/2010 16:43:09
Post by: CPT ArkAngel on 05/10/2010 17:27:58
The way i see it is, relative speed alone will produce measurement distortion of spacetime but acceleration produce true distortion of it... Correct me if i am wrong.
Post by: yor_on on 05/10/2010 18:02:31
It falls back to how I see an accelerating motion for me, or for that sake, take a circle drawn on a paper. Is it a really a 'bent form' or can I also see it as an infinite amount of straight lines put together? slightly placed at an angle to each other? That one seems 'legal' to ask, but the opposite, describing a straight line in form of infinitesimally small pieces of circles? That one seems to become contradictory in terms to me? It may all be semantics, but to me it creates confusion, not that this is any surprise, neither to you, nor me I guess :)
And differing the light seems to build on the assumption of them both having an common origin, and so a common 'history' defining them to each other, before they interpret the information the red/blue shifted signals will give them?
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To see how I think make it a 'black box scenario' for them both..
How will they decide? Stupid of me :)
Of course you're correct..
You don't need a common origin for that one, you only need a 'history' and some way of defining that what you are receiving comes from the same 'origin'.
But still, how do I define what acceleration really is?
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Drawn to its utmost conclusion it suddenly seems that the only way I can define acceleration is by assuming 'times arrow' to be a 'flow'. As treating 'times arrow' as 'instants' only brings me back to my first question?
Post by: yor_on on 05/10/2010 18:37:32
There can only be straight lines, and what 'bends' are SpaceTime.
And Times arrow have to be a flow :)
*Running under my table*
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Ah that should read *Most bravely running under my table*
Post by: lightarrow on 05/10/2010 19:09:52
There in lies the crux of the problem. All you can know from his signal is that it is red shifted when he is moving away and blue when he returns, all he can know from your signal is it's red shifted moving away and blue coming back. How can either of know which is the one moving?The one who is accelerating is simply the one who sends less signals.
I mean, if we know for sure that one is in an inertial frame and the other is not, with that simple way we can established who.
Post by: lightarrow on 05/10/2010 19:51:01
You should be correct because you use an accelerating frame of reference for the one who is accelerating (and or decelerating). You won't be correct if you use only inertial frames of reference for both of them.If both were in inertial frames at relative speed v ≠ 0, certainly we couldn't meet again to compare our time intervals, so it would be perfectly correct to say that the interval of time between two events is greater for me, in my frame, and that it's greater for him, in his frame.
Anyway, the twin paradox does not come from the fact that one is accelerating, in the sense that the *amount* of acceleration is not important; what counts is the fact that the situation is asymmetric, actually. You can see this asymmetry for example noting that in my frame I measure 4 light years as Earth-Proxima Centauri distance, while he measures less for lorentz contraction.
Quote
The way i see it is, relative speed alone will produce measurement distortion of spacetime but acceleration produce true distortion of it... Correct me if i am wrong.Not even acceleration produces true distortion of spacetime. True distortion (that is, curvature) is only produced by energy/momentum (to be more precise, stress energy tensor).
Post by: CPT ArkAngel on 05/10/2010 20:33:28
There in lies the crux of the problem. All you can know from his signal is that it is red shifted when he is moving away and blue when he returns, all he can know from your signal is it's red shifted moving away and blue coming back. How can either of know which is the one moving?The one who is accelerating is simply the one who sends less signals.
I mean, if we know for sure that one is in an inertial frame and the other is not, with that simple way we can established who.
The one who is accelerating can feel it or if you prefer, measure it...
Post by: CPT ArkAngel on 05/10/2010 20:42:32
You should be correct because you use an accelerating frame of reference for the one who is accelerating (and or decelerating). You won't be correct if you use only inertial frames of reference for both of them.If both were in inertial frames at relative speed v ≠ 0, certainly we couldn't meet again to compare our time intervals, so it would be perfectly correct to say that the interval of time between two events is greater for me, in my frame, and that it's greater for him, in his frame.
Anyway, the twin paradox does not come from the fact that one is accelerating, in the sense that the *amount* of acceleration is not important; what counts is the fact that the situation is asymmetric, actually. You can see this asymmetry for example noting that in my frame I measure 4 light years as Earth-Proxima Centauri distance, while he measures less for lorentz contraction.QuoteThe way i see it is, relative speed alone will produce measurement distortion of spacetime but acceleration produce true distortion of it... Correct me if i am wrong.Not even acceleration produces true distortion of spacetime. True distortion (that is, curvature) is only produced by energy/momentum (to be more precise, stress energy tensor).
What will happened to the energy momentum of an accelerating object? It will increase...
General relativity says that Gravity and acceleration are the same...
Post by: Ron Hughes on 05/10/2010 23:07:08
Post by: Ron Hughes on 06/10/2010 01:52:31
Post by: lightarrow on 06/10/2010 12:58:16
What will happened to the energy momentum of an accelerating object? It will increase...Not exactly, it's true only locally. But unfortunately I don't know much more of GR.
General relativity says that Gravity and acceleration are the same...
Post by: Ron Hughes on 07/10/2010 17:56:56
Post by: kenhikage on 08/10/2010 12:18:31
Post by: lightarrow on 08/10/2010 12:29:09
Do you mean that the inertial force I feel ten lights from Earth is different from what I would feel near Earth?No, I mean that *in a small region of spacetime* equivalence principle holds; globally it doesn't always hold, but unfortunately GR is very complex, I just know that because of someone more aknowledged than me.
Post by: Ron Hughes on 08/10/2010 17:24:28