Understanding the Paradox of Backward Time Travel: Why We Can't Go Back

[Alias]

We can't "go back" because the past does not exist within this universe.

What is the mechanism of time? Don't tell us what time is, tell us how time works.

 

[CJames]

Oh man what is going on in this thread? Stop trying to define time. It doesn't really have much of a definition, other then that which is measured by clocks. Hell, that's the definition Einstein used. Any other definition just end up using the word time in it or makes some mention of the past present and future or other literary contortions.

Instead, can we go to the past is more the subject we supposedly have here.

Do the past present and future exist, or just the present? That isn't provable, really, since all you can ever experience is the present. But it too, isn't really the point.

The point is, paradoxes pop up all over the place when you are allowed to travel to the past, many of which seem to violate other laws of physics. It may be possible, but my opinion is that it is a pipe dream. You can't visit the past.

 

[pelastration]

Time is what 'our' clocks measure.
Clocks are a convention between humans to have a reference system with which they can communicate about "the duration of certain temporal (mass and energy) structures and their decay".

Time is relative to the observers structure/level, thus time is determinated by his resonance frame.
Time is the observed progress and shift between matter and energy.

For a bird, a cell in my liver or Michio Kaku's carp their is another resonance field in which the progress/shift between matter and energy happens than in your human world.
So on every level there is a type of internal clock indicating in what velocity phase of matter/energy shift his/its local structure is (Jezus, I am sleepy, Whoow ... i need to phone mum, where is Kaku ... I want some food, ...). In all universal structures there are different types of time embedded, but only the resonant are observed (conscious related).

Travel in time would suppose that ALL billions of such shifts on all their levels would be reversed identically or preset correctly in advance.
Travel in the past would also implicate that each of such shifts of the past is stored somewhere and can be recupurated.

Good luck ;-) Hope to see you when I started his post.

 

[Messiah]

Originally posted by pelastration
Time is what 'our' clocks measure.
Clocks are a convention between humans to have a reference system with which they can communicate about "the duration of certain temporal (mass and energy) structures and their decay".

Time is relative to the observers structure/level, thus time is determinated by his resonance frame.
Time is the observed progress and shift between matter and energy.

For a bird, a cell in my liver or Michio Kaku's carp their is another resonance field in which the progress/shift between matter and energy happens than in your human world.
So on every level there is a type of internal clock indicating in what velocity phase of matter/energy shift his/its local structure is (Jezus, I am sleepy, Whoow ... i need to phone mum, where is Kaku ... I want some food, ...). In all universal structures there are different types of time embedded, but only the resonant are observed (conscious related).

Travel in time would suppose that ALL billions of such shifts on all their levels would be reversed identically or preset correctly in advance.
Travel in the past would also implicate that each of such shifts of the past is stored somewhere and can be recupurated.

Good luck ;-) Hope to see you when I started his post.

I think you are confusing time with metabolism. If your metabolism slows down, time SEEMS to speed up (a cesium atom SEEMS to pulse more quickly), if your metabolism speeds up, the reverse is true.

YOU are changing more quickly or slowly compared with the environment against you are measuring it.

 

[pelastration]

Thank you Lord ;-)

Your metabolism has its own time appreciation.

1. slowing metabolism : surrounding matter/energy shifts seems to be faster
2. faster metabolism : surrounding shifts seems to be slower

But the surrounding shifts have still their own speed.

It means that the observers resonant system has changed, not the surrounding. Meaning his conscious interprets the surrounding differently than before.

I don't see the confusion.

I think we said the same. ;-)

 

[Messiah]

Originally posted by pelastration
Thank you Lord ;-)

Your metabolism has its own time appreciation.

1. slowing metabolism : surrounding matter/energy shifts seems to be faster
2. faster metabolism : surrounding shifts seems to be slower

But the surrounding shifts have still their own speed.

It means that the observers resonant system has changed, not the surrounding. Meaning his conscious interprets the surrounding differently than before.

I don't see the confusion.

I think we said the same. ;-)

Actually, I think where we differ is that time does not need to be observed - it is a measurement of rate of change within an element or between elements - whether one of the elements is conscious of it or not...I guess I tend to define it in a more remote context.

(Te absolvo)

 

[Mentat]

Originally posted by Messiah
Mea Culpa - I DID misread your quote.

But saying change cannot exist without time is like saying distance cannot exist without inches.

What does time do if it does not measure change?

This is written perfectly backward, and your spatial analogy proves it. Change is like "inches". Inches measure the spatial dimensions, while rate of change measures the time dimension. The reasoning of your last question, when applied to the spatial analogy, would read: "What does space do, if it doesn't measure inches?".

 

[Mentat]

Originally posted by CJames
Oh man what is going on in this thread? Stop trying to define time. It doesn't really have much of a definition, other then that which is measured by clocks. Hell, that's the definition Einstein used. Any other definition just end up using the word time in it or makes some mention of the past present and future or other literary contortions.

Instead, can we go to the past is more the subject we supposedly have here.

Do the past present and future exist, or just the present? That isn't provable, really, since all you can ever experience is the present. But it too, isn't really the point.

The point is, paradoxes pop up all over the place when you are allowed to travel to the past, many of which seem to violate other laws of physics. It may be possible, but my opinion is that it is a pipe dream. You can't visit the past.

You are correct that time is what our clocks measure (btw, Einstein also said that space is "what we measure with measuring rods", that doesn't change the fact that he used it as a dimension), and not the other way around - namely, that time is just the measure of rates of orbit, or of movement of hands on a clock.

 

[Dave_3of5]

Hey my first post here.

Ive not read all this post so ill just post my view.

Time has no direction. i.e. past is not really past.

I know this sounds a bit weird saying past is notr really past is a contradiction. What I am saying is there is no futre or past only present this would eliminate all the questions that arise about paradox.

To travel back in time IS impossible -imo- as time has no direction in fact atm its not even going forward.

What we measure as time isn't really time its another component of space -Relativity-.

Its better if I do this visually:


A ---------------------------------> B


To get from point a to b you have to move period which means what we call distance AND what we call time.

So to do the opposite is impossible because A is know a different point in space time that what moving from a to b was.

Its hard to explain but mentats I am agreeing with you, you can't travel back in time, basically cause you can't travel back in space.

Edit: Read the post about metabolism and i have a question:
So can i reverse my metabolism?

 

[Messiah]

Originally posted by Mentat
This is written perfectly backward, and your spatial analogy proves it. Change is like "inches". Inches measure the spatial dimensions, while rate of change measures the time dimension. The reasoning of your last question, when applied to the spatial analogy, would read: "What does space do, if it doesn't measure inches?".

False analogy -
Space is not the same as distance - distance is a measurement, space is an existence. Try again.

 

[Mentat]

Originally posted by Messiah
False analogy -
Space is not the same as distance - distance is a measurement, space is an existence. Try again.

Exactly! Space is not the same as distance, just as time is not the same as change. Now, do you see why I've been debating against you? If time is a dimension, then it cannot also be a measurement - as you already know to be true of space.

 

[Mentat]

Originally posted by Dave_3of5
Hey my first post here.

Ive not read all this post so ill just post my view.

Time has no direction. i.e. past is not really past.

I know this sounds a bit weird saying past is notr really past is a contradiction. What I am saying is there is no futre or past only present this would eliminate all the questions that arise about paradox.

To travel back in time IS impossible -imo- as time has no direction in fact atm its not even going forward.

What we measure as time isn't really time its another component of space -Relativity-.

Its better if I do this visually:


A ---------------------------------> B


To get from point a to b you have to move period which means what we call distance AND what we call time.

So to do the opposite is impossible because A is know a different point in space time that what moving from a to b was.

Its hard to explain but mentats I am agreeing with you, you can't travel back in time, basically cause you can't travel back in space.

Edit: Read the post about metabolism and i have a question:
So can i reverse my metabolism?

A hearty WELCOME!, Dave_3of5.

Yes, your point has great merit. Alias has been trying to make a similar point, and I entirely agree with the idea that there is no past or future. My reasoning has always been that, in order for something to exist (as in, "exist at the present moment"), it must be in the present, not the past or future. The future hasn't come into existence yet, and the past no longer exists.

 

[Michael F. Dmitriyev]

Originally posted by Mentat
...
My reasoning has always been that, in order for something to exist (as in, "exist at the present moment"), it must be in the present, not the past or future. The future hasn't come into existence yet, and the past no longer exists.

Mentat
You are right here.
The Universe exists in realities in current of the quantum of time which it is possible to consider as " present time". This is advantageously with an energy standpoint. The unceasing processes, what they seem us, has require the unmeasuredly greater energy. The Nature can not be such profligate.

 

[Michael F. Dmitriyev]

Hereinafter content of a proposition. The People have long ago understood that a pulsed Action more effectively than unceasing one. The advantages of digital technology before analog were realized recently. If the Nature does saves Energy that why must be squander on other essences which is realized by people? I keep in mind Space and Time. Probably the Nature can not allow billions of light years to Space and just the same (!) number of the years of Time of existence. Such a System just has not controllability. The Nature has found such decision:
" And God had created a light. And God has seen a light that he is good.." This papers had been writed the thousands of years ago, but nobody has not understood their sense hitherto, regrettably.
Hereinafter, in accordance with text of the papers, God had created all objects of universe. What kind of the material was used it is possible to guess.
Exactly the Light solves all problems.
Our life in Universe this is a Light Show, has realized on the most high digital technology. It obeys to a single law. This is a Law of the conservation of Time. He causes a set of a powers and phenomenas for compensation and counteraction in an effort of any deviation. Including not known to people yet. By the way, a digital technologies this is the Information technologies. With all characteristics and possibilities of Information . I think we know far from all.
Considering said above, I'll not become to do a hard conclusions about possibilityes of information technology. While, may be.

 

[Messiah]

Originally posted by Mentat
Exactly! Space is not the same as distance, just as time is not the same as change.

The analogy is valid.

Distance is a MEASUREMENT of space.
Time is a MEASUREMENT of change.

 

[Mentat]

Originally posted by Messiah
The analogy is valid.

Distance is a MEASUREMENT of space.
Time is a MEASUREMENT of change.

If you really think this, then why do we call it "spacetime"? Why don't we call it "spacechange"? Space is a set of dimensions, and can thus be measured. Time is supposed to be a dimension also (hence they couple it with "space" in "spacetime"). However, if you think that it is really change that is the dimension, being measured, then why isn't it called "spacechange"?

 

[Messiah]

Originally posted by Mentat
If you really think this, then why do we call it "spacetime"? Why don't we call it "spacechange"? Space is a set of dimensions, and can thus be measured. Time is supposed to be a dimension also (hence they couple it with "space" in "spacetime"). However, if you think that it is really change that is the dimension, being measured, then why isn't it called "spacechange"?

I don't call it spacetime. Space exists in spatial dimensions. The word dimension denotes or infers a spatial relationship. I you want to coin some other use for the word 'dimension', a qualifying modifier would be appropriate...or you could call it something different like - 'volumechange'.

 

[Mentat]

Originally posted by Messiah
I don't call it spacetime. Space exists in spatial dimensions. The word dimension denotes or infers a spatial relationship. I you want to coin some other use for the word 'dimension', a qualifying modifier would be appropriate...or you could call it something different like - 'volumechange'.

I didn't coin the word, "spacetime". It was coined by the physicists who realized that time was also a dimension.

 

[Locutus]

Originally posted by Messiah
The word dimension denotes or infers a spatial relationship.

The word dimension describes a state of existence. Dimensions are not merely spatial measurements, because those are relative. Dimensions are almost entirely unrelated to all other ways of describing an object. For example, when describing the pen on my desk, I could say that it is about 7" in length. I could be mistaken, however, due to the effects of the doppler effect and relativity as the Earth is moving constantly. For example, a man driving past my house at 50% the speed of light would see the pen as much longer because his vision of it would be skewed. Dimensions are not the same way. I can conclude with absolute certainty that my pen has three dimensions (although they may be immeasurable, it does have a length, width, and height). Any observer in the same dimension as I would agree.

Thus, dimensions cannot be compared to other measurements, for other spatial measurements are a consequence of dimensional properties.

 

[Royce]

Time is a dimension just as east-west or up-down is a dimension. It is, it exists with or without us or if we measure it. We exist in space and in time which is redundant. If we exist in space we exist in time. - If we exist in time we exist in space.
If I go East does North, South and West cease to exist? If I go East does that mean that the only possible direction of motion is East? I don't think so; but to my perception since I can only see NOW and see EAST then to me and relative to me they no longer exist in my perception. I can smoothly change my direction and go West or North without having to change the motion of the universe. Simply because I, with my 3 dimensional brain cannot concieve of, nor adaquately discribe with words, the possiblity of moving but one direction in a smooth fashion along the time dimention doesn't make any other movement impossible. I am free to move in any direction along all of the other dimentions. What make this "Time" forth dimention different than all 3 of the others in spacetime?

 

[Mentat]

Originally posted by Royce
Time is a dimension just as east-west or up-down is a dimension. It is, it exists with or without us or if we measure it. We exist in space and in time which is redundant. If we exist in space we exist in time. - If we exist in time we exist in space.
If I go East does North, South and West cease to exist? If I go East does that mean that the only possible direction of motion is East? I don't think so; but to my perception since I can only see NOW and see EAST then to me and relative to me they no longer exist in my perception. I can smoothly change my direction and go West or North without having to change the motion of the universe. Simply because I, with my 3 dimensional brain cannot concieve of, nor adaquately discribe with words, the possiblity of moving but one direction in a smooth fashion along the time dimention doesn't make any other movement impossible. I am free to move in any direction along all of the other dimentions. What make this "Time" forth dimention different than all 3 of the others in spacetime?

My new good buddy!

It seems obvious to us, Royce, but others don't see it that way, for some reason.

 

[wimms]

No, Time is not just a dimension. Its what enables such concepts as "exist" or "move" in the first place. If I stopped timeflow in your timeframe now, and did let it continue in about 48 hours, you wouldn't feel or even notice anything. So, you see, time is very subjective thing. There exists no time if you are not around counting it. And there is no way you could go back, as its not you who's time you have to turn back, but mine.

To move, needs time. If it doesn't take time, then you must be at 2 places at once, or more correctly, there is no space between these two places. Spatial dimensions don't make sense without time, you couldn't move, you couldn't exist.

When you move East, you cease to exist at point you were before. While you exist into the future, past ceases to exist.

 

[Locutus]

Originally posted by wimms
No, Time is not just a dimension. Its what enables such concepts as "exist" or "move" in the first place. If I stopped timeflow in your timeframe now, and did let it continue in about 48 hours, you wouldn't feel or even notice anything. So, you see, time is very subjective thing. There exists no time if you are not around counting it. And there is no way you could go back, as its not you who's time you have to turn back, but mine.

To move, needs time. If it doesn't take time, then you must be at 2 places at once, or more correctly, there is no space between these two places. Spatial dimensions don't make sense without time, you couldn't move, you couldn't exist.

When you move East, you cease to exist at point you were before. While you exist into the future, past ceases to exist.

... you still haven't told us why time is "not just a dimension". And some of your arguments aren't 100% true. For example, your second paragraphs forgets the uncertainty principle. Photons travel at the speed of light, therefore do not expend time while moving. Because of the uncertainty principle, photons can be detected in two places at once! But that does not mean that there is no space between them.

All in all, time is just a dimension. The only thing special about it is that it is only linear (1-dimensional), whereas space is (3-dimensional). This fact alone is the best explanation for a lot of your arguments.

 

[dr-dock]

construction of time(time backward travel is possible)

say one system is regulated with F=PS
F=force
P=presure
S=surface
the three (F,P,S) is legal event if it respects the law
say you start from (F1,P1,S1) and endup in (F2,P2,S2)
the vector (dF,dP,dS)
in (F1,P1,S1) is (P1*dS+S1*dP,dP,dS)
and
in (F2,P2,S2) is (-P2*dS-S2*dP,-dP,-dS)
if you want the shortest distance from event1 to event2 it has to be
F=a(P1*dS+S1*dP)-b(P2*dS+S2*dP)=ab*dP*dS and
P=(a-b)dP and
S=(a-b)dS or
a(dF,dP,dS)(1)-b(dF,dP,dS)(2)=(F,P,S)
now find b(a);
b1=-0.5(P1/dP)-0.5(S1/dS)-0.5*sqrt(sqr((P1/dP)+(S1/dS))-8a);
b2=-0.5(P1/dP)-0.5(S1/dS)+0.5*sqrt(sqr((P1/dP)+(S1/dS))-8a);
now you get:
b=f(a)
F=f1(a,P1,P2,S1,S2)
P=f2(a,P1,P2)
S=f3(a,S1,S2)
where a is pure number and it is the quantum of time.
assign seconds to a and you get dimension time.

NOW da>0 MEANS FORWARD IN TIME WHILE da<0 MEANS BACKWARD IN TIME.
da=0 means time is frozen/no changes.
you see my concept of time is slightly different from the common one.

 

[Messiah]

Originally posted by Locutus
The word dimension describes a state of existence. Dimensions are not merely spatial measurements, because those are relative. Dimensions are almost entirely unrelated to all other ways of describing an object. For example, when describing the pen on my desk, I could say that it is about 7" in length. I could be mistaken, however, due to the effects of the doppler effect and relativity as the Earth is moving constantly. For example, a man driving past my house at 50% the speed of light would see the pen as much longer because his vision of it would be skewed. Dimensions are not the same way. I can conclude with absolute certainty that my pen has three dimensions (although they may be immeasurable, it does have a length, width, and height). Any observer in the same dimension as I would agree.

Thus, dimensions cannot be compared to other measurements, for other spatial measurements are a consequence of dimensional properties.

The measurement of a spatial relationship is independent of observation. Just because you 'observe' something which is altered between the object or process and the senses with which you view it does not change the 'reality' of the phenomenon...it just changes how you perceive it.

 

[Locutus]

Originally posted by Messiah
The measurement of a spatial relationship is independent of observation. Just because you 'observe' something which is altered between the object or process and the senses with which you view it does not change the 'reality' of the phenomenon...it just changes how you perceive it.

You're right, but this is what I was trying to say in my original post: that observers may percieve the physical existence of an object differently, yet they do agree on the number of dimensions. They must agree because dimensions cannot be distorted in such a way (relativity, etc) in free-moving space.

 

[wimms]

Originally posted by Locutus
... you still haven't told us why time is "not just a dimension". And some of your arguments aren't 100% true. For example, your second paragraphs forgets the uncertainty principle. Photons travel at the speed of light, therefore do not expend time while moving. Because of the uncertainty principle, photons can be detected in two places at once! But that does not mean that there is no space between them.

What photons "feel" is completely outside our world. It takes billions of years to reach us from stars, would you agree? If it took nanosecond, would we call it lightyears? Time for photons might flow differently, for them, ther might be no space. Uncertainty principle doesn't say that conservation laws doesn't hold, only that you can't measure any more precisely.
One same unit of energy can't be in two places at once, its either two photons, or detection error.

Please try to define concept "exist", then concept "move", then concept "distance" and "interact" in terms that never ever needs time.
After you try you might understand why 3-dimensional space does not make any sense without time. Mathmatical 3-space does not "exist", it is imaginary. We are in real world, we exist and interact.

 

[Locutus]

Originally posted by wimms
One same unit of energy can't be in two places at once, its either two photons, or detection error.

Detection, however, is everything. Reality is a wave function fluctuating with all possible outcomes until it is observed, at which time the act of observation disrupts the wave function and yields a definite outcome (Schrodinger's cat...).

What photons "feel" is completely outside our world. It takes billions of years to reach us from stars, would you agree? If it took nanosecond, would we call it lightyears? Time for photons might flow differently, for them, ther might be no space. Uncertainty principle doesn't say that conservation laws doesn't hold, only that you can't measure any more precisely.
Please try to define concept "exist", then concept "move", then concept "distance" and "interact" in terms that never ever needs time.
After you try you might understand why 3-dimensional space does not make any sense without time. Mathmatical 3-space does not "exist", it is imaginary. We are in real world, we exist and interact.

You bring up an interesting point - the way a photon "percieves" the universe. First of all, a photon travels at the speed of light. Time dilation predicts that something traveling the speed of light cannot measure time. Therefore, time MAY flow for photons, as you said, but it would be irrelevant because there would be no means of detection. By the same token, if one were to measure the position of a photon, the same problem occurs. Since the photon is constantly travelling, its position is in quantum flux analagous to the aforementioned wave function. When an observational attempt is made, the photon is shown to be in two places at once.

Is this logically erronous? Yes, but it is the reality of our universe.

 

[RuroumiKenshin]

Can't traveling to the past be solved with the multiple history theory?

 

[RuroumiKenshin]

Originally posted by wimms
No, Time is not just a dimension. Its what enables such concepts as "exist" or "move" in the first place. If I stopped timeflow in your timeframe now, and did let it continue in about 48 hours, you wouldn't feel or even notice anything. So, you see, time is very subjective thing. There exists no time if you are not around counting it. And there is no way you could go back, as its not you who's time you have to turn back, but mine.

Neurologically speaking, time is the function of the interval between each electrical charge between every straitial neuron that passes through the stratium.
Time always existed. Take, for an example, the big bang. No living thing was in existence when it happened. Yet, it took time to expand. We were not there to record its time. Therefore, time exists and it its existence is not based on our existence.

To move, needs time. If it doesn't take time, then you must be at 2 places at once, or more correctly, there is no space between these two places. Spatial dimensions don't make sense without time, you couldn't move, you couldn't exist.

Here you contradict your above statement.

 

[wimms]

Originally posted by Locutus
Detection, however, is everything. Reality is a wave function fluctuating with all possible outcomes until it is observed,

Detection is interaction. It preassumes time. Read your words: reality "is", "wave", "function", "fluctuating", "until", "observed". None of these terms obviously depends upon concept of time. Instead, when that wavefunction collapses, we detect concept of time, right? See, however much you try, you can't get rid of Time. Its fundamental. Not just a measure. You can get rid of any spatial dimension, or add some, and construct something that could possibly exist. But as soon as you remove Time, you remove concept "exist" - its impossible.

You bring up an interesting point - the way a photon "percieves" the universe. First of all, a photon travels at the speed of light. Time dilation predicts that something traveling the speed of light cannot measure time. Therefore, time MAY flow for photons, as you said, but it would be irrelevant because there would be no means of detection. By the same token, if one were to measure the position of a photon, the same problem occurs. Since the photon is constantly travelling, its position is in quantum flux analagous to the aforementioned wave function. When an observational attempt is made, the photon is shown to be in two places at once.]

First of all, photon does NOT travel at speed of light. Its speed depends on medium. Second, time dilation equations are undefined for case of speed of light, that is they do not work at that range. They stop being equations. They produce crap. And afterall, GR predicts that nothing can travel at speed of light in first place.

Assumption that photon has no timeflow defined in relation to our timeframe, is not warranted. And that's why imo:
We know that photons can be years inflight, being lost with reference to both source and target. Therefore photons can not be outside our space/time. Being in photons shoes might have other local time flow, but in no way is it 0. For photon to travel infinite distance in our terms in 0 time in its terms means that photon will not interact ever with anything in our world. If it was true, we would have to perceive photons differently, they'd either not exist, or exist as lines of infinite length and propagate at infinite velocity. This is not what we observe.
Anything that is outside time/space must be for us either nonexistent, or allpervasive always. There is no other possibility.
There might be a phenomena with such properties we don't know yet, but its not the photons themselves. They are from this world, they are finite. That doesn't mean that what they perceive is not completely different than that of us.

You just shouldn't forget that time stopping to zero is enormously strong statement.

Is this logically erronous? Yes, but it is the reality of our universe.[/B]

No, its reality of our physics models. We don't even know if photon exists in the first place.

MajinVegeta, I don't see contradiction. Please show it more clearly.

As to multiple history ideas, I'd think this analogy. Game of chess has enormous possible gameplays. Do they all *exist*? No, there are that many possibilities, but only that few will ever realize. Its not that there is some chessboard that permanently plays all possible chess games (fluctuates), and we occasionally take a look (collapse). One must make distinction between imaginary possibilities, and reality that exists now and here.

 

[Mentat]

Originally posted by wimms
Detection is interaction. It preassumes time. Read your words: reality "is", "wave", "function", "fluctuating", "until", "observed". None of these terms obviously depends upon concept of time. Instead, when that wavefunction collapses, we detect concept of time, right? See, however much you try, you can't get rid of Time. Its fundamental. Not just a measure. You can get rid of any spatial dimension, or add some, and construct something that could possibly exist. But as soon as you remove Time, you remove concept "exist" - its impossible.

First of all, photon does NOT travel at speed of light. Its speed depends on medium. Second, time dilation equations are undefined for case of speed of light, that is they do not work at that range. They stop being equations. They produce crap. And afterall, GR predicts that nothing can travel at speed of light in first place.

Assumption that photon has no timeflow defined in relation to our timeframe, is not warranted. And that's why imo:
We know that photons can be years inflight, being lost with reference to both source and target. Therefore photons can not be outside our space/time. Being in photons shoes might have other local time flow, but in no way is it 0. For photon to travel infinite distance in our terms in 0 time in its terms means that photon will not interact ever with anything in our world. If it was true, we would have to perceive photons differently, they'd either not exist, or exist as lines of infinite length and propagate at infinite velocity. This is not what we observe.
Anything that is outside time/space must be for us either nonexistent, or allpervasive always. There is no other possibility.
There might be a phenomena with such properties we don't know yet, but its not the photons themselves. They are from this world, they are finite. That doesn't mean that what they perceive is not completely different than that of us.

You just shouldn't forget that time stopping to zero is enormously strong statement.
No, its reality of our physics models. We don't even know if photon exists in the first place.

MajinVegeta, I don't see contradiction. Please show it more clearly.

As to multiple history ideas, I'd think this analogy. Game of chess has enormous possible gameplays. Do they all *exist*? No, there are that many possibilities, but only that few will ever realize. Its not that there is some chessboard that permanently plays all possible chess games (fluctuates), and we occasionally take a look (collapse). One must make distinction between imaginary possibilities, and reality that exists now and here.

Possibilities exist, here and now, otherwise how could I be conceiving of them, here and now?

 

[Locutus]

Originally posted by wimms
You can get rid of any spatial dimension, or add some, and construct something that could possibly exist. But as soon as you remove Time, you remove concept "exist" - its impossible.

Yes, but this is also true for space. If you remove all spatial dimensions, there is no existence either. If you remove one spatial dimension, things can still exist, but not if you remove all of them. The fact that the universe can't exist without its time dimension stems from the fact that time is one-dimensional. If there were multiple time dimensions, we could add/subtract them the same way we could add/subtract spatial dimensions.

 

[Mentat]

Originally posted by Locutus
Yes, but this is also true for space. If you remove all spatial dimensions, there is no existence either. If you remove one spatial dimension, things can still exist, but not if you remove all of them. The fact that the universe can't exist without its time dimension stems from the fact that time is one-dimensional. If there were multiple time dimensions, we could add/subtract them the same way we could add/subtract spatial dimensions.

Very good point.

 

[RuroumiKenshin]

In order for us to travel to the past, would the future already need to exist?