Time doesn't exist...?

[Vox]

You are right in that time does not have to exist as a dimension for time intervals to exist. Time is an arbitrary measure of change. Material entities objectively exist. They have physical dimensions and relationships to other material objects. And the objects, and their relationships, change. From that we abstract the concepts of time, space, momentum, inertia etc... These are just concepts that describe aspects of reality.

 

If we "try to go to "now"" as it actually is only what exist in cosmos "all the time " ;-) It can not contain any "time" itself as it is not the past nor the future..we can surely record time in past tense but now is consisting no time itself as all is just now.

 

I would compre time to be similar abstract as "North" and "South" or "up" and "down" in Cosmos, we as humans have agreed these to exist but they are not existing in real Cosmos

[Rade]

If we "try to go to "now"" as it actually is only what exist in cosmos "all the time " ;-) It can not contain any "time" itself as it is not the past nor the future..we can surely record time in past tense but now is consisting no time itself as all is just now

I agree. The "now" is a "moment" such as []. Time = that which is intermediate between moments []. So, a picture of time and three moments:

 

....<--- time ---->[]<--------time------->[]<------time----->[]<-----time ----->.....

 

Movement of time to the past applies to antimatter (see Feynman interpretation of Dirac equation for antimatter); movement of time to the future is for matter. See that each moment or now [] is both unique (different color) but also identical (same shape). This is a very important attribute of the "now" or moment.

 

There must always be time between moments [], moments cannot touch such as [][]. Why ? For same reason that a line is not made of points, a line is made of smaller lines--always. Just as points are always outside of the line, the "now" or moment [] is outside of time. Time can always be divided because time is continuous and infinite. For matter, each moment or now [] is where the future is transformed into the past. For antimatter, each moment [] is where the past is transformed into the future. I claim the transformation has magnitude of "Planck Time" (smallest quantum time possible), which is completely different concept of "time" than that which is between moments [].

[Vox]

I agree. The "now" is a "moment" such as []. Time = that which is intermediate between moments []. So, a picture of time and three moments:

 

....<--- time ---->[]<--------time------->[]<------time----->[]<-----time ----->.....

 

Movement of time to the past applies to antimatter (see Feynman interpretation of Dirac equation for antimatter); movement of time to the future is for matter. See that each moment or now [] is both unique (different color) but also identical (same shape). This is a very important attribute of the "now" or moment.

 

There must always be time between moments [], moments cannot touch such as [][]. Why ? For same reason that a line is not made of points, a line is made of smaller lines--always. Just as points are always outside of the line, the "now" or moment [] is outside of time. Time can always be divided because time is continuous and infinite. For matter, each moment or now [] is where the future is transformed into the past. For antimatter, each moment [] is where the past is transformed into the future. I claim the transformation has magnitude of "Planck Time" (smallest quantum time possible), which is completely different concept of "time" than that which is between moments [].

 

Nicely crafted!

[Qfwfq]

The past is what no longer exists, therefore it does not exist.

 

The future is what does not yet exist, therefore it does not exist.

 

The present is the mere boundary between past and future; being no more than the boundary between two inexistent things, it cannot exist.

 

Time is composed of past, present and future, three things none of which exist, so it does not exist.

:hyper:

 

Movement of time to the past applies to antimatter (see Feynman interpretation of Dirac equation for antimatter); movement of time to the future is for matter.

:umno:

 

That's not how PCT works, really. In interpreting the mathematicl formalism, the same element could in principle be either a particle going one way or antiparticle going the opposite way. The physical interpretation that make sense is whichever goes according to the passing of time. In the symbolism of Feynman diagrams, the element is an oriented line and a comparison of the t coordinates of the vertices which it joins determines the interpretation. In the equations the time ordering is sorted out by the Dyson T-product. Due to the tie between the sign of energy and that of [imath]\Delta t[/imath] this apparatus replaces the fictuous sea of positrons and hole theory.

[Rade]

Time is composed of past, present and future, three things none of which exist, so it does not exist.

Well, I do not agree with your view of what time is composed of--whether or not it exists. As I stated above, time is what is intermediate between the three moments (past, present, future). Consider any line ___________________. Would you claim that the line is "composed" of past points, future points, present points ? Of course not. You would claim that a long line ______________ is composed of smaller lines ____ _____ ____ TIME IS NOT COMPOSED OF MOMENTS, TIME IS COMPOSED OF TIME INTERVALS. Moments (past, future, present) are to time as points are to a line.

 

That's not how PCT works, really

OK, thank you for your interpretation.

 

But, as stated below, Feynman really did claim that his interpretation of the Dirac antimatter was that it can be viewed as propagating backward in time (his direct 1985 quote on the topic is in blue below). In my post above I was referring to what Feynman claimed about antimatter and how it propagates in time. See this discussion from internet http://arxiv.org/abs/physics/9812021v2

 

R. P. Feynman (3, 4, 5) developed earlier work by Stueckelberg (6) to produce the Feynman-Stueckelberg Interpretation of antimatter. This interpretation states that all the properties of antimatter are consistent with the view that antimatter and matter are identical except that their particles move in opposite directions in time. This view has never been refuted, but it is seldom discussed. The textbooks devote a few paragraphs to the topic: for example "Quarks and leptons" by Halzen and Martin (7). Yet the concept was central to Feynman's work in quantum electrodynamics. J.J. Sakurai's textbook (8) praises the simplicity and elegance of Feynman's approach, pointing out its mathematical equivalence to Tomonaga and Schwinger's more conventional and complex version. Sakurai prefers to regard Feynman's graphical method as a convenient pictorial device, rather than accept the motion of antiparticles backward in time as a suitable foundation for quantum electrodynamics. Interestingly, Sakurai bases his view not on the experimental unreality of motion backward in time, but on avoiding its "logical disadvantages". For similar philosophical reasons, physicists regard Feynman's version as "unphysical", preferring particles of opposite charge, for example, proceeding as usual in time, yet they also want time to be symmetrical.

 

Throughout Feynman's career he insisted that no experiment could detect a difference between his version of antimatter and the conventional one. As late as 1985, three years before his death, in his book "QED" (9) he stated that "every particle in Nature has an amplitude to move backwards in time, and therefore has an antiparticle". On the same page, in a footnote he says that antiparticles can be easily made and kept for weeks, so he had no problem with antiparticles moving backwards in time indefinitely. It is hard to find another example of a physicist of such legendary status being in a minority of one on his fundamental insight which had never been disproved. Feynman's view derived from Einstein's version of Lorentz invariant symmetry, together with Feynman's contention that the final probability of some quantum event was the square of the sum of the amplitudes of all possible paths to the result. Such paths included backward in time and faster than light paths. Indeed, the phenomenal accuracy of quantum electrodynamics is, according to Feynman, the result of painstaking calculation of more and more complex and unlikely paths, and adding their contribution to the result. He saw his theory as a marriage of quantum mechanics and relativity.

 

From our viewpoint of events proceeding from the past to the future, the general distaste for the Feynman-Stueckelberg interpretation is understandable, but is it justified? Imagine a physicist at time T1 creating an electron and a positron from a photon, storing them until time Tn when the antiparticle is annihilated by another electron. He describes the situation as negatively charged, positive energy electrons and a positively charged, negative energy positron, all moving forward in time. Feynman describes three otherwise identical electrons, one moving backwards in time. R. Penrose (10, 11) has popularized the concepts of unitary, deterministic evolution in time according to the Schrodinger equation, the "U-process", versus quantum state vector reduction, the "R-process", or collapse of the wave function. During the U-process, symmetric in time, a superposition of states exists in which all the possible fates of the two particles exist. Physicists insist that the Schrodinger equation is symmetric in time and has no preference for a particular now. Let us take this completely seriously. At some times T2, T3..... the physicist makes measurements and finds the two particles. For the antiparticle, moving backwards in time, superpositions of states must be available in the observer's future where it will exist at least until Tn when it appears, in order for it to move backward in time to be measured at ......T3, T2. For the electron, superpositions of states must be available in the observer's future at least until Tn when it disappears, in order for it to move forward in time to be measured at T2, T3..... What is the difference between these two situations? If the Schrodinger equation doesn't care about time direction between measurements why should we? Note that the Feynman diagram for the above process is the same as for the scattering of an incident electron by a photon which has previously produced a positron and electron pair, the positron going on to annihilate the incident electron (ref. 9, p.99), the remaining electron from the pair proceeding onward in time.

[Qfwfq]

As I stated above, time is what is intermediate between the three moments (past, present, future).

How do you consider past and future as being moments? The present separates time into past and future, which don't include it. By analogy, zero is between positive and negative real numbers.

 

Feynman really did claim that his interpretation of the Dirac antimatter was that it can be viewed as propagating backward in time (his direct 1985 quote on the topic is in blue below). In my post above I was referring to what Feynman claimed about antimatter and how it propagates in time. See this discussion from internet (http://arxiv.org/abs/physics/9812021v2):.

Man that's PCT that Feynman is talking about there. Can you expound on the "therefore" in that sentence? That discussion is a confused interpretation of his words, the sentence doesn't state that antiparticles go backwards in time. What I said yesterday is the "therefore" in the sentence; the antiparticle is a replacement for the time-reversed or negative energy particle, it is mathematically equivalent. Taking the math literally, you wouldn't have antiparticles at all.

 

Folks so often get it confused and I'm not surprised to read that misguided discussion, BTW the link doesn't seem to work.

[Rade]

Qfwfq...sorry about the link to the Feynman quote...here is one that should work:

 

[physics/9812021v2] Dark Matter, Antimatter and Time-Symmetry

 

==

 

Concerning your question about moments as they relate to time.

 

How do you consider past and future as being moments?

 

It would appear from this statement

 

Time is composed of past, present and future, three things none of which exist, so it does not exist.

 

that you find time to be composed of three parts, past time, present time, future time.

And you view the present time to be a type of boundary condition, so you appear to have this view, would this be correct ?

 

[past time] -> [present time] ->[future time]

 

==

 

This is not how I see the situation. My picture would look like this

 

....[past moment] <--(time)-->[present moment] <--(time)-->[future moment]....

 

==

 

So, I view "time" being relative to three "moments", past, present, future. Of course, we can also in this view discuss a "past time" (you would do this when you reach a future moment), and a "future time" (you would do this when you reach a present moment].

 

Note that my view allows for a possibility of time reversal.

 

==

 

Of course, my view of time and moments only makes sense in relation to something that has potential of "'movement". Without movement time makes no sense to me.

 

==

 

Let me use this example, and you can let me know where you disagree with me.

 

Suppose a quantum entity with a state that can be described using a wavefunction equation. We can view this state as having a unitary evolution (U) over time. Suppose we want to conduct two measurements on the state, and we call these state reductions ®. Our mind immediately forms concepts of "before" and "after" measurement, that is, a first measurement moment (R-before) and a second measurement moment (R-after). Thus we get this picture:

 

------(U)---->(R-----(U)---->(R-A)-----(U)------>

 

The state of (U) when it is intermediate between (R- and (R-A) is what I refer to as "time". Relative to this (U), (R- is a past moment and (R-A) is a future moment. Of course, each state reduction moment ® is outside of the unitary evolution (U), thus each moment is outside of time. So, this is what I mean when I say there is a "past moment" and a "future moment" in relation to "time".

 

Now, I consider each ® measurement event to itself have a begin and end. I view that what is intermediate to these two is what we call Planck Time. Thus, the time related to the unitary evolution (U) is completely different (yet closely connected via measurement) from Planck time.

 

Let me know where you disagree.

[Qfwfq]

And you view the present time to be a type of boundary condition, so you appear to have this view, would this be correct ?

I said a boundary.

 

My picture would look like this

 

....[past moment] <--(time)-->[present moment] <--(time)-->[future moment]....

 

==

 

So, I view "time" being relative to three "moments", past, present, future.

I don't see past and future as each being a moment.

 

Rade the last two steps in the argument mock presentism, which is the view that only the present exists. How can the boundary between two things exist, if neither of them exists?

[Boerseun]

Thermodynamics and the flow of entropy is a very convincing argument for the existence of such animals as "past" and "future". There must therefore be a point of transition, where the future turns into the past, or there would be no possible way for entropy to flow. That transitional point, where the future turns into the past, we handily call "now", or "the present". Any other speculation as to the existence or non-existence of time is merely philosophical gymnastics in the vein of the audible properties of trees falling in forests.

[jedaisoul]

Thermodynamics and the flow of entropy is a very convincing argument for the existence of such animals as "past" and "future". There must therefore be a point of transition, where the future turns into the past, or there would be no possible way for entropy to flow. That transitional point, where the future turns into the past, we handily call "now", or "the present".

I'm not sure why you exclude the possibility that thermodynamics and entropy are features of an ever changing present? The issue seems to me to be the view that the present is a "snapshot" of the universe, like a frame from a movie. The trouble with that sort of snapshot is that it omits all dynamic content. You see where everything is, but not where it is going. I see the present as including dynamic content, like velocity and momentum etc... In which case, I would suggest that the past and the future do not need to exist for thermodynamics and entropy to operate.

 

That, of course, is not evidence that the past and the future do not exist.

 

Any other speculation as to the existence or non-existence of time is merely philosophical gymnastics in the vein of the audible properties of trees falling in forests.

I disagree. The "tree falling" is a simple play on words, which depends on the meaning attributed to the work "sound". The existence of time as an entity in its own right, as opposed to time intervals, is a question which has scientific as well as philosophic importance. For example: If time existed as an entity in its own right, would it be possible for different objects to experience different amounts of time passing between two given events?

[Boerseun]

For example: If time existed as an entity in its own right, would it be possible for different objects to experience different amounts of time passing between two given events?

But they do experience different amounts of time passing between two given events, provided the two objects exist in two different inertial frames of reference.

[Qfwfq]

It looks like you misssed his point, he wasn't saying it isn't possible.

 

The trouble with that sort of snapshot is that it omits all dynamic content. You see where everything is, but not where it is going.

But that's not the way it is typically represented in mechanics.

I see the present as including dynamic content, like velocity and momentum etc...

You also need to include interactions, often summed up as the lagrangian or hamiltonian.

 

In which case, I would suggest that the past and the future do not need to exist for thermodynamics and entropy to operate.

 

That, of course, is not evidence that the past and the future do not exist.

The trouble is if one supposes they don't, and the present is only defined as the boundary between them.

 

That of course is not the only possible definition and at the same time presentism contains a few semantic issues too.

[jedaisoul]

But they do experience different amounts of time passing between two given events, provided the two objects exist in two different inertial frames of reference.

That is precisely my point. How could that be if time were an universal entity in its own right?

[Vox]

I agree. The "now" is a "moment" such as []. Time = that which is intermediate between moments []. So, a picture of time and three moments:

 

....<--- time ---->[]<--------time------->[]<------time----->[]<-----time ----->.....

 

Movement of time to the past applies to antimatter (see Feynman interpretation of Dirac equation for antimatter); movement of time to the future is for matter. See that each moment or now [] is both unique (different color) but also identical (same shape). This is a very important attribute of the "now" or moment.

 

There must always be time between moments [], moments cannot touch such as [][]. Why ? For same reason that a line is not made of points, a line is made of smaller lines--always. Just as points are always outside of the line, the "now" or moment [] is outside of time. Time can always be divided because time is continuous and infinite. For matter, each moment or now [] is where the future is transformed into the past. For antimatter, each moment [] is where the past is transformed into the future. I claim the transformation has magnitude of "Planck Time" (smallest quantum time possible), which is completely different concept of "time" than that which is between moments [].

 

Thinking visually.. if we remove the linear approach and apply the view where the colored frames still indicates the "Now" but it would be flow of colors totally replacing each other .. like piling up but there would not be pile existing (time) due state of now have changed/flowed completely within the now to another now within..so diffrent now would not "arrive outside of current now, New now would manifest within current now . So there would not be ""residue" left or intermidiate states"..if we assume that now do not contain time itself ..so "no time=now" changed/flowed to another "no time=now" within.

 

Although, This might be just playing with the words..your comments appriciated.

 

Also wondering from where the "Yesterday" could be found within reality if we can exist only in reality..how we could observe outside where we exist? Yesterday can not exist in the reality due now have been transformed to another reality within, without "residue left aside" which could be called yesterday?

 

My 2 cents..

[jedaisoul]

Also wondering from where the "Yesterday" could be found within reality if we can exist only in reality..how we could observe outside where we exist? Yesterday can not exist in the reality due now have been transformed to another reality within, without "residue left aside" which could be called yesterday?

This question seems to be the good old:

 

"If it takes time for light to reach us, and for us to comprehend what we are seeing, what we are seeing is the past. But how can that be if only the present exists?"

 

This "paradox" rests on the "snapshot" concept of the present that I've mentioned earlier. If we acknowledge that there is dynamic content in the present, the issue is resolved: E.g.:

 

time -->

A-----------------------B-C

 

An event occurs at time A, we see it at time B and we comprehend it at time C. by the time we comprehend it, the event is in the past and so no longer exists. But it DID exist at time A, and its effect (the light emission) continues to exist until it is absorbed by the eye at time B. Then it is converted into electro-chemical signals comprehended by the brain at time C. At time C neither the event at time A, nor the light absorbed at time B, exist. But their effect, the electro-chemical signals, DO exist. Hence there is no need for the past to exist for us to be able to see things that happened in the past. What we interact with now are the dynamic effects that exist in the present.

 

Does that make sense?

[Vox]

This question seems to be the good old:

 

"If it takes time for light to reach us, and for us to comprehend what we are seeing, what we are seeing is the past. But how can that be if only the present exists?"

 

This "paradox" rests on the "snapshot" concept of the present that I've mentioned earlier. If we acknowledge that there is dynamic content in the present, the issue is resolved: E.g.:

 

time -->

A-----------------------B-C

 

An event occurs at time A, we see it at time B and we comprehend it at time C. by the time we comprehend it, the event is in the past and so no longer exists. But it DID exist at time A, and its effect (the light emission) continues to exist until it is absorbed by the eye at time B. Then it is converted into electro-chemical signals comprehended by the brain at time C. At time C neither the event at time A, nor the light absorbed at time B, exist. But their effect, the electro-chemical signals, DO exist. Hence there is no need for the past to exist for us to be able to see things that happened in the past. What we interact with now are the dynamic effects that exist in the present.

 

Does that make sense?

 

I would rediscribe .. let´s take the point where photon hits the surface of the eye/cell.. let´s set that as realitypoint but at the same time it will the point where our delay of sensing consciously starts..that point of reality is funneled now to consiouss system and "travelling" towards conscious regognition ..and then sensing process ends to consciouss thought of the light, that councious manifest happens is the reality but combined content of different nows are tranformed to linear memory experience and thought of time is created? it is yesterday and only in our system/memory as out of sync of that start point reality. So this would be the the delay of our conscious observing at it is the delay /memory part which by memorizing diffrent nows creates illusion of time elapsed?

So we can never be conscioussly perfectly in sync with reality. Best described as blurry image if two snapshots of "reality" would be laid over each other..? So system delay is introduced and time is created in mind?..

Our "components"/ we as an event are/is existing in sync with reality, all the things manifest in the reality also the output point of the consiousness but the content of the thought ( illusion?) is out of sync with reality.

 

And going a bit dangerous waters, but what the heck :doh:

 

Could we state that thought is not existig as whole in reality, we are as components/event but not our thoughts/consciouss mind sytem? As we think/sense there will be delay before it is manifest itself? So thought patterns are an illusion?..just "perfect" reality energy states/vibrations from which our brain combines and creates an illusion (illusion of time also)?

[jedaisoul]

Vox,

 

I'm at a loss to understand what point you are making. It seems an awfully complicated way of saying that there is a delay between what the eye sees and what the brain comprehends. What is the big deal? We know that the CMBR that reaches us today, was emitted 13.7 billion years ago, but light from the Sun takes around eight minutes to reach us. So are we 13.7 billion years "out of sync with reality" or eight minutes? The question is nonsensical.

 

The whole idea of being in or out of sync with reality supposes that reality is, in this respect, "in sync" with itself. It isn't. These time delays between events happening and their effects on other objects are universal. But it, and we, ARE in sync in the sense that the whole process takes place in the present, including the delay in our perception.

 

You seem to be confusing the time elapsed between cause (Big Bang) and effect (CMBR) with a difference in when "now" is. They are just different "now"s.