Post by: MikeS on 26/03/2012 09:01:52
Time has two aspects. First, the arrow of time, it's direction. Second, the rate of flow or passage, the time dilation factor.
'Time' is what we percieve when something that travells at infinite speed (light in a vacuum) is 'slowed' to a finite speed. At infinite speed there is no causality at finite speed there is.
Why does light when unrestricted travel at infinite speed? We know that photons do not experience time. Therefore, in a sense they can be thought of as travelling at infinite speed. However, to travel at infinite speed implies a lack of causality which in turn implies no arrow or perhaps a double ended arrow to time. So, light to travel at infinite speed can only do so outside of time as we know it. Therefore, the concept of 'speed' becomes meaningless when talking about infinite speed.
The origins of Time.
Having established that Time has two aspects, the arrow and time dilation factor. Where do they come from? Obviously they are artefacts of the Universe. What does the Universe contain? Mass/energy, gravity and space-time.
We understand from GR that local time dilates near to a massive object due to it's gravity. (Local time as opposed to non-local time.) Therefore, one of the ingredients of time is gravity. Gravity slows light and gives it a finite speed.
We could measure the speed of light in the vacuum anywhere in the Universe and it would be the same. We can therefore use c as a clock. I would suggest the Universes master clock. What is light? Light (to the best of my knowledge) is the purest form of energy. A clock in an accelerated time frame runs faster. Obvious you might think but what does that actually mean. For that time frame to accelerate implies an input of energy. Therefore the other ingredient of time is energy.
Energy unrestricted would dissipate over maximum distance in zero time. But, under those circumstances both distance and time become meaningless concepts. Gravity introduces the concept of 'Time'. It introduces an arrow of time and the relationship between energy and gravity introduces a time dilation factor. Energy makes the clock run faster, gravity slows it down.
E=mc2 If we re-arrange this we get c2=E/m. If c can be used as a reference clock, which it can, then c represents the time dilation factor. In other words the time dilation factor (Td) is equal to energy divided by mass. Td=E/m. Which is what I have arrived at above.
Time is created by gravitational braking of the instantaneous dissipation of energy. For time to 'flow' energy must be consumed. No consumption of energy, no flow of time. Therefore, the arrow of time is entropy. All miner arrows are aspects of that.
Time within the Universe is both local and universal depending upon Td=E/m both locally and universally. Only if the energy/mass ratio of the Universe remains constant can Td remain constant. The energy/mass ratio does not remain constant. At this epoch mass is being converted into energy. That implies that time is speeding up (contracting) in relation to the past.
Time and gravity are so closely interwoven that it is impossible to talk about one without the other. It is therefore suggested that this post should be read in conjunction with http://www.thenakedscientists.com/forum/index.php?topic=43495.0
With apologies. When talking about time it is inevitable that certain words will be used in a confusing manner . For instance talking about the 'rate of flow' of time or 'passage of time' or 'speed of passage or flow' is technically incorrect but necessary due to the inadequacies of language.
Post by: Æthelwulf on 26/03/2012 09:38:02
First of all, there is no such thing as an arrow of time. It's a much-abused concept which goes back many years. I find links that can varify this. I usually make my own arguements however.
For instance, an arrow of time implies a directionality - which is linear in appearance. This could not be further from the truth considering that time only enters the equations through the appearance of a geometrical theory - the general theory of relativity. Time is not linear, more wobbly than flattened (but still remarkably flat due to precise measurements of space). To [presume] an arrow of time exists, would be like saying you are marking some point on a spacetime map and calling it the ''origin of the universe'', but there is no such place we can say everything came from, a so-called center of the universe. So how can one draw an arrow?
Instead, you'd need an infinite amount of arrows, each pointing in perpendicular directions throughout all of spacetime and call them the ''arrows of time.'' But this is unreasonable because it certainly cannot purport to a physical existence.
There cannot be an ''arrow of time.'' Unless by ''arrow'' we are somehow making the mistake we are projecting how we ''view'' time on the world at large. As has been noted before by myself, all the evidence points to time being a subjective phenomenon than a real physical one that pervades the universe. This is science that predicts this, not just my own contentions on it. So if by arrow of time, we really mean the psychological arrow of time (which is a real arrow) stating that time has a directionality about it, then we are making a mistake that such an arrow exists objectively of our experience of time.
Post by: Æthelwulf on 26/03/2012 09:47:31
Trust me, I've read more than what I reitterating here, I am just keeping it all to a minimum to give me some breath to talk.
From now on, I want you to start calling this ''Minkowski Space'' because that is what it is, this so--called ''space-time''. It is a four dimensional manifold that was mathematically realized by Einstein's teacher Minkowski after Einstein has formulated the theories of relativity. This was a later realization. Relativity worked fine before the united grounds between space and time.
Often I see arguements of change equalling time. Not only is this verbally wrong, but there is no such thing as a true time evolution in General Relativity - since you want to talk about space and time being united into one construction, maybe we should tackle this question of evolution in GR. Afterall, change therefore is not the same as the type of time evolution you might find in a quantum equation. This evolution allows you to shuffle spacetime coordinates about freely, a process called diffeomorphism invariance. So change is not described by your usual worldlines. Worldines are static, they have no past or future.
This is also a problem for the arrow of time, since it describes worldines. The corresponding equation crystalizes this problem when you quantize the EFE-equations. What you get back is the Wheeler de-Witt equation which describes timelessness on a Global Sense.
Post by: Æthelwulf on 26/03/2012 10:01:26
I don't know what you mean by this, but if there is any relevance, there is no such thing as an absolute clock.
''Why does light when unrestricted travel at infinite speed?''
I don't know if the photon's speed is exactly infinite, but if I get to the just of the point, it is because of the physical parameters of spacetime, called it's permittivity and permeability. We have
For a massless particle, this moves at the speed of light.
''Having established that Time has two aspects, the arrow and time dilation factor.''
I'm afraid you haven't for me. I accept dilation is an effect we measure using time, but time is only an instrument of measure. It was invented. It's not real. It only applies to our perception which seems to feel some ''flow of time''. Time doesn't even have a flow in physics.
''Energy makes the clock run faster, gravity slows it down.''
In what sense, because when I think of energy, I think of relativistic particles. Their frames of references are dilated as well.
''For time to 'flow' energy must be consumed. No consumption of energy, no flow of time.''
Again, I don't know what you mean. What is meant by consumption? That is an odd way to me to look at physical processes.
''Time and gravity are so closely interwoven that it is impossible to talk about one without the other. ''
It's perfectly possible to talk about gravity without time.
Post by: MikeS on 27/03/2012 09:30:03
I would be quite happy to answer all of your questions if we were at least on the same page but we are not.
At the start of your first post in this thread you say
"First of all, there is no such thing as an arrow of time."
Yes there is it's called entropy.
All processes no matter what use useful energy to do work and result in the remaining energy being of less use. This is the arrow of time and it is called entropy.
A simple example, a clock any type of clock, all types of clock use energy to tell the time. If we consider the clock to be a closed system then entropy within that system has increased with the passage of time.
I believe that is so self evident it requires no further explanation. If we cannot at least agree that there is an arrow of time then we are not likely to agree on anything to do with time.
Post by: Nizzle on 27/03/2012 09:57:38
All processes no matter what use useful energy to do work and result in the remaining energy being of less use. This is the arrow of time and it is called entropy.
That depends on your definition of useful and useless. I reckon photovoltaic cells and chlorophyll cells are doing a pretty good job at making energy more useful
Post by: Æthelwulf on 27/03/2012 12:00:34
ÆthelwulfWell, why haven't you refuted any statement like I have done with you?
I would be quite happy to answer all of your questions if we were at least on the same page but we are not.
At the start of your first post in this thread you say
"First of all, there is no such thing as an arrow of time."
Yes there is it's called entropy.
All processes no matter what use useful energy to do work and result in the remaining energy being of less use. This is the arrow of time and it is called entropy.
A simple example, a clock any type of clock, all types of clock use energy to tell the time. If we consider the clock to be a closed system then entropy within that system has increased with the passage of time.
I believe that is so self evident it requires no further explanation. If we cannot at least agree that there is an arrow of time then we are not likely to agree on anything to do with time.
Post by: MikeS on 27/03/2012 13:52:57
ÆthelwulfWell, why haven't you refuted any statement like I have done with you?
I would be quite happy to answer all of your questions if we were at least on the same page but we are not.
At the start of your first post in this thread you say
"First of all, there is no such thing as an arrow of time."
Yes there is it's called entropy.
All processes no matter what use useful energy to do work and result in the remaining energy being of less use. This is the arrow of time and it is called entropy.
A simple example, a clock any type of clock, all types of clock use energy to tell the time. If we consider the clock to be a closed system then entropy within that system has increased with the passage of time.
I believe that is so self evident it requires no further explanation. If we cannot at least agree that there is an arrow of time then we are not likely to agree on anything to do with time.
I did, your very first one.
Post by: MikeS on 27/03/2012 14:54:38
I never said useless, I said of less use. There is a difference. No it doesn't depend upon definition.All processes no matter what use useful energy to do work and result in the remaining energy being of less use. This is the arrow of time and it is called entropy.
That depends on your definition of useful and useless. I reckon photovoltaic cells and chlorophyll cells are doing a pretty good job at making energy more useful
The suns mass is held together by gravity. Gravitational energy forces the mass together increasing both its density and heat. This causes nuclear fusion. Fusion converts some of the suns mass into energy. Some of that energy does useful work. In the process the sun looses mass and useful energy. This is entropy.
Photvoltaic cells capture EMR (sunlight) and convert it into electricity. Electricity does work. Useful energy (sunlight) is used and energy of less use (essentially heat) is the result. This increases entropy.
Chlorophyll cells convert sunlight into chemical energy. The plant needs an input of energy (sunlight) to grow and function. Ultimately the plant dies and entropy increases. The energy that can be extracted from the dead plant tissue is less than the energy input and the missing energy is low grade and of little use.
In both cases the useful energy came from sunlight and in the process the sun lost fuel and entropy increased. Although there was in both cases an input of energy it came at the cost of an increase in overall entropy.
Post by: MikeS on 27/03/2012 15:46:12
''We could measure the speed of light in the vacuum anywhere in the Universe and it would be the same. We can therefore use c as a clock. I would suggest the Universes master clock. ''
I don't know what you mean by this, but if there is any relevance, there is no such thing as an absolute clock.
I never said there was but you could do an average of all local clocks.
''Why does light when unrestricted travel at infinite speed?''
I don't know if the photon's speed is exactly infinite, but if I get to the just of the point, it is because of the physical parameters of spacetime, called it's permittivity and permeability. We have
For a massless particle, this moves at the speed of light.
Light within the universe is not unrestricted. It has curved space-time to deal with.
''Having established that Time has two aspects, the arrow and time dilation factor.''
I'm afraid you haven't for me. I accept dilation is an effect we measure using time, but time is only an instrument of measure. It was invented. It's not real. It only applies to our perception which seems to feel some ''flow of time''. Time doesn't even have a flow in physics.
Strange then that clocks can measure it.
''Energy makes the clock run faster, gravity slows it down.''
In what sense, because when I think of energy, I think of relativistic particles. Their frames of references are dilated as well.
Yes their frames of reference are dilated as well. That's what local time is. Where I have said faster or slower that's in reference to a distant frame of reference.
''For time to 'flow' energy must be consumed. No consumption of energy, no flow of time.''
Again, I don't know what you mean. What is meant by consumption? That is an odd way to me to look at physical processes.
Consumed is perhaps a poor choice of words, used would be more appropriate.
''Time and gravity are so closely interwoven that it is impossible to talk about one without the other. ''
It's perfectly possible to talk about gravity without time.
Gravity affects time. Gravity is acceleration, an acceleration in time.
You can talk about gravity without time but you cannot explain gravity without time.
Gravity is acceleration. One of the components of acceleration is time. If time were not real there would not be gravity.
How would you account for gravity if time is not real?
Post by: imatfaal on 27/03/2012 15:50:22
Post by: Æthelwulf on 27/03/2012 17:01:20
''We could measure the speed of light in the vacuum anywhere in the Universe and it would be the same. We can therefore use c as a clock. I would suggest the Universes master clock. ''
I don't know what you mean by this, but if there is any relevance, there is no such thing as an absolute clock.
I never said there was but you could do an average of all local clocks.
''Why does light when unrestricted travel at infinite speed?''
I don't know if the photon's speed is exactly infinite, but if I get to the just of the point, it is because of the physical parameters of spacetime, called it's permittivity and permeability. We have
For a massless particle, this moves at the speed of light.
Light within the universe is not unrestricted. It has curved space-time to deal with.
''Having established that Time has two aspects, the arrow and time dilation factor.''
I'm afraid you haven't for me. I accept dilation is an effect we measure using time, but time is only an instrument of measure. It was invented. It's not real. It only applies to our perception which seems to feel some ''flow of time''. Time doesn't even have a flow in physics.
Strange then that clocks can measure it.
''Energy makes the clock run faster, gravity slows it down.''
In what sense, because when I think of energy, I think of relativistic particles. Their frames of references are dilated as well.
Yes their frames of reference are dilated as well. That's what local time is. Where I have said faster or slower that's in reference to a distant frame of reference.
''For time to 'flow' energy must be consumed. No consumption of energy, no flow of time.''
Again, I don't know what you mean. What is meant by consumption? That is an odd way to me to look at physical processes.
Consumed is perhaps a poor choice of words, used would be more appropriate.
''Time and gravity are so closely interwoven that it is impossible to talk about one without the other. ''
It's perfectly possible to talk about gravity without time.
Gravity affects time. Gravity is acceleration, an acceleration in time.
You can talk about gravity without time but you cannot explain gravity without time.
Gravity is acceleration. One of the components of acceleration is time. If time were not real there would not be gravity.
How would you account for gravity if time is not real?
A photon's speed is not infinite. In mathematical rigour it is a finite number called the Celeritas. There are no infinities contained in the equations, therefore it's speed cannot be infinite.
And for the clock thing, clocks are designed? Why is this so hard to understand? Man invented clocks to tick away completely subliminal durations we called ''time''. The very fact that you even brought clocks into this does not even persuade me to continue further.
Post by: MikeS on 27/03/2012 18:23:42
A photon's speed is not infinite. In mathematical rigour it is a finite number called the Celeritas. There are no infinities contained in the equations, therefore it's speed cannot be infinite.
And for the clock thing, clocks are designed? Why is this so hard to understand? Man invented clocks to tick away completely subliminal durations we called ''time''. The very fact that you even brought clocks into this does not even persuade me to continue further.
A photon does not experience time. That could be interpreted to mean it travels at infinite speed.
Yes clocks are designed. There are many different types of clocks all operating on different principles. Atomic, electronic, mechanical, speed of light, speed of nuclear decay etc. All of them together will record the same local time. Another set of identical clocks together in a different local time (different gravitational potential) will all record the same time but the two different sets of clocks will record a different passage of time. Obviously they are recording something that is the same for all of them but owes nothing to individual clock design. The thing they are recording is the passage of time.
If time does not exist what keeps each group of clocks synchronized with one another yet makes one group un-synchronized with the other? The amount of difference can be mathematically predicted. How do you account for that?
Subliminal implies the passage of time.
Perhaps you would like to answer the question from my last post.
How would you account for gravity if time is not real?
Post by: Æthelwulf on 27/03/2012 20:32:29
A photon's speed is not infinite. In mathematical rigour it is a finite number called the Celeritas. There are no infinities contained in the equations, therefore it's speed cannot be infinite.
And for the clock thing, clocks are designed? Why is this so hard to understand? Man invented clocks to tick away completely subliminal durations we called ''time''. The very fact that you even brought clocks into this does not even persuade me to continue further.
A photon does not experience time. That could be interpreted to mean it travels at infinite speed.
Yes clocks are designed. There are many different types of clocks all operating on different principles. Atomic, electronic, mechanical, speed of light, speed of nuclear decay etc. All of them together will record the same local time. Another set of identical clocks together in a different local time (different gravitational potential) will all record the same time but the two different sets of clocks will record a different passage of time. Obviously they are recording something that is the same for all of them but owes nothing to individual clock design. The thing they are recording is the passage of time.
If time does not exist what keeps each group of clocks synchronized with one another yet makes one group un-synchronized with the other? The amount of difference can be mathematically predicted. How do you account for that?
Subliminal implies the passage of time.
Perhaps you would like to answer the question from my last post.
How would you account for gravity if time is not real?
Well, if you want to get technical about this, a photon actually doesn't move at all. Saying a ''photon does not move in time'' as you stated, is actually the same (synonymous even) with the concept that a photon doesn't even move in space. In fact, if current scientific theory is right, a photon does not even possess a frame of reference to solve this problem.
Anyway, as for the clock, you are the one who said, 'observe the clock'. It's not as simple as that, in fact, time is not even a Hermitian Matrix, meaning it does not purport to an observable. What may be interesting however, this does not mean that time cannot be positive, unless we viewed time as an imaginary dimension, which Hawking admittedly has done. My arguement, including Markoupolou's, a Greek scientist who advocates the existence of Geometrogenesis, the idea that space arose late in the universes configuration, that what we really call ''fundamental'' is really the existence which precluded the existence itself of space and matter. In Geometrogenesis, matter and space exist within the low energy epoch. What is known, is that space must have emerged when the universe had grown quite old, it is not itself an artefect of the big bang, if the big bang that is the true explanation of creation.
Post by: Æthelwulf on 27/03/2012 20:33:34
Maybe the word should be defect?
Post by: MikeS on 01/04/2012 06:30:12
If time does not exist what keeps each group of clocks synchronized with one another yet makes one group un-synchronized with the other? The amount of difference can be mathematically predicted. How do you account for that?
Perhaps you would like to answer the question from my last post.
How would you account for gravity if time is not real?
Post by: Æthelwulf on 01/04/2012 13:14:55
Earlier in this thread you requested me to address specific points that you had made which I did. In my last post I asked you to address two points which you didn't. They were.
If time does not exist what keeps each group of clocks synchronized with one another yet makes one group un-synchronized with the other? The amount of difference can be mathematically predicted. How do you account for that?
Perhaps you would like to answer the question from my last post.
How would you account for gravity if time is not real?
Syncronization is a matter of relativity, not time itself.
Post by: MikeS on 02/04/2012 06:27:41
And that did not answer the question
"How would you account for gravity if time is not real?"
Post by: Æthelwulf on 02/04/2012 06:34:24
Relativity explains the difference in the two groups. It does not explain why all of the clocks in each group remain synchronized among themselves.
And that did not answer the question
"How would you account for gravity if time is not real?"
Why should I answer that last question?
All I need to do is point my finger in the way of GR and explain gravity in that way. Perhaps I need to remind you that GR is timeless.
Post by: Æthelwulf on 02/04/2012 06:35:53
Relativity explains the difference in the two groups. It does not explain why all of the clocks in each group remain synchronized among themselves.
And that did not answer the question
"How would you account for gravity if time is not real?"
Why should I answer that last question?
All I need to do is point my finger in the way of GR and explain gravity in that way. Perhaps I need to remind you that GR is timeless.
You just don't seem to be understanding the fact that GR is timeless - global time vanishes, changes are hard to define in a universe. You've concentrated on things like the abused ''arrow of time'' and ''time dilation'' and got lost in all it's mysticism.
Post by: MikeS on 02/04/2012 17:16:43
Anyone???
Post by: imatfaal on 03/04/2012 10:07:02
Post by: Nizzle on 03/04/2012 10:55:58
I would be very interested to hear anyone's simple explanation of gravity that does not include time? Gravity is acceleration. Acceleration is time dependent.
Anyone???
Gravity is more than acceleration I think. Because objects lying still on the ground with 0 acceleration are still subjected to gravity, otherwise they'd float. Acceleration can be used to simulate gravity, but it's not the same.
But that's besides the point. I can't explain gravity without time..
Post by: Æthelwulf on 03/04/2012 13:01:21
Post by: MikeS on 03/04/2012 15:25:21
Time in GR is difficult - you have worldlines and geodesics situated in a metric where time is just one of four dimensions (admittedly different sign). the worldline through spacetime of a test particle follows a route that is dependant on the curvature - it does not accelerate along this world line. the position and geometry of the worldline means that in 3d space an acceleration is measured, but in spacetime the particle "moves along" the worldline with its clock ticking normally.
Imatfaal
Good explanation.
The test particle follows a geodesic with it's clock ticking normally in its local time frame but according to an observer not in the test particles time frame it will be seen to accelerate as it enters successive time frames that are more and more dilated.
If I understand correctly that is the same as you have said above?
It still requires acceleration. The acceleration in this case is not 'in time' but 'of time' itself.
As each second is longer than its predecessor, so the test particle travels further. This is acceleration.
Post by: MikeS on 03/04/2012 15:50:02
I would be very interested to hear anyone's simple explanation of gravity that does not include time? Gravity is acceleration. Acceleration is time dependent.
Anyone???
Gravity is more than acceleration I think. Because objects lying still on the ground with 0 acceleration are still subjected to gravity, otherwise they'd float. Acceleration can be used to simulate gravity, but it's not the same.
But that's besides the point. I can't explain gravity without time..
No it's not. Gravity is acceleration. The ground is accelerating upwards through space-time. The ground is continuously travelling from a place where time is passing slowly to a place where time is passing faster. This is acceleration. If you place an accelerometer anywhere on the Earths surface at sea level it will give a readout of 1g acceleration.
You don't need to travel through any of the spacial dimension to accelerate. You only need to accelerate through time. This is gravity and it is what any large mass does.
That's why all objects fall at the same rate. In a sense they are not actually falling but it is the Earth that is accelerating towards them. It matters not whether it is a feather or a cannonball, the Earth accelerates toward them equally.
You might be interested to read my thread on gravity.
http://www.thenakedscientists.com/forum/index.php?topic=43495.0
Post by: MikeS on 03/04/2012 16:01:40
Gravity for me is simple. It is the presence of matter, which is the presence of curvature and is the presence of acceleration within the equations of relativity; this much he is partially correct, I've never truely doubted that. It's linking it directly with time which troubles me. I don't see time and gravity as synonymous objects. In fact, I see change, I don't see time per se. Only through the eyes of a mere human being, I can extrapolate that time is highly subjective and something I project as a ''feeling of past and future'' on the world outside. None of which actually exist.
My previous two posts explain why I believe, you can't talk about gravity without talking about time, or more correctly without talking about time dilation.
It is necessary to understand time dilation in order to understand gravity. Surely, if time did not exist, there could be no time dilation and therefore no such thing as gravity. Gravity exists and so does time.
Post by: Æthelwulf on 03/04/2012 21:04:42
Gravity for me is simple. It is the presence of matter, which is the presence of curvature and is the presence of acceleration within the equations of relativity; this much he is partially correct, I've never truely doubted that. It's linking it directly with time which troubles me. I don't see time and gravity as synonymous objects. In fact, I see change, I don't see time per se. Only through the eyes of a mere human being, I can extrapolate that time is highly subjective and something I project as a ''feeling of past and future'' on the world outside. None of which actually exist.
My previous two posts explain why I believe, you can't talk about gravity without talking about time, or more correctly without talking about time dilation.
It is necessary to understand time dilation in order to understand gravity. Surely, if time did not exist, there could be no time dilation and therefore no such thing as gravity. Gravity exists and so does time.
The dichotemy is much more complicated than that. If we were talking about time as being a local phenomenon, then yes this is true. If we are also talking time being experienced by Bradyons, or particles with mass, then time truely wasn't around until matter came out of the vacuum. But time for a universe, a universal global time vanishes. What is time then from the perspective of the universe if it does not exist globally? Is it only clocks moving below the speed of light that experience time, in which case the beginning of the universe certainly had no time and the end of the universe when all matter fields have returned to radiation fields, then the very future cone of our universe is also devoid of moving clocks.
Simply put, you can't have time without matter ... these moving relativistic clocks which tick off real time.
Post by: Æthelwulf on 03/04/2012 21:10:06
Post by: MikeS on 04/04/2012 07:00:19
I have answered most of your points in this thread.
http://www.thenakedscientists.com/forum/index.php?topic=43056.0
Gravity for me is simple. It is the presence of matter, which is the presence of curvature and is the presence of acceleration within the equations of relativity; this much he is partially correct, I've never truely doubted that. It's linking it directly with time which troubles me. I don't see time and gravity as synonymous objects. In fact, I see change, I don't see time per se. Only through the eyes of a mere human being, I can extrapolate that time is highly subjective and something I project as a ''feeling of past and future'' on the world outside. None of which actually exist.
My previous two posts explain why I believe, you can't talk about gravity without talking about time, or more correctly without talking about time dilation.
It is necessary to understand time dilation in order to understand gravity. Surely, if time did not exist, there could be no time dilation and therefore no such thing as gravity. Gravity exists and so does time.
The dichotemy is much more complicated than that. If we were talking about time as being a local phenomenon, then yes this is true. If we are also talking time being experienced by Bradyons, or particles with mass, then time truely wasn't around until matter came out of the vacuum. But time for a universe, a universal global time vanishes. What is time then from the perspective of the universe if it does not exist globally? Is it only clocks moving below the speed of light that experience time, in which case the beginning of the universe certainly had no time and the end of the universe when all matter fields have returned to radiation fields, then the very future cone of our universe is also devoid of moving clocks.
Simply put, you can't have time without matter ... these moving relativistic clocks which tick off real time.
There is little in the above that I do not agree with but my standpoint has not changed.
I agree that prior to the existence of mass, there was no time. [Others might not agree on that as photons are supposed to create gravity in which case mass would not be necessary for the existence of time.] However, one could debate whether before ,time, distance , speed and geometry all became meaningful concepts did the universe exist or was it just the quantum vacuum void?
Once the Universe became recognizable as the Universe I see no problem as to why there should not be a global or universal time in as much that it would be arrived at by taking an average of all of the local times. If time is the relationship between energy and mass in the universe and the percentage of these is constantly changing then the global or universal time dilation factor is also constantly changing. As stars are constantly converting some of their mass into energy then mass is decreasing as energy increases. So one could predict that time is contracting. A second now is shorter than a second in the cosmological past.
Post by: Æthelwulf on 04/04/2012 12:18:11
Æthelwulf
I have answered most of your points in this thread.
http://www.thenakedscientists.com/forum/index.php?topic=43056.0Gravity for me is simple. It is the presence of matter, which is the presence of curvature and is the presence of acceleration within the equations of relativity; this much he is partially correct, I've never truely doubted that. It's linking it directly with time which troubles me. I don't see time and gravity as synonymous objects. In fact, I see change, I don't see time per se. Only through the eyes of a mere human being, I can extrapolate that time is highly subjective and something I project as a ''feeling of past and future'' on the world outside. None of which actually exist.
My previous two posts explain why I believe, you can't talk about gravity without talking about time, or more correctly without talking about time dilation.
It is necessary to understand time dilation in order to understand gravity. Surely, if time did not exist, there could be no time dilation and therefore no such thing as gravity. Gravity exists and so does time.
The dichotemy is much more complicated than that. If we were talking about time as being a local phenomenon, then yes this is true. If we are also talking time being experienced by Bradyons, or particles with mass, then time truely wasn't around until matter came out of the vacuum. But time for a universe, a universal global time vanishes. What is time then from the perspective of the universe if it does not exist globally? Is it only clocks moving below the speed of light that experience time, in which case the beginning of the universe certainly had no time and the end of the universe when all matter fields have returned to radiation fields, then the very future cone of our universe is also devoid of moving clocks.
Simply put, you can't have time without matter ... these moving relativistic clocks which tick off real time.
There is little in the above that I do not agree with but my standpoint has not changed.
I agree that prior to the existence of mass, there was no time. [Others might not agree on that as photons are supposed to create gravity in which case mass would not be necessary for the existence of time.] However, one could debate whether before ,time, distance , speed and geometry all became meaningful concepts did the universe exist or was it just the quantum vacuum void?
Once the Universe became recognizable as the Universe I see no problem as to why there should not be a global or universal time in as much that it would be arrived at by taking an average of all of the local times. If time is the relationship between energy and mass in the universe and the percentage of these is constantly changing then the global or universal time dilation factor is also constantly changing. As stars are constantly converting some of their mass into energy then mass is decreasing as energy increases. So one could predict that time is contracting. A second now is shorter than a second in the cosmological past.
Well, if a scientist said there must still be time when gravity is present, I'd say that is false. Keep in mind, before you agreed with the layout above, I said strictly that time and gravity were completely two different objects. Time is more to do with the freedom of objects, but not concerned specifically whether objects change or not.
So, the reason why gravity cannot define time in radiation fields is because gravity really is just a ''distortion'' - a field, which as far as we can tell is a psuedoforce, not requiring any physical mediator. There are many scientists who describe gravity as a psuedoforce. This maybe another reason to dictate that gravity is not truely fundamental. For radiation, they do not possess clocks which tick away time. We will also find that gravity only became significant after the radiation period when black holes could form, otherwise, the effects of these radiation fields would still have been significantly weak.
Post by: Æthelwulf on 04/04/2012 12:21:45
There is perhaps what we would call a ''fundamental time'' and a ''geometric time'' according to Markoupoulou. I add that fundamental time does not really exist, but a geometric time does for a late evolution of the universe. Here I add a new concept: ''induced time'', meaning time is really an emergent phenomenae late on the universes history which is why the universe is devoid of a fundamental time.
Post by: MikeS on 04/04/2012 15:24:49
So let's see if I can lay this out some more.
There is perhaps what we would call a ''fundamental time'' and a ''geometric time'' according to Markoupoulou. I add that fundamental time does not really exist, but a geometric time does for a late evolution of the universe. Here I add a new concept: ''induced time'', meaning time is really an emergent phenomenae late on the universes history which is why the universe is devoid of a fundamental time.
I would argue that time is not an emergent phenomena 'late in the universes history.
'Late' implies that there was an earlier period. Without the backdrop of space-time there could have been no earlier period.
Therefore, talking about what happened when and where before the creation of time is pretty meaningless.
The history of the Universe can only date back to the creation of time.
Post by: Æthelwulf on 04/04/2012 15:27:43
So let's see if I can lay this out some more.
There is perhaps what we would call a ''fundamental time'' and a ''geometric time'' according to Markoupoulou. I add that fundamental time does not really exist, but a geometric time does for a late evolution of the universe. Here I add a new concept: ''induced time'', meaning time is really an emergent phenomenae late on the universes history which is why the universe is devoid of a fundamental time.
I would argue that time is not an emergent phenomena 'late in the universes history.
'Late' implies that there was an earlier period. Without the backdrop of space-time there could have been no earlier period.
Therefore, talking about what happened when and where before the creation of time is pretty meaningless.
The history of the Universe can only date back to the creation of time.
Late may imply there is an order. I may not be implying there could be time before matter - we may describe evolution in a different way. A purely static order before that order was broken, perhaps induced by a type of symmetry breaking.
Post by: MikeS on 05/04/2012 06:57:00
Late may imply there is an order. I may not be implying there could be time before matter - we may describe evolution in a different way. A purely static order before that order was broken, perhaps induced by a type of symmetry breaking.
I can't agree with that. Late and order imply causality. Before the creation of time there was neither.
Talking about before time is a minefield as we are limited by language. I have just used the word 'before' which is meaningless without time.
I agree that something must have happened prior to the creation of matter but it happened outside of time and therefore outside the history of the Universe.
Initially, as I understand it all that existed was energy in the void. Energy, travels instantaneously so any amount could appear here, there or anywhere at any time, if 'any amount', 'here', 'there', 'anywhere' and 'any time' were meaningful but they are not. What it does demonstrate is that in the Universe entropy rules. In the void without time there was no entropy.
Post by: Æthelwulf on 05/04/2012 09:46:37
Late may imply there is an order. I may not be implying there could be time before matter - we may describe evolution in a different way. A purely static order before that order was broken, perhaps induced by a type of symmetry breaking.
I can't agree with that. Late and order imply causality. Before the creation of time there was neither.
Talking about before time is a minefield as we are limited by language. I have just used the word 'before' which is meaningless without time.
I agree that something must have happened prior to the creation of matter but it happened outside of time and therefore outside the history of the Universe.
Initially, as I understand it all that existed was energy in the void. Energy, travels instantaneously so any amount could appear here, there or anywhere at any time, if 'any amount', 'here', 'there', 'anywhere' and 'any time' were meaningful but they are not. What it does demonstrate is that in the Universe entropy rules. In the void without time there was no entropy.
You seem to be forgetting however, that I have no problem with change. Orders may imply a change. Change does not necesserily mean time however. Take Barbours approach as a prime example. He says there is no time, only change.
Post by: MikeS on 05/04/2012 13:00:08
Just because you keep quoting Barbours approach saying there is no time only change, does not make it true. So far I haven't seen the slightest evidence that time does not exist whereas there is plenty of evidence that it does.
Post by: Æthelwulf on 05/04/2012 13:01:41
Æthelwulf
Just because you keep quoting Barbours approach saying there is no time only change, does not make it true. So far I haven't seen the slightest evidence that time does not exist whereas there is plenty of evidence that it does.
I don't just qoute Barbour, I gave you a perfect example of freezing an evolution of a system. If time really does exist, then systems don't need to change.
The zeno effect is a priori.
Post by: Æthelwulf on 05/04/2012 13:37:27
Æthelwulf
Just because you keep quoting Barbours approach saying there is no time only change, does not make it true. So far I haven't seen the slightest evidence that time does not exist whereas there is plenty of evidence that it does.
Since my time here also, I have asked for evidence of time. I can give one main reason why systems do need to change over time.
Since my time here, no one has provided conrete evidence of time existing. You said the fact we can see galaxies in space is evidence of time, I said that was rubbish more or less. I need physical evidence. There is none. Age is reserved for those who relatively see age.
Post by: MikeS on 05/04/2012 14:02:59
I have also given evidence that time is real. Time is what clocks record.
Any type of clock and all types of clock will record the same going rate locally despite differences in construction, mechanism, operation etc. Yet an identical set of clocks in a different gravitational potential will record a different going rate in comparison to the first group whilst still keeping in syncronisation with one another.
If they are not recording the passage of time, what are they recording and how do you account for it varying from one group to the next?
To help me to understand your viewpoint perhaps you would like to elaborate on " example of freezing an evolution of a system."
Post by: Æthelwulf on 05/04/2012 14:07:16
I have given evidence why on a macoscopic scale the zeno effect isrubbishnot real.
Sure the zeno effect does not describe macroscopic systems, I agree with this.
So let's, as consulting adults (lol) help ourselves to the prevailing theory of large matter, and resort to GR.
Oops! A new problem arises... the world is actually timeless.
I hope you are not one of these people who think GR is wrong.
Post by: MikeS on 07/04/2012 08:19:43
GR is about warped space-time so it is not timeless.
GR does not set out to prove or disprove the existence of time.