Post by: MikeS on 24/04/2012 07:08:21
Time has two components. The arrow which points from the past to the future and is the same in all reference frames. Secondly, the time dilation factor. Although time locally always passes at the same rate, from any non-local reference frame it is relative and can be seen to be variable.
At absolute cold, time stands still. The arrow of time remains but there is no passage of time.
Time as we know it does not exist.
At absolute hot, the passage of time is infinite. Therefore there is no causality. Times arrow is double ended.
Time as we know it does not exist.
So, is absolute hot the same as absolute cold?
Post by: MikeS on 24/04/2012 09:08:09
How can you differentiate between absolute hot and absolute cold if time (as we know it) does not exist for either of them? We can't feel the difference, neither can we measure it because that requires action or change.
Absolute hot has a double ended arrow (AB). If we remove one pointer from the arrow (B) the other remains and we have near absolute cold with time flowing in direction (A). [Or near absolute hot with time flowing in direction (B)].
If we reverse that arrow then we have near absolute hot with time flowing in direction (B). [Or near absolute cold with time flowing in direction (A)].
So, are hot and cold relative terms depending upon the direction of the arrow of time?
Entropy which is the arrow of time points from hot to cold.
Reverse time and you reverse entropy.
Post by: MikeS on 24/04/2012 10:17:20
For mass/energy to be attracted toward the singularity at the center of a black hole there has to be a gravitational gradient with gravity being the strongest at the singularity.
At the event horizon time stands still. The passage of time is related to the mass or gravity of the object. In other words, the greater the mass the more time is dilated. Time at the EH is already dilated to the maximum. So how can the increasing gravitational potential further dilate time. It can't. The EH is at maximum acceleration and ensures that not even light can escape. It would seem that inside a black hole, from OUR perspective, the normal laws of physics are suspended and travel above the speed of light is not only possible but mandatory. If so then time within the EH of a black hole is reversed in comparrison to the rest of the Universe.
Within the black hole nothing can travel faster than the speed of light. From a reference frame WITHIN the black hole, outside the EH travel above the speed of light is not only possible but mandatory.
Post by: simplified on 24/04/2012 14:41:18
Post by: MikeS on 24/04/2012 21:28:32
Cold takes energy and time.Hot gives energy and time.
Yes
Post by: Æthelwulf on 24/04/2012 21:39:02
No. One is very warm relatively associated with one which is very very cold.
I am perplexed by your logic.
... look. Theories should tackle either problems known, or problems yet to be solved. Not by speculations and certainly not by models which permit the old saying ''if it is not broke, why fix it?''
Post by: MikeS on 25/04/2012 10:46:28
Cold takes energy and time.Hot gives energy and time.
Æthelwulf
I think what simplified meant was cold represents a lack of usable energy and hence time dilates. Hot represents energy and time contraction.
No. One is very warm relatively associated with one which is very very cold.
I am perplexed by your logic.
... look. Theories should tackle either problems known, or problems yet to be solved. Not by speculations and certainly not by models which permit the old saying ''if it is not broke, why fix it?''
This thread arose in response to a another thread. What is the temperature inside a black hole. Some proposed it is near absolute hot, I proposed it is near absolute cold. This thread attempts to explain how two seemingly opposites can be the same thing.
Yes, it is speculation in as much as it is not proven but time reversal does come within the laws of physics as we understand them.
The physics of black-holes is fundamental to our understanding of the Universe and there is much we do not know. Debate is a means of reaching that goal.
I understand your frustration, because if time reversal were to be a proven fact then your ideas of the non-existence of time would be thrown out of the window.
Post by: pandey_23ajay on 25/04/2012 13:25:42
how cold or hot can be an object? it depends on chemical structure of material, each material can not achieve any temperature.
***at absolute cold time stands still*** at absolute cold, it is materiaL and surrondings which remain still, as there is no change, not the time,
TIME IS CHANGE, IF THERE IS NO CHANGE IN UNIVERSE, THEN TIME IS INSIGNIFICANT.
Post by: simplified on 25/04/2012 14:40:16
I have simple logic : the fattest milk is butter, the most low-fat milk is not butter.
No. One is very warm relatively associated with one which is very very cold.
I am perplexed by your logic.
... look. Theories should tackle either problems known, or problems yet to be solved. Not by speculations and certainly not by models which permit the old saying ''if it is not broke, why fix it?''
Post by: MikeS on 25/04/2012 15:26:39
i think, there is nothing like absolute hot or cold, it is more of theory and less practical.
how cold or hot can be an object? it depends on chemical structure of material, each material can not achieve any temperature.
***at absolute cold time stands still*** at absolute cold, it is materiaL and surrondings which remain still, as there is no change, not the time,
TIME IS CHANGE, IF THERE IS NO CHANGE IN UNIVERSE, THEN TIME IS INSIGNIFICANT.
Yes there is.
http://en.wikipedia.org/wiki/Absolute_zero
http://en.wikipedia.org/wiki/Absolute_hot
I am talking about absolutes, not any particular material. That's why it is called absolute.
YES we agree on something.
Post by: MikeS on 26/04/2012 05:57:01
In normal space-time this seems to be true but in the case of a black hole it does not seem to hold.
As an object enters the event horizon it enters a region of zero passage of time (relative a distant observer). In other words it is travelling at the speed of light or more correctly the event horizon of the black hole is accelerating toward it at the speed of light.
As regards whether it is the object accelerating toward the black hole or the black hole accelerating toward the object is a matter of what reference frame you use.
Either way mass accelerates up to the speed of light. An object accelerating in ordinary space-time is essentially accelerating in the SPACE aspect of space-time and is confined by GR. An object accelerating in the TIME aspect of space-time does not have this limitation.
So, as far as a black hole is concerned the cosmic censorship of no material object being able to reach the speed of light does not seem to apply. If that does not apply then one must ask can the speed of light be exceeded within a black hole?
What does it mean to go faster than the speed of light? Approaching c the arrow of time points toward c. You can't go faster as the passage of time has dilated to zero. Traveling slightly faster than the speed of light would mean the passage of time was almost dilated to zero, the arrow of time is still pointing toward c but from the other direction. The arrow of time would have reversed.
Does this hypothesis make any testable predictions?
Yes, I think it does. A matter particle entering the EH, from inside the EH would look like an antimatter particle leaving (traveling toward the EH from the inside). From inside the EH, a matter particle entering from outside the EH would look like an antimatter particle leaving.
The question is do black holes radiate significant quantities of antimatter particles from within the event horizon?
(Not Hawkin Radiation, that is much smaller and produced outside the EH.)
---------->l<---------- time
m EH a
<----------l----------> time
a m
Post by: imatfaal on 26/04/2012 16:02:12
I suppose you could have an abs hot by channelling all the energy available into a single system - but again this would be a logistical limit rather than a physical law.
Post by: MikeS on 27/04/2012 09:33:23
Post by: Æthelwulf on 28/04/2012 00:06:20
Cold takes energy and time.Hot gives energy and time.
Æthelwulf
I think what simplified meant was cold represents a lack of usable energy and hence time dilates. Hot represents energy and time contraction.
No. One is very warm relatively associated with one which is very very cold.
I am perplexed by your logic.
... look. Theories should tackle either problems known, or problems yet to be solved. Not by speculations and certainly not by models which permit the old saying ''if it is not broke, why fix it?''
This thread arose in response to a another thread. What is the temperature inside a black hole. Some proposed it is near absolute hot, I proposed it is near absolute cold. This thread attempts to explain how two seemingly opposites can be the same thing.
Yes, it is speculation in as much as it is not proven but time reversal does come within the laws of physics as we understand them.
The physics of black-holes is fundamental to our understanding of the Universe and there is much we do not know. Debate is a means of reaching that goal.
I understand your frustration, because if time reversal were to be a proven fact then your ideas of the non-existence of time would be thrown out of the window.
Time reversal might have significance for individual particles, but as far as the entire universe goes, the universe is asymmetric. If it was symmetric, we might expect things like a time reversal in physics... but as far as I understand physics, time reversal is a much abused concept. Such a symmetry is a simple mapping
But the observable universe does not contain such a transformation, the universe is largely asymmetric due to the second law of thermodynamics.
Post by: MikeS on 28/04/2012 06:03:21
Time reversal might have significance for individual particles, but as far as the entire universe goes, the universe is asymmetric. If it was symmetric, we might expect things like a time reversal in physics... but as far as I understand physics, time reversal is a much abused concept. Such a symmetry is a simple mapping
But the observable universe does not contain such a transformation, the universe is largely asymmetric due to the second law of thermodynamics.
Yes, the Universe is time asymmetric but that does not rule out time reversal.
If matter and antimatter are gravitationally repulsive then the universe may be cyclic with matter universe following antimatter universe etc. The arrow of time reverses on each cycle. Beings in an antimatter cycle would observe their universe to be just the same as ours. Matter and antimatter are just relative terms. The second law of thermodynamics would work just the same in an antimatter universe as it does in ours.
Black holes are holes in the space-time fabric of our Universe. We really do not know what happens inside the EH we can only theorize based upon what we do know of our universe.
What I have attempted to do is theorize as to how an object entering a black hole can continue to accelerate above the speed of light. Normally this would be impossible but possible if time reverses inside the EH. It does not break any physical laws.
Post by: MikeS on 28/04/2012 07:40:13
It would seem reasonable to assume that between the EH and the singularity there is a gravitational gradient with the gravitational potential increasing toward the singularity. (From our perspective, an object would accelerate from the EH to the singularity) A gravitational gradient is normally accompanied by a time dilation gradient. But at the EH of a black hole time is already infinitely dilated. Therefore the expected time dilation across the radius can not apply. The only way that I can see of correcting this is for the arrow of time to be reversed on the inside of the EH as compared to outside the EH. From a perspective inside the EH the same object is accelerating from the singularity to the EH.