Post by: annie123 on 11/02/2012 20:12:59
"Barbour argues that we live in a universe which has neither past nor future. A strange new world in which we are alive and dead in the same instant. In this eternal present, our sense of the passage of time is nothing more than a giant cosmic illusion." Discover Mag.
He says that there is no time, only change.Does he have a following?
Post by: JP on 12/02/2012 16:29:33
"Who's Julian Barbour?"
(In other words, his ideas haven't made much of an impact on physics.)
Post by: Bored chemist on 12/02/2012 17:06:29
"time is an illusion: lunchtime doubly so"
http://en.wikiquote.org/wiki/The_Hitchhiker's_Guide_to_the_Galaxy#Chapter_2
Post by: yor_on on 12/02/2012 22:20:51
Post by: Soul Surfer on 12/02/2012 22:23:10
Julian Barbour is a respected cosmologist and philosopher. I have had the book for some years and read it a couple of times His book includes a good general introduction.
It takes an interesting approach to making sense of the quantum approach to physics where the universe effectively "samples" all possible states on the way to settling down for an "observation" which is the sort of thing that we see or another particle interacts with.
This fits with the equations that describe the events which are in effect infinite integrals over all space and time.
The full reality is that both space and time are emergent properties of our universe which is fundamentally built out of energy and momentum but this is so unfamiliar that most people have great difficulty in coming to terms with it.
As always with these books the ideas when put into an extreme situation seem weird but have absolutely no effect on our own perceptions of "reality" describing something in terms of mathematics which works and produces very accurate predictions does not change the universe from what it IS in any way.
Post by: Geezer on 13/02/2012 02:36:15
I make this all quite clear in my book.
Post by: annie123 on 18/02/2012 23:16:17
To JP, Discover Magazine has a very long article about Julian Barbour this month. And yes, The End of Time is one of his books.
Post by: Soul Surfer on 22/02/2012 15:06:08
A very deep mathematical relationship exists between symmetries in nature and conservation laws. This is called Noether's theorem (look it up in wikipedia for more indformation). This is that all important symmetries have an associated conservation law. Now for an understandable universe the physical laws should not change arbitrarily according to where you are how you move about and in what direction you are looking
These simple "symmetry" requirements lead to the most fundamental conservation laws in our (or probably any) universe these are the conservation of energy, momentum and angular momentum respectively. It therefore follows that our universe is built from energy and momentum continually interacting with each other and locked together to create the more familiar aspects of space, time and matter.
Post by: Durgesh Dubhashi on 28/02/2012 13:36:03
Post by: yor_on on 28/02/2012 23:18:13
Post by: MikeS on 29/02/2012 07:44:06
Post by: Soul Surfer on 03/03/2012 22:24:40
Post by: MikeS on 04/03/2012 07:10:28
Mike Julian Barbour is not suggesting that time is in any way an illusion. It is very real and important from our point of view. However from the point of view of the mathematics of quantum mechanics our universe is continually visiting every state that can possibly exist and moving between the ones that have the best probability based on all the states that have occurred. making time an emergent property of the energy and momentum states possible in the universe. I would extend this and say space is also an emergent property as well but I am not sure if anyone has gone that far.
I would agree with that. I believe that the size of the universe (the space it contains is mostly down to the amount of free energy [radiation] that it contains.) If for example the Universe were to be consumed by a black hole then as mass and energy were consumed so space would shrink.
Post by: yor_on on 04/03/2012 18:17:04
Emergences, fields, excitations and all possible from there being an arrow to experience it in. So what came first :)
I say the arrow.
=
No arrow, nothing to discuss.
Post by: Soul Surfer on 08/03/2012 22:40:10
Post by: Geezer on 08/03/2012 23:44:45
Post by: Livewire on 09/03/2012 00:01:37
Post by: Bill S on 09/03/2012 16:28:43
He believes that you can question the reality of time, without throwing out general relativity. He expresses his belief in relativity, and says: “I am not claiming that the description of space-time given by Einstein and Minkowski is wrong. Far from it – they got it right ….” However, he adds a proviso: “…. but they described the finished product, and the complete story must also include the construction of the product.”
I think it would be difficult to accept GR without according some significance to time.
As far as the arrow of time is concerned, we have to distinguish between the idea of an arrow that flies through the air, and one that is painted on a sign to point the way. Obviously this brings in the arguments about tensed and untensed time, but without that distinction discussions tend to go round in circles.
Post by: yor_on on 11/03/2012 01:51:51
What is 'tensed and untensed time,'?
Post by: Geezer on 11/03/2012 04:24:48
Obviously this brings in the arguments about tensed and untensed time, but without that distinction discussions tend to go round in circles.
Should we then be referring to the boomerang of time, rather than the arrow?
Post by: yor_on on 12/03/2012 20:15:18
"Consider this one issue upon which philosophers are deeply divided: What sort of ontological differences are there among the present, past and future? There are three competing theories. Presentists argue that necessarily only present objects and present experiences are real, and we conscious beings recognize this in the special “vividness” of our present experience. The dinosaurs have slipped out of reality. However, according to the growing-universe or growing-block theory, the past and present are both real, but the future is not real because the future is indeterminate or merely potential. Dinosaurs are real, but our death is not. The third and more popular theory is that there are no significant ontological differences among present, past, and future because the differences are merely subjective. This view is called “the block universe theory” or “eternalism.”
That controversy raises the issue of tenseless versus tensed theories of time. The block universe theory implies a tenseless theory. The earliest version of this theory implied that tensed terminology can be replaced adequately with tenseless terminology. For example, the future-tensed sentence, “The Lakers will win the basketball game” might be analyzed as, “The Lakers do win at time t, and time t happens after the time of this utterance.” Notice that the future tense has been removed, and the new verb phrases “do win” and “happens after” are tenseless logically, although they are grammatically in the present tense. (Similarly, the present-tense verb “is” in “seven plus five is twelve” isn’t only about the present.) Advocates of a tensed theory object and say that tenseless terminology is not semantically basic but should be analyzed in tensed terms, and that tensed facts are needed to make tensed statements be true. For example, a tensed theory might imply that no adequate account of the present tensed fact that it is now midnight can be given without irreducible tensed properties such as presentness or now-ness. So, the philosophical debate is over whether tensed concepts have semantical priority over untensed concepts, and whether tensed facts have ontological priority over untensed facts." By Bradley Dowden in "Time" (IEP)
Post by: MikeS on 12/03/2012 20:58:44
Post by: Soul Surfer on 13/03/2012 10:49:32
Post by: Æthelwulf on 13/03/2012 19:16:29
I would like to know what orthodox physicists think of Julian Barbour's radical ideas about time. This also relates to he quantum mechanics theories that i also have a post about.
"Barbour argues that we live in a universe which has neither past nor future. A strange new world in which we are alive and dead in the same instant. In this eternal present, our sense of the passage of time is nothing more than a giant cosmic illusion." Discover Mag.
He says that there is no time, only change.Does he have a following?
Julian Barbour is absolutely correct. I have most appreciated his understanding of time over the last two years has it has been formulated http://www.fqxi.org/data/essay-contest-files/Barbour_The_Nature_of_Time.pdf?phpMyAdmin=0c371ccdae9b5ff3071bae814fb4f9e9 into Markoupoulou's title of the Problem of Time on the FQXI team and forum http://www.fqxi.org/data/essay-contest-files/Markopoulou_SpaceDNE.pdf , that space can be understood in a unique way in a model called Geometrogenesis: The intricate understanding that space is a low energy phenomenon - so it happens late in the universes history, and geometry according to Einstein's field equations, is directly linked to the curvature (the geometry) of space and time.
Timelessness may exist, according to Barbour. In Fotini Markoupoulou's interpretation, we can keep time by removing space. Her model is revolutionary but faulty - time will not exist either, for using her same methodologies, time would have no appearance at the big bang. Geometry is not concerned with high energy phenomena, atleast in the fundamental sense - geometry appears late in the universes history as an indication itself that not only the normal spatial geometry comes into question when you unify physics into absurdly small places, but you also get a problem in time as well since geometry according to the ''Minkowski'' view of space, was to be coupled to a fourth dimension of space.
But space at big bang did not exist, since there was no space since big bang happened at an infinitessimal point. So how can current theory tackle the prevailing truth?
Post by: Æthelwulf on 13/03/2012 21:51:27
As I said, he was right.
Post by: yor_on on 14/03/2012 04:17:19
Yep, it's called SpaceTime for a reason :)
As for Julian Barbour I tried to read him some year or so ago, but found it to intricate for my taste. I prefer simpler explanations :) as most of us , or maybe it's me getting senile :)
Post by: Æthelwulf on 19/03/2012 21:10:59
As an ordained priest in the church of orthodox physics, my answer would be,
"Who's Julian Barbour?"
(In other words, his ideas haven't made much of an impact on physics.)
Well, the subject he tackles is actually well known. It is called timelessness in GR and is born from the WDW equation. His approach was brilliant in removing time and only dealing with real observables.
Post by: MikeS on 20/03/2012 07:13:07
"I believe that a theory of the universe should explain why entropy increases."
Simple, Entropy increases because that is the preferred 'ground state' of the Universe.
The ground state being the most stable configuration possible.
Entropy is therefore the main arrow of time. All other arrows of time are essentially entropic in nature.
Change involves an increase in entropy and involves causality. We call this time.
Quote Julian Barbour.
"but the equations of physics are symmetric with respect to the direction of time? The equations of physics allow not only the shattering of a cup that is dropped on the floor but also the re-assembly of the pieces. However, that is never observed."
Hypothetically, an antimatter universe could exist in which the arrow of time is reversed in comparison to our universe. Time would still flow forward as observed by beings in that universe. This would allow time to be symmetric but still without re-assembly of the pieces. (Unless viewed by us)
Quote Julian Barbour.
"If we could stand outside the universe and ‘see it as it is’, it would appear to be static."
Assuming we viewed it from a similar and equivalent time frame why would it appear to be static. If you could manipulate your own time frame then you could appear to make it seem static but what would be the point?
Quotes are from
http://platonia.com/books.html
Post by: Æthelwulf on 20/03/2012 07:31:41
Post by: Æthelwulf on 20/03/2012 07:33:32
Post by: MikeS on 20/03/2012 07:47:55
"The ground state of a quantum mechanical system is its lowest-energy state; the energy of the ground state is known as the zero-point energy of the system."
http://en.wikipedia.org/wiki/Ground_state
Regardless of the universes starting conditions this is where it is heading.
It can do this in either one or the other of two ways.
The universe could expand until energy has completely dissipated.
or
The universe could contract into a black hole. Either way entropy is satisfied.
The ground state must have been the starting point prior to the start of the universe but talking about a starting point prior to the starting point is really meaningless. If you follow...
Post by: Æthelwulf on 20/03/2012 08:05:39
Quote Julian Barbour.
"I believe that a theory of the universe should explain why entropy increases."
Simple, Entropy increases because that is the preferred 'ground state' of the Universe.
The ground state being the most stable configuration possible.
Entropy is therefore the main arrow of time. All other arrows of time are essentially entropic in nature.
Change involves an increase in entropy and involves causality. We call this time.
Quote Julian Barbour.
"but the equations of physics are symmetric with respect to the direction of time? The equations of physics allow not only the shattering of a cup that is dropped on the floor but also the re-assembly of the pieces. However, that is never observed."
Hypothetically, an antimatter universe could exist in which the arrow of time is reversed in comparison to our universe. Time would still flow forward as observed by beings in that universe. This would allow time to be symmetric but still without re-assembly of the pieces.
Quote Julian Barbour.
"If we could stand outside the universe and ‘see it as it is’, it would appear to be static."
Assuming we viewed it from a similar and equivalent time frame why would it appear to be static. If you could manipulate your own time frame then you could appear to make it seem static but what would be the point?
Quote are from
http://platonia.com/books.html
''Hypothetically, an antimatter universe could exist in which the arrow of time is reversed in comparison to our universe. Time would still flow forward as observed by beings in that universe. This would allow time to be symmetric but still without re-assembly of the pieces.''
This isn't really Julians point. His point is that motion is a symmetry of the theory. True time evolution does not exist in GR. The past and future are only artefacts of a theory we have developed, if you like it has some kind of psychological arrow which implies a directionality to time, a past then a future state. But in GR wordlines are static. There is no past or future. There is, only the present.
This is also true with our direct experience of the world. We may ''feel'' like a time has past, but we don't actually experience a past, nor do we ever experience a future.
''Assuming we viewed it from a similar and equivalent time frame why would it appear to be static. If you could manipulate your own time frame then you could appear to make it seem static but what would be the point?''
It has something to do with weak measurements. It would be like an atom. An atom ripe to radiate energy can be suspended in time by making a series of observations on the system - this is called the Zeno Effect.
By the way, when I said:
''What is a ground state though? (Rhetorical question). ''
I never intended you link a ground state. I am well aware of what a ground state is. I am saying your assumption that ground state systems alone answers for the origin of entropy does not add up.
Post by: Æthelwulf on 20/03/2012 08:06:44
I disgree. Before the Big Bang, there was nothing.
Post by: MikeS on 20/03/2012 08:13:55
I am saying your assumption that ground state systems alone answers for the origin of entropy does not add up.Why?''The ground state must have been the starting point prior to the start of the universe ''
I disgree. Before the Big Bang, there was nothing.
Try taking it in context.
What I said was.
The ground state must have been the starting point prior to the start of the universe but talking about a starting point prior to the starting point is really meaningless. If you follow...
Post by: Æthelwulf on 20/03/2012 08:25:17
Call it a matter of conjecture. Your point is a conjecture. It isn't theory. It doesn't answer for instance, why entropy would be driven by a ground state, in let's say something preferential to an excited state.
Entropy, is in a loose way of speaking, a measure of change. You will find change most prominently in an excited state atom, ready to give up energy. That is a form of entropy as well.
''The ground state must have been the starting point prior to the start of the universe...''
You seem to be having a mental block - there was no ''prior state'' to the big bang. Ground, excited, give or take a little space, time nothing, nada, the big goose egg. If anything, there might have been a potential for a universe to come into existence (Such as a Hartle-Hawking Universe), but I've never fully understood that concept as it makes little sense when you are dealing with a non-system.
''but talking about a starting point prior to the starting point is really meaningless.''
Right.
Post by: MikeS on 20/03/2012 08:25:30
''The ground state must have been the starting point prior to the start of the universe ''
I disgree. Before the Big Bang, there was nothing.
In some sense that is debatable. If there was nothing then where did the universe come from? It is certainly true to say before the big bang there was no universe and that includes such concepts as time, distance and thought. Assuming the big bang to be correct of course.
I guess it depends on what you mean by nothing.
Post by: MikeS on 20/03/2012 08:29:39
It was a kind of 'tongue in cheek joke'.
Post by: Æthelwulf on 20/03/2012 08:33:03
There maybe reasons why the beginning is such. There is a theory right now which scientists are eager over called the Transactional Interpretation which can put a new spin on the beginning of things. Essentially, we could adopt the idea that the future cone of the universe is shaping up the past - the beginning is being formed by actions in our future horizon. So the future creates the past. There is actually experimental varification of this.
Post by: MikeS on 20/03/2012 09:10:52
You ask why saying something in a ground state answers for entropy is not enough?
Call it a matter of conjecture. Your point is a conjecture. It isn't theory. It doesn't answer for instance, why entropy would be driven by a ground state, in let's say something preferential to an excited state.
It is self evident that the Universe is driven by energy. As energy 'does work' so the entropy of the Universe increases. Ultimately the Universe will run out of energy and entropy will be at a maximum. This will be as close to the ground state as possible.
No it's not theory, neither is it conjecture. It is fact.
Post by: Nizzle on 20/03/2012 09:49:16
He says that there is no time, only change.Does he have a following?
This is like saying "There is no distance, only centimetres" or "There is no volume, only litres"....
Time is a physical property, like distance and volume. Change is one of the ways to measure it..
So he's contradicting himself in one short sentence. Not an easy feat. ;)
Post by: Æthelwulf on 20/03/2012 09:54:35
You ask why saying something in a ground state answers for entropy is not enough?
Call it a matter of conjecture. Your point is a conjecture. It isn't theory. It doesn't answer for instance, why entropy would be driven by a ground state, in let's say something preferential to an excited state.
It is self evident that the Universe is driven by energy. As energy 'does work' so the entropy of the Universe increases. Ultimately the Universe will run out of energy and entropy will be at a maximum. This will be as close to the ground state as possible.
No it's not theory, neither is it conjecture. It is fact.
Saying entropy is caused by a Ground State is about as enlightening as an unplugged Christmas Tree. As I have explained, it doesn't answer it at all. It answer it as much as an excited state would. It's pointless, meaningless speculation.
I was being kind when I said conjecture. All you are stating is a speculation, with no reason other than you thinking it sounding good.
Post by: Æthelwulf on 20/03/2012 09:55:20
He says that there is no time, only change.Does he have a following?
This is like saying "There is no distance, only centimetres" or "There is no volume, only litres"....
Time is a physical property, like distance and volume. Change is one of the ways to measure it..
So he's contradicting himself in one short sentence. Not an easy feat. ;)
Time is not physical. How can it be physical?
Physical things purport to Observables. Time is NOT an Observable.
Post by: Nizzle on 20/03/2012 10:07:32
He says that there is no time, only change.Does he have a following?
This is like saying "There is no distance, only centimetres" or "There is no volume, only litres"....
Time is a physical property, like distance and volume. Change is one of the ways to measure it..
So he's contradicting himself in one short sentence. Not an easy feat. ;)
Time is not physical. How can it be physical?
Physical things purport to Observables. Time is NOT an Observable.
So for you, wind is not physical either? Cause you can't see wind?
EDIT: I meant "Time is a physical quantity" not "property". It's a language thing, I'm not a native english speaker..
Post by: MikeS on 20/03/2012 11:17:40
You ask why saying something in a ground state answers for entropy is not enough?
Call it a matter of conjecture. Your point is a conjecture. It isn't theory. It doesn't answer for instance, why entropy would be driven by a ground state, in let's say something preferential to an excited state.
It is self evident that the Universe is driven by energy. As energy 'does work' so the entropy of the Universe increases. Ultimately the Universe will run out of energy and entropy will be at a maximum. This will be as close to the ground state as possible.
No it's not theory, neither is it conjecture. It is fact.
Saying entropy is caused by a Ground State is about as enlightening as an unplugged Christmas Tree.
I never actually said that.
The ground state is reached when entropy is at a maximum.
Sorry you don't like it but that's the way it is.
Post by: Æthelwulf on 20/03/2012 20:09:20
He says that there is no time, only change.Does he have a following?
This is like saying "There is no distance, only centimetres" or "There is no volume, only litres"....
Time is a physical property, like distance and volume. Change is one of the ways to measure it..
So he's contradicting himself in one short sentence. Not an easy feat. ;)
Time is not physical. How can it be physical?
Physical things purport to Observables. Time is NOT an Observable.
So for you, wind is not physical either? Cause you can't see wind?
EDIT: I meant "Time is a physical quantity" not "property". It's a language thing, I'm not a native english speaker..
Wind is made of molecules, atoms. Charged particles.
What is time made of, but the ethereal experience of it?
Seriously dude, go learn some physics before you make statements you can't support. Time should not be physical. Just because it is part of an understanding Minkowski made years and years ago that by treating it as a dimension has left physics following a wrong path - a deluded idea that perhaps time is also physical, that it is part of the manifold we call space. Sure, calculationally-wise, time is very useful when thought of as a dimension. Other than that, it has no physical appearance. Time is not an observable. It is not tangible.
Post by: Æthelwulf on 20/03/2012 20:11:37
You ask why saying something in a ground state answers for entropy is not enough?
Call it a matter of conjecture. Your point is a conjecture. It isn't theory. It doesn't answer for instance, why entropy would be driven by a ground state, in let's say something preferential to an excited state.
It is self evident that the Universe is driven by energy. As energy 'does work' so the entropy of the Universe increases. Ultimately the Universe will run out of energy and entropy will be at a maximum. This will be as close to the ground state as possible.
No it's not theory, neither is it conjecture. It is fact.
Saying entropy is caused by a Ground State is about as enlightening as an unplugged Christmas Tree.
I never actually said that.
The ground state is reached when entropy is at a maximum.
Sorry you don't like it but that's the way it is.
What's that supposed to mean anyway, ''when entropy is at a maximum'', I don't get it. Either a system is changing or not.
Post by: Æthelwulf on 20/03/2012 20:13:02
Time = Change
Time does not necesserily mean change at all. In fact, if anyone can follow the math of Julian Barbour, he shows you can deal with real observable things and omit time from the equations. Change can happen with real observables, the way physics should be.
Post by: Æthelwulf on 20/03/2012 23:51:23
You ask why saying something in a ground state answers for entropy is not enough?
Call it a matter of conjecture. Your point is a conjecture. It isn't theory. It doesn't answer for instance, why entropy would be driven by a ground state, in let's say something preferential to an excited state.
It is self evident that the Universe is driven by energy. As energy 'does work' so the entropy of the Universe increases. Ultimately the Universe will run out of energy and entropy will be at a maximum. This will be as close to the ground state as possible.
No it's not theory, neither is it conjecture. It is fact.
Saying entropy is caused by a Ground State is about as enlightening as an unplugged Christmas Tree.
I never actually said that.
The ground state is reached when entropy is at a maximum.
Sorry you don't like it but that's the way it is.
Reading this back, my brain has boggled in what you have meant... until now. You aren't perhaps talking about the relationship between the least action principle and the principle of maximum entropy... Well, since a least action is one which uses the least amount of energy (Ground State) I suppose this is what you are talking about.
In which case I have little add. I don't know this relationship well.
Post by: MikeS on 21/03/2012 05:35:57
Quote from: Æthelwulf link=topic=43056.msg383435#msg383435
clip
Time [i
clip
Time [i
"has no physical appearance. Time is not an observable. It is not tangible."[/i]
Two identical clocks, one on the Earths surface and one in orbit above the Earth will show a different passage of time. Time passing faster for the clock in orbit.
That's observable and tangible enough for me. You may not be able to see time directly but you can certainly see both the arrow and passage of time.
Post by: Æthelwulf on 21/03/2012 06:45:18
Quote from: Æthelwulf link=topic=43056.msg383435#msg383435
clip
Time [i"has no physical appearance. Time is not an observable. It is not tangible."[/i]
Two identical clocks, one on the Earths surface and one in orbit above the Earth will show a different passage of time. Time passing faster for the clock in orbit.
That's observable and tangible enough for me. You may not be able to see time directly but you can certainly see both the arrow and passage of time.
Time isn't an observable, and dilation is an effect.
Post by: Æthelwulf on 21/03/2012 06:50:08
http://meopemuk2.blogspot.co.uk/2006/07/is-there-observable-of-time.html
If not I am wasting my energy.
Post by: Nizzle on 21/03/2012 09:03:53
The biggest fall I seem to be seeing right now, is people making
Time = Change
Time does not necesserily mean change at all. In fact, if anyone can follow the math of Julian Barbour, he shows you can deal with real observable things and omit time from the equations. Change can happen with real observables, the way physics should be.
You are correct: Time does not equal Change, just as length does not equal metre or volume does not equal m3
But it's still a physical quantity for me. One of the base physical quantities even, together with Length, Mass, Temperature, Amount of Substance, Electric Current and Luminous Intensity, and I'm backed up by the International System of Units! See here (http://en.wikipedia.org/wiki/Physical_quantity#Base_quantities).
If this doesn't convince you I'm wasting my energy.
EDIT: Btw, if Barbour can eliminate Time from his equations to demonstrate 'Change', then how does he demonstrates 'Rate of Change'?
Post by: Æthelwulf on 21/03/2012 10:29:46
Anyway, this change without time, what are you wanting me to do, take you through Barbour's math or something?
Post by: Æthelwulf on 21/03/2012 10:34:13
Post by: imatfaal on 21/03/2012 10:57:01
Can we have fewer implications of lack of knowledge and less condescension? Let's keep this friendly.
Thanks
Post by: yor_on on 24/03/2012 16:37:09
Were they in SpaceTime doing it.
As they refute time?
Post by: yor_on on 24/03/2012 16:40:19
=
Although I agree with some of his observations. I too think it could be described as a 'static' universe from some weird point of view, as well as there is no real evidence for anything being as 'real' as the 'present'. But I also believe that there is something changing even though the changes only can be defined through history. Probability is using that 'history' to predict what may happen in a 'future', and the funny thing is that it works? Which becomes problematic if that history doesn't exist, as well as the predicted 'future'.
Post by: yor_on on 24/03/2012 16:55:54
Post by: Bill S on 24/03/2012 17:10:54
Quote
What is 'tensed and untensed time,'?
Sorry it has taken me a while for me to get back on this - busy!
Yor-on has covered this at length, but I was not thinking of anything as complex as that.
Put simply, its more like this:
Tensed time is “now relative”; it assumes an ever moving now, which progresses towards the future, always leaving more “past” behind it.
Tensless time relates to clock time, dates etc. and is regarded as being static. For example, 11.30 (GMT) on the 25th October 2007 is a tensless time; in relativistic terms it is an unchanging spacetime event. In this view there is no objective passage of time.
Post by: yor_on on 24/03/2012 17:51:56
A event is a description of something happening, something 'real'.
Events connect through causality.
Events when looked through history becomes a logic.
That logic holds for events still not 'here' (probability)
And as QM is probability to me?
Post by: Bill S on 24/03/2012 18:26:00
Quote
Two identical clocks, one on the Earths surface and one in orbit above the Earth will show a different passage of time. Time passing faster for the clock in orbit.
One clock "ticks" faster than the other. We interpret that as time passing faster, but is that necessarily the case?
Post by: yor_on on 24/03/2012 18:33:41
In one whole undivided SpaceTime it will be necessary, as the twin experiment can show us.
From 'locality' the arrow is of one measure though, the same wherever you go. But to do so you will question what a SpaceTime is.
Post by: Bill S on 25/03/2012 02:33:39
Post by: yor_on on 25/03/2012 03:31:44
They exist, and the twin experiment is correct. The question is more of what 'time' is. A geometry?
Post by: MikeS on 25/03/2012 08:12:12
NIST doesn't do thought experiments Bill, and they show the same effect, although minuscule (gravitational) time dilations.Yes.
They exist, and the twin experiment is correct. The question is more of what 'time' is. A geometry?
As gravity is geometry so to is time. Time has two components, the arrow and rate of passage (time dilation factor). It is possible to have one without the other but only in combination do they constitute 'time'. The direction of the arrow is always universal. (That is, it points in the same direction everywhere in the Universe.) The time dilation factor is always local.
Time or more correctly space-time is the medium in which entropy increases.
If you consider a clock (any clock) to be a closed system it requires energy to power it. This leads to an increase in entropy within that system.
Ultimately time, in a sense is a measure of the increase in entropy.
Entropy is necessary in order to measure time. Time is necessary in order to measure entropy.
The universe and everything it contains is trying to reach a more stable state. That state is approached by loosing useful energy which is an increase in entropy. So the ultimate ground state of the Universe would be zero useful energy. At which point time would cease to exist. (Time being infinitely dilated)
'Time is what allows things to happen but stops everything from happening all at once'.
Post by: Bill S on 25/03/2012 20:13:42
Post by: MikeS on 26/03/2012 06:08:32
Of course time dilation is real and has been measured both in terms of gravity and air travel; but what was really being measured? Surely, what was being measured was the rate at which measuring devices operate.
Yes and that's what we call time.
A measuring device (clock) measures the passage of local time. But not all localities have the same passage of time, so not all clocks agree.
Post by: Æthelwulf on 26/03/2012 06:25:22
Of course time dilation is real and has been measured both in terms of gravity and air travel; but what was really being measured? Surely, what was being measured was the rate at which measuring devices operate.
Yes and that's what we call time.
A measuring device (clock) measures the passage of local time. But not all localities have the same passage of time, so not all clocks agree.
Clocks, minutes, seconds... maybe even hours to centuries all man-made concepts. Time is an illusion that we have wrapped ourselves in. Time is a construction. An invention.
Post by: Geezer on 26/03/2012 07:17:02
Clocks, minutes, seconds... maybe even hours to centuries all man-made concepts. Time is an illusion that we have wrapped ourselves in. Time is a construction. An invention.
Ah right! But if there is no such thing as time, what is it that is controlling how matter decays? I could be wrong, but I'm pretty sure uranium does not turn into lead as a consequence of human willpower.
Post by: Æthelwulf on 26/03/2012 09:29:25
Clocks, minutes, seconds... maybe even hours to centuries all man-made concepts. Time is an illusion that we have wrapped ourselves in. Time is a construction. An invention.
Ah right! But if there is no such thing as time, what is it that is controlling how matter decays? I could be wrong, but I'm pretty sure uranium does not turn into lead as a consequence of human willpower.
Not quite sure of your point, apart from a frivolous question on human will power. What does the radiation, of an atom supposed to do with conversation at large? I have heard, that radiation processes are used in arguements against a predeterministic universe since they purport to truely random processes.
To this I turn our attention to zeno effect. It is completely possible to make your system deterministic by the power of observation. A scientist in the lab can make so-called weak measurements on the system and freeze it in time, making it completely predictable. This is because you are suspending the time evolution operator.
Post by: Geezer on 26/03/2012 10:07:49
Not quite sure of your point, apart from a frivolous question on human will power. What does the radiation, of an atom supposed to do with conversation at large? I have heard, that radiation processes are used in arguements against a predeterministic universe since they purport to truely random processes.
To this I turn our attention to zeno effect. It is completely possible to make your system deterministic by the power of observation. A scientist in the lab can make so-called weak measurements on the system and freeze it in time, making it completely predictable. This is because you are suspending the time evolution operator.
Nothing frivolous about it.
If it is not time, please explain what it is that causes differences in atomic decay.
Post by: Æthelwulf on 26/03/2012 10:19:47
Not quite sure of your point, apart from a frivolous question on human will power. What does the radiation, of an atom supposed to do with conversation at large? I have heard, that radiation processes are used in arguements against a predeterministic universe since they purport to truely random processes.
To this I turn our attention to zeno effect. It is completely possible to make your system deterministic by the power of observation. A scientist in the lab can make so-called weak measurements on the system and freeze it in time, making it completely predictable. This is because you are suspending the time evolution operator.
Nothing frivolous about it.
If it is not time, please explain what it is that causes differences in atomic decay.
Not sure what ''will-power'' has to do with this. Anyway, if equations help describe our world, then equations can describe changes quite well without time. Time is just a tool. Being ommitted from the equations does not stop us from using equations which don't require it.
Take Barbours work seriously. His equation can describe physical processes without time. His equation is a good example, because you might as well get comfortable with it. This is what GR predicts. A timeless universe.
Post by: Bill S on 26/03/2012 21:15:24
Quote from: MikeS
Yes and that's what we call time.
That sums up the situation perectly! There is, or feels as though there should be, this something. We can't see it, hear it, touch it, smell it or even agree as to what it might be. However, life seems to make a lot more sense with it than without it.
I'm with St Augustine on this one: "What then is time? If no one asks me, I know;
if I wish to explain it to someone who asks, I know not."
Post by: dkeizer05 on 27/03/2012 03:05:11
Is speed a tangible?
Seriously dude, go learn some physics before you make statements you can't support. Time should not be physical. Just because it is part of an understanding Minkowski made years and years ago that by treating it as a dimension has left physics following a wrong path - a deluded idea that perhaps time is also physical, that it is part of the manifold we call space. Sure, calculationally-wise, time is very useful when thought of as a dimension. Other than that, it has no physical appearance. Time is not an observable. It is not tangible.
Post by: MikeS on 27/03/2012 07:10:38
Of course time dilation is real and has been measured both in terms of gravity and air travel; but what was really being measured? Surely, what was being measured was the rate at which measuring devices operate.
Yes and that's what we call time.
A measuring device (clock) measures the passage of local time. But not all localities have the same passage of time, so not all clocks agree.
Clocks, minutes, seconds... maybe even hours to centuries all man-made concepts. Time is an illusion that we have wrapped ourselves in. Time is a construction. An invention.
They are all man named in as much as they are measures of time as referenced by the Earth and its orbit around the sun.
Time is real as Geezer has pointed out.
Any type of clock whether it be atomic, electronic, mechanical spring driven, mechanical gravity driven, atomic decay, speed of light etc. will all keep the same time in the same local time frame. Likewise identical clocks in a different local time frame where the gravitational potential is different will all keep pace with each other but show a time dilation effect relative to the first set of clocks.
Quite obviously both sets of clocks are measuring something.
They are measuring local time.
If they are not measuring local time, what are they measuring?
Post by: Æthelwulf on 27/03/2012 08:22:01
Is speed a tangible?
Seriously dude, go learn some physics before you make statements you can't support. Time should not be physical. Just because it is part of an understanding Minkowski made years and years ago that by treating it as a dimension has left physics following a wrong path - a deluded idea that perhaps time is also physical, that it is part of the manifold we call space. Sure, calculationally-wise, time is very useful when thought of as a dimension. Other than that, it has no physical appearance. Time is not an observable. It is not tangible.
Observables, real tangible properties which can be measured are provided by Hermitian Matrices. I will leave it to you as a task to find out what uses Hermitian Matrices.
Post by: imatfaal on 27/03/2012 10:24:10
Is speed a tangible?
Seriously dude, go learn some physics before you make statements you can't support. Time should not be physical. Just because it is part of an understanding Minkowski made years and years ago that by treating it as a dimension has left physics following a wrong path - a deluded idea that perhaps time is also physical, that it is part of the manifold we call space. Sure, calculationally-wise, time is very useful when thought of as a dimension. Other than that, it has no physical appearance. Time is not an observable. It is not tangible.
Observables, real tangible properties which can be measured are provided by Hermitian Matrices. I will leave it to you as a task to find out what uses Hermitian Matrices.
On your above comment properties are not "provided by Hermitian Matrices" - that is well and truly putting the quantum mechanical cart before the horse. Dynamic variables can be associated with a hermitian operator - which is not the same thing at all.
In quantum mechanics every variable (position, momentum, angular momentum, spin, energy, and many tothers) is able to be represented by a Hermitian operator that can be mathematically manipulated in a way to describe an action on the state of the system and the eigenvalues of which will correspond to the possible values that the dynamical variable can take. I would be interested on your take on momentum and energy which are well known and well used variables and associated hermitian operators - and how an absence of time would effect them.
Post by: Æthelwulf on 27/03/2012 11:55:51
Aethelwulf - please lose the superior attitude and keep it friendly.Is speed a tangible?
Seriously dude, go learn some physics before you make statements you can't support. Time should not be physical. Just because it is part of an understanding Minkowski made years and years ago that by treating it as a dimension has left physics following a wrong path - a deluded idea that perhaps time is also physical, that it is part of the manifold we call space. Sure, calculationally-wise, time is very useful when thought of as a dimension. Other than that, it has no physical appearance. Time is not an observable. It is not tangible.
Observables, real tangible properties which can be measured are provided by Hermitian Matrices. I will leave it to you as a task to find out what uses Hermitian Matrices.
On your above comment properties are not "provided by Hermitian Matrices" - that is well and truly putting the quantum mechanical cart before the horse. Dynamic variables can be associated with a hermitian operator - which is not the same thing at all.
In quantum mechanics every variable (position, momentum, angular momentum, spin, energy, and many tothers) is able to be represented by a Hermitian operator that can be mathematically manipulated in a way to describe an action on the state of the system and the eigenvalues of which will correspond to the possible values that the dynamical variable can take. I would be interested on your take on momentum and energy which are well known and well used variables and associated hermitian operators - and how an absence of time would effect them.
This has nothing to do with being superior. This has to do with being right. Why spurt off something which makes no sense? I am shrugging my shoulders here.
Anyway, observables, things that we can measure are Hermitian Matrices. This is well-established in quantum mechanics, that is, they are always real. Let's just cover what it implies.
You must first check to see if
and 
are complex conjugates of each other, 
. A less obvious case might be 
. Take 
multiplying it with the ket vector gives a new row vector. Take the inner product with 
and it spits out a number. We might say then that 
is acting complex conjugate 
where all rows and columns have been interchanged. Properly conjugated one has the form
However if it is Hermitian then
where the dagger notation is removed. If we have our
then a wee snippet to mention that it is simply the expectation 
. So I am unsure what it is really you have an objection about. My statement is very scientific.
Post by: yor_on on 30/03/2012 20:42:38
Assume that 'the arrow of time' is a component that can be ignored for a complete description. Then assume that you measure a 'photon path'. You find it to exist as it must through your weak measurements, which here will be amassed statistics as far as I see.
Then that 'path' is no path at all, it's the probability of a path. And the fact that you also see weak measurements as 'eliminating time', if I got it right, then must become a statement of that light not moving at all. And if it is so, which I sometimes think too, what about the 'paths' not taken?
Post by: Æthelwulf on 30/03/2012 21:01:17
Let us play out your idea a little Wulf :)
Assume that 'the arrow of time' is a component that can be ignored for a complete description. Then assume that you measure a 'photon path'. You find it to exist as it must through your weak measurements, which here will be amassed statistics as far as I see.
Then that 'path' is no path at all, it's the probability of a path. And the fact that you also see weak measurements as 'eliminating time', if I got it right, then must become a statement of that light not moving at all. And if it is so, which I sometimes think too, what about the 'paths' not taken?
I mentioned weak measurements before because someone mentioned atomic clocks radiating away energy. I mentioned weak measurements because the zeno effect can in fact freeze the evolution of systems.
Anyway, as for paths, we describe them in relativity with worldlines. Wordlines don't make a distinction of past and future - perhaps just as important, you can view worldines as static.
Post by: Pmb on 30/03/2012 23:00:16
Question: There was an article in Scientific American entitled Is Time an Illusion? Would you like to read it? If so then I'll take the time to upload it to the web and modify my website to accomodate it.
Pete
Post by: JP on 30/03/2012 23:02:54
Aethelwulf - please lose the superior attitude and keep it friendly.Is speed a tangible?
Seriously dude, go learn some physics before you make statements you can't support. Time should not be physical. Just because it is part of an understanding Minkowski made years and years ago that by treating it as a dimension has left physics following a wrong path - a deluded idea that perhaps time is also physical, that it is part of the manifold we call space. Sure, calculationally-wise, time is very useful when thought of as a dimension. Other than that, it has no physical appearance. Time is not an observable. It is not tangible.
Observables, real tangible properties which can be measured are provided by Hermitian Matrices. I will leave it to you as a task to find out what uses Hermitian Matrices.
On your above comment properties are not "provided by Hermitian Matrices" - that is well and truly putting the quantum mechanical cart before the horse. Dynamic variables can be associated with a hermitian operator - which is not the same thing at all.
In quantum mechanics every variable (position, momentum, angular momentum, spin, energy, and many tothers) is able to be represented by a Hermitian operator that can be mathematically manipulated in a way to describe an action on the state of the system and the eigenvalues of which will correspond to the possible values that the dynamical variable can take. I would be interested on your take on momentum and energy which are well known and well used variables and associated hermitian operators - and how an absence of time would effect them.
This has nothing to do with being superior. This has to do with being right. Why spurt off something which makes no sense? I am shrugging my shoulders here.
Anyway, observables, things that we can measure are Hermitian Matrices. This is well-established in quantum mechanics, that is, they are always real. Let's just cover what it implies.
You must first check to see if
However if it is Hermitian then
where the dagger notation is removed. If we have our
One should be careful not to assume that something must be an observable to be measured. You can measure arrival times or duration times quite well, even though you can't write "time" as a Hermitian operator. There's been a lot of recent advances in understanding how real-world measurements work in quantum mechanics (not the idealized types usually talked about in textbooks), and this has led to the idea of a positive operator-valued measure: http://en.wikipedia.org/wiki/POVM
There's a lot of math there, but the gist is that you can define useful operators that measure different time properties of a quantum state. These operators aren't unique, nor are they necessarily Hermitian, but within the POVM framework, they describe measurements of those time properties.
Post by: Æthelwulf on 31/03/2012 00:57:49
Assuming time can be measured because we can ''measure durations'' to me, is like falling back on that illusion we call time and once again projecting it on the world we tend to measure just because we ''think it exists objectively.'' There is however, no real evidence for this. In fact, I have found in my own studies that time more or less does not even exist within the modern framework of relativity. Physics also reshaped the idea that somehow time has a flow; which it doesn't.
Time isn't a ''state'' which comes about from a measurement. Hence again, it is not an observable.
Post by: Geezer on 31/03/2012 01:25:35
Time isn't a ''state'' which comes about from a measurement. Hence again, it is not an observable.
States don't come about by measurement. States are observed through measurement. States exist whether you measure them or not.
Time isn't a state, but time determines the state of everything.
Post by: acecharly on 31/03/2012 01:45:09
Post by: Æthelwulf on 31/03/2012 02:06:17
Time isn't a ''state'' which comes about from a measurement. Hence again, it is not an observable.
States don't come about by measurement. States are observed through measurement. States exist whether you measure them or not.
Time isn't a state, but time determines the state of everything.
I disagree.
According to the fundamental interpretation of quantum mechanics, objects exist in a superpositioning of states. Only upon a measurement can you pull a quantum system out of this superpositioning and create well-defined states.
Post by: Æthelwulf on 31/03/2012 02:07:44
Time isn't a ''state'' which comes about from a measurement. Hence again, it is not an observable.
States don't come about by measurement. States are observed through measurement. States exist whether you measure them or not.
Time isn't a state, but time determines the state of everything.
As for time is not a state, but determines states, who could argue with that? Still don't make it an observable.
Post by: Æthelwulf on 31/03/2012 02:10:27
I think time is odd. I think its an illusion and also not an illusion. My mind tells me that every state of the universe is fixed. We see a continual rolling of these states which gives us a perception of change in the universe just like a film rolling through a projector showing individual frames. Our brains perceive this as a moving picture or "time". I believe time is simply a change of the state of the universe. If every particle in the universe were to stop momenterily then time would stop until some particle made a first move. My concern though is how to describe one of these frames if you dont use time i.e. between each keystroke i make on this keyboard for example how many frames have been taken? is it the combined number of every particle of matter moving through space between 2 events?
If I was to believe in time, it would require some serious changes... past and future could not exist. Only an everlasting present moment, and inside the present sphere physical change occurs. I would also have to teach myself to believe that there is no flow to time as well. It does not extend from any past, nor to any future, because nothing exists in the past and nothing exists in the future.
But hey, I don't need to believe any of that, because I am convinced time is an invention and we keep attaching to the physical world outside, erreneously I should add.
Post by: Geezer on 31/03/2012 02:19:12
As for time is not a state, but determines states, who could argue with that? Still don't make it an observable.
So the changes in state that we observe are the result of what exactly? Or are you saying changes in state are an illusion too?
Post by: acecharly on 31/03/2012 02:30:07
I think time is odd. I think its an illusion and also not an illusion. My mind tells me that every state of the universe is fixed. We see a continual rolling of these states which gives us a perception of change in the universe just like a film rolling through a projector showing individual frames. Our brains perceive this as a moving picture or "time". I believe time is simply a change of the state of the universe. If every particle in the universe were to stop momenterily then time would stop until some particle made a first move. My concern though is how to describe one of these frames if you dont use time i.e. between each keystroke i make on this keyboard for example how many frames have been taken? is it the combined number of every particle of matter moving through space between 2 events?
If I was to believe in time, it would require some serious changes... past and future could not exist. Only an everlasting present moment, and inside the present sphere physical change occurs. I would also have to teach myself to believe that there is no flow to time as well. It does not extend from any past, nor to any future, because nothing exists in the past and nothing exists in the future.
But hey, I don't need to believe any of that, because I am convinced time is an invention and we keep attaching to the physical world outside, erreneously I should add.
You say..."in the present sphere physical change occurs" from which points do you believe change occurs though? We could assume that from the big bang to now could be that sphere or a kettle goin from cold to boiling. For change to occur we must have moved to the next sphere. Time is a consequence of physical change without it the universe would be impossible id have thought because all matter would be in every state it has ever been in and ever will be in if that makes sense. Isnt time similar to gravity? it exists as a consequence of warped space like a side effect.
Post by: Æthelwulf on 31/03/2012 02:36:28
This thread is too long to read all of it so I'm starting to read it here.
Question: There was an article in Scientific American entitled Is Time an Illusion? Would you like to read it? If so then I'll take the time to upload it to the web and modify my website to accomodate it.
Pete
To save you time, here is the article:
<link redacted pending copyright check>
Post by: Æthelwulf on 31/03/2012 02:37:50
As for time is not a state, but determines states, who could argue with that? Still don't make it an observable.
So the changes in state that we observe are the result of what exactly? Or are you saying changes in state are an illusion too?
Change is not synonymous with time. Changes can be decribed without a time evolution - these are just special ways of treating a new emerging physics.
The article, actually describes this above in my previous post. It is a good read, makes all the arguements I have made.
Post by: Æthelwulf on 31/03/2012 02:39:33
I think time is odd. I think its an illusion and also not an illusion. My mind tells me that every state of the universe is fixed. We see a continual rolling of these states which gives us a perception of change in the universe just like a film rolling through a projector showing individual frames. Our brains perceive this as a moving picture or "time". I believe time is simply a change of the state of the universe. If every particle in the universe were to stop momenterily then time would stop until some particle made a first move. My concern though is how to describe one of these frames if you dont use time i.e. between each keystroke i make on this keyboard for example how many frames have been taken? is it the combined number of every particle of matter moving through space between 2 events?
If I was to believe in time, it would require some serious changes... past and future could not exist. Only an everlasting present moment, and inside the present sphere physical change occurs. I would also have to teach myself to believe that there is no flow to time as well. It does not extend from any past, nor to any future, because nothing exists in the past and nothing exists in the future.
But hey, I don't need to believe any of that, because I am convinced time is an invention and we keep attaching to the physical world outside, erreneously I should add.
You say..."in the present sphere physical change occurs" from which points do you believe change occurs though? We could assume that from the big bang to now could be that sphere or a kettle goin from cold to boiling. For change to occur we must have moved to the next sphere. Time is a consequence of physical change without it the universe would be impossible id have thought because all matter would be in every state it has ever been in and ever will be in if that makes sense. Isnt time similar to gravity? it exists as a consequence of warped space like a side effect.
Time is a consequence of a subliminal feeling of some of time passing. To me, time is not a consequence of change, because time does not exist. Change does.
Post by: acecharly on 31/03/2012 02:39:47
As for time is not a state, but determines states, who could argue with that? Still don't make it an observable.
So the changes in state that we observe are the result of what exactly? Or are you saying changes in state are an illusion too?
Haha i do love mindbogglers like this.....isnt it kind of yes and no here? the state changes but at the same time its a different state not the same state that we started with...
Post by: acecharly on 31/03/2012 02:46:02
Post by: Æthelwulf on 31/03/2012 02:50:40
Hmmmm it seems a little bit of splitting hairs is taking place when you say you dont believe in time but you believe in change its a different word describing the same thing.
Well, I think there are serious problems if one cannot identify a difference between change and time. Will time still pass if an atom is frozen from evolving when measured (zeno effect)? See, an atom may be frozen from evolving by radiating away energy. Frozen in the sense no change happens, but we normally don't assume time itself has stopped, only the time evolution.
Change and time are really not describing the same things.
Post by: acecharly on 31/03/2012 03:06:13
Post by: JP on 31/03/2012 03:22:05
Well, if we are taking about something which can be measured, then we are talking about Eigenstates here. It seems quite simple enough that time is not an observable - it is not something we can see directly.
Assuming time can be measured because we can ''measure durations'' to me, is like falling back on that illusion we call time and once again projecting it on the world we tend to measure just because we ''think it exists objectively.'' There is however, no real evidence for this. In fact, I have found in my own studies that time more or less does not even exist within the modern framework of relativity. Physics also reshaped the idea that somehow time has a flow; which it doesn't.
Time isn't a ''state'' which comes about from a measurement. Hence again, it is not an observable.
Perhaps you should take a look at what POVM entails before dismissing it out of hand?
It's basically reformulating the concept of measurement in QM in terms of operators that get you real-valued results. The theory has showed (successfully) that the result of a measurement is not necessarily the result of applying a self-adjoint operator to your state. Even in this theory, there are still no "time eigenstates," but that's beside the point--we know that we can measure arrival times and this theory explains how.
It's also been a lot of use in quantum information theory, and is a pretty active area of research.
Here's a good link explaining how it differs from the more traditional view of measurables: http://www.springerlink.com/content/pmafpr8xt0cbve9b/fulltext.pdf
Post by: yor_on on 31/03/2012 08:12:20
Time isn't a ''state'' which comes about from a measurement. Hence again, it is not an observable.
States don't come about by measurement. States are observed through measurement. States exist whether you measure them or not.
Time isn't a state, but time determines the state of everything.
I disagree.
According to the fundamental interpretation of quantum mechanics, objects exist in a superpositioning of states. Only upon a measurement can you pull a quantum system out of this superpositioning and create well-defined states.
And what do you do that measurement in?
Post by: yor_on on 31/03/2012 08:19:35
And in a way the arrow becomes 'hair splitting' as we have no certain definition of it. To have a 'change' there is needed a mechanism for something to change. That mechanism is the arrow. Then the question becomes, as I'm starting to wonder and Wulf it seems, as well as some others here, if the arrow only can be observed on 'what changes' or if there is a arrow for something not changing too?
If you like me think that the arrow is a very local process then if there is no change locally the arrow is 'suspended' as I see it now. If you on the other hand conceive of SpaceTime as being 'one whole thing' then it becomes trickier.
Post by: yor_on on 31/03/2012 08:39:21
But if we instead use a strictly 'local' definition, then that what measures has a arrow for sure, but what it measures, if not changing, doesn't necessarily need to have it. But there is the added complication that this 'frozen thing' you measure on still exist after the measurement, not disappearing as we are 'moving on' in times arrow.
But I think (?) that might be explained from a static point of view, in where 'time' is what makes local arrow(s). Time then possibly described in terms of some sort of 'static field', and very conceptually so.
Because if what we have is a 'static reality' in some conceptual way, then everything we observe to 'change', or for that sake not 'change at all' is a expression of something we don't describe correctly, as we lack the observations needed to see that 'reality'.
Post by: simplified on 31/03/2012 11:29:19
Time can be money,if you can use it. ;)Time isn't a ''state'' which comes about from a measurement. Hence again, it is not an observable.
States don't come about by measurement. States are observed through measurement. States exist whether you measure them or not.
Time isn't a state, but time determines the state of everything.
Post by: Æthelwulf on 31/03/2012 11:31:22
Well, if we are taking about something which can be measured, then we are talking about Eigenstates here. It seems quite simple enough that time is not an observable - it is not something we can see directly.
Assuming time can be measured because we can ''measure durations'' to me, is like falling back on that illusion we call time and once again projecting it on the world we tend to measure just because we ''think it exists objectively.'' There is however, no real evidence for this. In fact, I have found in my own studies that time more or less does not even exist within the modern framework of relativity. Physics also reshaped the idea that somehow time has a flow; which it doesn't.
Time isn't a ''state'' which comes about from a measurement. Hence again, it is not an observable.
Perhaps you should take a look at what POVM entails before dismissing it out of hand?
It's basically reformulating the concept of measurement in QM in terms of operators that get you real-valued results. The theory has showed (successfully) that the result of a measurement is not necessarily the result of applying a self-adjoint operator to your state. Even in this theory, there are still no "time eigenstates," but that's beside the point--we know that we can measure arrival times and this theory explains how.
It's also been a lot of use in quantum information theory, and is a pretty active area of research.
Here's a good link explaining how it differs from the more traditional view of measurables: http://www.springerlink.com/content/pmafpr8xt0cbve9b/fulltext.pdf
I see Rovelli has done work on this operator.
Perhaps something interesting I can tell you, is that Rovelli is actually one of the biggest proponents for a timeless universe next to Julian Barbour. I read the paper, didn't understand all of it. What I did understand, I am still not convinced that time is a real observable.
Post by: JP on 31/03/2012 16:53:22
That's perfectly reasonable, but it's also not sitting on rigorous scientific ground at the moment insofar as no one (that I know of) come up with a testable hypothesis based on the idea. Until that happens it's interesting, but not really science.
But regardless of what future experiments demonstrate, the concept of time is certainly fruitful and leads to meaningful measurements in the types of experiments we're doing these days.
Post by: Æthelwulf on 01/04/2012 02:22:20
If you can prove to me Einstein's prediction's were in fact wrong, then you can prove in some sense that time is an observavble. But since our current theory does not hold, you will have to learn like I did.
Time is not real, yet this is real science.
Post by: Geezer on 01/04/2012 02:48:39
Change is not synonymous with time. Changes can be decribed without a time evolution -
I see. So state changes happen without any time. So where does the infinite energy come from to effect these changes, or is energy an illusion too?
Post by: Æthelwulf on 01/04/2012 02:56:28
Change is not synonymous with time. Changes can be decribed without a time evolution -
I see. So state changes happen without any time. So where does the infinite energy come from to effect these changes, or is energy an illusion too?
I can show mathematics which demonstrates that hypothesis.
In fact, this is called the null energy hypothesis. It does have a mathematical backing.
Post by: Æthelwulf on 01/04/2012 02:57:40
Post by: Geezer on 01/04/2012 03:38:03
In fact, this is called the null energy hypothesis. It does have a mathematical backing.
If you remove time from physics you are going to have to deal with a lot of infinites. Of course, you might be able to construct a model that uses something else, but when you peel back the covers, it's going to be doing pretty much the same thing that time does.
Time is ill-defined at the quantum level, but as scale increases, something seems to rectify the jitter to produce a bias - analogous to a direct current - that causes time to flow in a particular direction.
Post by: Æthelwulf on 01/04/2012 04:10:22
Could you perhaps, for my sake, highlight how the suspected infinities in your example arises?
Post by: Æthelwulf on 01/04/2012 04:17:05
Maybe for some interest, an electron only experiences infinite energy when we reduce particles to zero sizes... no dimensions, basically. Only non-zero electron dimensions actually experience finite energies.
But hey, I don't think this is what you are talking about. I'd still love to know what it is you are eluding too.
Post by: Geezer on 01/04/2012 06:41:27
You might have two states, A - sitting down, B - standing up. If you translate your mass between A and B without time, you have consumed more than all the available energy in this particular Universe, even though it may not be an infinite amount of energy.
I'm not saying that time isn't a very strange beast. It's certainly not what our perceptions might lead us to believe it is, but if we eliminate it from our vocabulary we better have some pretty good alternative models that work in its absence.
Mathematical models are only a description of reality. They do not define it.
Post by: yor_on on 01/04/2012 09:18:01
Which is lifting in those 'statistically proven significant' values we can see/find to be true outside the math, instead of the infinities we otherwise would get mathematically?
And it works, just as 'weak measurements' seem to be working for making predictions of a future event.
Math huh :)
But Geezer seems perfectly correct to me. If ones math doesn't describe our observations and fail our experiments then it's no description of our reality, which, on the other hand, doesn't state that it can't have a validity, somewhere else.
Post by: Æthelwulf on 01/04/2012 13:10:56
I was thinking of something far more prosaic.
You might have two states, A - sitting down, B - standing up. If you translate your mass between A and B without time, you have consumed more than all the available energy in this particular Universe, even though it may not be an infinite amount of energy.
Can you give me a working example?
There is one special connection between time and energy - known as Noethers Theorem - time is the conjugate of energy. Now, believe it or not, but timelessness might actually be the answer to solving many fundamental and cosmological problems. For instance, I have speculated that maybe if time does not exist, then you cannot measure an energy for a universe, because there is no way to make the correct translation in time, meaning the universe does not conserve energy.
What is good about this? Well, the universe is now receeding faster than light, and as Michio Kaku has pointed out, this could be an indication that the universe is using up energy much more faster. That is analogous to stating that the universe does not prefer to conserve energy and could answer for the recent rapid expansion. The mathematical approach would be my approach.
Just as an example of something good from timelessness.
Post by: Æthelwulf on 01/04/2012 13:12:19
Doesn't mathematical physics approximate reality through renormalization?
Yeah, but many scientists are uncomfortable with renormalization - thinking it is a cop-out. In fact Dirac was one of the strongest proponents against renormalization. I also don't agree with it, I think infinities like that are indications of the theory breaking down.
Post by: yor_on on 02/04/2012 03:31:42
That constant in a dynamic universe, defined by and through change, gives each observer different 'dynamic 3D slices' described through times arrow. To each observer that arrow is the same as I see it, and the proof for that is simple, you just need to superimpose them to see that all clocks have a same rate of change, using radiation. So everyones arrow must become a local definition which also must be true, as far as I can see.
That a Lorentz transformation always will give you your conceptual SpaceTime is easily explained through radiations constant, and is something of a misnomer to me as it to many seems as a proof of one whole united indivisible SpaceTime, same for all. To me that 'truth' is more subtle, what makes a Lorenz transformation possible is lights speed in a vacuum. And the only thing such a transformation state is the same as Einstein once went out from. That light is a constant.
To lift out 'the arrow' you, I don't know? A quantum computer comes to mind, or better still, indeterminacy. 'Virtual photons' do not fit such a concept though, as the idea behind it, to me, is something 'existing in time', at least as I think of it.
Post by: Geezer on 02/04/2012 06:51:15
Can you give me a working example?
I imagine F=ma would be a good place to start (an oldie, but still a goodie).
A force exerted in time is a measure of energy. If a force could accelerate a mass (any mass) in zero time, it would consume a heck of a lot of energy.
Post by: Æthelwulf on 02/04/2012 06:55:02
Can you give me a working example?
I imagine F=ma would be a good place to start (an oldie, but still a goodie).
A force exerted in time is a measure of energy. If a force could accelerate a mass (any mass) in zero time, it would consume a heck of a lot of energy.
Maybe I am missing something, but I've never heard that. In fact, let's use F=ma.
I push a ball down a hill and use F=Ma to calculate the force. However, this equation is time-independant any way. Now assume it for a collection of particles F=Miai - there is still no energy problems.
Don't know. Maybe it is just me?
Post by: Geezer on 02/04/2012 07:50:50
However, this equation is time-independant any way.
Acceleration (a) is the time derivative of velocity which is the time derivative of position. It is not just dependent on time; it is dependent on the square of time.
Post by: Æthelwulf on 02/04/2012 08:29:19
However, this equation is time-independant any way.
Acceleration (a) is the time derivative of velocity which is the time derivative of position. It is not just dependent on time; it is dependent on the square of time.
Fair point, I wasn't thinking along those lines. I still don't understand the energy propostions however.
All I know is that we will have to develop a theory which treats our theories without time. A number of physicists are already doing this.
Post by: Geezer on 02/04/2012 08:59:53
However, this equation is time-independant any way.
Acceleration (a) is the time derivative of velocity which is the time derivative of position. It is not just dependent on time; it is dependent on the square of time.
Fair point, I wasn't thinking along those lines. I still don't understand the energy propostions however.
All I know is that we will have to develop a theory which treats our theories without time. A number of physicists are already doing this.
But you must include energy. Energy is one of the few things that unite all the branches of Physics (I may be wrong, but I think String Theory is still based on energy.)
If you dispense with energy, you'll have to exclude any notion of it from all physics before you can exclude the idea of time. I'm not saying that is impossible, but I am saying you better have some very serious convictions if you are really prepared to do that.
Post by: Æthelwulf on 02/04/2012 09:05:02
When mass equals zero, energy is also zero and what you are left with is the metric. So when matter equals zero, this corresponds to the contention that matter does not fundmentally exist, what we end up with is energy going to zero as well. That is one solution.
Post by: Geezer on 02/04/2012 09:27:10
The energy may be nullified fundamentally. The arguement is, is that matter and geometry is not fundmental. Energy may also not be really fundamental, the reason why is because of the equation
When mass equals zero, energy is also zero and what you are left with is the metric. So when matter equals zero, this corresponds to the contention that matter does not fundmentally exist, what we end up with is energy going to zero as well. That is one solution.
Of course it does, but then you are left with "if time does not exist, mass cannot exist".
Does mass not exist?
Post by: steved1980 on 02/04/2012 11:15:03
Post by: Æthelwulf on 02/04/2012 11:19:14
The energy may be nullified fundamentally. The arguement is, is that matter and geometry is not fundmental. Energy may also not be really fundamental, the reason why is because of the equation
When mass equals zero, energy is also zero and what you are left with is the metric. So when matter equals zero, this corresponds to the contention that matter does not fundmentally exist, what we end up with is energy going to zero as well. That is one solution.
Of course it does, but then you are left with "if time does not exist, mass cannot exist".
Does mass not exist?
Well, this was a position Einstein held. In remarks to his famous E=Mc^2 equation, he often dictated that there was no such thing as mass, that everything was really just differential forms of energy.
Post by: Æthelwulf on 02/04/2012 11:20:47
Is it possible that time is not a measurable thing? Maybe clocks were invented for practical purposes. The projection of the future exist in our brains. The memory of the past exist in our brains. But the actual past and future never exist, right? We are trying to theorize about something that doesn’t exist. “Right now” exist and everything that “changes” in the now only changes based on our perception, the universe doesn’t know the difference between a glass and a shattered glass.
Indeed it is possible and yes, clocks really are an invention, the kind atleast we attribute to clocks hanging on walls.
Post by: MikeS on 02/04/2012 17:00:16
The energy may be nullified fundamentally. The arguement is, is that matter and geometry is not fundmental. Energy may also not be really fundamental, the reason why is because of the equation
When mass equals zero, energy is also zero and what you are left with is the metric. So when matter equals zero, this corresponds to the contention that matter does not fundmentally exist, what we end up with is energy going to zero as well. That is one solution.
Of course it does, but then you are left with "if time does not exist, mass cannot exist".
Does mass not exist?
Exactly but I would put it the other way around. If mass does not exist, time cannot exist.
For time to exist it requires both mass (gravity) and energy.
The energy may be nullified fundamentally. The arguement is, is that matter and geometry is not fundmental. Energy may also not be really fundamental, the reason why is because of the equation
When mass equals zero, energy is also zero and what you are left with is the metric. So when matter equals zero, this corresponds to the contention that matter does not fundmentally exist, what we end up with is energy going to zero as well. That is one solution.
Of course it does, but then you are left with "if time does not exist, mass cannot exist".
Does mass not exist?
Well, this was a position Einstein held. In remarks to his famous E=Mc^2 equation, he often dictated that there was no such thing as mass, that everything was really just differential forms of energy.
That does not alter what I have said above. Mass is a very concentrated form of energy. So concentrated that it possesses measurable gravity and it is gravity that is important in both creating an en-tropic arrow of time and rate of passage.
Post by: Æthelwulf on 02/04/2012 17:52:33
When the universe came into existence, time could not exist. The reason why is because there was no geometry. This is a well established fact, that at some point there where little to no degrees of freedom. It wasn't until the universe grew sufficiently old could matter appear: matter can be thought about the organization space of particles. Geometrogenesis dictates that this is when geometry also appeared, that is, geometry itself is synonymous with the presence of matter.
There are more reasons now to think that there is no time and there is no matter fundamentally. It is only the high energy physics range we are interested in, the one universally-believed to be the way to unifying the forces of nature.
Post by: yadi999 on 02/04/2012 23:10:04
They both exist just as much as the other...
If your asking does anything exist then yeh, 'I think therefore i am.' right?
Post by: Kalopin on 02/04/2012 23:26:37
I say time and money are only entities made up by man in an attempt to better organize chaos. What would either matter if there was no intelligent life to measure them?
Man thinks on such a much smaller and more accelerated scale of time than the activity in the universe. It seems a whole different level. Maybe philosophically speaking. ;)
Post by: steved1980 on 02/04/2012 23:38:14
Is it possible that time is not a measurable thing? Maybe clocks were invented for practical purposes. The projection of the future exist in our brains. The memory of the past exist in our brains. But the actual past and future never exist, right? We are trying to theorize about something that doesn’t exist. “Right now” exist and everything that “changes” in the now only changes based on our perception, the universe doesn’t know the difference between a glass and a shattered glass.
Indeed it is possible and yes, clocks really are an invention, the kind atleast we attribute to clocks hanging on walls.
It's like a schizophrenic trying to come up with an equation that proves the voice in it's head is real. His mind is creating the voice and his mind can create theories to explain it but outside his brain the voice doesn't exist.
It's funny that science is this complicated structure that can come crashing down if one little thing is removed, perception.
Post by: Æthelwulf on 03/04/2012 00:21:25
Time is the measurement of change as a metre is a measurement of distance.
They both exist just as much as the other...
If your asking does anything exist then yeh, 'I think therefore i am.' right?
As I have explained a few times, time itself is not synonymous with change. You can have frozen systems as well. There is no special relationship here.
Post by: Æthelwulf on 03/04/2012 00:22:06
Time is the measurement of change as a metre is a measurement of distance.
They both exist just as much as the other...
If your asking does anything exist then yeh, 'I think therefore i am.' right?
As I have explained a few times, time itself is not synonymous with change. You can have frozen systems as well. There is no special relationship here.
And Barbour has his own theory, where there is no time, only change. Seperate entities see.
Post by: yor_on on 03/04/2012 07:03:43
Without that 'linear' consciousness, using a arrow, we only have indeterminacy. It's our primary tool for solving any and all mysteries :)
Post by: MikeS on 03/04/2012 16:16:00
I still think it is. I can't see how you could have change without it taking place in time?Time is the measurement of change as a metre is a measurement of distance.
They both exist just as much as the other...
If your asking does anything exist then yeh, 'I think therefore i am.' right?
As I have explained a few times, time itself is not synonymous with change. You can have frozen systems as well. There is no special relationship here.
And Barbour has his own theory, where there is no time, only change. Seperate entities see.
In a truly frozen system with the temperature as close to absolute zero as possible there is no 'usable' energy available and time has effectively stopped therefore there can be no change.
Post by: Æthelwulf on 03/04/2012 16:47:35
I still think it is. I can't see how you could have change without it taking place in time?Time is the measurement of change as a metre is a measurement of distance.
They both exist just as much as the other...
If your asking does anything exist then yeh, 'I think therefore i am.' right?
As I have explained a few times, time itself is not synonymous with change. You can have frozen systems as well. There is no special relationship here.
And Barbour has his own theory, where there is no time, only change. Seperate entities see.
In a truly frozen system with the temperature as close to absolute zero as possible there is no 'usable' energy available and time has effectively stopped therefore there can be no change.
Personally, I don't understand why people can't understand change without invoking time. Neither concept are even the same thing, in many demonstrations you can speak about time without a system even changing state which is evidence alone neither concepts are truely the same. Time is more of a parameter than being the same thing in normal circumstances, or if you like it provides freedom; but time is not change itself.
Secondly, the idea of it providing freedom is the idea it is also part of geometry. What part then also amuses me why no one picks up on the obvious truth that when the universe came into existence, there was in fact no geometry one could talk of... so time is not really a real artefect of the world. If time exists, it appeared late in the universes history when matter clocks where able to define time itself. Worse off, there is no evidence time actually exists ''out there'' so thinking it does is speculation - or perhaps worse than that even, that we are projecting our own experiences on the world outside thinking it exists objectively. This is most obvious when one realizes that memories of a past and feeling a future to be expectant are all illusions of the mind. Even Einstein once said, ''the distinction of past and future are only stubbornly persistent illusions.''
Post by: yor_on on 04/04/2012 01:16:57
And I, as well as you, use 'clocks' to measure time, where the best one must be radiation. But that is the 'arrow of time', not what I call 'time'. And you're perfectly right in that clocks came at a later 'time' :) but the concept of a arrow must have a origin somewhere. Possibly as a result of there coming to be a geometry?
Post by: MikeS on 04/04/2012 05:56:28
I still think it is. I can't see how you could have change without it taking place in time?Time is the measurement of change as a metre is a measurement of distance.
They both exist just as much as the other...
If your asking does anything exist then yeh, 'I think therefore i am.' right?
As I have explained a few times, time itself is not synonymous with change. You can have frozen systems as well. There is no special relationship here.
And Barbour has his own theory, where there is no time, only change. Seperate entities see.
In a truly frozen system with the temperature as close to absolute zero as possible there is no 'usable' energy available and time has effectively stopped therefore there can be no change.
Personally, I don't understand why people can't understand change without invoking time. Neither concept are even the same thing, in many demonstrations you can speak about time without a system even changing state which is evidence alone neither concepts are truely the same. Time is more of a parameter than being the same thing in normal circumstances, or if you like it provides freedom; but time is not change itself.
Secondly, the idea of it providing freedom is the idea it is also part of geometry. What part then also amuses me why no one picks up on the obvious truth that when the universe came into existence, there was in fact no geometry one could talk of... so time is not really a real artefect of the world. If time exists, it appeared late in the universes history when matter clocks where able to define time itself. Worse off, there is no evidence time actually exists ''out there'' so thinking it does is speculation - or perhaps worse than that even, that we are projecting our own experiences on the world outside thinking it exists objectively. This is most obvious when one realizes that memories of a past and feeling a future to be expectant are all illusions of the mind. Even Einstein once said, ''the distinction of past and future are only stubbornly persistent illusions.''
I think you are wrong. You can't speak about time without a system changing state. A clock requires energy to run. No energy, or if that energy is frozen then the clock does not run. No time.
Time is change. If there is no change there is no time.
Without time, distance and hence geometry become pretty meaningless. Without mass to both define the arrow of time and to give it a time dilation factor then time as we know it does not exist but that does not preclude change. It does preclude causality. The arrow of time without mass is double ended and everything happens all at once.
The question should be is this very early state before the creation of mass a state of the universe or its precursor? Maybe it is just a very hot state within the quantum vacuum that cooled to become the Universe.
When the 'universe' cooled sufficiently for mass to form then it would meet our description of what we consider to be the Universe. At that point 'Time' came into existence.
I agree that something happened before (whatever that means as 'before' is meaningless without time) that point but whether it is correct to think of it as within or prior to the universe is debatable.
We have no reason to believe that time would not exist out there. Everywhere in the Universe there is energy and gravity so there must be local time. Thinking that time does not exist out there is pure speculation.
Post by: Æthelwulf on 04/04/2012 10:11:56
No Wulf, to me it's not the same. If you read what I wrote before it's perfectly possible to define it from locality, as you observing having a arrow, which you must as you're the one observing, although that what you observe is without change intrinsically, and so exhibiting 'no arrow' as defined from your observation. The problem comes when you want a undivided same SpaceTime, because in such a one there must be arrow encompassing both the 'frozen' object you observe, as well as yourself, and everything else existing.
And I, as well as you, use 'clocks' to measure time, where the best one must be radiation. But that is the 'arrow of time', not what I call 'time'. And you're perfectly right in that clocks came at a later 'time' :) but the concept of a arrow must have a origin somewhere. Possibly as a result of there coming to be a geometry?
Radiation fields are actually the worse kind, not the best. They don't act as clocks, which has been my point all along. The universe arose in radiation fields, not matter field. Only the latter here act as clocks.
Post by: Æthelwulf on 04/04/2012 10:25:08
I still think it is. I can't see how you could have change without it taking place in time?Time is the measurement of change as a metre is a measurement of distance.
They both exist just as much as the other...
If your asking does anything exist then yeh, 'I think therefore i am.' right?
As I have explained a few times, time itself is not synonymous with change. You can have frozen systems as well. There is no special relationship here.
And Barbour has his own theory, where there is no time, only change. Seperate entities see.
In a truly frozen system with the temperature as close to absolute zero as possible there is no 'usable' energy available and time has effectively stopped therefore there can be no change.
Personally, I don't understand why people can't understand change without invoking time. Neither concept are even the same thing, in many demonstrations you can speak about time without a system even changing state which is evidence alone neither concepts are truely the same. Time is more of a parameter than being the same thing in normal circumstances, or if you like it provides freedom; but time is not change itself.
Secondly, the idea of it providing freedom is the idea it is also part of geometry. What part then also amuses me why no one picks up on the obvious truth that when the universe came into existence, there was in fact no geometry one could talk of... so time is not really a real artefect of the world. If time exists, it appeared late in the universes history when matter clocks where able to define time itself. Worse off, there is no evidence time actually exists ''out there'' so thinking it does is speculation - or perhaps worse than that even, that we are projecting our own experiences on the world outside thinking it exists objectively. This is most obvious when one realizes that memories of a past and feeling a future to be expectant are all illusions of the mind. Even Einstein once said, ''the distinction of past and future are only stubbornly persistent illusions.''
I think you are wrong. You can't speak about time without a system changing state. A clock requires energy to run. No energy, or if that energy is frozen then the clock does not run. No time.
Time is change. If there is no change there is no time.
Without time, distance and hence geometry become pretty meaningless. Without mass to both define the arrow of time and to give it a time dilation factor then time as we know it does not exist but that does not preclude change. It does preclude causality. The arrow of time without mass is double ended and everything happens all at once.
The question should be is this very early state before the creation of mass a state of the universe or its precursor? Maybe it is just a very hot state within the quantum vacuum that cooled to become the Universe.
When the 'universe' cooled sufficiently for mass to form then it would meet our description of what we consider to be the Universe. At that point 'Time' came into existence.
I agree that something happened before (whatever that means as 'before' is meaningless without time) that point but whether it is correct to think of it as within or prior to the universe is debatable.
We have no reason to believe that time would not exist out there. Everywhere in the Universe there is energy and gravity so there must be local time. Thinking that time does not exist out there is pure speculation.
First of all, as far as quantum mechanics is concerned - if your time evolution is frozen, nothing about the system is truely physically changing. Take the zeno effect. Observe a particle and you may freeze the system in time, so to speak, nothing physical is changing.
''When the 'universe' cooled sufficiently for mass to form then it would meet our description of what we consider to be the Universe. At that point 'Time' came into existence. ''
Then we essentially agree with something. Time only becomes significant if you like, later in the universes history. Be this as it may, it makes time geometrical and not fundamental. Anyone who knows the implications of those words will come to realize that what exists fundamentally is not time - that alone has serious implications on whether it truely exists.
As for thinking time does exist out there, I think that is speculatory. What evidence do we have other than our own subjective experiences? Can you give a working example?
Post by: Æthelwulf on 04/04/2012 10:26:38
Post by: Æthelwulf on 04/04/2012 10:28:24
In fact, think of time as being emergent of matter and geometry. It's a by-product.
Perhaps the technical term would be ''induced time''.
Post by: acecharly on 04/04/2012 13:12:27
In fact, think of time as being emergent of matter and geometry. It's a by-product.
Perhaps the technical term would be ''induced time''.
so now your saying maybe some kind of time does exist then?
Post by: Æthelwulf on 04/04/2012 13:15:00
In fact, think of time as being emergent of matter and geometry. It's a by-product.
Perhaps the technical term would be ''induced time''.
so now your saying maybe some kind of time does exist then?
No.
Time is an emergent phenomenon. In other words, it's a psuedo-dimension. It's not really real.
Post by: acecharly on 04/04/2012 13:19:38
In fact, think of time as being emergent of matter and geometry. It's a by-product.
Perhaps the technical term would be ''induced time''.
so now your saying maybe some kind of time does exist then?
No.
Time is an emergent phenomenon. In other words, it's a psuedo-dimension. It's not really real.
And do these emergent phenomina not add up?
Post by: Æthelwulf on 04/04/2012 13:25:31
In fact, think of time as being emergent of matter and geometry. It's a by-product.
Perhaps the technical term would be ''induced time''.
so now your saying maybe some kind of time does exist then?
No.
Time is an emergent phenomenon. In other words, it's a psuedo-dimension. It's not really real.
And do these emergent phenomina not add up?
they are not fundamental, the kind of science is primarily interested in, in an approach to unification of the forces.
Post by: acecharly on 04/04/2012 13:35:22
Time only exists in the moment from what I can make out your saying.
Its almost asthough your not saying time does not exist but all time does not exist at once. Well it couldnt everything would have to happen at once and it doesnt from how we observe changes of our view of the world around us.
Post by: Æthelwulf on 04/04/2012 13:39:56
Can you explain how you believe the order of what is said to be 'time' takes place in the order it does. i.e why we get up eat breakfast then dinner then tea for example not just any random order.
Time only exists in the moment from what I can make out your saying.
Its almost asthough your not saying time does not exist but all time does not exist at once. Well it couldnt everything would have to happen at once and it doesnt from how we observe changes of our view of the world around us.
Yes, order appears because of the psychological arrow of time. It is this specific arrow which makes us believe there is an essential physical arrow of time to existence, which it doesn't of course. Time if anything is not linear, there is no arrow. It has geometrical features. And no, not everything needs to happen at once. From our viewpoint, nothing does happen at once. Alone, we are bradyons stuck in time; these bradyons feels time pass. Other than a subjective feeling, there is no physical reality to time.
Post by: Æthelwulf on 04/04/2012 13:41:36
Post by: acecharly on 04/04/2012 14:02:49
Post by: MikeS on 04/04/2012 14:59:46
I still think it is. I can't see how you could have change without it taking place in time?Time is the measurement of change as a metre is a measurement of distance.
They both exist just as much as the other...
If your asking does anything exist then yeh, 'I think therefore i am.' right?
As I have explained a few times, time itself is not synonymous with change. You can have frozen systems as well. There is no special relationship here.
And Barbour has his own theory, where there is no time, only change. Seperate entities see.
In a truly frozen system with the temperature as close to absolute zero as possible there is no 'usable' energy available and time has effectively stopped therefore there can be no change.
Personally, I don't understand why people can't understand change without invoking time. Neither concept are even the same thing, in many demonstrations you can speak about time without a system even changing state which is evidence alone neither concepts are truely the same. Time is more of a parameter than being the same thing in normal circumstances, or if you like it provides freedom; but time is not change itself.
Secondly, the idea of it providing freedom is the idea it is also part of geometry. What part then also amuses me why no one picks up on the obvious truth that when the universe came into existence, there was in fact no geometry one could talk of... so time is not really a real artefect of the world. If time exists, it appeared late in the universes history when matter clocks where able to define time itself. Worse off, there is no evidence time actually exists ''out there'' so thinking it does is speculation - or perhaps worse than that even, that we are projecting our own experiences on the world outside thinking it exists objectively. This is most obvious when one realizes that memories of a past and feeling a future to be expectant are all illusions of the mind. Even Einstein once said, ''the distinction of past and future are only stubbornly persistent illusions.''
I think you are wrong. You can't speak about time without a system changing state. A clock requires energy to run. No energy, or if that energy is frozen then the clock does not run. No time.
Time is change. If there is no change there is no time.
Without time, distance and hence geometry become pretty meaningless. Without mass to both define the arrow of time and to give it a time dilation factor then time as we know it does not exist but that does not preclude change. It does preclude causality. The arrow of time without mass is double ended and everything happens all at once.
The question should be is this very early state before the creation of mass a state of the universe or its precursor? Maybe it is just a very hot state within the quantum vacuum that cooled to become the Universe.
When the 'universe' cooled sufficiently for mass to form then it would meet our description of what we consider to be the Universe. At that point 'Time' came into existence.
I agree that something happened before (whatever that means as 'before' is meaningless without time) that point but whether it is correct to think of it as within or prior to the universe is debatable.
We have no reason to believe that time would not exist out there. Everywhere in the Universe there is energy and gravity so there must be local time. Thinking that time does not exist out there is pure speculation.
First of all, as far as quantum mechanics is concerned - if your time evolution is frozen, nothing about the system is truely physically changing. Take the zeno effect. Observe a particle and you may freeze the system in time, so to speak, nothing physical is changing.
''When the 'universe' cooled sufficiently for mass to form then it would meet our description of what we consider to be the Universe. At that point 'Time' came into existence. ''
Then we essentially agree with something. Time only becomes significant if you like, later in the universes history. Be this as it may, it makes time geometrical and not fundamental. Anyone who knows the implications of those words will come to realize that what exists fundamentally is not time - that alone has serious implications on whether it truely exists.
As for thinking time does exist out there, I think that is speculatory. What evidence do we have other than our own subjective experiences? Can you give a working example?
That's taking it out of context.
As I said it is debatable whether it is reasonable to call it the Universe prior to the creation of time and geometry. It would seem more reasonable perhaps to consider it the void. In which case time is fundamental. It's clearly as fundamental as gravity.
Nearly everywhere we care to look we can see distant galaxies, quasars etc as they existed billions of years ago. That's good enough evidence for me of the existence of time throughout the Universe.
Post by: Æthelwulf on 04/04/2012 15:23:50
I still think it is. I can't see how you could have change without it taking place in time?Time is the measurement of change as a metre is a measurement of distance.
They both exist just as much as the other...
If your asking does anything exist then yeh, 'I think therefore i am.' right?
As I have explained a few times, time itself is not synonymous with change. You can have frozen systems as well. There is no special relationship here.
And Barbour has his own theory, where there is no time, only change. Seperate entities see.
In a truly frozen system with the temperature as close to absolute zero as possible there is no 'usable' energy available and time has effectively stopped therefore there can be no change.
Personally, I don't understand why people can't understand change without invoking time. Neither concept are even the same thing, in many demonstrations you can speak about time without a system even changing state which is evidence alone neither concepts are truely the same. Time is more of a parameter than being the same thing in normal circumstances, or if you like it provides freedom; but time is not change itself.
Secondly, the idea of it providing freedom is the idea it is also part of geometry. What part then also amuses me why no one picks up on the obvious truth that when the universe came into existence, there was in fact no geometry one could talk of... so time is not really a real artefect of the world. If time exists, it appeared late in the universes history when matter clocks where able to define time itself. Worse off, there is no evidence time actually exists ''out there'' so thinking it does is speculation - or perhaps worse than that even, that we are projecting our own experiences on the world outside thinking it exists objectively. This is most obvious when one realizes that memories of a past and feeling a future to be expectant are all illusions of the mind. Even Einstein once said, ''the distinction of past and future are only stubbornly persistent illusions.''
I think you are wrong. You can't speak about time without a system changing state. A clock requires energy to run. No energy, or if that energy is frozen then the clock does not run. No time.
Time is change. If there is no change there is no time.
Without time, distance and hence geometry become pretty meaningless. Without mass to both define the arrow of time and to give it a time dilation factor then time as we know it does not exist but that does not preclude change. It does preclude causality. The arrow of time without mass is double ended and everything happens all at once.
The question should be is this very early state before the creation of mass a state of the universe or its precursor? Maybe it is just a very hot state within the quantum vacuum that cooled to become the Universe.
When the 'universe' cooled sufficiently for mass to form then it would meet our description of what we consider to be the Universe. At that point 'Time' came into existence.
I agree that something happened before (whatever that means as 'before' is meaningless without time) that point but whether it is correct to think of it as within or prior to the universe is debatable.
We have no reason to believe that time would not exist out there. Everywhere in the Universe there is energy and gravity so there must be local time. Thinking that time does not exist out there is pure speculation.
First of all, as far as quantum mechanics is concerned - if your time evolution is frozen, nothing about the system is truely physically changing. Take the zeno effect. Observe a particle and you may freeze the system in time, so to speak, nothing physical is changing.
''When the 'universe' cooled sufficiently for mass to form then it would meet our description of what we consider to be the Universe. At that point 'Time' came into existence. ''
Then we essentially agree with something. Time only becomes significant if you like, later in the universes history. Be this as it may, it makes time geometrical and not fundamental. Anyone who knows the implications of those words will come to realize that what exists fundamentally is not time - that alone has serious implications on whether it truely exists.
As for thinking time does exist out there, I think that is speculatory. What evidence do we have other than our own subjective experiences? Can you give a working example?
That's taking it out of context.
As I said it is debatable whether it is reasonable to call it the Universe prior to the creation of time and geometry. It would seem more reasonable perhaps to consider it the void. In which case time is fundamental. It's clearly as fundamental as gravity.
Nearly everywhere we care to look we can see distant galaxies, quasars etc as they existed billions of years ago. That's good enough evidence for me of the existence of time throughout the Universe.
I strongly protest that your vision of time is fundamental. It is certainly not a void prior to the matter fields. If it truely is a void, then you may as well go for a nullified approach: nullify all matter and energy, including appreciating there is no time.
Anyway, I don't see looking at systems, whether those being distant galaxies or being a dice rolled on a table. There are reasons why prominent scientists like Rovelli and Barbour are in fact saying this is a timeless universe. Do you not realize that these scientists are quite aware of similar questions you are posing. There are obvious reasons why simply observing a system is not evidence for time.
In fact, I should write up a thread on time myself and explain it in my terms.
Post by: Æthelwulf on 04/04/2012 16:12:23
ah so maybe our perception of time is our perception of change which are exactly the same thing with a different title. Time is not the ticking of a watch it is just a change of state.
I like your thinking, but to think the perception of change is the same as the perception of time has atleast an underlying problem: that change and time are not synonymous. Nor is perception inherently the same as the outside world. One major problem we don't understand in neuroscience, is how the brain actually takes a two dimesnsional object and recasts it into the three dimensional phenomenon - in fact, our brain takes signals from the outside world and recreates it in our brains, creates if you like, a type of holograph of the world in the name of perception. Our feelings of the world, and the real world at large, are two different types of realities, completely.
Post by: MikeS on 04/04/2012 16:52:32
quote
"There are obvious reasons why simply observing a system is not evidence for time."
It's certainly not obvious to me. Perhaps you would care to explain?
Post by: Æthelwulf on 04/04/2012 16:55:32
Æthelwulf
quote
"There are obvious reasons why simply observing a system is not evidence for time."
It's certainly not obvious to me. Perhaps you would care to explain?
I've told you sir countless times. The zeno effect punches holes in the change equals time motive.
Observe a system and you may suspend any changes in it's evolution. As far as quantum mechanics is concerned, you observe a system, you may actually suspend it's evolution... but if time still existed, how can time and change be synonymous... if anything, time, change and static should all mean the same thing. But I don't go as far as that. I draw the line somewhere. Guess where?
Post by: MikeS on 05/04/2012 06:24:19
"The arrow paradox
“ If everything when it occupies an equal space is at rest, and if that which is in locomotion is always occupying such a space at any moment, the flying arrow is therefore motionless. ”
—Aristotle, Physics VI:9, 239b5
In the arrow paradox (also known as the fletcher's paradox), Zeno states that for motion to occur, an object must change the position which it occupies. He gives an example of an arrow in flight. He states that in any one (durationless) instant of time, the arrow is neither moving to where it is, nor to where it is not.[11] It cannot move to where it is not, because no time elapses for it to move there; it cannot move to where it is, because it is already there. In other words, at every instant of time there is no motion occurring. If everything is motionless at every instant, and time is entirely composed of instants, then motion is impossible.
Whereas the first two paradoxes presented divide space, this paradox starts by dividing time—and not into segments, but into points.[12]"
http://en.wikipedia.org/wiki/Zeno's_paradoxes
This paradox fails as it assumes every instant to be timeless. Whereas every instant in time is not zero but equals planck time.
"Nick Huggett argues that Zeno is begging the question when he says that objects that occupy the same space as they do at rest must be at rest.[12]
Hans Reichenbach has proposed that the paradox may arise from considering space and time as separate entities. In a theory like general relativity, which presumes a single space-time continuum, the paradox may be blocked.[27]"
http://en.wikipedia.org/wiki/Zeno's_paradoxes
That seems to be how the macro world works. The quantum world is strange.
Post by: yor_on on 05/04/2012 08:32:30
No Wulf, to me it's not the same. If you read what I wrote before it's perfectly possible to define it from locality, as you observing having a arrow, which you must as you're the one observing, although that what you observe is without change intrinsically, and so exhibiting 'no arrow' as defined from your observation. The problem comes when you want a undivided same SpaceTime, because in such a one there must be arrow encompassing both the 'frozen' object you observe, as well as yourself, and everything else existing.
And I, as well as you, use 'clocks' to measure time, where the best one must be radiation. But that is the 'arrow of time', not what I call 'time'. And you're perfectly right in that clocks came at a later 'time' :) but the concept of a arrow must have a origin somewhere. Possibly as a result of there coming to be a geometry?
Radiation fields are actually the worse kind, not the best. They don't act as clocks, which has been my point all along. The universe arose in radiation fields, not matter field. Only the latter here act as clocks.
Sorry, now you lost me. The constant 'c' is the worst 'clock'?
Why?
Because you find it to be a constant?
Radiation is the ultimate clock you can find as far as I'm concerned :)
And it is the same locally everywhere.
Post by: Æthelwulf on 05/04/2012 09:15:50
No Wulf, to me it's not the same. If you read what I wrote before it's perfectly possible to define it from locality, as you observing having a arrow, which you must as you're the one observing, although that what you observe is without change intrinsically, and so exhibiting 'no arrow' as defined from your observation. The problem comes when you want a undivided same SpaceTime, because in such a one there must be arrow encompassing both the 'frozen' object you observe, as well as yourself, and everything else existing.
And I, as well as you, use 'clocks' to measure time, where the best one must be radiation. But that is the 'arrow of time', not what I call 'time'. And you're perfectly right in that clocks came at a later 'time' :) but the concept of a arrow must have a origin somewhere. Possibly as a result of there coming to be a geometry?
Radiation fields are actually the worse kind, not the best. They don't act as clocks, which has been my point all along. The universe arose in radiation fields, not matter field. Only the latter here act as clocks.
Sorry, now you lost me. The constant 'c' is the worst 'clock'?
Why?
Because you find it to be a constant?
Radiation is the ultimate clock you can find as far as I'm concerned :)
And it is the same locally everywhere.
Well you must know that time does not pass for photons?
Post by: Æthelwulf on 05/04/2012 09:17:02
If your theory relies upon the zeno effect which seems to be an explainable paradox then it is on a shaky footing.
"The arrow paradox
“ If everything when it occupies an equal space is at rest, and if that which is in locomotion is always occupying such a space at any moment, the flying arrow is therefore motionless. ”
—Aristotle, Physics VI:9, 239b5
In the arrow paradox (also known as the fletcher's paradox), Zeno states that for motion to occur, an object must change the position which it occupies. He gives an example of an arrow in flight. He states that in any one (durationless) instant of time, the arrow is neither moving to where it is, nor to where it is not.[11] It cannot move to where it is not, because no time elapses for it to move there; it cannot move to where it is, because it is already there. In other words, at every instant of time there is no motion occurring. If everything is motionless at every instant, and time is entirely composed of instants, then motion is impossible.
Whereas the first two paradoxes presented divide space, this paradox starts by dividing time—and not into segments, but into points.[12]"
http://en.wikipedia.org/wiki/Zeno's_paradoxes
This paradox fails as it assumes every instant to be timeless. Whereas every instant in time is not zero but equals planck time.
"Nick Huggett argues that Zeno is begging the question when he says that objects that occupy the same space as they do at rest must be at rest.[12]
Hans Reichenbach has proposed that the paradox may arise from considering space and time as separate entities. In a theory like general relativity, which presumes a single space-time continuum, the paradox may be blocked.[27]"
http://en.wikipedia.org/wiki/Zeno's_paradoxes
That seems to be how the macro world works. The quantum world is strange.
Ahem, I am saying change is not necessery over time! If indeed time exists, then some things don't change and the zeno effect is a PERFECT example.
Post by: Æthelwulf on 05/04/2012 10:08:40
No Wulf, to me it's not the same. If you read what I wrote before it's perfectly possible to define it from locality, as you observing having a arrow, which you must as you're the one observing, although that what you observe is without change intrinsically, and so exhibiting 'no arrow' as defined from your observation. The problem comes when you want a undivided same SpaceTime, because in such a one there must be arrow encompassing both the 'frozen' object you observe, as well as yourself, and everything else existing.
And I, as well as you, use 'clocks' to measure time, where the best one must be radiation. But that is the 'arrow of time', not what I call 'time'. And you're perfectly right in that clocks came at a later 'time' :) but the concept of a arrow must have a origin somewhere. Possibly as a result of there coming to be a geometry?
Radiation fields are actually the worse kind, not the best. They don't act as clocks, which has been my point all along. The universe arose in radiation fields, not matter field. Only the latter here act as clocks.
Sorry, now you lost me. The constant 'c' is the worst 'clock'?
Why?
Because you find it to be a constant?
Radiation is the ultimate clock you can find as far as I'm concerned :)
And it is the same locally everywhere.
Well you must know that time does not pass for photons?
I actually honor myself for being able to talk about physics to people, so let me try and explain this better.
If we have two moving clocks, Bob and Alice, both of them possess frames of reference to measure time. However, as they approach the speed of light, both observers measure a time dilation. If Alice was magical, and managed to move to the speed of light, something remarkable would happen. Bob will still measure her speeding off a way ahead, but something strange has happened to Alice. Dilation has stretched to infinity. Indeed, when we speak about infinities they usually do not purport to reality, so sometimes many physicists agree to state that, Alice no longer really has a frame of reference.
Post by: JP on 05/04/2012 10:43:14
Post by: Æthelwulf on 05/04/2012 10:59:30
Photons don't have a frame of reference, so calling them timeless is misleading. The step in your argument when Alice becomes "magical" and reaches the speed of light breaks the laws of physics, so you can't meaningfully use them anymore. This includes predicting what a clock carried by Alice does.
Bolded by me. I actually said that at the end.
This was a thought experiment JP, to show that you can't talk about time purely for radiation fields - they don't make good clocks.
Are you disagreeing with this?
Post by: imatfaal on 05/04/2012 12:30:09
Post by: Æthelwulf on 05/04/2012 12:34:00
A thought experiment which includes a massive object travelling at light speed cannot derive anything from special relativity
Could you my friend, elaborate your point a bit better?
Special Relativity deals with moving clocks in a flat spacetime. It's only approximately correct, which is why GR was created.
Post by: imatfaal on 05/04/2012 13:44:23
A thought experiment which includes a massive object travelling at light speed cannot derive anything from special relativity
Could you my friend, elaborate your point a bit better?
Special Relativity deals with moving clocks in a flat spacetime. It's only approximately correct, which is why GR was created.
You have posited a thought experiment based on special relativity . SR does not admit to a frame of reference for a massive object that moves at the speed of light. Anything you get out of the thought experiment is bust, because you broke one of the axioms of SR to start with; gigo.
On your second point - SR is only approx correct, yes but so what; in the small enough local limit curved space time will approximate flat and anyways your thought experiment was very much an SR thang not GR
Post by: Æthelwulf on 05/04/2012 13:50:54
A thought experiment which includes a massive object travelling at light speed cannot derive anything from special relativity
Could you my friend, elaborate your point a bit better?
Special Relativity deals with moving clocks in a flat spacetime. It's only approximately correct, which is why GR was created.
You have posited a thought experiment based on special relativity . SR does not admit to a frame of reference for a massive object that moves at the speed of light. Anything you get out of the thought experiment is bust, because you broke one of the axioms of SR to start with; gigo.
On your second point - SR is only approx correct, yes but so what; in the small enough local limit curved space time will approximate flat and anyways your thought experiment was very much an SR thang not GR
I can see why it might be appealing to say ''so what?'' however, it's a big reason because GR is global not local like SR. It's like approximating a local neighbourhood of a black hole. The space might be flat, but it does not describe the system in totality.
Post by: Manoo on 05/04/2012 15:13:14
Even what is described as 'stationary' is only relative to some motion.
Motion occurs through time: there are no instantaneous reactions in nature.
Motion through space is also motion through time (and change is also motion).
Space is, therefore, a proxy for time.
Any movement through space is also a movement through time. Even if you return to the same space, it is not the 'same' because it is in a different moment in time.
As long as there is space, time exists.
Space and time are indivisible.
Post by: Æthelwulf on 05/04/2012 16:19:50
Everything (all matter) is in motion.
Even what is described as 'stationary' is only relative to some motion.
Motion occurs through time: there are no instantaneous reactions in nature.
Motion through space is also motion through time (and change is also motion).
Space is, therefore, a proxy for time.
Any movement through space is also a movement through time. Even if you return to the same space, it is not the 'same' because it is in a different moment in time.
As long as there is space, time exists.
Space and time are indivisible.
One problem, relativity says time does not exist, so you can say all you did above, just try and interpret it without time, now it becomes difficult.
Post by: yor_on on 06/04/2012 08:44:29
No Wulf, to me it's not the same. If you read what I wrote before it's perfectly possible to define it from locality, as you observing having a arrow, which you must as you're the one observing, although that what you observe is without change intrinsically, and so exhibiting 'no arrow' as defined from your observation. The problem comes when you want a undivided same SpaceTime, because in such a one there must be arrow encompassing both the 'frozen' object you observe, as well as yourself, and everything else existing.
And I, as well as you, use 'clocks' to measure time, where the best one must be radiation. But that is the 'arrow of time', not what I call 'time'. And you're perfectly right in that clocks came at a later 'time' :) but the concept of a arrow must have a origin somewhere. Possibly as a result of there coming to be a geometry?
Radiation fields are actually the worse kind, not the best. They don't act as clocks, which has been my point all along. The universe arose in radiation fields, not matter field. Only the latter here act as clocks.
Sorry, now you lost me. The constant 'c' is the worst 'clock'?
Why?
Because you find it to be a constant?
Radiation is the ultimate clock you can find as far as I'm concerned :)
And it is the same locally everywhere.
Well you must know that time does not pass for photons?
Yes, but radiation measure the arrow to us still.
And I can't think of anything more precise?
You might find this interesting. NIST. (http://www.nist.gov/pml/div688/logic_clock.cfm)
"NIST scientists use lasers to cool the two ions which are held 4 thousandths of a millimeter apart in an electromagnetic trap. Aluminum is the larger of the two ions, while the beryllium emits light under the conditions of this experiment. Scientists hit the ions with pulses from a "clock laser" within a narrow frequency range. If the laser frequency is at the center of the frequency range, the precise "resonance frequency" of aluminum, this ion jumps to a higher energy level, or 1 in the binary language of computers. Otherwise, the ion remains in the lower energy state, or 0.
If there is no change in the aluminum ion, then another laser pulse causes both ions to begin rocking side to side in unison because of their physical proximity and the interaction of their electrical charges. An additional laser pulse converts this motion into a change in the internal energy level of the beryllium ion. This pulse reverses the direction of the ion's magnetic "spin," and the beryllium goes dark, a signal that the aluminum remained in the 0 state.
On the other hand, if the aluminum ion jumps to the higher energy level, then the additional laser pulses fail to stimulate a shared rocking motion and have no effect on the beryllium ion, which keeps emitting light. Scientists detect this light as a signal that the aluminum ion jumped from 0 to 1.
The goal is to tune the clock laser to the exact frequency that prompts the aluminum to jump from 0 to 1. The actual measurement of the ticking of the clock is provided not by the ions but rather by the clock laser's precisely tuned center frequency, which is measured with a "frequency comb," a tool for measuring very high optical frequencies, or colors of light."
Post by: Aksgenius1997 on 07/04/2012 05:41:40
Post by: yor_on on 07/04/2012 14:46:02
But we haven't a precise definition of it. Although if you believe in your math solely? You might exchange it.
While you're doing that, you're inside the arrow.
Post by: Æthelwulf on 07/04/2012 16:35:18
Time Cannot be called an illusion. Its a part of space-time. It can also be called the 4th dimension. You move because of time. Time is like a snake's movement. It can go Zig-Zag,straight, 90 degree turned. It passes through you. O8)
I move because of time?
I do enjoy these little physics lessons I get from people time to time at this place. And here was me thinking that a body has motion because of kinetic energy.
And as I have said before, it is true that Minkowski space is a manifold which treats time as a space dimension, but I have also explained that before that understanding, Relativity described space quite well. Perhaps it was indeed a little bit more complicated, but we could still deal with spatial dimensions without time. If special relativity was the sister theory, it's brother theory General Relativity seems to be pointing towards the idea that time does not exist, or atleast time does not change in a global sense.
Post by: Æthelwulf on 07/04/2012 16:37:48
No Wulf, to me it's not the same. If you read what I wrote before it's perfectly possible to define it from locality, as you observing having a arrow, which you must as you're the one observing, although that what you observe is without change intrinsically, and so exhibiting 'no arrow' as defined from your observation. The problem comes when you want a undivided same SpaceTime, because in such a one there must be arrow encompassing both the 'frozen' object you observe, as well as yourself, and everything else existing.
And I, as well as you, use 'clocks' to measure time, where the best one must be radiation. But that is the 'arrow of time', not what I call 'time'. And you're perfectly right in that clocks came at a later 'time' :) but the concept of a arrow must have a origin somewhere. Possibly as a result of there coming to be a geometry?
Radiation fields are actually the worse kind, not the best. They don't act as clocks, which has been my point all along. The universe arose in radiation fields, not matter field. Only the latter here act as clocks.
Sorry, now you lost me. The constant 'c' is the worst 'clock'?
Why?
Because you find it to be a constant?
Radiation is the ultimate clock you can find as far as I'm concerned :)
And it is the same locally everywhere.
Well you must know that time does not pass for photons?
Yes, but radiation measure the arrow to us still.
And I can't think of anything more precise?
You might find this interesting. NIST. (http://www.nist.gov/pml/div688/logic_clock.cfm)
"NIST scientists use lasers to cool the two ions which are held 4 thousandths of a millimeter apart in an electromagnetic trap. Aluminum is the larger of the two ions, while the beryllium emits light under the conditions of this experiment. Scientists hit the ions with pulses from a "clock laser" within a narrow frequency range. If the laser frequency is at the center of the frequency range, the precise "resonance frequency" of aluminum, this ion jumps to a higher energy level, or 1 in the binary language of computers. Otherwise, the ion remains in the lower energy state, or 0.
If there is no change in the aluminum ion, then another laser pulse causes both ions to begin rocking side to side in unison because of their physical proximity and the interaction of their electrical charges. An additional laser pulse converts this motion into a change in the internal energy level of the beryllium ion. This pulse reverses the direction of the ion's magnetic "spin," and the beryllium goes dark, a signal that the aluminum remained in the 0 state.
On the other hand, if the aluminum ion jumps to the higher energy level, then the additional laser pulses fail to stimulate a shared rocking motion and have no effect on the beryllium ion, which keeps emitting light. Scientists detect this light as a signal that the aluminum ion jumped from 0 to 1.
The goal is to tune the clock laser to the exact frequency that prompts the aluminum to jump from 0 to 1. The actual measurement of the ticking of the clock is provided not by the ions but rather by the clock laser's precisely tuned center frequency, which is measured with a "frequency comb," a tool for measuring very high optical frequencies, or colors of light."
I think you are not quite understanding what I mean. Forget matter. Forget us that is measuring this radiation. I am talking about when the universe first came into existence, there was only radiation fields. None of these radiation fields ticked away time.
Post by: Geezer on 07/04/2012 18:52:46
I do enjoy these little physics lessons I get from people time to time at this place.
If you want to continue receiving physics lessons at this place, you better omit the condescending comments.
MODERATOR
Post by: Æthelwulf on 07/04/2012 20:00:37
I do enjoy these little physics lessons I get from people time to time at this place.
If you want to continue receiving physics lessons at this place, you better omit the condescending comments.
MODERATOR
Then I am personally going to take time out from posting here. I don't mean to be condescending, I am just sick of rehashing statements I have made countless times now.
Post by: annie123 on 08/04/2012 21:59:46
Be as smart as you can, but remember that it is always better to be wise than to be smart.
Alan Alda
Be smart, but never show it.
Louis B. Mayer
Post by: yor_on on 09/04/2012 07:43:24
Post by: MikeS on 09/04/2012 08:03:44
Nice one.
Post by: yor_on on 09/04/2012 09:51:36
Otherwise I would agree, if I assume radiation without propagation.
Post by: MikeS on 10/04/2012 07:51:22
Radiation is energy, measurable. As soon you get that you need a arrow, if we assume a propagation. Without assuming a propagation you have indeterminacy, but if assuming 'constant emanations' of radiation at some spatially defined 'place' there must be some aspect of a 'arrow' to make it definable.
Otherwise I would agree, if I assume radiation without propagation.
Or, propagating in both time directions simultaneously. (Which is not time)
You need mass to give that propagation a direction in time and a finite speed.
Post by: Æthelwulf on 11/04/2012 00:33:01
Radiation is energy, measurable. As soon you get that you need a arrow, if we assume a propagation. Without assuming a propagation you have indeterminacy, but if assuming 'constant emanations' of radiation at some spatially defined 'place' there must be some aspect of a 'arrow' to make it definable.
Otherwise I would agree, if I assume radiation without propagation.
Yes... In which case ironically enough I was talking about a second ago, there is no preferred directionality of time, meaning time certainly could not have an arrow, but it doesn't defete the idea that perhaps information is shared in a ''handshake'' as Doctor Cramer puts it through what we might call time.
Or, propagating in both time directions simultaneously. (Which is not time)
You need mass to give that propagation a direction in time and a finite speed.
Post by: Æthelwulf on 11/04/2012 00:37:22
Radiation is energy, measurable. As soon you get that you need a arrow, if we assume a propagation. Without assuming a propagation you have indeterminacy, but if assuming 'constant emanations' of radiation at some spatially defined 'place' there must be some aspect of a 'arrow' to make it definable.
Otherwise I would agree, if I assume radiation without propagation.
Only from slow matter can radiation move from one point to another. If you were a photon, you would not see anyone elses frame of reference.
Atleast accept that space and time arose from no space or time. And even the short moments in which space was about to arrange along with time needed to inlude real, slow moving (or atleast relativistically-speaking) matter.
Then GR cannot speak about time or matter when the universe appeared. In fact, any theory entertaining time as a real dimension and maybe even those who take space as fundamental, must be seriously missing the holy grail. Afterall, the universe appeared from no space and no time, atleast fundmentally.
Post by: MikeS on 12/04/2012 05:52:06
Well we agree on something, I have always thought that before the Universe there was no space and no time.
Post by: JP on 12/04/2012 09:28:38
Æthelwulf
Well we agree on something, I have always thought that before the Universe there was no space and no time.
Of course, using the word 'before' implies there was time...
Post by: @/antic on 12/04/2012 10:56:21
Post by: MikeS on 12/04/2012 12:04:46
Yes that one keeps cropping up. There was obviously something in which things happened but defining what it was requires time and the language of time, length and causality. I think it is probably fair to say something happened in the void before the universe that led to the universe. Although we are essentially only familiar with time flowing in one direction there is nothing to say that time cannot flow in both directions instantly simultaneously. However, it then is not time, by our definition of time. Once time came into existence and we can relate it to something that led up to it, I think it is fair to call it before, even if before was meaningless before time, before the beginning of the universe. It is no longer meaningless from the perspective of time.
Post by: simplified on 12/04/2012 18:58:10
Time and energy are reasons of movements.You use the same word "time" for definition of sequence of events.Æthelwulf
Well we agree on something, I have always thought that before the Universe there was no space and no time.
Of course, using the word 'before' implies there was time...
Post by: Geezer on 12/04/2012 19:10:23
You use the same word "time" for definition of sequence of events.
Sorry - that won't work either. You can't have a "sequence" without time, so you are using time to define time.
Nice try though.
Post by: simplified on 12/04/2012 19:44:53
People are using the one word to two different values.I'll try to make math of time in New Theories.
You use the same word "time" for definition of sequence of events.
so you are using time to define time.
Post by: Æthelwulf on 14/04/2012 05:47:53
People are using the one word to two different values.I'll try to make math of time in New Theories.
You use the same word "time" for definition of sequence of events.
so you are using time to define time.
Let me lead you on a hypothetical way to approach this ''math'' you will conjecture: none of it however I take seriously.
If I was to entertain some ''arrow'' of time, you'd think of time as being linear. Even though time is not linear, you'd also model the past as being something real, which it's not. But hey ho, I am here to entertain the idea for a bit.
This would mean the past + a time delay, equals the present moment, if
was the past, 
was a time delay and 
was the present time. This seems pretty much correct for a linear view of time and for a sentient being. Afterall, our present moment is in fact information with a time delay: information our brain processes from one point to another is in fact information collected of a situation which lay in our pasts, and the time delay is what it takes for that information to get processed in our own present time sphere. In a similar tune, you can rearrange this formula for the past.
By simply rearranging our formula here, we have the past equalling the present moment minus some time delay. Of course, this time delay might be large or small, but for the comparrison of sentient beings, we may consider it as a small time delay. The future then would be:
If
was our future, then it is made by calculating the present moment including some time delay. To make a distinction of a time delay made in the past to the future however, we perhaps should denote 
for two unique systems. But time is not linear, time cannot be described in this way, nor does it make sense taking about the ''now'' in terms of things which might have passed and things yet too.
Post by: simplified on 15/04/2012 13:44:56
Don't forget that your math is not my math. :PPeople are using the one word to two different values.I'll try to make math of time in New Theories.
You use the same word "time" for definition of sequence of events.
so you are using time to define time.
Let me lead you on a hypothetical way to approach this ''math'' you will conjecture: none of it however I take seriously.
Post by: wwwwwhizz on 15/04/2012 22:00:05
Post by: Æthelwulf on 16/04/2012 18:24:53
Those who stand in the camp of timelessness know who they are, equally for those who don't, despite how flawed we may think the former or latter is.
Post by: Æthelwulf on 16/04/2012 18:26:41
I predict most of us will move away from this discussion. I can see people agreeing with timelessness and those who still see change synonymous with time.
Those who stand in the camp of timelessness know who they are, equally for those who don't, despite how flawed we may think the former or latter is.
I will leave one last food for thought. Time if it is a dimension, still is not responsible for movement or moving bodies more precisely. In physics, we know that the kinetic energy of bodies are responsible for moving bodies, not time. Time if it exists, is a degree of freedom, not the reason why things move.
Post by: MikeS on 17/04/2012 06:11:04
I predict most of us will move away from this discussion. I can see people agreeing with timelessness and those who still see change synonymous with time.
Those who stand in the camp of timelessness know who they are, equally for those who don't, despite how flawed we may think the former or latter is.
I will leave one last food for thought. Time if it is a dimension, still is not responsible for movement or moving bodies more precisely. In physics, we know that the kinetic energy of bodies are responsible for moving bodies, not time. Time if it exists, is a degree of freedom, not the reason why things move.
I don't think anyone ever said it was.
Post by: Æthelwulf on 17/04/2012 06:15:44
I predict most of us will move away from this discussion. I can see people agreeing with timelessness and those who still see change synonymous with time.
Those who stand in the camp of timelessness know who they are, equally for those who don't, despite how flawed we may think the former or latter is.
I will leave one last food for thought. Time if it is a dimension, still is not responsible for movement or moving bodies more precisely. In physics, we know that the kinetic energy of bodies are responsible for moving bodies, not time. Time if it exists, is a degree of freedom, not the reason why things move.
I don't think anyone ever said it was.
Yes they have. Someone recently said it and it has stuck in my mind. I believe they said ''energy and time is the reason for movement''.
Then someone before this said plainly that time was responsible for movement. Atleast two people have made this statement. I even received a warning for replying to one of them, supposedly, ''in a condescending manner.'' So I remember this well.
Post by: simplified on 22/04/2012 05:06:54
I did. http://www.thenakedscientists.com/forum/index.php?topic=43852.0I predict most of us will move away from this discussion. I can see people agreeing with timelessness and those who still see change synonymous with time.
Those who stand in the camp of timelessness know who they are, equally for those who don't, despite how flawed we may think the former or latter is.
I will leave one last food for thought. Time if it is a dimension, still is not responsible for movement or moving bodies more precisely. In physics, we know that the kinetic energy of bodies are responsible for moving bodies, not time. Time if it exists, is a degree of freedom, not the reason why things move.
I don't think anyone ever said it was.
Post by: Mad Mark on 22/04/2012 23:45:14
Maybe ,maybe not. Either way i'm going to need time to think about that!
Post by: Aksgenius1997 on 14/12/2012 11:58:35
Time Cannot be called an illusion. Its a part of space-time. It can also be called the 4th dimension. You move because of time. Time is like a snake's movement. It can go Zig-Zag,straight, 90 degree turned. It passes through you. O8)
I move because of time?
I do enjoy these little physics lessons I get from people time to time at this place. And here was me thinking that a body has motion because of kinetic energy.
And as I have said before, it is true that Minkowski space is a manifold which treats time as a space dimension, but I have also explained that before that understanding, Relativity described space quite well. Perhaps it was indeed a little bit more complicated, but we could still deal with spatial dimensions without time. If special relativity was the sister theory, it's brother theory General Relativity seems to be pointing towards the idea that time does not exist, or atleast time does not change in a global sense.
You don't get it, do you?
Let me explain.
The formula for kinetic energy is = mv2/2
i.e. Mass/*Velocity square divided by 2
Velocity = Displacement/time
So, Kinetic Energy is related to time. This kinetic Energy Exists in space because of time. As We are the 3rd dimension We don't understand the further dimensions (as an object is any dimension can't understand (or see) the further dimensions.
Post by: Bill S on 24/12/2012 23:31:21
Post by: yor_on on 29/12/2012 08:39:38
Post by: Pmb on 29/12/2012 10:29:13
I would like to know what orthodox physicists think of Julian Barbour's radical ideas about time. This also relates to he quantum mechanics theories that i also have a post about.Ignore Julian Barbour. From what I read of his work he only uses semantics to argue his point. I.e. he chooses specific definitions of things like "real" and "exist" etc and then makes arguements such that using his basic assumptions he gets the answers he wanted to arrive at.
"Barbour argues that we live in a universe which has neither past nor future. A strange new world in which we are alive and dead in the same instant. In this eternal present, our sense of the passage of time is nothing more than a giant cosmic illusion." Discover Mag.
He says that there is no time, only change.Does he have a following?
Time is simply a concept we use to describe the fact the things in nature change in more than a merely spatial manner. Making more of it than that is merely a way to come up with little ideas to sell books and publish etc. In the end what does it give you?
Post by: Bill S on 03/01/2013 18:03:31
I struggled with Barbour's "The End of Time", and wondered if the impression I had that he was at times creating definitions to suit his arguments arose from my lack of understanding.
However, I was fascinated by his concept of “Platonia”, presented as a timeless “land” in which nothing happens, but everything exists. (I apologise to Julian Barbour if this is a misrepresentation of Platonia or if I should have seen more through the coloured mists that shroud that land). The particular reason for my interest was that there seemed to be considerable similarity between the concept of Platonia and the idea of a cosmos that was infinite, timeless and changeless, at which I had arrived, albeit by a much less scientific path, some time ago.
The two ideas share some problems. The difficulties of describing a timeless arena are comparable to those of describing an infinite arena. In both cases it seems that time-dependent descriptions become unavoidable. Barbour talks about experiencing instants, one at a time. The idea of experiencing instants “one at a time” surely implies a passage of time. I accept that the passage of time may be only in our perception, but how do we distinguish between “reality” and our perceptions of reality? Is there, in fact, any difference?
Linked to the difficulty of distinguishing between perception and reality is the difficulty of imagining our world of three spatial dimensions embedded in a universe of many, or even infinite, dimensions. Barbour says:
“….when we think we see motion at some instant, the underlying reality is that our brain at that instant contains data corresponding to several different positions of the object perceived to be in motion. My brain contains, at any one instant, several ‘snapshots’ at once. The brain, through the way in which it presents data to consciousness, somehow ‘plays the movie’ for me.”
What I believe we have to acknowledge is that, even if we accept Barbour’s idea that time and motion are all in our heads, our perception is, and has to be, our reality. So, if our perception is our reality; progression from one snapshot to another must be real.
The same sort of problem arises with the idea of regarding time as a series of “snapshots”. David Deutsch and Barbour both make use of these snapshots, but in order to make distinctly different points. However, in both cases, some degree of sequential experience must be assumed in order to (in Deutsch’s case) realise the universe you are in, and (in Barbour’s case) to produce the impression of motion, or the passage of time, where none is actually present.
Of course, the same problem arises if one tries to distinguish any two points in an infinite “landscape”, so it will be obvious that I am not trying to use these examples in order to detract from Barbour’s basic idea; because as I pointed out above, it does seem to jibe with my own thoughts, which is always gratifying. However, I think it is important to stress the difficulties involved in trying to describe either the infinite, or the timeless, without recourse to finite and time-dependent terminology, since our lives are intimately entwined in both time and finite dimensions.
Post by: Pmb on 16/10/2013 12:37:13
Quote from: imatfaal
In quantum mechanics every variable (position, momentum, angular momentum, spin, energy, and many tothers) is able to be represented by a Hermitian operator ...Sorry for commenting on an old post but I just came across this one while reviewing the thread.
Not all variables in quantum mechanics can be represented by a Hermitian operator. Only those corresponding to observables are Hermitian.
A good example of a variable which is not an observable and therefore has no corresponding QM operator is a phasor.
Post by: webplodder on 19/10/2013 15:11:00
I can't see how to ignore times arrow? Not here and now anyway. We have the idea of quantum computers as well as how all paths are take simultaneously with only one path 'left' to us finally (by its probability) and this could maybe been seen as a 'state' of timelessness. But it's not here, we live by outcomes, and those define all physics.
How do we really know that event b is an outcome of event a? What if, instead, events a and b are somehow "paired" together or correlated such that they are predetermined to occur within some frame of reference and that their causal relationship is just an illusion? Commonsense has taught us that if we drop an apple it falls to earth but why should the order of these events always be from the same direction? Why can't we introduce the idea of "negative time" where the causal relationship is reversed? It seems to me that it is because we separate things out from one another that the concept of causality arises and at a fundamental level reality may be non-local and unified so that every event exists now and time has no meaning. Could "spooky action at a distance" be pointing to this?
Post by: Bill S on 19/10/2013 15:49:05
Quote from: Webplodder
Why can't we introduce the idea of "negative time" where the causal relationship is reversed? It seems to me that it is because we separate things out from one another that the concept of causality arises and at a fundamental level reality may be non-local and unified so that every event exists now and time has no meaning. Could "spooky action at a distance" be pointing to this?
I suspect that negative time would raise some complications, as well as upsetting “Bill Ockham”.
You could achieve the same thing, e.g. explaining "spooky action at a distance", by arguing that our Universe is a finite Universe “embedded” in an infinite cosmos. The problem with both approaches is that they require assumptions that scientists have problems with. :)
I think the idea of negative time could provoke some interesting discussion though. Go for it, Webplodder!
Post by: Pmb on 22/10/2013 07:19:37
Quote from: webplodder
How do we really know that event b is an outcome of event a?That can only be answered in specific instances. We develope laws of cause and effect by experimentation and observation. Then we postulate causes and effects. Saying that we "know" them as such gets deep into sematics and epistemology.
Quote from: webplodder
What if, instead, events a and b are somehow "paired" together or correlated such that they are predetermined to occur within some frame of reference and that their causal relationship is just an illusion?I'm sure that happens a great deal of the time. But that's outside the laws of nature and now you're talking about something else.
Quote from: webplodder
Commonsense has taught us that if we drop an apple it falls to earth but why should the order of these events always be from the same direction?What do you mean when you speak of events being from a direction?
Quote from: webplodder
Why can't we introduce the idea of "negative time" where the causal relationship is reversed?You're confusing the ordering of events with the causality of the events. I see no reason to do so. I'm also not clear on what you mean by negative time.
Post by: webplodder on 22/10/2013 10:25:48
Quote
We develope laws of cause and effect by experimentation and observation. Then we postulate causes and effects. Saying that we "know" them as such gets deep into sematics and epistemology.
The problem with this is that when we attempt to trace such causes and effects backwards in time we find we can never find an original moment that gave rise to causality since we can always ask:"what happened before that?", which gets us into a universe with no beginning, leading to the problem of explaining where causality came from. This model is so contradictory that perhaps we should consider other models of reality where time does not "flow" in a forward direction but only appears to exist as an emergent property of consciousness. Dispensing with the " arrow of time" concept frees us from having to deal with infinities and we are left with a multiverse which is fundamentally non-local in nature, time and space being appearances that we human beings have evolved to navigate through in the interests of survival. With this model it is unnecessary to ask about where the universe came from because time becomes irrelevant at the most fundamental level. It also means causality is an illusion since time is not real, leading to the conclusion that events are really part of a much greater whole that is inseparable. What we really see when we witness one event apparently following another is different aspects of this greater whole, not one being a consequence of another but both existing at the same time. It is our human psychology that is telling us event a) causes event b) and this is quite understandable when we see the usefulness of this approach in the history of our (and indeed other) species in adapting to the environment. This is where " common sense" has its practical value but is not reliable when attempting to probe the true nature of reality.
Post by: webplodder on 22/10/2013 10:43:18
Quote
You're confusing the ordering of events with the causality of the events. I see no reason to do so. I'm also not clear on what you mean by negative time.
If the model I have expounded above is correct then it should be (at least, theoretically) possible to treat an event we appear to observe as causing another event as, itself, a consequence of that other event. It may be because we are so "hard-wired" to see time as a unidirectional flow that we have built our scientific theories to reflect this, however, such theories are ultimately based upon observational data which, of course, rely on our human perceptions to events developed over evolutionary time which enabled living things to survive.
Post by: Pmb on 22/10/2013 17:07:45
Quote from: webplodder
The problem with this is that when we attempt to trace such causes and effects backwards in time we find we can never find an original moment that gave rise to causality since we can always ask:"what happened before that?", which gets us into a universe with no beginning, leading to the problem of explaining where causality came from.Why? Who said that we couldn’t ask what happened before the big bang? I recall when I was an undergraduate and the subject of what happened before the big bang came up one day and the often quoted response “You can’t ask that question <=” Also came up along with it. My physics advisor commented, and I’ll never forget this, that such a comment was a terrible thing to say since there’s nothing wrong with asking questions like that. People who make those kinds of statements didn’t learn from the history of physics. Now, almost 25 years later, he’s proven to be quite right! :)
Quote from: webplodder
This model is so contradictory …..I’m going to stop right here until we clear this assertion up.
Please provide your arguments as to why this is the case since I don’t see it in the least.
Post by: AndroidNeox on 22/10/2013 22:05:48
Post by: Pmb on 22/10/2013 22:59:05
Quote from: AndroidNeox
Relativity requires that all past and future events exist within spacetime.Since spacetime is actually defined as the set of all events your statement is only tautologically true.
Quote from: AndroidNeox
This is because different observers must agree on what events take place (causality) but not on when or even what sequence they take place.That does not hold true in general. The spacetime separation determines whether two events can be causally related or not.
Quote from: AndroidNeox
Regarding the fact that entropy increases with time, it's easy to show that sequences can only be observer within systems of increasing entropy.Okay. Since it’s so easy please show this. Thanks.
Quote from: AndroidNeox
To observer a sequence (which is what we always do when we observe time) one needs to retain information from previous states.Please post an example of this.
Post by: AndroidNeox on 23/10/2013 00:29:02
Quote from: AndroidNeoxRelativity requires that all past and future events exist within spacetime.Since spacetime is actually defined as the set of all events your statement is only tautologically true.Quote from: AndroidNeoxThis is because different observers must agree on what events take place (causality) but not on when or even what sequence they take place.That does not hold true in general. The spacetime separation determines whether two events can be causally related or not.Quote from: AndroidNeoxRegarding the fact that entropy increases with time, it's easy to show that sequences can only be observer within systems of increasing entropy.Okay. Since it’s so easy please show this. Thanks.Quote from: AndroidNeoxTo observer a sequence (which is what we always do when we observe time) one needs to retain information from previous states.Please post an example of this.
"Since spacetime is actually defined as the set of all events your statement is only tautologically true."
No, this isn't just a tautology. It's a requirement of Relativity. It concerned Einstein because he felt it left no room for free will.
"That does not hold true in general. The spacetime separation determines whether two events can be causally related or not."
It's true that different observers must agree on what events take place but not time or sequence. While that may not be relevant for humans living on Earth, my statement is most definitely true.
"Okay. Since it’s so easy please show this. Thanks."
I explained it but will try again. Observation of time is observation of sequence. Observation of sequence requires retaining information from prior states. Retaining information from prior states yields increase in entropy. Hence, time is only observable when the observer's system is increasing in entropy.
Simple enough?
Post by: webplodder on 23/10/2013 09:01:04
Quote from: webplodderThe problem with this is that when we attempt to trace such causes and effects backwards in time we find we can never find an original moment that gave rise to causality since we can always ask:"what happened before that?", which gets us into a universe with no beginning, leading to the problem of explaining where causality came from.Why? Who said that we couldn’t ask what happened before the big bang? I recall when I was an undergraduate and the subject of what happened before the big bang came up one day and the often quoted response “You can’t ask that question <=” Also came up along with it. My physics advisor commented, and I’ll never forget this, that such a comment was a terrible thing to say since there’s nothing wrong with asking questions like that. People who make those kinds of statements didn’t learn from the history of physics. Now, almost 25 years later, he’s proven to be quite right! :)Quote from: webplodderThis model is so contradictory …..I’m going to stop right here until we clear this assertion up.
Please provide your arguments as to why this is the case since I don’t see it in the least.
I'm sorry, it appears we are at cross-purposes here. I wasn't just talking about before the Big Bang but whatever gave rise to that and whatever gave rise to that and so on. The central point here is that once you accept time is a continuous flow in one direction you are forced into an infinite model of reality which throws up contradictions surrounding causality. How can cause-and-effect be valid in a universe that has no cause? No matter how far back you go it is always possible to ask what went before, so it is an exercise in futility. For this reason, I reject the idea of "the arrow of time" and am forced into the conclusion that time and space exist as a unified, unbroken whole where time and space are simply emergent properties experienced as "real" by conscious observers such as us and other sentient beings.
Post by: yor_on on 30/10/2013 20:31:15
Post by: AndroidNeox on 05/11/2013 23:09:59
I'm sorry, it appears we are at cross-purposes here. I wasn't just talking about before the Big Bang but whatever gave rise to that and whatever gave rise to that and so on. The central point here is that once you accept time is a continuous flow in one direction you are forced into an infinite model of reality which throws up contradictions surrounding causality. How can cause-and-effect be valid in a universe that has no cause? No matter how far back you go it is always possible to ask what went before, so it is an exercise in futility. For this reason, I reject the idea of "the arrow of time" and am forced into the conclusion that time and space exist as a unified, unbroken whole where time and space are simply emergent properties experienced as "real" by conscious observers such as us and other sentient beings.
Personally, I think this is the most interesting question facing physics. All our knowledge and observations of physical reality show it to be causal. No violations of physical conservation symmetries, ever. Except when we look back 13.8 billion years to time = zero, when causality breaks down entirely.
Suppose the prior condition was non-causal? What would be the characteristics of a non-causal condition? There would be no conserved quantities. There would be no observable sequences so no time. Perhaps the ancients were right that our orderly reality sprung from chaos.
Post by: yor_on on 08/11/2013 23:50:24
=
Or a symmetry to decoherence, if one like.