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Is the empty space between particles or other matter something?
Posted: 22 December 2011 02:07 PM   [ Ignore ]   [ # 46 ]
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GdB - 22 December 2011 12:44 AM
TimB - 21 December 2011 03:00 PM

GdB, are you saying that one should not question whether time really is only unidirectional?  Or are you saying that it makes no sense to hypothesize whether it only seems unidirectional due to our perceptual limitations? Or are you saying something else, entirely.

No, I am saying that it makes not much sense about asking what was before time, because the use of the concept ‘before’ presupposes time. Also, asking for the cause of time suffers from this problem, as we usually see a cause of an event as preceding the event. Even the concept ‘event’ presupposes time. So it is a conceptual limitation.

How then can physics talk about time? Well it can on the cost of abstraction, in which e.g. the idea of a direction of time disappears, as well our daily experience of the past, now, and the future. And in this framework one can build at least a consistent, but abstract and mathematical model of the universe.

I think you lost me again in that 2nd part about physics being able to talk about time “on the cost of abstraction…”.  (I know almost nothing about physics, quantum physics and their mathematical models, but I seem to recall that the mathematical models do not rule out, or maybe even support that time could be other than unidirectional.)

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Posted: 22 December 2011 02:31 PM   [ Ignore ]   [ # 47 ]
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quote]

Tim, I am ignorant (but very interested) on the subject. But reread my post #16

If we assume that there was no time before the beginning, it follows that you cannot go backward past that point. The beginning of the universe (spacetime) is where history (the passage of time) begins.
Thus time moves forward, as the universe evolves. If it were possible to go back in time, such as during “inflation” when energy expanded at FTL (faster than light speed), we would end up back at the BB in an infinite loop, which it obviously did not. My conclusion is that “inflation” (an almost infinitely small instant) could happen because spacetime was not yet existent and the universals associated with “spacetime” were not yet instantiated.

Today, when we look back billions of years we can see the traces of the BB. We popularly say that we are looking back in time, but in reality we are looking back at the history of the universe and we are not actually travelling back in time, because even as we look, time is still travelling forward in our present.

In a proof once offered by a Japanese physicist, he devised a mental experiment to see if he could go back in time and kill himself.
He posited that he had a gun, loaded it, all of which took 3 minutes. Then he opened a window back in time 3 minutes before his present time.
He saw himself standing in his room, gun in hand which was not yet loaded, and unusable for shooting. Thus if he killed himself at that time, he could not have had a loaded gun in the present and the gun in his hand at the present time would be unloaded and he would be unable to kill himself at that prior moment back in time. If he then proceeded to load the gun, which would take him 3 more minutes and try to repeat his experiment, he would end up looking at his present time (three minutes past), opening the window into time to kill himself 3 minutes back in time. But then he would again see himself standing with an empty gun in his hand, etc, etc. Thus in fact he was not travelling back in time but only looking back in history and never be able to change it as his present would always be three minutes ahead of his history and he would not be able to kill himself with a gun which he had not yet loaded.

IMO, this proved that even if we were able to travel back in time, we would not be able to change anything, because the condition in the present would prevent us from altering the past. Al we can hope for is to “look” back in history (time) watching ourselves as a memory, unable to influence that memory in any way. I hope that this a correct interpretation of the time paradox.

IMO, it is actually impossible to reverse time, because in doing so we would be dissembling all the history which brought us to the present, including ourselves, which would prevent us from reversing time from the present.

Time can only move forward, not because time moves independently of events, but rather that time is created by the events, i.e. the time it “takes” for an event to become instantiated. I posit that SOL (speed of light) is the fastest possible way (duration) for physical reality to become manifest. Even virtual particles can only be created by accelerating other particles to near SOL and colliding them in order to create enough energy for a virtual particle to become manifest (be measured) for an instant in time before it disappears beyond the event horizon.
I believe this is how they seek to discover the Higgs boson.

Perhaps this is why we call SOL the event horizon. It is impossible for a physical object to travel faster than SOL and (theoretically) going back in time. As I understand it, it would take all the energy in the universe to be able to accomplish that and that would instantly tear the entire universe into shreds.

However, at STL (slower than light speed) time becomes relative. We can create conditions which slow time down for an event, but only relative to another object or observer. We have the story of the astronaut travelling a great distance at near SOL, returning to back to earth younger than the people on earth, as time for them passed relatively faster than for the traveler. But for the traveler his time passed normally. Thus time at STL is a relative experience, but always moves forward.

Write4U, I appreciate your thoughts. I enjoy science fiction about time travel and related paradoxes, but I was not thinking of time travel.  My question was referencing whether time itself is in fact only as we percieve it, in terms of going from the past to the present to the future.  We have memories of the past, but has or could anyone ever have a memory of what we percieve as the future?  possible answers: 1) no, because time truly is unidirectional as we typically percieve it to be, 2) no, because our brains are not structured to remember the future 3) someday a quantum computer will be built that recognizes that time is bi-directional, and will remember the future, but will summarily destroy itself in accordance with Issac Asimov’s prime directive that it can do nothing harmful to man.

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Posted: 22 December 2011 02:57 PM   [ Ignore ]   [ # 48 ]
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dougsmith - 22 December 2011 08:39 AM
GdB - 22 December 2011 08:35 AM

Hmmm… A epiphenomalist says that consciousness has no causal effects. At the same time his utterance is difficult to understand when his consciousness did not cause him to state what he does. Consistently, he should ask “Eh…? What is that, ‘consciousness’? No idea what you are talking about!”

Right, it’s difficult to understand why it would be true, or why one would think it true, given the apparent causal role that consciousness plays in our daily lives. But I don’t think that that paradoxicality (in the loose sense of the word) makes it self refuting. Only unconvincing.

To take another example, I believe in the existence of abstracta, which are objects that play no causal role. They only play a structural role in causal theories. I wouldn’t want to say that one is making a self-refuting claim simply by claiming that there are objects which are not causally efficacious.

I hate to think it, and it strains my brain, to do so, but if time is, in actuality, bidirectional, which would suggest that everything that has and will happen has already happened, then those crazy epiphenomalists could be right. smile In which case, why are we even discussing such things, other than it is entertaining to do so.

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Posted: 23 December 2011 12:01 AM   [ Ignore ]   [ # 49 ]
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sorry, my post was interrupted by that scammer.

[ Edited: 23 December 2011 12:39 AM by Write4U ]
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Posted: 23 December 2011 12:01 AM   [ Ignore ]   [ # 50 ]
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GdB
Well, at least evolution is evolution in time, that is where the word originally stems from: ‘the gradual development of something’. I don’t know what a development without time could possibly mean.

Are you telling me that future time already exists?  I posited that time is created during the evolutionary development of events. Are we not always in the present?

[ Edited: 23 December 2011 12:18 AM by Write4U ]
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Posted: 23 December 2011 12:10 AM   [ Ignore ]   [ # 51 ]
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TimB - 22 December 2011 02:31 PM

Tim, I am ignorant (but very interested) on the subject. But reread my post #16

If we assume that there was no time before the beginning, it follows that you cannot go backward past that point. The beginning of the universe (spacetime) is where history (the passage of time) begins.
Thus time moves forward, as the universe evolves. If it were possible to go back in time, such as during “inflation” when energy expanded at FTL (faster than light speed), we would end up back at the BB in an infinite loop, which it obviously did not. My conclusion is that “inflation” (an almost infinitely small instant) could happen because spacetime was not yet existent and the universals associated with “spacetime” were not yet instantiated.

Today, when we look back billions of years we can see the traces of the BB. We popularly say that we are looking back in time, but in reality we are looking back at the history of the universe and we are not actually travelling back in time, because even as we look, time is still travelling forward in our present.

In a proof once offered by a Japanese physicist, he devised a mental experiment to see if he could go back in time and kill himself.
He posited that he had a gun, loaded it, all of which took 3 minutes. Then he opened a window back in time 3 minutes before his present time.
He saw himself standing in his room, gun in hand which was not yet loaded, and unusable for shooting. Thus if he killed himself at that time, he could not have had a loaded gun in the present and the gun in his hand at the present time would be unloaded and he would be unable to kill himself at that prior moment back in time. If he then proceeded to load the gun, which would take him 3 more minutes and try to repeat his experiment, he would end up looking at his present time (three minutes past), opening the window into time to kill himself 3 minutes back in time. But then he would again see himself standing with an empty gun in his hand, etc, etc. Thus in fact he was not travelling back in time but only looking back in history and never be able to change it as his present would always be three minutes ahead of his history and he would not be able to kill himself with a gun which he had not yet loaded.

IMO, this proved that even if we were able to travel back in time, we would not be able to change anything, because the condition in the present would prevent us from altering the past. Al we can hope for is to “look” back in history (time) watching ourselves as a memory, unable to influence that memory in any way. I hope that this a correct interpretation of the time paradox.

IMO, it is actually impossible to reverse time, because in doing so we would be dissembling all the history which brought us to the present, including ourselves, which would prevent us from reversing time from the present.

Time can only move forward, not because time moves independently of events, but rather that time is created by the events, i.e. the time it “takes” for an event to become instantiated. I posit that SOL (speed of light) is the fastest possible way (duration) for physical reality to become manifest. Even virtual particles can only be created by accelerating other particles to near SOL and colliding them in order to create enough energy for a virtual particle to become manifest (be measured) for an instant in time before it disappears beyond the event horizon.
I believe this is how they seek to discover the Higgs boson.

Perhaps this is why we call SOL the event horizon. It is impossible for a physical object to travel faster than SOL and (theoretically) going back in time. As I understand it, it would take all the energy in the universe to be able to accomplish that and that would instantly tear the entire universe into shreds.

However, at STL (slower than light speed) time becomes relative. We can create conditions which slow time down for an event, but only relative to another object or observer. We have the story of the astronaut travelling a great distance at near SOL, returning to back to earth younger than the people on earth, as time for them passed relatively faster than for the traveler. But for the traveler his time passed normally. Thus time at STL is a relative experience, but always moves forward.

Write4U, I appreciate your thoughts. I enjoy science fiction about time travel and related paradoxes, but I was not thinking of time travel.  My question was referencing whether time itself is in fact only as we percieve it, in terms of going from the past to the present to the future.  We have memories of the past, but has or could anyone ever have a memory of what we percieve as the future?  possible answers: 1) no, because time truly is unidirectional as we typically percieve it to be, 2) no, because our brains are not structured to remember the future 3) someday a quantum computer will be built that recognizes that time is bi-directional, and will remember the future, but will summarily destroy itself in accordance with Issac Asimov’s prime directive that it can do nothing harmful to man.

Sorry if I was a little verbose….. red face  But I believe I made the point that IMO time only travels forward and when we look back in time we are not actually reversing time but looking at history going forward and coming towards the present.

[ Edited: 23 December 2011 12:16 AM by Write4U ]
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Posted: 23 December 2011 12:43 AM   [ Ignore ]   [ # 52 ]
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back on track…. excaim

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Posted: 23 December 2011 05:11 AM   [ Ignore ]   [ # 53 ]
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TimB - 22 December 2011 02:57 PM

I hate to think it, and it strains my brain, to do so, but if time is, in actuality, bidirectional, which would suggest that everything that has and will happen has already happened, then those crazy epiphenomalists could be right. smile In which case, why are we even discussing such things, other than it is entertaining to do so.

I’m not sure I follow your reasoning here. I don’t see what time has to do with epiphenomenalism. Also, I’m not sure I would phrase it that if the arrow of time is in some sense illusory that “everything has already happened”. The problem with that locution is that the past tense is used specifically to direct us to what is in the past from our POV. You would need for there to be a hypertime in which everything in our time was past in order to make that locution true, and we really don’t need a notion of hypertime otherwise.

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Posted: 23 December 2011 07:42 PM   [ Ignore ]   [ # 54 ]
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Here is a video of physicist Renate Loll talking on the Quantum Origins of Space and Time:

http://www.youtube.com/watch?v=fv2gBjQ8xIo

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Posted: 26 December 2011 06:31 AM   [ Ignore ]   [ # 55 ]
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Here is another video by Renate Loll:

What is time?

Close to the end she states that time did not begin at the big bang. It is just space that developed from there.

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Posted: 26 December 2011 03:08 PM   [ Ignore ]   [ # 56 ]
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TimB - 16 December 2011 05:47 PM

If the empty space between things is not nothing, what is it?  Is there such a thing as empty space?

(Should anyone respond, at least initially, please try to keep your answers relatively simple, i.e. directed toward a lay person, such as I, being able to potentially understand what you are saying.)

We once used the term “empty space” but we are now well aware that is not empty at all.  In fact, not long ago we referred to matter as that which reflects light but we now know what we call normal matter reflecting light is only about 4% of whats out there.
What is the other 96%?  We don’t know but we are trying to discover what it is.  We call it dark matter and also know there is something called dark energy and we call it dark because it won’t reflect light.  So is space empty?  No.

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Posted: 26 December 2011 07:06 PM   [ Ignore ]   [ # 57 ]
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I am going out on a very thin limb. And I do not speak from authority, but…..I disagree with the notion that time existed before space.
There is spacetime. There can be no “nothingtime” or “selftime”, or just “time”. It is a meaningless term unless it relates to an event.
Assuming the possibility of other universes, the following logic would still apply, but I’ll just concentrate on the creation of our universe.

My reasoning is as follows.

a) Is there empty Space beyond universal space or is there an Absolute Nothing before empty space?

According to Loll (and many others), empty space (between particles) was created as a result of the BB. But that means that there was no space before the BB. How could space have existed prior to it becoming into existence? Spacefoam and all other planckian phenomena are properties of empty space, but could not have been present in the nothing that was before space itself. I undertsand that theoretically CDT geometry can lead us to the very beginning of the formation of space. But you cannot go past a singularity. If the BB stemmed from a singularity, CDT has no application beyond that.

b) Can there be Time in an absolute nothingness, independent of (empty) space?

If CDT was not applicable before a singularity, then what would be the function of time?
According to Ockham there would be no need for time.

c) Gravity functions in quanta. Quantum Gravity.

In the beginning of the universe, space and all its properties (quantum gravity, quantum time) started from a singularity during the BB. The gravitational mass of this singularity must have been equivalent to the gravitational mass of the entire universe. We know it expressed itself with the equivalent of all universal energy in a single mega quantum event, releasing all universal energy “all at the same time”. This disputes Loll’s assertion that time keeps things from happening all at once. The BB was an event where everything did happen all at once.

d) Within a Quantum Gravity field time also moves (relative to gravity) as quanta, Quantum Time.

If time slows down in the gravitanional field of a massive object, then a quantum of time must have been frozen (a state of quantum suspension) in the gravitational presence of a singularity (a quanta) of everything. Thus there cannot have been a passage of time until there was the creation of space spreading the gravitational field out as the volume of space increased from the singularity, alowing time itself to become quantized and countable as the “movement of time”.
This scenario would explain the (incredibly small) inflationary period.  Just after the BB the gravitanional field of the expanding singularity was still so strong at that small scale that time could only pass so slow that “inflation” was possible at an “apparent” FTL.  This might also account for the “missing time” which has been an area of much interst. At a certain point the universe expanded sufficiently for time to become countably functional (albeit relative) and the universe expanded as spacetime as we know it.

IMO in an infinity of nothing, time has no meaning. Until there is space (keeping things apart) there is no need for time (keeping things from happening all at once), i.e. Space + Time = spacetime. One is meaningless without the other. Until they are expressed as reality these properties lie dormant as metaphysical “vagueness” or “potential”, latent properties of that which may become reality.

If this analogy fails then there never was a beginning. If the condition before spacetime was an infinite something other than space but subject to the passage of time, then the creation of space and the fabric of spacetime was an emergent result from what?  I prefer the notion of a spontaneous instantaneous event from a singularity. Instantaneous collapse of an infinite timeless nothing into a singularity. This collapse would be a dynamic process, perhaps with the potential to be expressed as pure energy (vagueness) from which reality itself was shaped. vague energy.

If anyone cares to respond to that I would be most interested to hear where my logic fails.

[ Edited: 26 December 2011 10:15 PM by Write4U ]
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Posted: 27 December 2011 01:57 AM   [ Ignore ]   [ # 58 ]
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Write,

This is all way above your and my head. If laymen could just propose such things as you do, physics would be an easy science. Just a little bit of logic….

What I picked up from Loll’s (and Co.) article in ‘Scientific American’ (I read the German translation in ‘Spektrum der Wissenschaft’) is that the early addition of causality (the cause of an event precedes the event) into the model (that’s why it is called CDT) leads to the geometry of the universe as we know it, including a cosmological constant (dark energy). The theory as Loll presents it has a minimum of theoretical assumptions, and it is robust against variations of the few constants needed. That means that even if the constants are varied, the outcome is about the same. So this could be a step in the direction of a solution of the fine tuned universe. Adding causality as presumption to the theory means time must already exist, otherwise ‘preceding’ could have no meaning.

Picking from another source (Lawrence Krauss) we know from Cobe and WMAP that the universe is flat (i.e. Eucledian geometry is valid in the universe on big scales), and a flat universe means the energy content of the universe is exactly zero: the positive energy of the contents of the universe is cancelled by the negative energy of gravity). So the universe as a whole could be one single quantum fluctuation.

But none of this is established science, yet. So maybe it is all wrong, but at least it counts as a scientific theory. It tries to derive aspects of our real world from basic principles. It is using established quantum algorithms on space itself.

Your reference to Occam’s razor is wrong. It is not a metaphysical principle, but a scientific guideline: ‘among competing hypotheses, selecting the one that makes the fewest new assumptions usually provides the correct one, and that the simplest explanation will be the most plausible until evidence is presented to prove it false’ Loll’s theory needs time to get to the result that fits our reality.

But Occam’s razor might be the only ground on which will be decided which theory is the correct one. At the moment there is no way to measure events that come even near the Planck scale.

Edit: language improvement (I hope…)

[ Edited: 27 December 2011 08:39 AM by GdB ]
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Posted: 27 December 2011 01:29 PM   [ Ignore ]   [ # 59 ]
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dougsmith - 23 December 2011 05:11 AM
TimB - 22 December 2011 02:57 PM

I hate to think it, and it strains my brain, to do so, but if time is, in actuality, bidirectional, which would suggest that everything that has and will happen has already happened, then those crazy epiphenomalists could be right. smile In which case, why are we even discussing such things, other than it is entertaining to do so.

I’m not sure I follow your reasoning here. I don’t see what time has to do with epiphenomenalism. Also, I’m not sure I would phrase it that if the arrow of time is in some sense illusory that “everything has already happened”. The problem with that locution is that the past tense is used specifically to direct us to what is in the past from our POV. You would need for there to be a hypertime in which everything in our time was past in order to make that locution true, and we really don’t need a notion of hypertime otherwise.

Well, it occurred to me that if our space time continuum is finite, and that the begiinning and the end and all the time in between, exists, as is consistent, I think, with some mathematical models, then perhaps we are all just bit actors on the stage of space time, and that, indeed, perhaps our consciousness has no causal effect in how things play out, as the drama of life, the universe, and everything is already contained in the whole of our finite space time continuum.  (My apologies for the run on sentence.)

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Posted: 27 December 2011 02:01 PM   [ Ignore ]   [ # 60 ]
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deros - 26 December 2011 03:08 PM
TimB - 16 December 2011 05:47 PM

If the empty space between things is not nothing, what is it?  Is there such a thing as empty space?

(Should anyone respond, at least initially, please try to keep your answers relatively simple, i.e. directed toward a lay person, such as I, being able to potentially understand what you are saying.)

We once used the term “empty space” but we are now well aware that is not empty at all.  In fact, not long ago we referred to matter as that which reflects light but we now know what we call normal matter reflecting light is only about 4% of whats out there.
What is the other 96%?  We don’t know but we are trying to discover what it is.  We call it dark matter and also know there is something called dark energy and we call it dark because it won’t reflect light.  So is space empty?  No.

I am assuming that you are speaking of cosmic space (re: dark energy and matter existing).  Do you know if this is the case in regards to the space between subatomic particles, as well?

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