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BISMARCK
2007-Jul-01, 01:01 AM
Imagine a Big Rip scenario taken to its logical end where at any one point in space, there is no matter and no energy, except for the still present Dark Energy.

If there is no matter or any carrier particles of the various forces, is it possible for an event to happen? And if not, then does that mean that time doesn't exist in any meaningful way?

Ken G
2007-Jul-01, 03:07 AM
Probably time would not exist in any meaningful way, a trickier question is if anything would have meaning, but it's probably a bridge you have to cross to know! Maybe all the illusions of meaning would be stripped away, leaving only what had meaning all along. Or maybe it's what is happening now that has meaning, and nothing then will have any. Who knows?

Celestial Mechanic
2007-Jul-01, 04:12 AM
Probably time would not exist in any meaningful way, a trickier question is if anything would have meaning, but it's probably a bridge you have to cross to know! Maybe all the illusions of meaning would be stripped away, leaving only what had meaning all along. Or maybe it's what is happening now that has meaning, and nothing then will have any. Who knows?
Does that mean we'll finally hear the sound of one hand clapping? :)

loglo
2007-Jul-01, 04:44 AM
Does that mean we'll finally hear the sound of one hand clapping? :)

:D

"Wizards don't like philosophy very much. As far as they are concerned, one hand clapping makes a sound like 'cl'.
Terry Pratchett
Sourcery

Ken G
2007-Jul-01, 05:35 AM
Does that mean we'll finally hear the sound of one hand clapping?

Exactly. We'll finally know the secret of creation, and slap our heads and say, "Aw-- I could have had a V8!"

foreignkid
2007-Jul-01, 06:02 AM
Imagine a Big Rip scenario taken to its logical end where at any one point in space, there is no matter and no energy, except for the still present Dark Energy.

If there is no matter or any carrier particles of the various forces, is it possible for an event to happen? And if not, then does that mean that time doesn't exist in any meaningful way?

To my knowledge, space and time are intricately interconnected (say 10x fast.) That would mean that there would be time and there would be nothing happening during the time, except for the dark matter's continued existence. But don't take my word for it.

Moonhead
2007-Jul-01, 09:59 AM
Imagine a Big Rip scenario taken to its logical end where at any one point in space, there is no matter and no energy, except for the still present Dark Energy.

If there is no matter or any carrier particles of the various forces, is it possible for an event to happen? And if not, then does that mean that time doesn't exist in any meaningful way?

It would seem to me that indeed no invent could happen, and that therefor time would not exist in a meaningdul way. Actually I think time is a property of matter-energy: the speed at which the forces of nature interact, rather than some sort of a canvas for events to take place.



Does that mean we'll finally hear the sound of one hand clapping? :)

I never understood that paradox... I can perfectly clap with one hand, by just closing and opening it fast. If I hadn't been suffering from stage anxiety, I would have made a carreer out of it.

hhEb09'1
2007-Jul-02, 04:36 AM
I never understood that paradox... You're doing it wrong :)

foreignkid
2007-Jul-02, 04:49 AM
I never understood that paradox... I can perfectly clap with one hand, by just closing and opening it fast. If I hadn't been suffering from stage anxiety, I would have made a carreer out of it.

Heretic!! How DARE you do something so out of the ordinary!! There is only ONE way to clap, the right way. The number of hands clapping must be two. No more, no less. You shall not clap with one hand, nor shall you clap with 3. 4 is far out.

Chuck
2007-Jul-02, 04:53 AM
The sound of one hand clapping is the same as the sound of one philosopher making sense.

Celestial Mechanic
2007-Jul-02, 12:45 PM
The sound of one hand clapping is the same as the sound of one philosopher making sense.
At long last, someone who gets it! :)

Ken G
2007-Jul-02, 02:11 PM
At long last, someone who gets it!
The difference between a philosopher and someone who "gets it" is that the someone only gets what he gets, while the philosopher at least "gets" what it is that he doesn't get. Or more simply, "you get what you get and you don't get upset."

Celestial Mechanic
2007-Jul-02, 04:02 PM
The difference between a philosopher and someone who "gets it" is that the someone only gets what he gets, while the philosopher at least "gets" what it is that he doesn't get.
And makes the worst possible use of it -- an excuse to propagate word salad.

Or more simply, "you get what you get and you don't get upset."
It may be said of philosphers, "You've got what you've got and it don't mean squat." ;)

hhEb09'1
2007-Jul-02, 04:07 PM
It may be said of philosphers, "You've got what you've got and it don't mean squat." You've been hurt by a philosopher, haven't you? :)

Ken G
2007-Jul-02, 04:35 PM
It may be said of philosphers, "You've got what you've got and it don't mean squat." ;)I used to think that way as well. It is very easy to dismiss various things that humans can do with our minds by using meaningless expressions like "word salad". In Amadeus, there's a scene where Salieri dismisses Mozart's music as having "too many notes"-- it's a similar level of ridicule that bites its own master. What made me realize the value of philosophy was when I realized that it should not be looked at as a means to a result, in the way that science is, because philosophy lacks the judge and jury of quantifiable experiment. When held to that standard, it fails pretty badly-- as evidenced by the striking lack of consensus among so many of the most brilliant minds human society has generated.

But the value of philosophy, in my view, is in its ability to locate, explore, and give form to all the possibilities-- it's more like a Lewis and Clark expedition than a trip to the supermarket. You end up with a map of possible destinations, and you can't eat any of them. But it's the opposite of dogmatic thinking. And dismissing philosophy, unfortunately, is actually just another example of reason by dogma-- "if it ain't ____, it's doo-doo". If you can fill in that blank-- you have dogma.

Celestial Mechanic
2007-Jul-02, 05:13 PM
You've been hurt by a philosopher, haven't you? :)
Yes, a Kantian frightened me with a monad when I was four. :D

Celestial Mechanic
2007-Jul-02, 05:40 PM
I used to think that way as well. It is very easy to dismiss various things that humans can do with our minds by using meaningless expressions like "word salad". In Amadeus, there's a scene where Salieri dismisses Mozart's music as having "too many notes"-- it's a similar level of ridicule that bites its own master.
Very true. Salieri's music has way too many notes--every single one he scribbled down.

What made me realize the value of philosophy was when I realized that it should not be looked at as a means to a result, in the way that science is, because philosophy lacks the judge and jury of quantifiable experiment. When held to that standard, it fails pretty badly-- as evidenced by the striking lack of consensus among so many of the most brilliant minds human society has generated. {Emphasis mine}
Shouldn't that tell you something? :think:

But the value of philosophy, in my view, is in its ability to locate, explore, and give form to all the possibilities--it's more like a Lewis and Clark expedition than a trip to the supermarket. You end up with a map of possible destinations, and you can't eat any of them. [Snip!]
Remind me not to go grocery shopping with you--I'd starve to death! But tell me, just what wonderful "possibilities" have the philosophers of the 20th century, let's say, come up with? Twentieth century science has given us quantum mechanics, relativity (special and general), and our first glimpses of what the universe is made of and just how large it is. And 20th century philosophy has given us what? Sartre? Wittgenstein? Kuhn and Popper?

But before this becomes a YAUPT (Yet Another Unproductive Philosophy Thread), let me get back to BISMARCK's original question:

Imagine a Big Rip scenario taken to its logical end where at any one point in space, there is no matter and no energy, except for the still present Dark Energy.

If there is no matter or any carrier particles of the various forces, is it possible for an event to happen? And if not, then does that mean that time doesn't exist in any meaningful way?
We can't really say that there is no matter because there would still be neutrinos, electrons and positrons, although quite diluted. (Quite an understatement, actually.) I am not sure if baryons and other hadronic particles can be pulled apart, even by the expanding spacetime. As soon as the quarks and/or antiquarks are pulled apart, more quark-antiquark pairs form, hadronize, and then are pulled apart. Where would the energy have to come from? I am conjecturing that some of the "dark energy" would have to be expended on this.

Nor do I think that the carrier particles will go away either. Again, they will be fantastically diluted, but they will still be there.

At any rate, there is still a possibility (based on known physics, not on philosophical wool-gathering) that events can occur (the repeated "shredding", and formation of hadrons) and thus time will continue to be meaningful.

Ken G
2007-Jul-02, 06:08 PM
Very true. Salieri's music has way too many notes--every single one he scribbled down.I don't know it, but I'll take your word for it-- he certainly seemed quite envious of Mozart's.


Shouldn't that tell you something? But that's just the point-- it does tell me something. It tells me that consensus, i.e., a single answer, is not the objective. This is the part that is easy to miss when one is used to science, but even in science there are many situations where a single answer is not the objective-- generally in regard to pictures of reality rather than quantifiable predictions.


Remind me not to go grocery shopping with you--I'd starve to death! But tell me, just what wonderful "possibilities" have the philosophers of the 20th century, let's say, come up with? Twentieth century science has given us quantum mechanics, relativity (special and general), and our first glimpses of what the universe is made of and just how large it is. And 20th century philosophy has given us what? Sartre? Wittgenstein? Kuhn and Popper?I will grant you that "progress" in philosophy is terribly slow, as even the ancient Greeks had some pretty interesting things to say about it. But the ancient Greeks also knew the size and shape of our planet, so in a way, even modern geography is just incremental progress. Again, I think the key point is that modern philosophers are not any more "correct" than the Greeks were, but they've gone to new places and looked around. The error may be in casting it as "I have seen the answer" kinds of approaches to philosophy, but that's kind of the tradition. They might do better saying, "I've seen an assumption you are all making that does not necessarily follow, and here's what you get if you replace that with a different assumption. It's hard to test these assumptions scientifically so that we can elevate them to hypotheses, but at least we can look at why or why not we might choose to make them."


But before this becomes a YAUPT (Yet Another Unproductive Philosophy Thread), let me get back to BISMARCK's original question:Can you guess what YAUBBT stands for? I'll bet you can.

Warren Platts
2007-Jul-04, 08:43 PM
We can't really say that there is no matter because there would still be neutrinos, electrons and positrons, although quite diluted. (Quite an understatement, actually.) I am not sure if baryons and other hadronic particles can be pulled apart, even by the expanding spacetime. As soon as the quarks and/or antiquarks are pulled apart, more quark-antiquark pairs form, hadronize, and then are pulled apart. Where would the energy have to come from? I am conjecturing that some of the "dark energy" would have to be expended on this.

:clap::dance::clap: Boy that sure looks good! Pass the ranch please!

Celestial Mechanic
2007-Jul-05, 04:00 AM
We can't really say that there is no matter because there would still be neutrinos, electrons and positrons, although quite diluted. (Quite an understatement, actually.) I am not sure if baryons and other hadronic particles can be pulled apart, even by the expanding spacetime. As soon as the quarks and/or antiquarks are pulled apart, more quark-antiquark pairs form, hadronize, and then are pulled apart. Where would the energy have to come from? I am conjecturing that some of the "dark energy" would have to be expended on this.:clap::dance::clap: Boy that sure looks good! Pass the ranch please!
I'm sorry that you are incapable of understanding an answer given to the original poster's question in plain English. Get thee to a library and study some physics (and NOT philosophy) until you do and maybe then you might be able to contribute something worthwhile on the topic.

Warren Platts
2007-Jul-05, 06:18 AM
Don't worry about me. I've studied my share of physics. Indeed, I was once hired by the Department of Physics at Colorado State--as a philosopher! :D

Celestial Mechanic
2007-Jul-05, 03:14 PM
Don't worry about me. I've studied my share of physics. Indeed, I was once hired by the Department of Physics at Colorado State--as a philosopher! :D
A brief perusal of the website for this physics department reveals a probably competent group of physicists, but no cutting-edge research being done there--probably because they are wasting their budget on philosophers instead of using it to hire physicists.

If my answer to BISMARCK doesn't please you, why don't you take a whack at answering his questions? But please, hold the Aristotelian pap and the oh-so-trendy Existentialism, OK? ;)

Ken G
2007-Jul-05, 04:24 PM
Celestial Mechanic, I think it's pretty disingenuous of you to give highly speculative pseudo-scientific answers to the OP, even as you deride more philosophical but equally speculative responses. The OP had an extremely philosophical bent to it, it is simply not a physics question. As a physics question, there is just one scientifically responsible answer: "no one has the least idea". Given that, we can all go and speculate, whether philosophically or pseudo-scientifically. Neither is a provably better approach, indeed the historical track record of both is quite poor.

Celestial Mechanic
2007-Jul-05, 05:53 PM
Celestial Mechanic, I think it's pretty disingenuous of you to give highly speculative pseudo-scientific answers to the OP, even as you deride more philosophical but equally speculative responses. The OP had an extremely philosophical bent to it, it is simply not a physics question. As a physics question, there is just one scientifically responsible answer: "no one has the least idea". Given that, we can all go and speculate, whether philosophically or pseudo-scientifically. Neither is a provably better approach, indeed the historical track record of both is quite poor.
Ken G: I think it is quite disingenuous of you to consider my answer to BISMARCK to be pseudo-scientific. Highly speculative, perhaps, but well-rooted in science, as I will attempt to show.

Here is my answer to BISMARCK's question that displeases you and Warren Platts so much:

We can't really say that there is no matter because there would still be neutrinos, electrons and positrons, although quite diluted. (Quite an understatement, actually.) I am not sure if baryons and other hadronic particles can be pulled apart, even by the expanding spacetime. As soon as the quarks and/or antiquarks are pulled apart, more quark-antiquark pairs form, hadronize, and then are pulled apart. Where would the energy have to come from? I am conjecturing that some of the "dark energy" would have to be expended on this.

Nor do I think that the carrier particles will go away either. Again, they will be fantastically diluted, but they will still be there.

At any rate, there is still a possibility (based on known physics, not on philosophical wool-gathering) that events can occur (the repeated "shredding", and formation of hadrons) and thus time will continue to be meaningful.
Now let's take it point-by-point:

We can't really say that there is no matter because there would still be neutrinos, electrons and positrons, although quite diluted. (Quite an understatement, actually.)
I see nothing pseudo-scientific here. All the "big rip" can do is dilute the most elementary particles since for all practical purposes they are point-like. If these structures do have components, then they are not the most elementary and some other even more elementary particles will survive. In any event 10-1,000,000 particles per cubic gigaparsec is still not zero. That's mathematics, not pseudo-science.

I am not sure if baryons and other hadronic particles can be pulled apart, even by the expanding spacetime. As soon as the quarks and/or antiquarks are pulled apart, more quark-antiquark pairs form, hadronize, and then are pulled apart.
No pseudo-science here. In fact this property of hadrons was the inspiration for the original string theory in the late 60s.

Where would the energy have to come from? I am conjecturing that some of the "dark energy" would have to be expended on this.
Conservation of energy is rock-solid science. The energy to pull hadrons apart and form new ones has to come from somewhere. In a big rip scenario, the dark energy causing the big rip is the primary source of energy at hand. It is quite logical, maybe even Aristotelian ( ;) ), to suggest that dark energy be the source of the energy; it is, after all, the source of the "problem".

Nor do I think that the carrier particles will go away either. Again, they will be fantastically diluted, but they will still be there.
Where can the carrier particles, once emitted, disappear to? They will still arrive at their destinations, it just may take 101,000,000 years to do so. A very long time, but still not an eternity. (Except to us.) And guess what? No pseudo-science here, either.

And lastly:

At any rate, there is still a possibility (based on known physics, not on philosophical wool-gathering) that events can occur (the repeated "shredding", and formation of hadrons) and thus time will continue to be meaningful.
I have used science, not the works of Kierkegaard or Schopenhauer, as a guide in my speculations. I may have the toes of one foot out in the thin air of speculation, but the heel and the other foot are firmly rooted in science. That you find my answer "pseudo-scientific" is particularly offensive to me. If I were as thin-skinned as many of the people who float ATM theories seem to be, I would have already pressed the triangle button on your post. I have no intention of doing so.

You wrote:

As a physics question, there is just one scientifically responsible answer: "no one has the least idea".

Unfortunately all too often this is taken as an excuse to say, "We have no way of knowing and never will know", and that (along with the dozens of pages of arguments that usually follow) is what I take issue with.

Twinsun
2007-Jul-05, 05:58 PM
well this thing u are reffering to is in fact the so called 'nothingness' and well it isn't present WITHIN real matter so it's in fact the 'thing' that was before our Universe existed ;) and nope, time can't exist there as it is the result of matter evolving

BISMARCK
2007-Jul-05, 07:09 PM
Well, I suppose I didn't necessarily phrase my initial question in a way that gets to the heart of what I'm asking. So I'll try again:

Can time be defined solely as a function of interactions involving matter and/or energy? If all that existed in the Universe was one single photon, would time exist?

astromark
2007-Jul-05, 07:25 PM
From the inside, Yes. From the outside, No.
Thats the problem with being over educated. You can not except 'We don't know.' All the pontificating in the world does not answer the question we have no answer to. Just put it aside and drink more coffee.

Celestial Mechanic
2007-Jul-05, 07:29 PM
From the inside, Yes. From the outside, No.
Thats the problem with being over-educated. You cannot accept 'We don't know.' All the pontificating in the world does not answer the question we have no answer to. Just put it aside and drink more coffee.
I think my friends from grad school might accept an invitation to coffee in order to discuss my ideas on hadronization and the big rip -- but over in a new thread in ATM, not here.

Ken G
2007-Jul-05, 08:12 PM
Ken G: I think it is quite disingenuous of you to consider my answer to BISMARCK to be pseudo-scientific. Highly speculative, perhaps, but well-rooted in science, as I will attempt to show.A valiant effort, but I will show that it is not "well-rooted" at all.

All the "big rip" can do is dilute the most elementary particles since for all practical purposes they are point-like. If these structures do have components, then they are not the most elementary and some other even more elementary particles will survive. In any event 10-1,000,000 particles per cubic gigaparsec is still not zero. That's mathematics, not pseudo-science.On the contrary, nothing physical can happen to a single elementary particle. All of physics treats interactions between particles-- one particle cannot have an "event" occur. So saying that there would still be "matter" at arbitrarily low density is indeed pseudo-science, because at some point we simply have no useful definition of the word "matter". Matter is what matter does, the rest is all just our own models, that live entirely in our heads. If matter cannot do anything, it is certainly not the matter we currently talk about. This is the key point, which is philosophical in nature-- we have to understand the limitations of our own language, and here that means "matter" and "events" and "interactions", or we are just pretending to know that which we do not know. If you doubt this, just ask yourself this question: what would be the evolution over an infinititude of time of an entire universe comprised of one single electron in an infinity of empty space? Do you think modern physics has the least idea how to answer that? It does not, none of the words I used could even be defined meaningfully for a universe like that, and even if they could, we still just don't have any physics that could say anything meaningful at all. We could claim that nothing would ever happen in such a universe, but that would still be nothing beyond philosophically plausible.



No pseudo-science here. In fact this property of hadrons was the inspiration for the original string theory in the late 60s.Again I must beg to differ. You suggest that new particles will "hadronize" and then get pulled apart, but I see no physical reason to suspect that virtual particles can become real enough to get pulled apart, in the absence of the kinds of interactions we normally need to do physics.


Conservation of energy is rock-solid science. The energy to pull hadrons apart and form new ones has to come from somewhere. In a big rip scenario, the dark energy causing the big rip is the primary source of energy at hand. It is quite logical, maybe even Aristotelian ( ;) ), to suggest that dark energy be the source of the energy; it is, after all, the source of the "problem".Again, that is just pseudoscience. First of all, conservation of energy is simply a principle that is useful in a wide array of situations, but can be taken too seriously, just as everything else in physics can be taken too seriously. Has it ever been tested on the timescales of a Big Rip scenario? Of course not. Should we expect it to work anyway? I hardly think so. One might expect it to work, and of course we'll never know, but I think even a cursory examination of the history of science would dictate otherwise. For example, we now know that is quite important for certain processes (like the hydrogen fusion that gave us life) that energy is not conserved on short enough timescales for virtual processes to occur. Also, it is not at all clear that energy is conserved by global processes like the Big Bang itself. They are just examples of the dangers of over-extrapolation of a principle, which I would classify as pseudo-science, although not in the same way as "horrendously bad science" (which is what the term generally applies to and may be what you are taking umbrage too-- I just mean science beyond where it has been established as useful).

Also, there is no reason to expect "dark energy" to be able to manifest itself in the generation of particles. Dark energy might be a form of energy that can undergo no transitions of any kind without some kind of phase change happening in the vacuum. Now, we should neither expect vacuum to undergo phase changes, nor to not undergo phase changes, if the universe expands arbitrarily-- we simply have no idea. But my point is, given that we have no idea, it is kind of silly to make particular predictions about what dark energy will or will not do. To me, the question is no different from speculating about what happens to your awareness after you die-- you can apply some minimal physics understanding, or some minimal faith-based reasoning, and come up with various answers, but to think that one or the other is more likely to be correct in the absence of any corroborative evidence at all is certainly not scientific.


Where can the carrier particles, once emitted, disappear to? They will still arrive at their destinations, it just may take 101,000,000 years to do so.Carrier particles are virtual particles. We have not the least idea how virtual particles would act in a dynamical universe on that scale, nor do we have any idea that the whole "carrier particle" conceptual model would even apply. That's how physics works-- we come up with the models to explain the data. We don't do it the other way around-- that would be pseudoscience. We do use theories to make testable hypotheses, but I did not see any of those in your post, and we don't claim our hypotheses are "on a firm footing"-- we just say, let's test this.


I have used science, not the works of Kierkegaard or Schopenhauer, as a guide in my speculations. As a guide yes, but then you left the guide way behind and set off on your own. Just like the philosophers did.


That you find my answer "pseudo-scientific" is particularly offensive to me. If I were as thin-skinned as many of the people who float ATM theories seem to be, I would have already pressed the triangle button on your post. I do not mean to offend. Indeed, I can see how one might make the extrapolation you do. My point is simply that it should be recognized that it is nevertheless highly extrapolated, and the history of science has shown us over and over that extreme extrapolations are extremely wrong. That doesn't make it a sin to do the extrapolation-- it's interesting to learn about theories by thinking about their hypothetical extrapolations. But it's hard to do validly, even within the model itself, never minding the likelihood that extrapolations are themselves invalid. But that's still not a sin, it's just a try-- the sin is in thinking that the try is somehow on firmer scientific footing than a more philosophical answer. In fact, it is on a less firm footing, because scientific answers are held to scientific standards, and philosophy is held to philosophical standards. The philosophical goals are generally easier to achieve in an environment completely lacking supporting data, which is the argument for giving a philosophical answer to the OP.



Unfortunately all too often this is taken as an excuse to say, "We have no way of knowing and never will know", and that (along with the dozens of pages of arguments that usually follow) is what I take issue with.The question here is, which is the greater evil: to admit that which we simply don't know and likely never will, or to pretend that we do know and use it as a club with which to bludgeon others who think differently, when in fact we have not the least idea?

Ken G
2007-Jul-05, 08:27 PM
Can time be defined solely as a function of interactions involving matter and/or energy? If all that existed in the Universe was one single photon, would time exist?
The question is not "can time be defined such-and-such", it is "how is time defined"? Time is a word that we made up, and we equipped that word with a definition. We think it corresponds to something "real", but that also depends on how we cook up a definition for the word "real". The way we define time, it would certainly not exist in a universe comprised of just one photon, we need simply look at how time is defined. That definition requires a vastly more complex and interesting universe-- for example, it certainly requires something that can serve as a clock. I would say it also requires something intelligent that can dream up the concept of "time" in the first place, but that seems to be a more controversial stance.

grav
2007-Jul-05, 09:59 PM
Well, I suppose I didn't necessarily phrase my initial question in a way that gets to the heart of what I'm asking. So I'll try again:

Can time be defined solely as a function of interactions involving matter and/or energy? Yes, in my opinion anyway, that is the best way. It takes some training of the mind to get over staring at the clock all the while, but even that should give us a clue as to what we are comparing, the steady cycle of motion of the hands to that of something else, nothing more, but if one can attempt to imagine everything in the universe all at once, or at least locally for all they can see, one realizes time is the act of the constant displacement of matter, of relative motion, and the temporal dimension is really just that which allows this motion to take place to begin with, so is really just another aspect of space itself, which allows such motion to take place within it. If one thinks this way, they will realize that there is really no such thing as the passage of time per say, but only as a measurement and comparison of various motions and the displacements involved, as the constant rearranging of matter within the present only. Of course, it is nearly impossible to think about it in this way without the complete abolishment of a timeline as a frame of reference at first, which should only come after, when we then assign some steadily paced cycle of motion by which to compare all others.


If all that existed in the Universe was one single photon, would time exist?No, not in the traditional sense, I would say, since it would only exist in its own frame of reference with nothing else by which to compare, so it can be considered stationary, if the meaning of such a definition would even apply in that case, although it could still be argued that we could come up with some imaginary stationary origin, in order to assign some speed to it, and then measure the photon's displacement from the origin likewise over time, but without something else to apply a force and therefore an acceleration, the displacement would still remain completely inertial. Unless of course, it is also argued that the origin is accelerating... :)

Len Moran
2007-Jul-06, 06:36 AM
The question is not "can time be defined such-and-such", it is "how is time defined"? Time is a word that we made up, and we equipped that word with a definition. We think it corresponds to something "real", but that also depends on how we cook up a definition for the word "real". The way we define time, it would certainly not exist in a universe comprised of just one photon, we need simply look at how time is defined. That definition requires a vastly more complex and interesting universe-- for example, it certainly requires something that can serve as a clock. I would say it also requires something intelligent that can dream up the concept of "time" in the first place, but that seems to be a more controversial stance.

Well such a controversial stance is shared here:

"There is no time except in relation to processes involving material objects. ...Time appears to me to be nothing more than a man made creation, invented to more easily discuss the relative frequencies of collection of periodic events."

....Dr Neal Graneau, "Immediate Distant Action and Correlation in Modern Physics"

Ken G
2007-Jul-06, 03:34 PM
Excellent quotation, it sounds like Graneau has his head on straight-- at least you and I seem to think so. He's just paying attention to what we are actually doing when we use these words. It also sounds like that book might be relevant to the quantum entanglement thread that petered out recently after getting pretty interesting.

hhEb09'1
2007-Jul-06, 07:43 PM
"There is no time except in relation to processes involving material objects. ...Time appears to me to be nothing more than a man made creation, invented to more easily discuss the relative frequencies of collection of periodic events."
He's just paying attention to what we are actually doing when we use these words. You mean, chasing them around and around? :)

I'd like to see him define "relative frequency" without the use of time, especially in these post-einsteinian days

Ken G
2007-Jul-06, 08:35 PM
It depends on what he means. I agree with you that on the surface, "relative frequencies" are just as much a man-made creation as "time"-- the fundamental paradox is that everything we type is going to be a part of language and hence a part of a man-made creation. But I think what he might be saying is that although all we have to communicate with is man-made symbols that are intended to connect with our shared experience, and among those shared experiences are clocks and the concept of time, it nevertheless behooves us to recognize the limitations we accept whenever we choose to connect in that way. Not all forms of human communication adopt that approach-- witness music and art, which are better for some types of communication and worse for others. Apparently, Graneau sees the phrase "relative frequency" of "periodic systems" to be a more fundamental type of experience than "time", such that our understanding of the latter hinges on a deeper connection to the former. To me, it is the importance of recognizing these types of connections, and to look at them as an integral part of our understanding of reality, that is what matters here-- not necessarily the details of whether time is less fundamental a concept than periodicity. He might be right, but it would require more thought and more investigation-- and none of that thought and investigation would be "chasing around and around", it would be quite crucial for us to really understand our own minds. And by direct association-- our own science.

Moonhead
2007-Jul-06, 09:50 PM
"There is no time except in relation to processes involving material objects. ...Time appears to me to be nothing more than a man made creation, invented to more easily discuss the relative frequencies of collection of periodic events."

....Dr Neal Graneau, "Immediate Distant Action and Correlation in Modern Physics"

Beautiful quote! This makes perfect sense to me. I admit that I am not very well educated in physics (what I know is limited to popular scientific publications and sites, and wikipedia articles), but I am somewhat amazed to learn that the above point of view is apparently not yet the mainstream science point of view of "time".
Actually, when I was a kid I was a big fan of Doctor Who (Tom Baker was the fourth doctor and he's still one of my earliest heroes). And I started thinking about the time travelling part, and consequently anout 'time' itself and I eventually came to a 'working hypothesis' similar to Dr. Graneau's quote (although I probably would have phrased it much simpler and probably less accurate; plus, Dr. Graneau will probably (hopefully!) has a more developed understanding of the universe than I had when I was six yo :) ). But that was, and still is, the only point of view of 'time' that makes sense to me. Still, I admit that I still often visualize time as some sort of a tunnel, through which everything moves - an improper but almost unavoidable representation that, I think, is the source of the misconception of time may people hold.


I'd like to see him define "relative frequency" without the use of time, especially in these post-einsteinian days
That might be very difficult and maybe even impossible, but that is because 'time' is a fundamental concept within the human mind; it is no proof or even an indication that 'time' is anything other than a function of matter-energy.

Just like the verb "to be" (or variations of that concept, like the noun "existence") is (almost?) impossible to descibe without using any derivations of "to be" (like "is"), it is (almost?) impossible to describe time without using any concepts that already have some connotation of 'time going by' to them. Grav does an excellent job a few posts above this one:

[...] time is the act of the constant displacement of matter, of relative motion, and the temporal dimension is really just that which allows this motion to take place to begin with, so is really just another aspect of space itself, which allows such motion to take place within it.
yet uses the word "constant", a word which builds its meaning upon the concept of the passage of time. Any definition will probably have such words in it. But the explanation for this is in the psychological domain, not the physical.

Well, just my 2 cts.

Celestial Mechanic
2007-Jul-07, 04:33 AM
I think my friends from grad school might accept an invitation to coffee in order to discuss my ideas on hadronization and the big rip -- but over in a new thread in ATM, not here.
Promise (some might think it a threat :D ) fulfilled here (http://www.bautforum.com/showthread.php?t=61742). Enjoy!

publius
2007-Jul-07, 05:14 AM
From what I gather, a "Big Rip" will overwhelm the strong/color force. The local "ripping" tides of expansion will become so great that no local structure can hold together.

The Big Rip is a type of singularity, a singularity in scale factor. One way it is put is the size of the observable universe around any point shrinks to zero, down to the point itself. The expansion rate just blows up, and every point becomes causally disconnected from every other point.


-Richard

Warren Platts
2007-Jul-07, 09:55 PM
If my answer to BISMARCK doesn't please you, why don't you take a whack at answering his questions? But please, hold the Aristotelian pap and the oh-so-trendy Existentialism, OK? ;)
OK. Einstein said that time is what a clock measures. So if the the universe consisted of nothing but empty space and a Casio watch, the question is whether the watch would still work or not. I don't see why it wouldn't, in which case time would still happen.

However, according to the big rip scenario, if it were really the case, as Publius says that a watch, no matter how small would be ripped apart, I say that there would still be time. The very act of disintegration of a clock would in effect be a measurement of time--the rate being determined by the rate of disintegration.

How's that? Real simple, if a bit philosophical. :D

EvilEye
2007-Jul-07, 11:14 PM
The watch itself would create time. Because it has movement over a distance.

Celestial Mechanic
2007-Jul-08, 04:27 AM
[Snip!] How's that? Real simple, if a bit philosophical. :D
Very good! :clap:

Some nitpicky readers might take exception to the bit about the rate of disintegration being a measure of time, asking, "Well, how do you measure time once the watch has disintegrated and every point-particle has been scattered to unimaginable distances?" I would answer that there will still be events, photons received over unimaginable distances at unimaginably long intervals. You could not measure time with them, but they would still be events with intervals of time in between, and that's all that matters.

Ken G
2007-Jul-08, 04:56 AM
The Big Rip is a type of singularity, a singularity in scale factor. One way it is put is the size of the observable universe around any point shrinks to zero, down to the point itself. The expansion rate just blows up, and every point becomes causally disconnected from every other point.


Does that happen in finite time in that model? If so, it is clearly the future analog of the Big Bang, and then anyone who claims that the Big Bang originated time must avow that the Big Rip would end it, despite above claims to the contrary. Of course, I find neither claim to be terribly scientific.

Ken G
2007-Jul-08, 04:58 AM
I would answer that there will still be events, photons received over unimaginable distances at unimaginably long intervals. You could not measure time with them, but they would still be events with intervals of time in between, and that's all that matters.

If you think that time can exist after there is no longer a way to measure it, then it is you who are the philosopher after all. Because that sure isn't science, my friend.

publius
2007-Jul-08, 05:09 AM
Does that happen in finite time in that model? If so, it is clearly the future analog of the Big Bang, and then anyone who claims that the Big Bang originated time must avow that the Big Rip would end it, despite above claims to the contrary. Of course, I find neither claim to be terribly scientific.


I don't know if this "rip tide" singularity occurs in finite time or not, that is if it goes to infinity in finite time. But even if it doesn't get to infinity in finite time, it might as well be after some finite time. I guess when the observable universe relative to you gets down to a planck length, it might as well be infinite. :)

-Richard

Celestial Mechanic
2007-Jul-08, 05:26 AM
If you think that time can exist after there is no longer a way to measure it, then it is you who are the philosopher after all. Because that sure isn't science, my friend.
Time existed before clocks were possible, long before philosophers wore watches, and time will still exist long after the last page of philosophic scribbling has been ripped apart in the big rip. That is scientific fact. Deal with it.

hhEb09'1
2007-Jul-08, 05:31 AM
He might be right, but it would require more thought and more investigation-- and none of that thought and investigation would be "chasing around and around", it would be quite crucial for us to really understand our own minds. And by direct association-- our own science.Asserting the answer before we know the answer is definitely not going to help though :)

We've all worked with different formulations of equivalent systems. Wave mechanics versus matrix mechanics, for instance. Different bases for the same space, things like that. One may be more convenient in some instances than the other, at the moment, but to say things like "Time appears to me to be nothing more than a man made creation" with absolutely nothing to back it up, other than a "translation to a different basis", seems careless to me.

RussT
2007-Jul-08, 05:33 AM
If you think that time can exist after there is no longer a way to measure it, then it is you who are the philosopher after all. Because that sure isn't science, my friend.

It is no less scientific than postulating T=0 and then steadfastly holding to that, while defining anything different than that as Woo Woo that winds up being Career Suicide.

Ken G
2007-Jul-08, 02:07 PM
I don't know if this "rip tide" singularity occurs in finite time or not, that is if it goes to infinity in finite time. But even if it doesn't get to infinity in finite time, it might as well be after some finite time. I guess when the observable universe relative to you gets down to a planck length, it might as well be infinite.

Probably long before that, but I see what you mean!

Ken G
2007-Jul-08, 02:10 PM
Time existed before clocks were possible, long before philosophers wore watches, and time will still exist long after the last page of philosophic scribbling has been ripped apart in the big rip. That is scientific fact. Deal with it.
You are incorrect, sir. You are simply using too narrow a definition of a "clock". In science, a clock is anything that can mark time, period. That is why we have atomic clocks, based on, you guessed it, atoms as clocks. I say that there was no such thing as time before "clocks" were possible, and essentially that same argument has been used to claim that time started with the Big Bang. The "definition" of time that you are using is nonscientific-- indeed, just what definition are you using? Try to find one that will be preserved when the Big Rip eliminates interactions between particles (as publius has pointed out but which you have apparently ignored). The fundamental inconsistency in your argument is that it is entirely philosophical, because it has parted company from all scientifically realizable definitions, even as you claim in the same breath that philosophy is pointless! That doesn't make it wrong, it makes it philosophy-- can you not see the fallacy in your position?

Ken G
2007-Jul-08, 02:24 PM
Asserting the answer before we know the answer is definitely not going to help though It might help, not so much insofar as we should take the assertion as true, but rather that we should see it as in invitation to notice there is something there to notice. That's always a pretty important first step, and is just the one that many people overlook when they think they understand time.


We've all worked with different formulations of equivalent systems. Wave mechanics versus matrix mechanics, for instance. Different bases for the same space, things like that. One may be more convenient in some instances than the other, at the moment, but to say things like "Time appears to me to be nothing more than a man made creation" with absolutely nothing to back it up, other than a "translation to a different basis", seems careless to me.I agree with your "translation" characterization, but I think his point is that the translation does accomplish something-- it grounds a seemingly esoteric concept (time) with a more concrete phenomenon (periodicity). Here is my own take on time, but I think it resonates with what Graneau is saying (unless I'm just reading something into it). Time is actually two separate concepts that are often mistaken for each other. The first is a purely local concept of ordering, in relation to something that has been identified as a clock. The second is nonlocal, and isn't time at all, it is simultaneity-- it's purpose is to properly order nonlocal events such that we can understand cause-and-effect relationships in a quantitative way. Both have an arbitrary characeter (and you know all about the arbitrariness in the latter concept from relativity), but prudent choices simplify the interpretation and the mathematics. The local time (rightly called proper time) is a useful construct expressly because all systems appear to respond to it the same way, in other words, it doesn't matter what you choose as the clock, they all "tick" together. The rate at which they tick is the arbitrary part-- we have no knowledge of that, all rates are equivalent as long as they tick together in unison (which they apparently do). So when we recognize periodicity we arbitrarily decide to associate that with a repeated time interval, thereby manually establishing an unnecessary but simplifying "constant flow of time". That is what I think Graneau is saying, and if so, it just comes from noticing what we are really doing when we think about time in terms of a "constant flow".

Len Moran
2007-Jul-08, 05:42 PM
So when we recognize periodicity we arbitrarily decide to associate that with a repeated time interval, thereby manually establishing an unnecessary but simplifying "constant flow of time". That is what I think Graneau is saying, and if so, it just comes from noticing what we are really doing when we think about time in terms of a "constant flow".

The text that I quoted by Dr Neal Graneau was connected to a discussion regarding instantaneous action at a distance as part of the book mentioned, which is a compilation of several scientists who propose such a notion in differing ways. Dr Graneau, along with his brother Dr Peter Graneau discuss the evidence and consequences of the notion of Newtonian instantaneous forces.

Because of the nature of the book, it's a little difficult for me to place the quote in a broad context, it was stated along with other contributions in relation to an agreed statement by all the contributers, namely, "There is no time except in relation to processes involving material objects". The discussion made distinctions between time as a succession of states (i.e as being discrete) and time as a continuous parameter. The former was considered to belong to the domain of time measurement - by means of time standards relying upon cyclic phenomena, the latter to be an abstraction, a conceptual transition from discrete measurements to a continuous variable, which allows the application of calculus to physics.

So I am unsure of the true nature of what he meant by his statement, (that time is nothing more than a man made creation) but in part, at any rate, it seems to be aimed at the discrete nature in which we measure periodicity, for he later says, as an argument against motion being quantised, (a view put forward by another contributer) "...my vision of inertia allows motion to happen smoothly as predicted by Newtonian dynamics.."

But I admit also to being a little unsure of what you are saying. Are you saying periodicity doesn't require an association with an (arbitrary) time interval and so does not require an association with a "constant flow of time"? It's almost as if you are saying a sine wave does not indicate a flow of time, we assign such a notion to it.

Clarification here would perhaps help me understand the context in which Dr Graneau made the statement.

EvilEye
2007-Jul-08, 06:22 PM
Everything requires some sort of reference for us.

But time is just one of them.

You have a point in the unverse, and you look across the street and there another one is.

You know for YOU that it will take "time" to get there.

But in reality, they are in existence at once.

Even with non-locality. ALL of it exists at that moment. Your observation of it and calculation is what we call time.
Cause and effect are things that we observe. I think "if and then" is a bad analogy.

I think it should be "when & then".

You can't fool physics even with free will or observation.

This is going to happen, when that happens is always true given the same variables. You cannot change it. You cannot go back and fix it. You can't stop yourself from making the decision you ultimately make, and time will do what it does....just be.

You are along for the ride no matter how much you like to think you made a decision, or an observation.

If you change your mind, and don't do something... You still made the original decision whether you changed it or not. And then you made ANOTHER decision.

grav
2007-Jul-08, 08:10 PM
In my opinion, Ken G and Celestial Mechanic, you are really both correct here, depending upon how one thinks about it. The reason is that, although I have have also said something to the effect that motion produces time, in actuality, it is not so much a "chicken and egg" thing, but rather that they go hand in hand, together, as one, so that one cannot exist without the other. The problem with the concept of time arises because we cannot imagine motion without time, but we can easily imagine time without motion, but this is only because time is exactly that, a concept, a construct within our own minds, while observations of motion are real. As such, our minds can always reconstruct a timeline subconsciously by which to compare, even when applying it to a timeless universe, because such a concept of time will always exist for us, within our minds, somewhere in the back of our heads. This is why I think it is important to initially abolish that time-line from our minds when considering how these motions take place and how we have used them to create a definition of time in the first place, in which case it can be seen that the motions we observe do indeed precede our own concept of time as a measure of them, in reference to how the concept of time has come about, but then also that the concept of time, once formed, trumps motion since it can always be applied no matter what, sort of transcending reality, because it is just that, a concept. But ultimately, the reality and the concept must always go hand in hand simply because one is a measure of the other.

Ken G
2007-Jul-08, 11:13 PM
Are you saying periodicity doesn't require an association with an (arbitrary) time interval and so does not require an association with a "constant flow of time"? It's almost as if you are saying a sine wave does not indicate a flow of time, we assign such a notion to it.I'm really just saying that all concepts of science are inextricably linked to how we measure them, and then we just extend abstractly to mathematical domains that we cannot actually measure (like continuous motion and calculus-- we only measure the result of our abstract thinking when projected onto what is actually measurable discretely). The theory happens at the abstract level, but the tests of the theory are at the level of measurement. So any theory that involves the use of the concept of time must be able to connect to periodic measurements, because the periodicity is the standard we always use to measure time. It is perfectly logical to assume that a process that repeats in precisely the same way over and over should do so in the same amount of "time", but that is still an arbitrary assumption that we make when we define time in terms of how it is measured. The abstract extension of that measurable to something that flows constantly and continuously is entirely an abstraction of our brains, albeit a highly convenient one.

In terms of those contributions in that book, it sounds like they are making the same mistake as many who analyze "Zeno's paradoxes". They ask if time is "really" continuous, even though it is measured discretely, or if it must be discrete because that is how it is measured. But physics has always relied on a synergy between what can be measured and what can be abstractly reasoned, and this is no different. Reality is reality, and physics is physics-- we must not mistake the latter for the former, or we are just going to spend a lot of time cooking up "paradoxes" that are more like looking at our minds than at reality.

grav
2007-Jul-09, 12:11 AM
That doesn't make it wrong, it makes it philosophy...On this particular point, though, in keeping with my last post, I do have to add this. Thinking about the concept of time as based upon a measure and comparison of motions does, in my opinion, seem avowedly more scientific than thinking of matter as flowing through a river of time, which appears to me to be much more on the philosophical side, although again, that doesn't make it incorrect, just more abstract. It raises abstract questions like what is now, what happens to the past and how does the future come into being, does time flow in increments or is it continuous, can we reverse time, are alternate time-lines possible, and what is it about time that allows it to flow? All of these also seem rather philosophical. The answers to most of them become immediately obvious when we think about time as being based upon motion, but then again, some do not, but are instead replaced with alternative questions like does space exist in increments or is it continuous and what is it about space that allows motion to take place within it? Although, I have to say here also that to me, even the questions that result from thinking about it in this way seem more scientifically acknowledgeable as well.

EvilEye
2007-Jul-09, 01:28 AM
Flowing through a river of time is exactly how Einstein put it.


More succinctly... On the river... on a wave.

As I was driving home after dropping off my kids tonioght, I was moving in my truck, and saw a bird fly by across the front of it.

I imagined if the bird were a wave, and how I would feel if I were on his back.

The bird would be still and the gound under me would be moving one way, and the truck would be racing past me.

That is what relativity is all about.

Your OWN perspective.

all of it happened at ONCE, but from each perspective, things happened completely differently.

Ken G
2007-Jul-09, 01:50 AM
The problem with the concept of time arises because we cannot imagine motion without time, but we can easily imagine time without motion, but this is only because time is exactly that, a concept, a construct within our own minds, while observations of motion are real. As such, our minds can always reconstruct a timeline subconsciously by which to compare, even when applying it to a timeless universe, because such a concept of time will always exist for us, within our minds, somewhere in the back of our heads.But is it just pure philosophy when we attempt to apply that to a universe after the Big Rip, with no reference points, no periodic phenomena, and no interactions that can be tracked? I think it is pure illusion at that point, but it certainly isn't science.


This is why I think it is important to initially abolish that time-line from our minds when considering how these motions take place and how we have used them to create a definition of time in the first place, in which case it can be seen that the motions we observe do indeed precede our own concept of time as a measure of them, in reference to how the concept of time has come about, but then also that the concept of time, once formed, trumps motion since it can always be applied no matter what, sort of transcending reality, because it is just that, a concept.True, concepts are abstracted from and separated from reality, but it's like asking if mathematics still "exists" in a perfectly empty universe. It's angels on the head of a pin-- competely moot from the point of view of both science and the philosophy of science, but as a purely philosophical issue, it can be discussed. I find that ironic, given the statements about philosophy in this thread.


But ultimately, the reality and the concept must always go hand in hand simply because one is a measure of the other.If by going hand in hand you mean the former validates the latter, I agree. It is the converse direction that scientific logic does not flow, despite the way it you will often see it applied.

Ken G
2007-Jul-09, 01:54 AM
Thinking about the concept of time as based upon a measure and comparison of motions does, in my opinion, seem avowedly more scientific than thinking of matter as flowing through a river of time, which appears to me to be much more on the philosophical side, although again, that doesn't make it incorrect, just more abstract. I agree with that.
It raises abstract questions like what is now, what happens to the past and how does the future come into being, does time flow in increments or is it continuous, can we reverse time, are alternate time-lines possible, and what is it about time that allows it to flow? All of these also seem rather philosophical. Indeed, to me every one of those questions is taking the concept of time way too seriously. I think the very reason we don't have answers to those questions, despite our vast experience with time, is that the concept of time itself is inappropriate to generate useful answers to those questions. It's just not what the concept was designed to do, and that's why it can't do it.

EvilEye
2007-Jul-09, 02:02 AM
An angel on the head of a pin still exists (if it is "there") and is still as pertinent as an atom, an elephant or a star.

Smallness coupled with distance doesn't equal nonexistence.

Ken G
2007-Jul-09, 03:45 AM
I think you are missing the point of the "angel on a pin" expression-- the idea is that if you have no way to measure or quantify what you are talking about, like time when there are no more clocks or angels on a pin, then you simply cannot be talking about science. However, it is also true that science does rely on abstract concepts too-- science is the synergy of what can be measured and what can be contemplated, and lacking either it is barren.

EvilEye
2007-Jul-09, 03:58 AM
I think you are missing the point of the "angel on a pin" expression-- the idea is that if you have no way to measure or quantify what you are talking about, like time when there are no more clocks or angels on a pin, then you simply cannot be talking about science. However, it is also true that science does rely on abstract concepts too-- science is the synergy of what can be measured and what can be contemplated, and lacking either it is barren.

If I am "there" then I can measure it....or I can measure me.

No universe = no time.

Anything other than nothing = time.... because ANYTHING can be measured.

Any THING regardless of size, has a distance from one side to the other. Distance is measured with what? Time.

publius
2007-Jul-09, 06:22 AM
More on the timeline of the Big Rip (as proposed by "phantom energy" theories: this "stuff" has an equation of state with w < -1, and variable or something). The universe will last about 20 billion more years, or ~35 billion years after the Big Bang.

And the scale factor does become infinite in finite time. It doesn't take off until very near the end. Galaxies will hold together until the last 60 million years. Solar systems will hold together until the last 3 months. Planets and stars will hold together until a few minutes before the end. And then, in the last seconds, atoms go, and then boom, singularity. All she wrote. Infinite expansion.

-Richard

RussT
2007-Jul-09, 07:53 AM
and then boom, singularity. All she wrote. Infinite expansion.

This is incredible! The Naked Singularity 'expanding' FLRW EFE has you all so bamboozled it isn't even funny!

The ONLY way for a 'real' singularity to be formed, is for a "REAL" stellar or Massive Black Hole to form, where the "REAL" event horizon can form to spiral down to r=0=Planck length for the MBH's!!! The "Real" singularities ALWAYS being covered by an Event Horizon!

Starting Time off at T=0, closing the universe from anything coming in continuously from the outside, and then closing the universe at the MBH's singularities, causing the 'flipping' of space/time inside the event horizon, making the singularity 'repulsive' (or anti-gravity or flipping the + - sign), is just "ONE" of the ways that Time is being misinterpreted.

In the accelerated universe scenario, the farther and farther we look out in space the farther and farther 'BACK' in Time we are seeing, However...at the same time the farther and farther away we look the 'Future' is expanding away faster and faster the farther we look...and that's meant to be impossible.

Ken G
2007-Jul-09, 01:12 PM
The universe will last about 20 billion more years, or ~35 billion years after the Big Bang.

And the scale factor does become infinite in finite time.

Thank you, that is interesting indeed-- a timeline that is closed at both ends! I'd say that quite definitively answers the OP.

BISMARCK
2007-Jul-09, 02:12 PM
It does?

Ken G
2007-Jul-09, 02:22 PM
Certainly. It makes the question "what will happen to time after the Big Rip" essentially the same as "what happened before the Big Bang". Answer: our concept of time is completely inadequate for answering those questions, so no one knows. All we could say is that the scientific concept of time started at the Big Bang and would end at the Big Rip (if that model is even appropriate), but who knows what "really" happens.

BISMARCK
2007-Jul-09, 03:40 PM
Ok, I see your point.

publius
2007-Jul-09, 05:09 PM
This is incredible! The Naked Singularity 'expanding' FLRW EFE has you all so bamboozled it isn't even funny!

The ONLY way for a 'real' singularity to be formed, is for a "REAL" stellar or Massive Black Hole to form, where the "REAL" event horizon can form to spiral down to r=0=Planck length for the MBH's!!! The "Real" singularities ALWAYS being covered by an Event Horizon!

Russ,

This is a different type of singularity. A singularity is simply where something becomes infinite (or something becomes zero that you have to divide by, which is the same thing).

This "phantom energy" model, under whatever conditions they have, leads to the expansion becoming infinite in the future. That infinite term is the singularity here, and that's the "Big Rip".

-Richard

Len Moran
2007-Jul-09, 06:31 PM
I'm really just saying that all concepts of science are inextricably linked to how we measure them, and then we just extend abstractly to mathematical domains that we cannot actually measure (like continuous motion and calculus-- we only measure the result of our abstract thinking when projected onto what is actually measurable discretely). The theory happens at the abstract level, but the tests of the theory are at the level of measurement. So any theory that involves the use of the concept of time must be able to connect to periodic measurements, because the periodicity is the standard we always use to measure time.


Thanks for that clarification. As I understand you, our abstract thinking can conceive of a continuous flow of time, but to assign a measurement of time to a real event involves an act of measurement, that by definition, is in a discrete form. The act of measurement described is intrinsic to how we quantify nature, and in the case of the relationship of processes involving material objects, how we quantify time. So in this sense, time is indeed a man made creation, and so to remove us as sentient beings from this relationship of processes would seem to require a different type of question to be asked regarding what exactly this relationship would be.




It raises abstract questions like what is now, what happens to the past and how does the future come into being, does time flow in increments or is it continuous, can we reverse time, are alternate time-lines possible, and what is it about time that allows it to flow? All of these also seem rather philosophical.


I agree with that.Indeed, to me every one of those questions is taking the concept of time way too seriously. I think the very reason we don't have answers to those questions, despite our vast experience with time, is that the concept of time itself is inappropriate to generate useful answers to those questions. It's just not what the concept was designed to do, and that's why it can't do it.


I have often been puzzled by terms like past, present and future, defined in this incremental way. It implies the present as being a fleeting moment of reality, defined as an increment of time, but what duration should this "present reality" be? A second, a microsecond, or what about a nanosecond? It is just meaningless, but I think I have allowed myself to become trapped in just the way you have described, I have taken the act of time measurement too seriously.

publius
2007-Jul-09, 07:17 PM
Russ,

You're getting hung up on this singularity business, particularly this naked singularity stuff. A singularity is just where a mathematical term goes to infinity. Consider a classical point charge in EM theory. There is a singularity there in the potential and the field. Now, something real going to infinity is considered a "breakdown", you can't have a physical quantity going to infinity like that -- it just defies logic. That's what the problem is. Now, QED comes along and has a lot to say about what a "point charge" really is. I don't think it completely solves the infinite self-energy problem, but that doesn't blow up as fast as it does in classical EM, and they figure and hope a TOE will solve it.

General Relativity is a mathematical description of space-time. A singularity here is when components of that description go to infinity at various places in that space-time. There are coordinates and there are invariants, which complicate things. A real, essential singularity is when something real blows up. Coordinate singularities are when your particular ruler and clock have a problem describing space-time. Event horizons are examples of coordinate singularities.

There is a big theorem that says General Relavity, in completely reasonable energy conditions will lead to real singularities in space-time. Collapse to a black hole is such an example.

And so that is taken as a breakdown of the theory -- something else, such as quantum gravity is hoped to take over and prevent the infinity from occuring.

A singularity in this context is thus considered to be "offensive", the ultimate type of obscenity so to speak. So, enter the Cosmic Censorship Hypothesis, which roughly says, the universe will shield such obscenity from our delicate eyes. In more precise terms, it conjectures that singularities are causally disconnected from the rest of space-time; if you see one, you don't live to tell about it, IOW. And that's the way it is for black holes.

However, that is just a conjecture. General Relativity admits all sort of naked singularity solutions, where singularities are not causally disconnected; and observer can go to one and come back out. The simplest example of this is a charged black hole where the charge to mass ratio exceeds a certain value, simply one in God's units. Gravity there, however, becomes repulsive at some point, and so such a thing could not hold itself together, as the force required to do so becomes infinite. So, while that is a solution to the EFE, it is not possible, because other physics (can't have infinite force) prevents it.

So, the Cosmic Censorship conjecture says that the same thing happens to all naked singularity solutions, they are ruled out by other physics. But, turns out that may not be the case.

And that's all this is. There are many different types of singularity, and by type, I mean "ways space-time can blow up". The black hole singularity is one way. There are many others.

The singularity of the Big Rip is another type. The scale factor goes to infinity.

-Richard

Ken G
2007-Jul-09, 08:09 PM
As I understand you, our abstract thinking can conceive of a continuous flow of time, but to assign a measurement of time to a real event involves an act of measurement, that by definition, is in a discrete form. The act of measurement described is intrinsic to how we quantify nature, and in the case of the relationship of processes involving material objects, how we quantify time.Yes.
So in this sense, time is indeed a man made creation, and so to remove us as sentient beings from this relationship of processes would seem to require a different type of question to be asked regarding what exactly this relationship would be.

There are two levels of "measurement"-- the ones we can actually use to check theories, which require real live clocks, and hypothetical ones that happen to trees that fall in the woods with no one around. Typically science does not distinguish these levels of measurement, as we never include complexities until they are necessary, so we just assume that hypothetical clocks (like a passing atom that could in principle interact with the system in question) work as well as real ones (that actually interact in a way that we notice), when we conceptualize events. The problem in regard to the Big Rip is that no clocks, real or hypothetical, can avoid being ripped apart in a finite time, just as no clocks, real or hypothetical, can be self-consistently imagined to precede the Big Bang. So it is on that basis that I would say our concept of time has a beginning and an end in the Big Bang/Big Rip scenario, without getting into the issue of consciousness and trees falling in the woods (which is too much in its infancy from the scientific perspective-- we don't really even know what consciousness is). The concept of time lives in our consciousnesses, but the efficacy of the concept seems to apply quite well even in terms of hypothetical (but possible) clocks.


I have often been puzzled by terms like past, present and future, defined in this incremental way. It implies the present as being a fleeting moment of reality, defined as an increment of time, but what duration should this "present reality" be? A second, a microsecond, or what about a nanosecond? It is just meaningless, but I think I have allowed myself to become trapped in just the way you have described, I have taken the act of time measurement too seriously.Then it shall be my pleasure to liberate you! These are all just constructs, and they work for some things and not for others. I would say that the "present" can mean different things in different situations. In physics, our present is the mathematical boundary between everything that can affect us and everything we could have affected. As those lists keep changing, so does that boundary. There is also a large "limbo" region where we can neither effect nor could have affected us, and we have no temporal name for that but we call it a "spacelike separation", and that region gives rise to the concept of distance. Are any of these boundaries really infinitely sharp? No, quantum mechanics tells us they are not, but we don't need quantum mechanics in every situation, so we often get away with treating them as though they were sharp, just as we take limits that are not "real" when we conceptualize calculus. But that shouldn't surprise us-- mathematics was never meant to be used as anything but a useful simulacrum of reality.

publius
2007-Jul-09, 09:29 PM
More on the singularities of General Relavity, which are sometimes simply called gravitational singularities. There are two general types, curvature singularities and "conical" singularities. The former is when an invariant quantity, something about the curvature tensor, blows up. That is, space-time really blows up in some fashion at some event, and not merely the coordinates fail.

The second type, conical, is, well, when space-time develops a "kink" or a "corner", which can be thought of as the point of a cone. None of the invariants blow up there, but their derivatives do in some fashion. For example, consider a curve with a "corner". The derivative, the slope, experiences a discontinuity.

Singular space-times, at least of the former, curvature type, suffer from "geodesic incompleteness". The world lines of free-falling observers are of finite extent. They hit, or originate from the singularity and just end there.

This is what happens to matter collapsing into a black hole in its own proper time. Its world line just stops, ends, ceases to be. In the Big Bang metrics, everything starts there. All proper time began from that "point".

I put "point" in quotes in order to make another point. We are speaking of a point or points (region) in space-time. What is space and what is time depends on the observer, that's the basic point of all relativity. So "where" and "when" a singularity is is a coordinate dependent thing. And that can trip you up.

To the Schwarzschild observer, the singularity occurs at a point in space, r = 0, and extends through all time. The "location" of the singularity is a sort of a line (0, t) in his 4 dimensional coordinates. But, to a radial free-faller, space and time split in another way. The singularity exists at point in time, and extends over all space (at least in one dimension of it).

Now, in the various Big Bang metrics, we essentially are just running that radial free-faller's time backwards. That just a solution under different initial conditions. Time "starts" at a point, and goes out from there, with space expanding. The radial free-faller's notion of space just collapses as he hits the "wall in time", which is what the singularity is to him. Running it backwards, he starts out at the wall in time, and his notion of space just expands around him.

But note that to any "exterior" observer, if such a thing has meaning, that reversed free-faller's time is space to him. As I've become fond of saying, space and time just do things our minds cannot grasp. You've got to let your absolute notions of these things go before you can appreciate this stuff.

For us in this Big Bang metric, the question is not "where" is any "outside", but *when*. Point in the direction of the future. That's "where" the outside is. And we can never get to it because we'd have to move along our world lines faster than 'c', move through time faster than, well, time moves for us to catch up with the "outside".

Trying to imagine what the Big Bang would look like from the outside doesn't work. In doing so, you're trying to imagine some absolute notion of space and time. You can't do that. From our perspective as a co-expanding observer, that outside just doesn't exist.

-Richard

EvilEye
2007-Jul-09, 09:48 PM
Much like life itself.

You could theoretically remember time from your conception to your death, and your existence after that could still be shown (either physical as in your dead body, or as a record of you having been alive).

But you (and anyone else) can't remember your own time before you were concieved. You simply didn't exist.

Your existence started, and will go on forever. There was a NO you, and forever now, you will have existed.

RussT
2007-Jul-10, 09:00 AM
More on the singularities of General Relavity, which are sometimes simply called gravitational singularities. There are two general types, curvature singularities and "conical" singularities. The former is when an invariant quantity, something about the curvature tensor, blows up. That is, space-time really blows up in some fashion at some event, and not merely the coordinates fail.

The second type, conical, is, well, when space-time develops a "kink" or a "corner", which can be thought of as the point of a cone. None of the invariants blow up there, but their derivatives do in some fashion. For example, consider a curve with a "corner". The derivative, the slope, experiences a discontinuity.

Singular space-times, at least of the former, curvature type, suffer from "geodesic incompleteness". The world lines of free-falling observers are of finite extent. They hit, or originate from the singularity and just end there.

This is what happens to matter collapsing into a black hole in its own proper time. Its world line just stops, ends, ceases to be. In the Big Bang metrics, everything starts there. All proper time began from that "point".

I put "point" in quotes in order to make another point. We are speaking of a point or points (region) in space-time. What is space and what is time depends on the observer, that's the basic point of all relativity. So "where" and "when" a singularity is is a coordinate dependent thing. And that can trip you up.

To the Schwarzschild observer, the singularity occurs at a point in space, r = 0, and extends through all time. The "location" of the singularity is a sort of a line (0, t) in his 4 dimensional coordinates. But, to a radial free-faller, space and time split in another way. The singularity exists at point in time, and extends over all space (at least in one dimension of it).

Now, in the various Big Bang metrics, we essentially are just running that radial free-faller's time backwards. That just a solution under different initial conditions. Time "starts" at a point, and goes out from there, with space expanding. The radial free-faller's notion of space just collapses as he hits the "wall in time", which is what the singularity is to him. Running it backwards, he starts out at the wall in time, and his notion of space just expands around him.

But note that to any "exterior" observer, if such a thing has meaning, that reversed free-faller's time is space to him. As I've become fond of saying, space and time just do things our minds cannot grasp. You've got to let your absolute notions of these things go before you can appreciate this stuff.

For us in this Big Bang metric, the question is not "where" is any "outside", but *when*. Point in the direction of the future. That's "where" the outside is. And we can never get to it because we'd have to move along our world lines faster than 'c', move through time faster than, well, time moves for us to catch up with the "outside".

Trying to imagine what the Big Bang would look like from the outside doesn't work. In doing so, you're trying to imagine some absolute notion of space and time. You can't do that. From our perspective as a co-expanding observer, that outside just doesn't exist.

-Richard

Richard, Everything you posted here and the post above, ASSUMES a Naked Singularity can even exist!!!

And then it defines everything as though it does exist.

And then it defines the Universe as that Naked Singularity is 'everywhere' the center of the universe.

And then it says that at one time the universe must have been smaller and smaller, 'everywhere', and so ALL of the baryonic Matter we see now MUST have been in a very small/dense state 'everywhere, and so the universe MUST have started off HOT 'everywhere'.

Now, run this calculation...collapse all the baryonic matter, that is everywhere currently, down to 'everywhere', where it started...what do ya come up with?

Not only that, BUT, with the Voids in the way, only the galaxy clusters should be collapsing in on themselves.

Now, to get back to the particulars of singularities.



The former is when an invariant quantity, something about the curvature tensor, blows up. That is, space-time really blows up in some fashion at some event, and not merely the coordinates fail.

Take this 'interpretation' for example. Ya'll think that this is 'real'...that it is a major stumbling block...where the 'equations' 'blow up', and it is in a way, BUT not the way that it is being portrayed.

What it is really saying is that the 'understanding' is 'blowing up'!!!

SO, "IF" the universe didn't "Start All at Once", as "One Whole Universe/Entity", then there is no need to get from T=10^-43 down to r=0/T=0...therefore10^-43 is just the limiting 'size/length' of the r=0 "Ring Singularity", and we are still using 'some' form of GR...correct?

Now, the Big Bang postulate has shown us that there MUST be 'something' outside of our universe if the universe is finite but unbounded, to supply our universe with 'some kind' of initial conditions for us to be here, right?

SO , if there is a singularity that can be shown to be attached to 'something' outside our universe, and through that attachment, it can be shown that that would supply our universe with an initial condition that could be recognized/interpeted/observed, that should/could/would count as a consistent/critically derived form of evidence, shouldn't it?

publius
2007-Jul-11, 03:28 AM
Russ,

I'll just have to let this go, and we can agree to disagree here, I suppose.

Thorne, Preskill, and Hawking are still going on the Cosmic Censorship Hypothesis, that is, no naked singularities are physically possible (except for the Big Bang, which is a big exception indeed).

Thorne and Preskill bet against censorship, Hawking is for it. Hawking conceded the first bet, but protests it was a mere technicality, and Thorne and Preskill agreed:

Original bet on naked singularities (http://www.theory.caltech.edu/people/preskill/old_naked_bet.html)

They have reformulated the bet to eliminate the technicality:

New bet on naked singularities (http://www.theory.caltech.edu/people/preskill/new_naked_bet.html)

Note in the original bet, each one considered his own own opinion to be worth "50 pounds stirling". :lol:

And note the conditions of the new bet that eliminate the
technicalities. Note they define a naked singularity as one with "past incomplete null geodesics".

I think I'm gonna have to throw in with the 100 pound stirling side. The weakness of Hawking's 50 pound is to me is best expressed by the "except for the Big Bang" part. :lol: But I'll grant this is about can one form with what we have now. The Big Bang doesn't fit that bill.

Note that all our world lines are "past incomplete". :lol: They extend back to the Big Bang and no further..................

-Richard

Robert TG
2007-Jul-11, 06:53 AM
Well, I suppose I didn't necessarily phrase my initial question in a way that gets to the heart of what I'm asking. So I'll try again:

Can time be defined solely as a function of interactions involving matter and/or energy? If all that existed in the Universe was one single photon, would time exist?

Yes, I think time would exist if there was one single photon.

We live in a space/time 4 dimensional universe where all matter has length, width, height and exists in time. An object cannot have just length with no height in our universe, nor can it have length, width and height and not exist in time. If only one photon exists in our universe, then it must exist in time.

RussT
2007-Jul-11, 07:56 AM
Russ,

I'll just have to let this go, and we can agree to disagree here, I suppose.

Thorne, Preskill, and Hawking are still going on the Cosmic Censorship Hypothesis, that is, no naked singularities are physically possible (except for the Big Bang, which is a big exception indeed).

Thorne and Preskill bet against censorship, Hawking is for it. Hawking conceded the first bet, but protests it was a mere technicality, and Thorne and Preskill agreed:

Original bet on naked singularities (http://www.theory.caltech.edu/people/preskill/old_naked_bet.html)

They have reformulated the bet to eliminate the technicality:

New bet on naked singularities (http://www.theory.caltech.edu/people/preskill/new_naked_bet.html)

Note in the original bet, each one considered his own own opinion to be worth "50 pounds stirling". :lol:

And note the conditions of the new bet that eliminate the
technicalities. Note they define a naked singularity as one with "past incomplete null geodesics".

I think I'm gonna have to throw in with the 100 pound stirling side. The weakness of Hawking's 50 pound is to me is best expressed by the "except for the Big Bang" part. :lol: But I'll grant this is about can one form with what we have now. The Big Bang doesn't fit that bill.

Note that all our world lines are "past incomplete". :lol: They extend back to the Big Bang and no further..................

-Richard

Geezzzzzzzzzzzz:) I wasn't asking you to 'choose' one or the other:)

There were three questions there...

SO, "IF" the universe didn't "Start All at Once", as "One Whole Universe/Entity", then there is no need to get from T=10^-43 down to r=0/T=0...therefore10^-43 is just the limiting 'size/length' of the r=0 "Ring Singularity", and we are still using 'some' form of GR...correct?
__________________________________________________ ______________
Now, the Big Bang postulate has shown us that there MUST be 'something' outside of our universe if the universe is finite but unbounded, to supply our universe with 'some kind' of initial conditions for us to be here, right?
__________________________________________________ ______________
SO , if there is a singularity that can be shown to be attached to 'something' outside our universe, and through that attachment, it can be shown that that would supply our universe with an initial condition that could be recognized/interpeted/observed, that should/could/would count as a consistent/critically derived form of evidence, shouldn't it?

RussT
2007-Jul-11, 08:10 AM
Russ,

I'll just have to let this go, and we can agree to disagree here, I suppose.

Thorne, Preskill, and Hawking are still going on the Cosmic Censorship Hypothesis, that is, no naked singularities are physically possible (except for the Big Bang, which is a big exception indeed).

Thorne and Preskill bet against censorship, Hawking is for it. Hawking conceded the first bet, but protests it was a mere technicality, and Thorne and Preskill agreed:

Original bet on naked singularities (http://www.theory.caltech.edu/people/preskill/old_naked_bet.html)

They have reformulated the bet to eliminate the technicality:

New bet on naked singularities (http://www.theory.caltech.edu/people/preskill/new_naked_bet.html)

Note in the original bet, each one considered his own own opinion to be worth "50 pounds stirling". :lol:

And note the conditions of the new bet that eliminate the
technicalities. Note they define a naked singularity as one with "past incomplete null geodesics".

I think I'm gonna have to throw in with the 100 pound stirling side. The weakness of Hawking's 50 pound is to me is best expressed by the "except for the Big Bang" part. :lol: But I'll grant this is about can one form with what we have now. The Big Bang doesn't fit that bill.

Note that all our world lines are "past incomplete". :lol: They extend back to the Big Bang and no further..................

-Richard

[Note that all our world lines are "past incomplete". :lol: They extend back to the Big Bang and no further..................]

Yes, which appears to have taken the question of 'where's the Event Horizon', right out of the picture!!!:doh:

Hawking should have stuck to his guns, that NO singularity can be created without an Event Horizon and that singularity MUST always be covered (Until it does fade away through some kind of evaporation, BUT that has got to take Gazillions of years). The funny thing is, the other (coordinate singularity) 'might' wind up applying to the stellar black holes, because they are not powerful enough to 'tunnel' through space/time:lol:

He should have stuck to his guns on 'information loss' in MBH's and gone the one step further, and understood there is a difference between MBH's and stellar bh's...that being as I said, that SMBH"s can Tunnel all the way through space/time...the Point Particle/Gravity being created there, and coming to us!

EvilEye
2007-Jul-11, 05:00 PM
When has HAwkings ever stuck to his guns?

And when haven't one of his bets involved nudie pictures? :lol:

publius
2007-Jul-11, 05:14 PM
I believe it was more Brother Thorne whose geodesics gravitated to the nudie pictures. But as I understand it, Mrs. Thorne applied a rather substantial force to deviate him away from those "bodies" pretty good.


-Richard

RussT
2007-Jul-11, 09:26 PM
I believe it was more Brother Thorne whose geodesics gravitated to the nudie pictures. But as I understand it, Mrs. Thorne applied a rather substantial force to deviate him away from those "bodies" pretty good.


-Richard

Naa, he was just 'freefalling':lol:

Please respond to the 'meat' (No PUN!!!) of my last 2 posts:)

publius
2007-Jul-11, 10:24 PM
Russ,

Well, I don't really know how to respond, there. As I mentioned, above, General Relativity allows naked singularities. Valid solutions of the field equations exist which have singularities in space-time that are not "covered". That is simply a mathematical fact. The charged black hole solution where
Q/M > 1 in natural units is the most trivial example. The Kerr solution where L/M exceeds a certain value, which I think is simply 1 as well in natural units is another.

These are solutions. Therefore, General Relativity admits naked singularities. The cosmic censorship business says other physics will prevent solutions of that sort from being realized in all cases (except for the Big Bang, of course). There is no proof for that either way yet, with the "technicalities" removed, and that's what Thorne and Hawking are wagering on.

So, I can't really go any further. You say naked singularities of any sort are not possible and I say they are.

-Richard

RussT
2007-Jul-12, 08:33 AM
So, I can't really go any further. You say naked singularities of any sort are not possible and I say they are.

Yes, I thought I had made it clear that I was agreeing that a Naked Singularity initial condition was possible...I restated that I wasn't asking you to 'choose'.

But, The Big Bang postulates that 'something' from the outside caused/supplied what they are assuming was the initial energy to power the expansion that had some kind of 'phase transition' to become High Energy Gamma Radiation. SO, that is Option "A".

SO, here is Option "B"...

SO, "IF" the universe didn't "Start All at Once", as "One Whole Universe/Entity", then there is no need to get from T=10^-43 down to r=0/T=0...therefore10^-43 is just the limiting 'size/length' of the r=0 "Ring Singularity", and we are still using 'some' form of GR...correct?
__________________________________________________ ______________
Now, the Big Bang postulate has shown us that there MUST be 'something' outside of our universe if the universe is finite but unbounded, to supply our universe with 'some kind' of initial conditions for us to be here, right?
__________________________________________________ ______________
SO , if there is a singularity that can be shown to be attached to 'something' outside our universe, and through that attachment, it can be shown that that would supply our universe with an initial condition that could be recognized/interpeted/observed, that should/could/would count as a consistent/critically derived form of evidence, shouldn't it?

Now, if we as humans don't even allow Option "B" to be examined, how can that be considered 'good science'?

I have seen you and many others saying something to the effect...The universe doesn't have to be operating according to 'your' (Being whoever you or anyone else would have been admonishing:lol:) ideas on how it should be.

hhEb09'1
2007-Jul-12, 09:06 AM
But, The Big Bang postulates that 'something' from the outside caused/supplied what they are assuming was the initial energy I hadn't heard about this. Do you have a reference?

astromark
2007-Jul-12, 09:26 AM
A philosophical conundrum.. unanswerable. But that does not sagest we need to support this idea of a ' Something' from outside. I do not think outside is a reasonable reference point when the big bang is concerned.

astromark
2007-Jul-12, 09:35 AM
I do not want to sound like a ... something I'm not. Could we at least stop using this Big Bang, I would like the great minds to actually agree that 'The Beginning' might better say what we mean. Note, that I did not add the 'In' to that as I do not except an outside at this point of beginning. If you follow my daft logic.

RussT
2007-Jul-12, 10:28 AM
I hadn't heard about this. Do you have a reference?

You might want to ask Ed Whitten, Lee Smolin, and all the rest of the "String/"M", LQG, and a gazillion others what this might mean...I'm sure they would have an idea or two for YA.

hhEb09'1
2007-Jul-12, 09:00 PM
You might want to ask Ed Whitten, Lee Smolin, and all the rest of the "String/"M", LQG, and a gazillion others what this might mean...I'm sure they would have an idea or two for YA.I just looked around, and found this wiki article (http://en.wikipedia.org/wiki/Big_Bang). You seem to be talking about Speculative physics beyond the Big Bang (http://en.wikipedia.org/wiki/Big_Bang#Speculative_physics_beyond_the_Big_Bang) but that wouldn't be a part of what the Big Bang postulates, then, right?

RussT
2007-Jul-13, 02:08 AM
I am NOT going to play this rigged game NOR am I going to respond with a long (Because that is what it takes, and I have already done it in numerous ways and numerous times) post breaking it all down to show how it is rigged and winds up being a shell game in several different ways!!!

The crux winds up being...For NOT saying anything about 'The Beginning', The Big Bang sure has a whole lot of defining things to say about the beginning, to then turn around and say....oops, we can't get there, we can only get to T=10^-43, SOOOOOOOOOOOOO the theory doesn't say 'anything' about a "Beginning".

And that doesn't even get into...the "Naked" singularity being 'everywhere the center of the universe........because of course....the theory doesn't say 'anything' about the 'beginning' or what caused it....BUT...

The Energy Had To Come From Somewhere 'Outside' of what currently exists (AND, there is absolutely NOTHING that says that it has to be "Energy/Gamma Radiation First"!!!), if the universe is finite but unbounded (and even that is not necessarily true!)

They have NO idea what even causes the "Highest" Gamma Radiation to be created, OR even what that Highest is!!!

EvilEye
2007-Jul-13, 02:13 AM
If any of us ever figure it out they'll get the Nobel prize fo Physics.

hhEb09'1
2007-Jul-13, 01:49 PM
The Energy Had To Come From Somewhere 'Outside' of what currently exists That seems to be your opinion, not a part of the what the "The Big Bang postulates". But the first step on your logic in that post (http://www.bautforum.com/questions-answers/61382-regarding-continued-existence-time-5.html#post1028550) seems to depend upon that. It seems to fall apart there.

Nereid
2007-Jul-14, 08:00 PM
Imagine a Big Rip scenario taken to its logical end where at any one point in space, there is no matter and no energy, except for the still present Dark Energy.

If there is no matter or any carrier particles of the various forces, is it possible for an event to happen? And if not, then does that mean that time doesn't exist in any meaningful way?Back to the OP ...

I think publius answered it well, within the scope of phantom energy and Big Rip.

Along the way there was a (rather too common, but interesting) discussion of the nature of time and its dependence on other things; FWIW, I think this site (http://www.galilean-library.org/academy/viewforum.php?f=8) would be a much better place to have an informed discussion of these aspects than BAUT .... if only because BAUT's avowed scope intrudes so little into philosophy.

However, there are some aspects, betwixt finite and infinite, but still within BAUT's scope, that I feel have not been explored.

For example, if the nearest other particle were 10^10^10^10 Mpc away, the universe would not be empty, nor would interactions never happen ... they'd just be a little slower than we blobs of C, H, N, O etc are used to.

In such a universe, how might a clock be constructed? how might it work? What could a denizen of such a universe use for a ruler?

For practical physicists* - the 'shut up and calculate' kind - in such a universe, what could be observed? measured? Could such practical physicists test GR? QED? QCD?

*and astronomers and cosmologists

EvilEye
2007-Jul-15, 12:43 AM
Back to the OP ...

I think publius answered it well, within the scope of phantom energy and Big Rip.

Along the way there was a (rather too common, but interesting) discussion of the nature of time and its dependence on other things; FWIW, I think this site (http://www.galilean-library.org/academy/viewforum.php?f=8) would be a much better place to have an informed discussion of these aspects than BAUT .... if only because BAUT's avowed scope intrudes so little into philosophy.

However, there are some aspects, betwixt finite and infinite, but still within BAUT's scope, that I feel have not been explored.

For example, if the nearest other particle were 10^10^10^10 Mpc away, the universe would not be empty, nor would interactions never happen ... they'd just be a little slower than we blobs of C, H, N, O etc are used to.

In such a universe, how might a clock be constructed? how might it work? What could a denizen of such a universe use for a ruler?

For practical physicists* - the 'shut up and calculate' kind - in such a universe, what could be observed? measured? Could such practical physicists test GR? QED? QCD?

*and astronomers and cosmologists



In a situation where there were only two particles... I think (I don't know) that time would exist as the relative motion between the two, regardless of how far away from each other they were. The weird thing about having only 2 objects against which to measure time... is that their time would be the same.

So...

A clock in that situation would have the center between them, and the ends of the hands would represent them and their motion. (The hands could become longer and shorter, but would still move in a circle.) ...at least that's how I envision it.

Ken G
2007-Jul-15, 01:02 AM
For example, if the nearest other particle were 10^10^10^10 Mpc away, the universe would not be empty, nor would interactions never happen ... they'd just be a little slower than we blobs of C, H, N, O etc are used to.But the OP is about the "Big Rip", not just a very low density universe. There'd be no interactions at all in the Big Rip, because it reaches infinity in finite time. One could even imagine universes that don't reach infinity, but every particle passes out of the event horizon of every other particle, so again there are no interactions and no meaningful concept of time. But we could diverge from the OP and just consider a static universe that is nevertheless spectacularly low density, and pose your question. I suspect that such a universe might be surprisingly similar to ours, if ours was actually static-- you could map the two together with an extreme rescaling of the meaning of distance and time. But the main thing is, such a universe would really have to be static-- evolution at even a very slow rate would mess up the possibility for the kinds of things we recognize to happen, as you don't want your universe to change faster than your sentient beings can think.

publius
2007-Jul-16, 05:32 AM
I just got to doing something dangerous -- reading some papers written by the high priests on the Big Rip against local systems. It's dangerous because I don't really understand things well enough, and I'll certainly get a lot of those red -1's, if not an outright error.

Basic question: What happens to a black hole in an expanding universe? In a deSitter universe, nothing happens. The black hole horizon remains fixed. If something is far enough away, it gets pulled away, but the black hole itself is fixed.

I was reading a paper about this. That's a very special case where the "dark energy" is an exact cosmological constant type, p = -rho. How about in an accelerating expansion? What happens then?

Well, they apparently showed you can have an expanding horizon, a "comoving horizon". The black hole is being pulled apart by the expansion. Weird stuff happens, described in a lot of high-priest language (such a conformal Killing fields doing big-word-big-word yada-yada stuff). Troubling was that a *real* singularity developed at the horizon, not just a coordinate one. Something real blew up there. But yet, they said it was only a "weak" singularity, whatever that meant. Something else happened as well, something about "superluminal" fluid velociy (what the fluid was -- the dark energy or the regular background energy of the expanding universe, I don't know), but they were sure that was just an artifact of some simplifying condition they imposed......

Anyway, conclusion was: Black Hole blow up in Big Rip. And maybe even before the final moment! If that's so, well, that is naked singularity time, but even they aren't sure just what the heck it's saying. Anyway, if the Big Rip can pull apart a black hole (whatever that really means -- I don't they are even sure), then well, that's pretty saying nothing can hold together.

-Richard

Michael Noonan
2007-Jul-16, 07:56 AM
Along the way there was a (rather too common, but interesting) discussion of the nature of time and its dependence on other things; FWIW, I think this site would be a much better place to have an informed discussion of these aspects than BAUT .... if only because BAUT's avowed scope intrudes so little into philosophy.



Well found Nereid, it does allow a more extended range of ideas, thanks. One of the main reasons I feel the ATM is here is that along with developing an idea that there is 'hope' that the ATMer will benefit from good science like the rest of the community.

The ATM is first and foremost a place to announce an idea, maybe to promote it but only in the ATM for the 30 days allowed.

Maybe a sticky note in the ATM and Conspiracy Area for that matter to list other forums more suited to certain types of alternate ideas and a brief description of what those forums are looking for. That way when an ATMer has had their day in the spotlight of BAUT they can be directed to a more appropriate online community that does actually want their sort of output.

That way BAUT remains a teaching site for the scientific method, the ATMer can still be a passive part of a great online community. They still gain access to the latest findings here, enjoy the other discussions and keep in touch.

It is good for the mainstream here as it provides a teaching and social function and relocates those who because of "promoting" may be really considered just pests.

Michael Noonan
2007-Jul-16, 08:06 AM
"Oops" this should be in "Why do we have an ATM anyway", got distracted but the link to other sites may be helpful and redirect the few who need to post but can't find the right section (like me, one of my absent daze again).

Nereid
2007-Jul-16, 11:25 PM
But the OP is about the "Big Rip", not just a very low density universe. There'd be no interactions at all in the Big Rip, because it reaches infinity in finite time. One could even imagine universes that don't reach infinity, but every particle passes out of the event horizon of every other particle, so again there are no interactions and no meaningful concept of time. But we could diverge from the OP and just consider a static universe that is nevertheless spectacularly low density, and pose your question. I suspect that such a universe might be surprisingly similar to ours, if ours was actually static-- you could map the two together with an extreme rescaling of the meaning of distance and time. But the main thing is, such a universe would really have to be static-- evolution at even a very slow rate would mess up the possibility for the kinds of things we recognize to happen, as you don't want your universe to change faster than your sentient beings can think.Apart from 'black holes meet big rip', I considered the OP's question to be pretty much answered ... in a universe with only one, indivisible, particle, what clocks and rulers could be constructed?

If no clocks or rulers could be constructed, what meaning would 'time' or 'distance' have?

The scope of my question excludes everything about who (or what) does (or could) do the constructing, reading of clocks or rulers, or even thinking about them.

If two (indivisible) particles, ... ? three? ...

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

One other aspect I think is worth repeating (it's already been covered): many physical regimes well 'before' the ultimate rip are far, far, far beyond anything any of those our best physics theories today have been tested in.

A cool look at the history of physics suggests that when we do get to examine some of these regimes we will find some new physics ... and such new physics may make the question in the OP look downright silly, or irrelevant, or quaint, or ...

But the point is we, today, can't tell what that new physics is (if any).

Oh, and then there's the fact that Dark Energy may turn out to be incapable of doing a big rip on the universe ...

Ken G
2007-Jul-17, 12:11 AM
A cool look at the history of physics suggests that when we do get to examine some of these regimes we will find some new physics ... and such new physics may make the question in the OP look downright silly, or irrelevant, or quaint, or ...

But the point is we, today, can't tell what that new physics is (if any).
Yes, that is the main point to remember. The OP can focus on the Big Rip scenario if it chooses, but it's hard to take any model we can make now terribly seriously if that were to actually happen.

Oh, and then there's the fact that Dark Energy may turn out to be incapable of doing a big rip on the universe ...
Indeed, I think the "cosmological constant" approach is the current frontrunner, partly because of some minor observational successes, and partly because it is so simple and so far so unfalsified.

EvilEye
2007-Jul-17, 12:54 AM
I thought (maybe I am wrong) that Black holes only gather enough mass to equalize, and then stabilize.....and then "evaporate".

If that's the case, the evaporation of the black holes during the big rip would be the justification......?