The Dimension of Time
in [Relativity]
|
Prev: Relativity Researcher: Increase Your Research Productivity with the Leading Web 2.0 Research Portal
Next: Radio Waves, Photons, and Wave Speed.
From: Ste on 30 Dec 2009 04:32 On 29 Dec, 18:18, PD <thedraperfam...(a)gmail.com> wrote: > On Dec 29, 12:21 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > On 28 Dec, 23:48, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > Sure it can. I'm comparing two states, A and B, with different values > > > > > of entropy. > > > > > State B has a higher numerical entropy than state A. I can do this > > > > > without any labeling with time at all. > > > > > Lol. Ok I'll run with this for now. > > > > > > Now, what I observe in nature is that in a closed system, and while > > > > > measuring time, state B happens to be always after state A in that > > > > > time sequence. > > > > > There is no obvious reason why this should be. It could have been just > > > > > as likely that state B occurred before state A. > > > > > But it DOESN'T. > > > > > But in some cases state A *never* becomes state B. So does that mean > > > > time stands still when entropy doesn't change? > > > > Not at all. Why would you say that? > > > The question is about whether there is any preferential order in time > > > from the point of view of physical processes. If it there were no > > > preferred order or arrow of time, then all physical processes would be > > > observed to be symmetric in time -- running just as often from state A > > > at earlier time to state B at later time, compared to state B at > > > earlier time to state A at later time. > > > But there's an asymmetry OBSERVED. > > > I get your point. What I'm saying is that the theoretical model we > > have to explain our observations needs to be questioned. > > There is no real interpretation involved other than simple > observation. I think you'll find there is. > Either the processes occur symmetrically or they don't. > It's observed that they do not. There is no point in having a > "theoretical model" that says they are really symmetric after all. But often what appears on casual observation to be "asymmetrical" by virtue of its complexity, is in fact symmetrical. If a transformation of energy today only has its re-transformation eons after humans have ceased to exist, then that would largely explain why "observations" over a few years appear asymmetrical. Indeed, a pendulum, observed only for a tiny interval during it's swing, may appear to be an "asymmetrical" process - and indeed, depending on where in the swing the pendulum is at the time of observation, legitimate extrapolations can be made that say the pendulum is accelerating to infinity, or decelerating to a full-stop for all time. But in fact neither extrapolation would be correct, because the problem is that the observer lacks necessary perspective. > > People once > > saw the Sun move over the sky, and assumed that the Sun orbited the > > Earth. And the credibility of that model, and the credulity of the > > very best and brightest, remained long after a better and more simpler > > model had been conceived - that of the Earth orbiting the Sun. > > > Indeed the problem is that humans are apparently very poor at > > developing perspective. Physical processes may well be symmetric in > > time - in that every transformation of energy can ultimately be > > reversed by the fundamental forces of nature. And indeed I think that > > is true, and it is a snug fit with other laws like energy > > conservation. > > That is true, it is consistent with OTHER observations. But the model > would ALSO have to be consistent with the *observed* asymmetry of > physical processes and the *observed* one-way growth of entropy in > closed systems. If the model is not consistent with those > observations, then it is wrong. Well I think I've largely addressed that above. What I would add though about entropy is that there is no evidence that the entropy of the universe is increasing. The only possible compatibility between the 2nd law and the conservation law, is to say that entropy remains constant if the universe is a closed system. Alternatively, if the univerese is an open system, then the 2nd law has no application (for it deals only with closed systems). > > And yet, we cling to the model of time flowing ever- > > forwards, of entropy ever-increasing - and clinging to this model > > means that every new discovery puts a new epicycle into contemporary > > theoretical physics, in the same way that in the middle ages every new > > star discovered, every new telescope developed, put another epicycle > > into the contemporary astronomer's model of the sky. > > What is epicyclic about entropy? Nothing is epicyclic about entropy - the 2nd law is compatible with the conservation law, in that energy is never created nor destroyed, and entropy can remain constant. Epicycles only become necessary when people insist entropy is always increasing. Another epicycle is the forward flow of time - it forces us to deal with "time travel", "worm holes", "cause preceding effect". > > That is why I don't place any value on the existing maths in > > theoretical physics, because a model begins life in its most > > mathematically refined state, to which only epicycles can then be > > added. And if you commit yourself to fitting your theories around the > > existing hoard of counter-intuitive epicycles, > > What is counterintuitive about entropy? I was actually talking about more than just entropy. But nothing is counter-intuitive about entropy, if you realise that the laws of thermodynamics were developed during the heyday of the industrial revolution. Once you have that perspective, it becomes easy to see why ever-increasing entropy was a legitimate interpretation of observations made at the time of its development, in the same way that classical mechanics was a legitimate interpretation of observations made at the time. That is, I fully understand entropy at an intuitive level - for example I know that the temperature of hot water in a kettle will eventually reach equilibrium with the room temperature (the hot water having given up heat to the room) - but none of this leads me to believe the process is fundamentally irreversible. And the reason is because I do not give the universe an anthropocentric character. The fact that humans cannot boil a kettle at will without expending limited energy stores elsewhere, does not mean the fundamental forces of nature cannot. Indeed, I would say that the boiling of the kettle, and the subsequent dissipation of heat, is the very expression of those fundamental forces existing in equilibrium - coal is formed, coal is burned, element heats water, water heats atmosphere, organic matter dies off, coal is formed. The same with the solar system. Gravity crunches, fusion starts, elements distributed, planets form, life forms, sun dies, life dies, gravity crunches, fusion starts. Of course, that's a simplification, but you can understand my approach to the issue. > Furthermore, let's get one thing straight: In a confrontation between > experimental observation and intuition, intuition must and always does > lose. Not at all. For an educated man, the two should be one and the same. If a phenomenon is not intuitive, then either the mechanism is not observed enough to develop understanding, or your theory is a nonsense. Clearly, if a mechanism is both regularly observed, and not intuitively understood, then that leaves just one possibility: your theory is wrong. Of course, what we mean in everyday parlance by "counter-intuitive" is precisely that: your existing theories are wrong. I seem to remember reading a quote of Bohr's to the effect of: "we don't have to understand it, as long as it works". By which he meant, if the maths work, then we don't have to have any more fundamental understanding of the mechanism. And I think too many people take that approach to scientific inquiry, but of course I don't agree. A fundamentally flawed theory can still have a lot of predictive power if it incorporates the real variables indirectly. > > you'll spend a life's > > work at the rump of your subject. > > > Indeed if there is one thing I know from my broad knowledge in many > > subjects, it is that those who talk of asymmetry, of complexity, of > > change, of difference, actually don't have perspective on their > > subject, and those who can talk *convincingly* of symmetry, of > > simplicity, of constancy, of similarity, do have perspective. > > ??? > > This doesn't have to do with perspective. It has to do with whether > nature EXHIBITS in EXPERIMENT an asymmetry or not. > This isn't philosophy. It's physics, which is a study of how nature > ACTUALLY BEHAVES, not how we think it ought to behave. I agree the aim is to ascertain how nature actually behaves, but see my opening statement above for why too little perspective can actually lead one astray from understanding the true nature of things. I find if you observe asymmetry, then you haven't made enough observations, or you haven't made a connection between two apparently unconnected observations. Any true physicist knows (say it with me children!) each and every action has an equal and opposite reaction. That is a statement of symmetry. Each action and counter-action may not occur simultaneously in time, but that's the point: the symmetry is in the relationship *overall*. If an action is observed to occur, then you can be sure that it's counter-action has previously preceded and will eventually follow. > > > This idealization of systems is essential to physics. > > > Not at all. Science is supposed to be about idealising the model in > > the first place, and then making allowances for it's practical > > implementation. > > I completely disagree. All models of all types are idealizations -- No. Some models are not idealisations of reality, they are just wrong. > that is, there are factors that are neglected in the treatment of any > real system. My view is that the "neglected factors" should be in the implementation, not the idealisation. If there are neglected idealisations in the theory, then the theory is wrong. And while it may be useful when simplicity is desirable for some practical purposes, regard to "practical purposes" should not be a significant consideration in *theoretical* physics. > In reality, every real system is distinct from every other real > system, Only insofar as no distinction is made in the first place between real systems that cannot be distinguished from each other in some way. Hence this statement is a tautology in practice. > which means that a strictly correct treatment would be a one- > off in every case. But the value of science is to aggregate various > real systems so that they can be treated with a common model, to the > extent that the differences can be ignored for the purposes of the > prediction being made. As I say, there is a difference between theoretical science, and practical science. In practical science, simplifcations are fine. In theoretical science, it isn't. And because theoretical science precedes practical science, if you start treating them as one and the same, your dead in the water. Consider the simplification of maths where instead of scrupulously "doin't one side what you do t'other" (as a tutor once put it in Wigan drawl), you simply move the value and change it's operator. The theory of equality is simple. But implementing it in practice uses more ink than is necessary, so you use the simplification. But in that way, the practical simplification came after the theory. And unless you know the theory behind it, you don't understand the simplification - it may as well be magic, and you will often apply it incorrectly. > A first-semester physics book has a chapter on 2D kinematics and > projectile motion. With that model, application after application is > drilled into students, even knowing that air drag, air lift, > variations in g, curvature of the earth, rotation of the earth, etc., > are all being ignored. Indeed. That's because that course is about training people to implement the theory in practice, not about giving them the education necessary to question existing theories and develop new better ones. > > > > > OK, then please note the distinction between "yet to be falsified" and > > > > > "unfalsifiable". > > > > > Indeed. Reminds me of a joke actually, that there are only two types > > > > of scientific theory... > > > > And so your problem with this is what? > > > I don't have a problem. I was just acknowledging that I know the > > difference between "unfalsifiable" and "not yet falsified", and then I > > went on to reflect comically on the fact that the only scientific > > theories that will not eventually be falsified are those that are > > unfalsifiable. > > OK, so what does this have to do with whether a theory of multiple > universes is unfalsifiable? > It seems there are experimental tests... Oh? > > No, and with respect I don't think I want to know, because something > > that includes the "past and future" model of time is bound to confound > > me. > > Well, here's a problem then. > You propose a philosophical statement about time that imposes symmetry No, I said time is a function of the human mind, not of the material world. > and make the claim that it is BETTER than any model that acknowledges > asymmetry of time. But you also acknowledge that your comparison is > hampered by the fact that you don't even understand any model that > acknowledges asymmetry of time, and that moreover you don't even want > to know any more about any model that acknowledges asymmetry of time > because such a model would confound you. I understand the asymmetric model of time perfectly. It's one I've taken for granted all my life. Until a few weeks ago, when I suddenly realised that relativity doesn't require it, and there is no test for it. > This is known commonly as the "My model is right because I understand > it" fallacy. It is fairly commonplace among crank circles. I would > have thought you would not want to associate yourself with this kind > of nonsense. Indeed. But I don't need to study theology first in order to reject its truth. I reject the forward-flowing model of time in theoretical physics because like La Place I'm content to say there is no need of the hypothesis, and in fact appears to bring unnecessary baggage to the table. If you discard time as a physical dimension, then you can wholly discard wormholes, black hole "singularities" where "time stops", and all the rest of that bunk. > > > > > > > > If energy is consumed in the future in order to send matter back in > > > > > > > > time, > > > > > > > > What makes you think this is consistent with the laws of physics? > > > > > > > Which part? I certainly don't think time travel is consistent with the > > > > > > laws of physics, because my very position is that I don't accept that > > > > > > time is flowing at all. > > > > > > I don't know that time travel is consistent with the laws of physics, > > > > > either. Who says it is? > > > > > It is not so much that anyone is saying that time travel is consistent > > > > with the laws of physics, only that the current laws of physics > > > > themselves seem to suggest such a possibility, for if you can go > > > > forward in time, then you must be able to go backward in time - > > > > otherwise the concept of backwards and forwards becomes meaningless.. > > > > That's nonsense. The forward is accessible to us in a causal manner, > > > the backwards is not. This doesn't render one of them meaningless. Nor > > > does having meaning associated with both imply that we would be able > > > to causally influence the past. > > > My point is that "cause and effect" are an arbitrary classification to > > describe something of meaning to humans. The reason the "past" can > > never be "affected" in a "causal" manner is because, by its very > > definition, cause always precedes effect in the forward-flowing model > > of time. > > On the contrary, cause and effect doesn't imply time ordering. No and therein lies the contradiction! How on Earth did anyone ever conceive of a model where the effect precedes the cause in time? > What it states is that given two conditions A and B, altering A always > alters B. This is how we determine whether A causes B, not by what > sequence they have in time. But again, this rests on the idea that a cause of an observed effect can happen after the effect itself. I consider that not only a corruption of the language, but utter nonsense in itself. Indeed, such a model is actually unfalsifiable, because if the effect were observed, and then the cause removed, all memory of the effect having been measured in the first place would necessarily have been erased - unless human memory exists outside of the material world. Honestly, PD, commit this model to the flames. > > > > Indeed, if we must use backwards and forwards notation, then I would > > > > say the astronaut twin has gone "backwards" in time, if only in the > > > > sense that when he returns to earth, the homebody is ahead of his > > > > brother in age, and the astronaut is astern of his brother in age. > > > > But he HASN'T gone backwards in time. He's aged -- that's FORWARD in > > > time. It's just that his Earth buddy has gone forward in time faster. > > > But that's because "going backwards in time", to you, means someone's > > age reducing in *absolute* terms. To me, the fact that one twin is > > younger than the other is evidence that one has gone back in time > > *relatively*. > > That would be an interpretation carried by you, rather singly. It would be nice if that were the case. > > > > Of course most people don't accept this notation. They say only that > > > > the astronaut has gone "slower forwards". > > > > > However, on my reading of relativity, it does not actually require an > > > > absolute forward flow of time, relativity merely suggests that events > > > > can move either ahead, or astern, of other events. > > > > No, relativity says nothing of the kind. Perhaps you need some > > > guidance on your reading of relativity. > > > I think perhaps others need reminding about the implications of > > relativity. People just about seem happy with relative positions in > > space. They seem less happy with relative positions in time. > > I think you could use a little better background on what relativity > really says, You mean I need a better background on what mainstream physicists really say about relativity? > rather than you just taking a comic book exposure and > then layering your own pseudo-scientific interpretations on top of it. What is a pseudo-scientific interpretation as distinct from a scientific interpretation? > Would you like a reading reference? If it treats the issue of relative time, and explains why this is incompatible with relativity, yes.
From: PD on 30 Dec 2009 12:39 On Dec 30, 3:32 am, Ste <ste_ro...(a)hotmail.com> wrote: > On 29 Dec, 18:18, PD <thedraperfam...(a)gmail.com> wrote: > > > On Dec 29, 12:21 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > On 28 Dec, 23:48, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > Sure it can. I'm comparing two states, A and B, with different values > > > > > > of entropy. > > > > > > State B has a higher numerical entropy than state A. I can do this > > > > > > without any labeling with time at all. > > > > > > Lol. Ok I'll run with this for now. > > > > > > > Now, what I observe in nature is that in a closed system, and while > > > > > > measuring time, state B happens to be always after state A in that > > > > > > time sequence. > > > > > > There is no obvious reason why this should be. It could have been just > > > > > > as likely that state B occurred before state A. > > > > > > But it DOESN'T. > > > > > > But in some cases state A *never* becomes state B. So does that mean > > > > > time stands still when entropy doesn't change? > > > > > Not at all. Why would you say that? > > > > The question is about whether there is any preferential order in time > > > > from the point of view of physical processes. If it there were no > > > > preferred order or arrow of time, then all physical processes would be > > > > observed to be symmetric in time -- running just as often from state A > > > > at earlier time to state B at later time, compared to state B at > > > > earlier time to state A at later time. > > > > But there's an asymmetry OBSERVED. > > > > I get your point. What I'm saying is that the theoretical model we > > > have to explain our observations needs to be questioned. > > > There is no real interpretation involved other than simple > > observation. > > I think you'll find there is. > > > Either the processes occur symmetrically or they don't. > > It's observed that they do not. There is no point in having a > > "theoretical model" that says they are really symmetric after all. > > But often what appears on casual observation to be "asymmetrical" by > virtue of its complexity, is in fact symmetrical. If a transformation > of energy today only has its re-transformation eons after humans have > ceased to exist, then that would largely explain why "observations" > over a few years appear asymmetrical. OK, but now you are talking about something that is by definition unfalsifiable, since you are positing something that will erase the observed asymmetry long after humans have ceased to exist to observe it. Science is about understanding the laws of nature as they can be confirmed by observations and measurements we CAN conduct. Postulating something that is inconsistent with observations, because you LIKE symmetry better than asymmetry, and then excusing the lack of symmetry by saying that it is by nature unobservable, puts it in the realm of religious faith and not science any longer. When you can posit your notions in a manner that it produces predictions that can be *tested* by reasonably accessible experiment, then you will have returned to science. > > Indeed, a pendulum, observed only for a tiny interval during it's > swing, may appear to be an "asymmetrical" process - and indeed, > depending on where in the swing the pendulum is at the time of > observation, legitimate extrapolations can be made that say the > pendulum is accelerating to infinity, or decelerating to a full-stop > for all time. But in fact neither extrapolation would be correct, > because the problem is that the observer lacks necessary perspective. > > > > People once > > > saw the Sun move over the sky, and assumed that the Sun orbited the > > > Earth. And the credibility of that model, and the credulity of the > > > very best and brightest, remained long after a better and more simpler > > > model had been conceived - that of the Earth orbiting the Sun. > > > > Indeed the problem is that humans are apparently very poor at > > > developing perspective. Physical processes may well be symmetric in > > > time - in that every transformation of energy can ultimately be > > > reversed by the fundamental forces of nature. And indeed I think that > > > is true, and it is a snug fit with other laws like energy > > > conservation. > > > That is true, it is consistent with OTHER observations. But the model > > would ALSO have to be consistent with the *observed* asymmetry of > > physical processes and the *observed* one-way growth of entropy in > > closed systems. If the model is not consistent with those > > observations, then it is wrong. > > Well I think I've largely addressed that above. > > What I would add though about entropy is that there is no evidence > that the entropy of the universe is increasing. That's actually not the case. There is cosmological evidence that it IS increasing. You didn't know this, I take it. > The only possible > compatibility between the 2nd law and the conservation law, is to say > that entropy remains constant if the universe is a closed system. > Alternatively, if the univerese is an open system, then the 2nd law > has no application (for it deals only with closed systems). > > > > And yet, we cling to the model of time flowing ever- > > > forwards, of entropy ever-increasing - and clinging to this model > > > means that every new discovery puts a new epicycle into contemporary > > > theoretical physics, in the same way that in the middle ages every new > > > star discovered, every new telescope developed, put another epicycle > > > into the contemporary astronomer's model of the sky. > > > What is epicyclic about entropy? > > Nothing is epicyclic about entropy - the 2nd law is compatible with > the conservation law, in that energy is never created nor destroyed, > and entropy can remain constant. Energy and entropy are not the same thing. Entropy is related to the number of available microstates. The energy of a closed system can remain completely constant and the entropy increase nonetheless. > Epicycles only become necessary when > people insist entropy is always increasing. Why is increasing entropy epicyclic? > Another epicycle is the > forward flow of time - it forces us to deal with "time travel", "worm > holes", "cause preceding effect". What is epicyclic abot any of these? I believe you are overlapping in your mind "epicyclic" and "counterintuitive". > > > > That is why I don't place any value on the existing maths in > > > theoretical physics, because a model begins life in its most > > > mathematically refined state, to which only epicycles can then be > > > added. And if you commit yourself to fitting your theories around the > > > existing hoard of counter-intuitive epicycles, > > > What is counterintuitive about entropy? > > I was actually talking about more than just entropy. > > But nothing is counter-intuitive about entropy, if you realise that > the laws of thermodynamics were developed during the heyday of the > industrial revolution. Notice, however, that they are not restricted to industrial applications. They are laws of physics, which means that, even in the most idealized of situations, they still apply. > Once you have that perspective, it becomes easy > to see why ever-increasing entropy was a legitimate interpretation of > observations made at the time of its development, in the same way that > classical mechanics was a legitimate interpretation of observations > made at the time. > > That is, I fully understand entropy at an intuitive level - for > example I know that the temperature of hot water in a kettle will > eventually reach equilibrium with the room temperature (the hot water > having given up heat to the room) - but none of this leads me to > believe the process is fundamentally irreversible. Whether you believe it or not is not really relevant. What matters is whether there is any *evidence* that it is fundamentally reversible. This is where observation plays a key role and what separates physics from philosophy. The moment you believe that the underlying truth of nature is something other than what is observed, and that the fundamental truth *cannot* be observed, because observations obstruct the truth, then you have abandoned science as an investigation and you are just doing philosophy. > > And the reason is because I do not give the universe an > anthropocentric character. The fact that humans cannot boil a kettle > at will without expending limited energy stores elsewhere, does not > mean the fundamental forces of nature cannot. Indeed, I would say that > the boiling of the kettle, and the subsequent dissipation of heat, is > the very expression of those fundamental forces existing in > equilibrium - coal is formed, coal is burned, element heats water, > water heats atmosphere, organic matter dies off, coal is formed. > > The same with the solar system. Gravity crunches, fusion starts, > elements distributed, planets form, life forms, sun dies, life dies, > gravity crunches, fusion starts. Of course, that's a simplification, > but you can understand my approach to the issue. > > > Furthermore, let's get one thing straight: In a confrontation between > > experimental observation and intuition, intuition must and always does > > lose. > > Not at all. For an educated man, the two should be one and the same. Not necessarily! Nature is surprising. We develop mental models that are best guesses as to how nature works, and then we TEST that model to see if it really describes nature the way we think it does. But more often than not, we find that nature is not what we thought it was. > If a phenomenon is not intuitive, then either the mechanism is not > observed enough to develop understanding, or your theory is a > nonsense. Clearly, if a mechanism is both regularly observed, and not > intuitively understood, then that leaves just one possibility: your > theory is wrong. > > Of course, what we mean in everyday parlance by "counter-intuitive" is > precisely that: your existing theories are wrong. > > I seem to remember reading a quote of Bohr's to the effect of: "we > don't have to understand it, as long as it works". By which he meant, > if the maths work, then we don't have to have any more fundamental > understanding of the mechanism. This approach is really not what's taken, though a lot of people use it as a provisional approach to be sure that the model tests out properly. Once this is verified to a reasonable degree, THEN the conceptual framework is worked out to buttress the model. There's nothing wrong with that. It takes a while to readjust a conceptual framework. Scientists are humans too, and there are certain deep-seated notions that are difficult to dislodge, even when a model clearly says the notions are wrong and the model agrees with experiment beautifully. > And I think too many people take that > approach to scientific inquiry, but of course I don't agree. A > fundamentally flawed theory can still have a lot of predictive power > if it incorporates the real variables indirectly. > > > > you'll spend a life's > > > work at the rump of your subject. > > > > Indeed if there is one thing I know from my broad knowledge in many > > > subjects, it is that those who talk of asymmetry, of complexity, of > > > change, of difference, actually don't have perspective on their > > > subject, and those who can talk *convincingly* of symmetry, of > > > simplicity, of constancy, of similarity, do have perspective. > > > ??? > > > This doesn't have to do with perspective. It has to do with whether > > nature EXHIBITS in EXPERIMENT an asymmetry or not. > > This isn't philosophy. It's physics, which is a study of how nature > > ACTUALLY BEHAVES, not how we think it ought to behave. > > I agree the aim is to ascertain how nature actually behaves, but see > my opening statement above for why too little perspective can actually > lead one astray from understanding the true nature of things. I find > if you observe asymmetry, then you haven't made enough observations, > or you haven't made a connection between two apparently unconnected > observations. Any true physicist knows (say it with me children!) each > and every action has an equal and opposite reaction. That is a > statement of symmetry. Each action and counter-action may not occur > simultaneously in time, but that's the point: the symmetry is in the > relationship *overall*. If an action is observed to occur, then you > can be sure that it's counter-action has previously preceded and will > eventually follow. I'm not saying there's no symmetry in nature. There's plenty of symmetry. But there are also observed asymmetries. And a decent model will acknowledge them, rather than insist that symmetry must rule everywhere and we are just under some ILLUSION that there's asymmetry at a fundamental level. > > > > > This idealization of systems is essential to physics. > > > > Not at all. Science is supposed to be about idealising the model in > > > the first place, and then making allowances for it's practical > > > implementation. > > > I completely disagree. All models of all types are idealizations -- > > No. Some models are not idealisations of reality, they are just wrong. Even the right models are idealizations of reality. > > > that is, there are factors that are neglected in the treatment of any > > real system. > > My view is that the "neglected factors" should be in the > implementation, not the idealisation. If there are neglected > idealisations in the theory, then the theory is wrong. And while it > may be useful when simplicity is desirable for some practical > purposes, regard to "practical purposes" should not be a significant > consideration in *theoretical* physics. I'm sorry, but the WHOLE POINT of physical models is to learn to what degree an idealized model can be applied to this or that situation to (adequately) predict the outcomes of those situations. > > > In reality, every real system is distinct from every other real > > system, > > Only insofar as no distinction is made in the first place between real > systems that cannot be distinguished from each other in some way. > Hence this statement is a tautology in practice. > > > which means that a strictly correct treatment would be a one- > > off in every case. But the value of science is to aggregate various > > real systems so that they can be treated with a common model, to the > > extent that the differences can be ignored for the purposes of the > > prediction being made. > > As I say, there is a difference between theoretical science, and > practical science. In practical science, simplifcations are fine. In > theoretical science, it isn't. And because theoretical science > precedes practical science, if you start treating them as one and the > same, your dead in the water. At this point, I just say I believe you're off base. I suspect a hole in your training in science and what science does. Would you mind telling me something about your background? It's a little dodgy for a nonscientist to tell a scientist, "If this is what you do and you call it science, then you're doing the wrong thing, because science should be about something else." It's like a lawyer telling a plumber that what the plumber is doing isn't really plumbing and that in the lawyer's opinion, plumbing is about something else. > > Consider the simplification of maths where instead of scrupulously > "doin't one side what you do t'other" (as a tutor once put it in Wigan > drawl), you simply move the value and change it's operator. The theory > of equality is simple. But implementing it in practice uses more ink > than is necessary, so you use the simplification. But in that way, the > practical simplification came after the theory. And unless you know > the theory behind it, you don't understand the simplification - it may > as well be magic, and you will often apply it incorrectly. > > > A first-semester physics book has a chapter on 2D kinematics and > > projectile motion. With that model, application after application is > > drilled into students, even knowing that air drag, air lift, > > variations in g, curvature of the earth, rotation of the earth, etc., > > are all being ignored. > > Indeed. That's because that course is about training people to > implement the theory in practice, not about giving them the education > necessary to question existing theories and develop new better ones. I completely disagree. The purpose of doing this is so that students know what a model DOES, what is included and excluded in a model and why, how models are tested, and how they are proven (by observation) to be lacking, and then how to use that evidence to try to infer a better one, and then test THAT. You have this illusion that questioning theories and developing new ones is a wholly mental process, like philosophy, separated from observation and practical application. Thsi is NOT how science works, nor should it be. > > > > > > > OK, then please note the distinction between "yet to be falsified" and > > > > > > "unfalsifiable". > > > > > > Indeed. Reminds me of a joke actually, that there are only two types > > > > > of scientific theory... > > > > > And so your problem with this is what? > > > > I don't have a problem. I was just acknowledging that I know the > > > difference between "unfalsifiable" and "not yet falsified", and then I > > > went on to reflect comically on the fact that the only scientific > > > theories that will not eventually be falsified are those that are > > > unfalsifiable. > > > OK, so what does this have to do with whether a theory of multiple > > universes is unfalsifiable? > > It seems there are experimental tests... > > Oh? Yes! This is what I pointed you to. The RESULTS of the tests are not back yet, but this doesn't mean that it is unfalsifiABLE, it means that it hasn't yet been falsified or confirmed. What we know is that the results will tell us one way or the other. It's like the search for the Higgs. We know where the Higgs should be, if it's there. This means the Higgs theory is falsifiABLE. If it's found where we expect it, then the theory is confirmed. If it's not where we expect it, then the theory is falsified. > > > > No, and with respect I don't think I want to know, because something > > > that includes the "past and future" model of time is bound to confound > > > me. > > > Well, here's a problem then. > > You propose a philosophical statement about time that imposes symmetry > > No, I said time is a function of the human mind, not of the material > world. Translate this, please, into experimentally confirmable predictions. > > > and make the claim that it is BETTER than any model that acknowledges > > asymmetry of time. But you also acknowledge that your comparison is > > hampered by the fact that you don't even understand any model that > > acknowledges asymmetry of time, and that moreover you don't even want > > to know any more about any model that acknowledges asymmetry of time > > because such a model would confound you. > > I understand the asymmetric model of time perfectly. It's one I've > taken for granted all my life. Until a few weeks ago, when I suddenly > realised that relativity doesn't require it, and there is no test for > it. You're right, relativity doesn't require it. That doesn't mean that it isn't there ANYWAY. The theory of electromagnetism doesn't require curved spacetime, either. But that doesn't mean that it's not curved ANYWAY. > > > This is known commonly as the "My model is right because I understand > > it" fallacy. It is fairly commonplace among crank circles. I would > > have thought you would not want to associate yourself with this kind > > of nonsense. > > Indeed. But I don't need to study theology first in order to reject > its truth. I reject the forward-flowing model of time in theoretical > physics because like La Place I'm content to say there is no need of > the hypothesis, and in fact appears to bring unnecessary baggage to > the table. If you discard time as a physical dimension, then you can > wholly discard wormholes, black hole "singularities" where "time > stops", and all the rest of that bunk. > > > > > > > > > > If energy is consumed in the future in order to send matter back in > > > > > > > > > time, > > > > > > > > > What makes you think this is consistent with the laws of physics? > > > > > > > > Which part? I certainly don't think time travel is consistent with the > > > > > > > laws of physics, because my very position is that I don't accept that > > > > > > > time is flowing at all. > > > > > > > I don't know that time travel is consistent with the laws of physics, > > > > > > either. Who says it is? > > > > > > It is not so much that anyone is saying that time travel is consistent > > > > > with the laws of physics, only that the current laws of physics > > > > > themselves seem to suggest such a possibility, for if you can go > > > > > forward in time, then you must be able to go backward in time - > > > > > otherwise the concept of backwards and forwards becomes meaningless. > > > > > That's nonsense. The forward is accessible to us in a causal manner, > > > > the backwards is not. This doesn't render one of them meaningless. Nor > > > > does having meaning associated with both imply that we would be able > > > > to causally influence the past. > > > > My point is that "cause and effect" are an arbitrary classification to > > > describe something of meaning to humans. The reason the "past" can > > > never be "affected" in a "causal" manner is because, by its very > > > definition, cause always precedes effect in the forward-flowing model > > > of time. > > > On the contrary, cause and effect doesn't imply time ordering. > > No and therein lies the contradiction! How on Earth did anyone ever > conceive of a model where the effect precedes the cause in time? It's simple. Change state A and that is associated with the observation that state B changes. If B precedes A in time, then this does not alter the statement that A causes B. > > > What it states is that given two conditions A and B, altering A always > > alters B. This is how we determine whether A causes B, not by what > > sequence they have in time. > > But again, this rests on the idea that a cause of an observed effect > can happen after the effect itself. I consider that not only a > corruption of the language, but utter nonsense in itself. Indeed, such > a model is actually unfalsifiable, because if the effect were > observed, and then the cause removed, all memory of the effect having > been measured in the first place would necessarily have been erased - > unless human memory exists outside of the material world. Honestly, > PD, commit this model to the flames. > > > > > > Indeed, if we must use backwards and forwards notation, then I would > > > > > say the astronaut twin has gone "backwards" in time, if only in the > > > > > sense that when he returns to earth, the homebody is ahead of his > > > > > brother in age, and the astronaut is astern of his brother in age.. > > > > > But he HASN'T gone backwards in time. He's aged -- that's FORWARD in > > > > time. It's just that his Earth buddy has gone forward in time faster. > > > > But that's because "going backwards in time", to you, means someone's > > > age reducing in *absolute* terms. To me, the fact that one twin is > > > younger than the other is evidence that one has gone back in time > > > *relatively*. > > > That would be an interpretation carried by you, rather singly. > > It would be nice if that were the case. > > > > > > Of course most people don't accept this notation. They say only that > > > > > the astronaut has gone "slower forwards". > > > > > > However, on my reading of relativity, it does not actually require an > > > > > absolute forward flow of time, relativity merely suggests that events > > > > > can move either ahead, or astern, of other events. > > > > > No, relativity says nothing of the kind. Perhaps you need some > > > > guidance on your reading of relativity. > > > > I think perhaps others need reminding about the implications of > > > relativity. People just about seem happy with relative positions in > > > space. They seem less happy with relative positions in time. > > > I think you could use a little better background on what relativity > > really says, > > You mean I need a better background on what mainstream physicists > really say about relativity? Relativity is a theory developed by physicists. If you think relativity means something other than what it does mean, then you're no longer talking about relativity. You're talking about your notions and you're APPROPRIATING the name relativity to tack on to your notions. > > > rather than you just taking a comic book exposure and > > then layering your own pseudo-scientific interpretations on top of it. > > What is a pseudo-scientific interpretation as distinct from a > scientific interpretation? > > > Would you like a reading reference? > > If it treats the issue of relative time, and explains why this is > incompatible with relativity, yes.
From: Ste on 31 Dec 2009 05:20 On 30 Dec, 17:39, PD <thedraperfam...(a)gmail.com> wrote: > On Dec 30, 3:32 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > Either the processes occur symmetrically or they don't. > > > It's observed that they do not. There is no point in having a > > > "theoretical model" that says they are really symmetric after all. > > > But often what appears on casual observation to be "asymmetrical" by > > virtue of its complexity, is in fact symmetrical. If a transformation > > of energy today only has its re-transformation eons after humans have > > ceased to exist, then that would largely explain why "observations" > > over a few years appear asymmetrical. > > OK, but now you are talking about something that is by definition > unfalsifiable, since you are positing something that will erase the > observed asymmetry long after humans have ceased to exist to observe > it. > > Science is about understanding the laws of nature as they can be > confirmed by observations and measurements we CAN conduct. > > Postulating something that is inconsistent with observations, because > you LIKE symmetry better than asymmetry, and then excusing the lack of > symmetry by saying that it is by nature unobservable, puts it in the > realm of religious faith and not science any longer. > > When you can posit your notions in a manner that it produces > predictions that can be *tested* by reasonably accessible experiment, > then you will have returned to science. I knew you'd say that. But the truth is that what I'm positing about a symmetry of fundamental forces *is* a scientific theory, in that it can theoretically be tested against the material world. Indeed it doesn't actually predict anything exotic - it says only that the forces of the universe exist in harmony - and in fact wipes away many of the exotic predictions or difficult questions of existing theories. It's the same with my relativist interpretation of time. It's actually conceptually simpler, and wipes away the exotic (and generally paradoxical) predictions of wormholes, classical time travel, singularities, etc. The geocentric model of the heavens, and the reason why people refused to discard it despite a simpler model being available, should be something taught in every science class. And the reason, as always, is political. The geocentric model utterly discredited the idea of the Earth being the jewel in the crown of God's creation - and if that was false, then *what else* was false about the teachings of the Catholic church? Can you think of why fundamental asymmetry in the universe is very important to liberal ideology today? > > > > People once > > > > saw the Sun move over the sky, and assumed that the Sun orbited the > > > > Earth. And the credibility of that model, and the credulity of the > > > > very best and brightest, remained long after a better and more simpler > > > > model had been conceived - that of the Earth orbiting the Sun. > > > > > Indeed the problem is that humans are apparently very poor at > > > > developing perspective. Physical processes may well be symmetric in > > > > time - in that every transformation of energy can ultimately be > > > > reversed by the fundamental forces of nature. And indeed I think that > > > > is true, and it is a snug fit with other laws like energy > > > > conservation. > > > > That is true, it is consistent with OTHER observations. But the model > > > would ALSO have to be consistent with the *observed* asymmetry of > > > physical processes and the *observed* one-way growth of entropy in > > > closed systems. If the model is not consistent with those > > > observations, then it is wrong. > > > Well I think I've largely addressed that above. > > > What I would add though about entropy is that there is no evidence > > that the entropy of the universe is increasing. > > That's actually not the case. There is cosmological evidence that it > IS increasing. You didn't know this, I take it. I know I'll find that this "evidence" can interpreted more than one way. And although I don't know what specific cosmological evidence you refer to, I have of course heard a number of conclusions drawn from what has been observed in the cosmos. I've heard for example that matter at the edge of the universe is moving outwards at more than the speed of light. I've heard that energy goes into black holes and never comes out. Etcetera. But let us assume for one moment that matter at the edge of the universe is *not* moving outwards at more than the speed of light, and let us assume that energy that goes into black holes is *not* lost forever. What part of existing theory has to give to allow those assumptions to be correct? If your answer is "all of existing theory has to give to allow these assumptions to be correct", then that is clearly what must happen. > > > > And yet, we cling to the model of time flowing ever- > > > > forwards, of entropy ever-increasing - and clinging to this model > > > > means that every new discovery puts a new epicycle into contemporary > > > > theoretical physics, in the same way that in the middle ages every new > > > > star discovered, every new telescope developed, put another epicycle > > > > into the contemporary astronomer's model of the sky. > > > > What is epicyclic about entropy? > > > Nothing is epicyclic about entropy - the 2nd law is compatible with > > the conservation law, in that energy is never created nor destroyed, > > and entropy can remain constant. > > Energy and entropy are not the same thing. I fully understand that. I wasn't trying to say those two laws are synonymous. > Entropy is related to the > number of available microstates. The energy of a closed system can > remain completely constant and the entropy increase nonetheless. I'm afraid I don't agree. Clearly there many fundamental phenomena that can only exist in discrete states. An electron, for example, apparently has a discrete level of charge. If you have a closed system in which fundamental forces never tire or wear out, and in which there is energy that can only take discrete forms, and in which states can only change at a finite speed, then entropy can't increase - you get an oscillation of states, or a rotation of states. Like the kinetic balls toy - without friction, the mechanism would never tire, because gravity never tires, and the momentum of the balls would always be conserved. The only reason the mechanism does tire is because it is not a closed system (and in any event the toy is not designed to be in balance with all the fundamental forces of nature). So to summarise, it is the existence of discrete states, and finite velocities, that can lead to observed change in closed systems without any increase in entropy. Thinking scientifically I suppose the problem with testing this hypothesis is that a closed system is unmeasurable by those outside it, and incomprehensible to those within it. In this way, closed systems can theoretically exist, but are untestable. > > Epicycles only become necessary when > > people insist entropy is always increasing. > > Why is increasing entropy epicyclic? For the reason first that the 2nd law does not say entropy must increase over time. It says entropy in a closed system will either remain constant, or increase. Secondly, the law of conservation says that energy remains constant. If the universe is an open system, then the 2nd law doesn't apply - and therefore there is no basis on which to assert that entropy is increasing in the universe. Also, if the universe is open, then the question remains what exists outside of it, and at what level does the system become closed (the hypothesis that the material world is infinitely open is, obviously, a hypothesis that is not even theoretically testable nor intuitively comprehensible). Or, if the universe itself is a closed system[1], then the question is whether energy must take discrete forms. If energy does not take discrete forms, then the whole place will be just a homogenous, grey, moderately-warm mush, for all eternity[2]. Of course, the universe is not such a homogenous place, so that suggests energy *does* have to take discrete forms. And that is what we find, that energy often has to take discrete forms. And if energy has to take discrete forms, then you can observe a repeating pattern of change for all eternity. [1] See above where I concede the problems about testing closed systems, and the obvious implications for science if the hypothesis of a closed universe is untestable. The only real difference between the open and the closed hypothesis is that the closed hypothesis can be readily understood intuitively, whereas the open hypothesis cannot. [2] You may be driven to contemplate the notion of a "recently-closed system", where energy is added, the system sealed, and left to reach equilibrium. Of course, you realise that a "recently-closed system" is not a closed system at all - it is in fact an open system, which is part of some larger system (whether that larger system is open or closed, non constat). > > Another epicycle is the > > forward flow of time - it forces us to deal with "time travel", "worm > > holes", "cause preceding effect". > > What is epicyclic abot any of these? I believe you are overlapping in > your mind "epicyclic" and "counterintuitive". Now you put me on the spot, I suppose I'm suggesting that they are indeed one and the same. Anything that can be rationally understood, eventually becomes intuitive with practice. If you have no intuition for your subject, then you don't understand it. As with neoclassical economics, modern physics appears to be infected by people who understand maths intuitively, but not the physical world. And since the maths is supposed to be a *description* of the physical world, the conclusion one must reach where modern physicists understand their mathematical descriptions but not the physical world, is that their descriptions do not actually describe the physical world (even in an idealised way)! > > > > That is why I don't place any value on the existing maths in > > > > theoretical physics, because a model begins life in its most > > > > mathematically refined state, to which only epicycles can then be > > > > added. And if you commit yourself to fitting your theories around the > > > > existing hoard of counter-intuitive epicycles, > > > > What is counterintuitive about entropy? > > > I was actually talking about more than just entropy. > > > But nothing is counter-intuitive about entropy, if you realise that > > the laws of thermodynamics were developed during the heyday of the > > industrial revolution. > > Notice, however, that they are not restricted to industrial > applications. They are laws of physics, which means that, even in the > most idealized of situations, they still apply. As you can see from what I've said above, I do not actually question any of the laws themselves. Merely the way in which the laws of physics as a whole are being interpreted and applied to the question. The fact is that there is no closed system in which entropy will increase overall, if energy takes discrete forms and is conserved. As I say, the fact that the second law predicts any increase at all in entropy within closed systems is because it was formulated at a time when a hypothesis of discrete states of energy, and the means by which energy is transformed between these states, would not have been known. Temperature apparently does not have a discrete state, and that is why someone studying thermodynamics can legitimately observe equilibrium coming about, and conclude that temperature always reaches equilibrium. The point is that the known forces of nature apparently do have the potential to reverse that equilibrium. > > Once you have that perspective, it becomes easy > > to see why ever-increasing entropy was a legitimate interpretation of > > observations made at the time of its development, in the same way that > > classical mechanics was a legitimate interpretation of observations > > made at the time. > > > That is, I fully understand entropy at an intuitive level - for > > example I know that the temperature of hot water in a kettle will > > eventually reach equilibrium with the room temperature (the hot water > > having given up heat to the room) - but none of this leads me to > > believe the process is fundamentally irreversible. > > Whether you believe it or not is not really relevant. What matters is > whether there is any *evidence* that it is fundamentally reversible. > This is where observation plays a key role and what separates physics > from philosophy. Science does have a philosophy you know. > The moment you believe that the underlying truth of nature is > something other than what is observed, and that the fundamental truth > *cannot* be observed, because observations obstruct the truth, then > you have abandoned science as an investigation and you are just doing > philosophy. It's not a question of what is observed. It is a question of *interpreting* those observations. The Sun did not stop rising in the east and setting in the west with the advent of the heliocentric model. The point is that people's interpretation of what they were observing changed. I challenge you to find me a mainstream research paper that simply states what was observed, and does not also offer a hypothesis to explain what is observed (i.e. an interpretation). Put another way, I've no intention of challenging the observations of physics, what I am going to do is challenge the interpretation. > > > Furthermore, let's get one thing straight: In a confrontation between > > > experimental observation and intuition, intuition must and always does > > > lose. > > > Not at all. For an educated man, the two should be one and the same. > > Not necessarily! Nature is surprising. We develop mental models that > are best guesses as to how nature works, and then we TEST that model > to see if it really describes nature the way we think it does. But > more often than not, we find that nature is not what we thought it > was. Precisely my view of the matter! Which is why I'm saying for an *educated* man observation and intuition should be the same - there should only be dissonance between the two for a short time when something fundamentally new is observed. Of course, for the ignorant man, observation will regularly contradict intuition. > > If a phenomenon is not intuitive, then either the mechanism is not > > observed enough to develop understanding, or your theory is a > > nonsense. Clearly, if a mechanism is both regularly observed, and not > > intuitively understood, then that leaves just one possibility: your > > theory is wrong. > > > Of course, what we mean in everyday parlance by "counter-intuitive" is > > precisely that: your existing theories are wrong. > > > I seem to remember reading a quote of Bohr's to the effect of: "we > > don't have to understand it, as long as it works". By which he meant, > > if the maths work, then we don't have to have any more fundamental > > understanding of the mechanism. > > This approach is really not what's taken, though a lot of people use > it as a provisional approach to be sure that the model tests out > properly. But this approach is not provisional at all. From what I've read it has become the accepted norm. Incidentally I can't find the exact quote, but I think it was probably Feynman, not Bohr, who said it. The physical sciences should not be about coming up with a mathematical model and seeing if it fits. On the contrary, a mechanism of action should be conceived first, and then the maths merely used to describe it. As people have said about economics, a sufficiently complex algorithm can always be made to fit the existing data, without necessarily giving any insight at all into the nature of the variables. Physicists are doing precisely the same, in fitting (extremely complex) maths to the observations, with no attempt to describe the physical nature of the variables. > Once this is verified to a reasonable degree, THEN the conceptual > framework is worked out to buttress the model. There's nothing wrong > with that. It takes a while to readjust a conceptual framework. > Scientists are humans too, and there are certain deep-seated notions > that are difficult to dislodge, even when a model clearly says the > notions are wrong and the model agrees with experiment beautifully. I'm afraid I don't see the problem like that. Modern physics seems to be almost entirely a mathematical model. The notion that has been wrongfully dislodged in modern physics is that idea that mathematical models have to be described in physical terms, where you can understand the mechanism of action *mechanically*. Every attempt I've seen to describe modern theories in mechanical terms have left me utterly unimpressed, and the maths involves a sufficient complexity, and a sufficient number of arbitrary constants, as to be an obvious contrivance, force-fitted to the data. > > > This doesn't have to do with perspective. It has to do with whether > > > nature EXHIBITS in EXPERIMENT an asymmetry or not. > > > This isn't philosophy. It's physics, which is a study of how nature > > > ACTUALLY BEHAVES, not how we think it ought to behave. > > > I agree the aim is to ascertain how nature actually behaves, but see > > my opening statement above for why too little perspective can actually > > lead one astray from understanding the true nature of things. I find > > if you observe asymmetry, then you haven't made enough observations, > > or you haven't made a connection between two apparently unconnected > > observations. Any true physicist knows (say it with me children!) each > > and every action has an equal and opposite reaction. That is a > > statement of symmetry. Each action and counter-action may not occur > > simultaneously in time, but that's the point: the symmetry is in the > > relationship *overall*. If an action is observed to occur, then you > > can be sure that it's counter-action has previously preceded and will > > eventually follow. > > I'm not saying there's no symmetry in nature. There's plenty of > symmetry. But there are also observed asymmetries. And a decent model > will acknowledge them, rather than insist that symmetry must rule > everywhere and we are just under some ILLUSION that there's asymmetry > at a fundamental level. I disagree. If you look at the history of science, you find that everything that was originally held to be asymmetrical, in fact became symmetrical. And I'm afraid I don't accept that 'this time it's different' - certainly, that hypothesis would not be consistent with historical observation. What we observe from history is that people each time *say* that it is 'different this time', and each time it ultimately turns out not to be. > > > that is, there are factors that are neglected in the treatment of any > > > real system. > > > My view is that the "neglected factors" should be in the > > implementation, not the idealisation. If there are neglected > > idealisations in the theory, then the theory is wrong. And while it > > may be useful when simplicity is desirable for some practical > > purposes, regard to "practical purposes" should not be a significant > > consideration in *theoretical* physics. > > I'm sorry, but the WHOLE POINT of physical models is to learn to what > degree an idealized model can be applied to this or that situation to > (adequately) predict the outcomes of those situations. I'm afraid I disagree. I make a distinction between what in engineering is called "tolerance", and what in graphic design might be called "an idealised model". Tolerance is limited by technical ability in the real world. Models are limited only by imagination. In other words, the former problem exists because our engineers' don't have the technology. The latter problem exists because our theoretical physicists don't have the imagination (or, more likely, like the heliocentric model, they are unable to consider the truth without also rejecting a lot of ideological baggage). > > > which means that a strictly correct treatment would be a one- > > > off in every case. But the value of science is to aggregate various > > > real systems so that they can be treated with a common model, to the > > > extent that the differences can be ignored for the purposes of the > > > prediction being made. > > > As I say, there is a difference between theoretical science, and > > practical science. In practical science, simplifcations are fine. In > > theoretical science, it isn't. And because theoretical science > > precedes practical science, if you start treating them as one and the > > same, your dead in the water. > > At this point, I just say I believe you're off base. I suspect a hole > in your training in science and what science does. > Would you mind telling me something about your background? I'm basically a small businessman. I've never studied science formally. > It's a little dodgy for a nonscientist to tell a scientist, "If this > is what you do and you call it science, then you're doing the wrong > thing, because science should be about something else." It's like a > lawyer telling a plumber that what the plumber is doing isn't really > plumbing and that in the lawyer's opinion, plumbing is about something > else. I like to think it's more a case of the doctor telling the patient that they are delusional, and the patient saying "no, Doctor, I'm afraid that's not correct". Of course, I don't want to strain that analogy to breaking point, but the point is that because that scientists say they are doing something, and appear to believe what they say in good faith, does not mean it is actually how science as an institution works. Most scientists have never actually studied the sociology or history of their profession. Indeed the reason we have social sciences is because the real dynamics of society are often not explicitly obvious to people, in the same way the workings of the physical world are not immediately obvious. > > > A first-semester physics book has a chapter on 2D kinematics and > > > projectile motion. With that model, application after application is > > > drilled into students, even knowing that air drag, air lift, > > > variations in g, curvature of the earth, rotation of the earth, etc., > > > are all being ignored. > > > Indeed. That's because that course is about training people to > > implement the theory in practice, not about giving them the education > > necessary to question existing theories and develop new better ones. > > I completely disagree. The purpose of doing this is so that students > know what a model DOES, what is included and excluded in a model and > why, how models are tested, and how they are proven (by observation) > to be lacking, and then how to use that evidence to try to infer a > better one, and then test THAT. And why on Earth would they need to be drilled about the myriad applications of the same theory, and know it off-by-heart, if their real future role in society is expected to be imagining credible new theories, and testing them? You may say this is necessary in order to train future theoretical physicists, but I'm afraid I disagree - I think the real reason is that few if any of them are actually expected to become theoretical physicists, and on the contrary they will instead be expected to deploy existing scientific theories in a practical fashion. > You have this illusion that questioning theories and developing new > ones is a wholly mental process, like philosophy, separated from > observation and practical application. Thsi is NOT how science works, > nor should it be. On the contrary. What I'm saying is that often questions are *not* asked of the theory, or the *philosophy* on which it is necessarily based. Just observe how much I've become a cat amongst the pigeons here for suggesting that time is relative. Clearly no one here had ever seriously considered the idea, despite its obvious synergy with the theory of relativity, and the potentially compelling fit with all the other laws of physics. The fact that many people (not you, but others) on a physics discussion group have been outright abusive at the suggestion, rather than simply referring me to an experiment that has falsified the hypothesis, proves surely that the hypothesis of classical time is not based on observation at all, but merely on a classical interpretation of what is observed. And because the classical interpretation was there first, people are loath to even reconsider it, let alone reject it. > > > > > > > OK, then please note the distinction between "yet to be falsified" and > > > > > > > "unfalsifiable". > > > > > > > Indeed. Reminds me of a joke actually, that there are only two types > > > > > > of scientific theory... > > > > > > And so your problem with this is what? > > > > > I don't have a problem. I was just acknowledging that I know the > > > > difference between "unfalsifiable" and "not yet falsified", and then I > > > > went on to reflect comically on the fact that the only scientific > > > > theories that will not eventually be falsified are those that are > > > > unfalsifiable. > > > > OK, so what does this have to do with whether a theory of multiple > > > universes is unfalsifiable? > > > It seems there are experimental tests... > > > Oh? > > Yes! This is what I pointed you to. The RESULTS of the tests are not > back yet, but this doesn't mean that it is unfalsifiABLE, it means > that it hasn't yet been falsified or confirmed. What we know is that > the results will tell us one way or the other. > > It's like the search for the Higgs. We know where the Higgs should be, > if it's there. This means the Higgs theory is falsifiABLE. If it's > found where we expect it, then the theory is confirmed. If it's not > where we expect it, then the theory is falsified. Indeed. I don't dispute the point about the Higgs. And if indeed there is a test for multiple universes (and I'd be very interested to hear how), the question is not whether the theory is falsifiable (it surely is), but why the theory was ever thought credible enough in the first place to bother testing. > > > > No, and with respect I don't think I want to know, because something > > > > that includes the "past and future" model of time is bound to confound > > > > me. > > > > Well, here's a problem then. > > > You propose a philosophical statement about time that imposes symmetry > > > No, I said time is a function of the human mind, not of the material > > world. > > Translate this, please, into experimentally confirmable predictions. I think you have it backwards. The onus is not on me to show that you can't navigate time, and that the past exists only in our memories. The onus is on you to show that you can navigate time, and that the past and future exist materially. The fact that no one ever has demonstrably navigated time, and the fact that existing theories suggest it would be paradoxical and in any event require more than an infinite amount of energy to achieve, should cause a sensible person to reflect on why the hypothesis seems to already have universal acceptance of its "obvious" truth. Indeed, even the outcome of the twins paradox can be interpreted not as time travel, but of fundamental physical processes having simply occurred at a slower rate; as such "time dilation" does not even require reference to time in order to explain - one can simply say that the clock ran slower, not that time ran slower. > > > and make the claim that it is BETTER than any model that acknowledges > > > asymmetry of time. But you also acknowledge that your comparison is > > > hampered by the fact that you don't even understand any model that > > > acknowledges asymmetry of time, and that moreover you don't even want > > > to know any more about any model that acknowledges asymmetry of time > > > because such a model would confound you. > > > I understand the asymmetric model of time perfectly. It's one I've > > taken for granted all my life. Until a few weeks ago, when I suddenly > > realised that relativity doesn't require it, and there is no test for > > it. > > You're right, relativity doesn't require it. That doesn't mean that it > isn't there ANYWAY. Oooh! > The theory of electromagnetism doesn't require curved spacetime, > either. But that doesn't mean that it's not curved ANYWAY. The question is whether *any* coherent theory requires it. I haven't heard any explanation yet for why the curvature of spacetime is distinguishable from forces acting acting on matter in the classical way in Euclidean space. > > > > > That's nonsense. The forward is accessible to us in a causal manner, > > > > > the backwards is not. This doesn't render one of them meaningless.. Nor > > > > > does having meaning associated with both imply that we would be able > > > > > to causally influence the past. > > > > > My point is that "cause and effect" are an arbitrary classification to > > > > describe something of meaning to humans. The reason the "past" can > > > > never be "affected" in a "causal" manner is because, by its very > > > > definition, cause always precedes effect in the forward-flowing model > > > > of time. > > > > On the contrary, cause and effect doesn't imply time ordering. > > > No and therein lies the contradiction! How on Earth did anyone ever > > conceive of a model where the effect precedes the cause in time? > > It's simple. Change state A and that is associated with the > observation that state B changes. If B precedes A in time, then this > does not alter the statement that A causes B. But this fails to address the real issue, which is that if an observation is conditional on a future cause, then that either presupposes that the cause has already happened (thus violating the idea that the effect came first in time), or it must be the case that time self-corrects, and therefore erases your memory of the past (and therefore you would not remember the effect even if it had in fact happened). Or a third option is that the existence of the effect compels the cause to happen, in order to maintain consistency - but in that event you may as well refer to the effect by its real name: "cause". In any event, I've yet to hear of any experiment that has demonstrated an effect preceding the cause - and I would genuinely be interested to discuss such experiments, if indeed any exist. > > > > > > Of course most people don't accept this notation. They say only that > > > > > > the astronaut has gone "slower forwards". > > > > > > > However, on my reading of relativity, it does not actually require an > > > > > > absolute forward flow of time, relativity merely suggests that events > > > > > > can move either ahead, or astern, of other events. > > > > > > No, relativity says nothing of the kind. Perhaps you need some > > > > > guidance on your reading of relativity. > > > > > I think perhaps others need reminding about the implications of > > > > relativity. People just about seem happy with relative positions in > > > > space. They seem less happy with relative positions in time. > > > > I think you could use a little better background on what relativity > > > really says, > > > You mean I need a better background on what mainstream physicists > > really say about relativity? > > Relativity is a theory developed by physicists. If you think > relativity means something other than what it does mean, then you're > no longer talking about relativity. You're talking about your notions > and you're APPROPRIATING the name relativity to tack on to your > notions. No, the point I was making was that by "what relativity says" you really mean "what mainstream physicists say about relativity". There is a significant difference between having an idea speak for itself, and having someone else speak for the idea. That is, the theory of relativity developed by physicists speaks for itself on the question of relative time - there is no problem with it. What you mean is that I need a better background in something *other* than relativity, so that I can interpret relativity correctly. But of course, my point is that it is not relativity that needs to be questioned, but the background against which it is currently interpreted.
From: PD on 31 Dec 2009 14:59 On Dec 31, 4:20 am, Ste <ste_ro...(a)hotmail.com> wrote: > On 30 Dec, 17:39, PD <thedraperfam...(a)gmail.com> wrote: > > > On Dec 30, 3:32 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > Either the processes occur symmetrically or they don't. > > > > It's observed that they do not. There is no point in having a > > > > "theoretical model" that says they are really symmetric after all. > > > > But often what appears on casual observation to be "asymmetrical" by > > > virtue of its complexity, is in fact symmetrical. If a transformation > > > of energy today only has its re-transformation eons after humans have > > > ceased to exist, then that would largely explain why "observations" > > > over a few years appear asymmetrical. > > > OK, but now you are talking about something that is by definition > > unfalsifiable, since you are positing something that will erase the > > observed asymmetry long after humans have ceased to exist to observe > > it. > > > Science is about understanding the laws of nature as they can be > > confirmed by observations and measurements we CAN conduct. > > > Postulating something that is inconsistent with observations, because > > you LIKE symmetry better than asymmetry, and then excusing the lack of > > symmetry by saying that it is by nature unobservable, puts it in the > > realm of religious faith and not science any longer. > > > When you can posit your notions in a manner that it produces > > predictions that can be *tested* by reasonably accessible experiment, > > then you will have returned to science. > > I knew you'd say that. But the truth is that what I'm positing about a > symmetry of fundamental forces *is* a scientific theory, in that it > can theoretically be tested against the material world. Where is the experimental test that distinguishes this theory from the currently held thinking? > Indeed it > doesn't actually predict anything exotic - it says only that the > forces of the universe exist in harmony - and in fact wipes away many > of the exotic predictions or difficult questions of existing theories. Well, first of all, I would say it at best does a swap of one exotic prediction for another. For example, you claim that symmetry will only be restored long after humans are dead and gone, and so the experimental test of that appears to be inaccessible. This is not exotic? Secondly, nature is no more exotic than what it really is. There is nothing in current theories that should be taken as "difficult" to swallow, as long as it matches what is seen in experiment or makes predictions that can be tested in the foreseeable future. > > It's the same with my relativist interpretation of time. I'm sorry, but your interpretation of time is not the relativist interpretation of time. I've already mentioned some aspects of the relativist interpretation (fast and future light cones, for example) which you find hard to swallow. Your interpretation is your own and needs to have a new label rather than appropriating one reserved for something else. > It's actually > conceptually simpler, and wipes away the exotic (and generally > paradoxical) predictions of wormholes, classical time travel, > singularities, etc. What do you think is paradoxical about wormholes and singularities? And relativity does not admit classical time travel, and I don't know where you got the idea it did. > > The geocentric model of the heavens, and the reason why people refused > to discard it despite a simpler model being available, should be > something taught in every science class. And the reason, as always, is > political. The geocentric model utterly discredited the idea of the > Earth being the jewel in the crown of God's creation - and if that was > false, then *what else* was false about the teachings of the Catholic > church? > > Can you think of why fundamental asymmetry in the universe is very > important to liberal ideology today? Oh dear, now you are wandering deep into Crank Zone. > > > > > > People once > > > > > saw the Sun move over the sky, and assumed that the Sun orbited the > > > > > Earth. And the credibility of that model, and the credulity of the > > > > > very best and brightest, remained long after a better and more simpler > > > > > model had been conceived - that of the Earth orbiting the Sun. > > > > > > Indeed the problem is that humans are apparently very poor at > > > > > developing perspective. Physical processes may well be symmetric in > > > > > time - in that every transformation of energy can ultimately be > > > > > reversed by the fundamental forces of nature. And indeed I think that > > > > > is true, and it is a snug fit with other laws like energy > > > > > conservation. > > > > > That is true, it is consistent with OTHER observations. But the model > > > > would ALSO have to be consistent with the *observed* asymmetry of > > > > physical processes and the *observed* one-way growth of entropy in > > > > closed systems. If the model is not consistent with those > > > > observations, then it is wrong. > > > > Well I think I've largely addressed that above. > > > > What I would add though about entropy is that there is no evidence > > > that the entropy of the universe is increasing. > > > That's actually not the case. There is cosmological evidence that it > > IS increasing. You didn't know this, I take it. > > I know I'll find that this "evidence" can interpreted more than one > way. That's the nice thing about experimental evidence. It's usually pretty unambiguous. It's a common misconception among hacks and hobbyists that any experimental data can be "interpreted" to support any model desired. (And Ptolemy and Copernicus are used as the neophyte example.) > > And although I don't know what specific cosmological evidence you > refer to, I have of course heard a number of conclusions drawn from > what has been observed in the cosmos. I've heard for example that > matter at the edge of the universe is moving outwards at more than the > speed of light. Relative to us, yes. Is there a problem? > I've heard that energy goes into black holes and never > comes out. Aside from radiation, yes. Is there a problem? > Etcetera. But let us assume for one moment that matter at > the edge of the universe is *not* moving outwards at more than the > speed of light, and let us assume that energy that goes into black > holes is *not* lost forever. What part of existing theory has to give > to allow those assumptions to be correct? What evidence would support such a proposition? Note that the claim about the mass at the edge of the universe is supported by DATA. Note that there are gravitational objects that are absorbing huge amounts of energy and mass and do not shine, as seen in direct observation. What is the point of diddling with countersuppositions, when the current suppositions are supported by experimental data? > > If your answer is "all of existing theory has to give to allow these > assumptions to be correct", then that is clearly what must happen. > > > > > > And yet, we cling to the model of time flowing ever- > > > > > forwards, of entropy ever-increasing - and clinging to this model > > > > > means that every new discovery puts a new epicycle into contemporary > > > > > theoretical physics, in the same way that in the middle ages every new > > > > > star discovered, every new telescope developed, put another epicycle > > > > > into the contemporary astronomer's model of the sky. > > > > > What is epicyclic about entropy? > > > > Nothing is epicyclic about entropy - the 2nd law is compatible with > > > the conservation law, in that energy is never created nor destroyed, > > > and entropy can remain constant. > > > Energy and entropy are not the same thing. > > I fully understand that. I wasn't trying to say those two laws are > synonymous. > > > Entropy is related to the > > number of available microstates. The energy of a closed system can > > remain completely constant and the entropy increase nonetheless. > > I'm afraid I don't agree. Then I suggest you take a course in thermodynamics to learn what the *definition* of entropy is. > Clearly there many fundamental phenomena > that can only exist in discrete states. An electron, for example, > apparently has a discrete level of charge. If you have a closed system > in which fundamental forces never tire or wear out, and in which there > is energy that can only take discrete forms, and in which states can > only change at a finite speed, then entropy can't increase - you get > an oscillation of states, or a rotation of states. I didn't say there weren't closed systems where entropy didn't stay constant. What is true is that in closed systems, entropy doesn't DECREASE. And what is also true is that in many closed systems, entropy DOES increase. > > Like the kinetic balls toy - without friction, the mechanism would > never tire, because gravity never tires, and the momentum of the balls > would always be conserved. The only reason the mechanism does tire is > because it is not a closed system (and in any event the toy is not > designed to be in balance with all the fundamental forces of nature). That's not entirely correct. I don't know what you think is going on in that system that causes it to wind down. > > So to summarise, it is the existence of discrete states, and finite > velocities, that can lead to observed change in closed systems without > any increase in entropy. > > Thinking scientifically I suppose the problem with testing this > hypothesis is that a closed system is unmeasurable by those outside > it, and incomprehensible to those within it. In this way, closed > systems can theoretically exist, but are untestable. That's also wrong. There are two ways this can be done. One is that the measuring device be INCLUDED in the system, and the entropy change of that device is included in the closed system sum. The other way is to prepare a state and then close the system, let a process operate, and then open the system and measure its final state. This can be done in such a way that the end-effects can be accounted for. I'm afraid your lack of experimental experience is impeding you. Science is not philosophy. > > > > Epicycles only become necessary when > > > people insist entropy is always increasing. > > > Why is increasing entropy epicyclic? > > For the reason first that the 2nd law does not say entropy must > increase over time. It says entropy in a closed system will either > remain constant, or increase. Yes, I didn't dispute that. > Secondly, the law of conservation says > that energy remains constant. Yes, I didn't dispute that either. Why is increasing entropy epicyclic again? > > If the universe is an open system, I didn't say the universe was open. I just said that the universe is not the only closed system for the purposes of experimental test. > then the 2nd law doesn't apply - > and therefore there is no basis on which to assert that entropy is > increasing in the universe. Also, if the universe is open, then the > question remains what exists outside of it, and at what level does the > system become closed (the hypothesis that the material world is > infinitely open is, obviously, a hypothesis that is not even > theoretically testable nor intuitively comprehensible). > > Or, if the universe itself is a closed system[1], then the question is > whether energy must take discrete forms. If energy does not take > discrete forms, then the whole place will be just a homogenous, grey, > moderately-warm mush, for all eternity[2]. What? Why? Continuousness does not imply isotropy. Anisotropy does not imply discreteness. > Of course, the universe is > not such a homogenous place, so that suggests energy *does* have to > take discrete forms. And that is what we find, that energy often has > to take discrete forms. > > And if energy has to take discrete forms, then you can observe a > repeating pattern of change for all eternity. > > [1] See above where I concede the problems about testing closed > systems, and the obvious implications for science if the hypothesis of > a closed universe is untestable. The only real difference between the > open and the closed hypothesis is that the closed hypothesis can be > readily understood intuitively, whereas the open hypothesis cannot. > > [2] You may be driven to contemplate the notion of a "recently-closed > system", where energy is added, the system sealed, and left to reach > equilibrium. Of course, you realise that a "recently-closed system" is > not a closed system at all - it is in fact an open system, which is > part of some larger system (whether that larger system is open or > closed, non constat). > > > > Another epicycle is the > > > forward flow of time - it forces us to deal with "time travel", "worm > > > holes", "cause preceding effect". > > > What is epicyclic abot any of these? I believe you are overlapping in > > your mind "epicyclic" and "counterintuitive". > > Now you put me on the spot, I suppose I'm suggesting that they are > indeed one and the same. Then you have misunderstood the meaning of epicyclic. > Anything that can be rationally understood, > eventually becomes intuitive with practice. I completely agree with that. And there is nothing counterintuitive about relativity or gravitation or quantum mechanics that isn't resolved with practice. > If you have no intuition > for your subject, then you don't understand it. As with neoclassical > economics, modern physics appears to be infected by people who > understand maths intuitively, but not the physical world. I disagree. They just understand the physical world intuitively differently than you do with your intuition. But you haven't had appropriate practice. > And since > the maths is supposed to be a *description* of the physical world, the > conclusion one must reach where modern physicists understand their > mathematical descriptions but not the physical world, is that their > descriptions do not actually describe the physical world (even in an > idealised way)! The PHYSICAL models describe the physical world, and the mathematical casting of the physical model is what allows physicists to make testable predictions. > > > > > > That is why I don't place any value on the existing maths in > > > > > theoretical physics, because a model begins life in its most > > > > > mathematically refined state, to which only epicycles can then be > > > > > added. And if you commit yourself to fitting your theories around the > > > > > existing hoard of counter-intuitive epicycles, > > > > > What is counterintuitive about entropy? > > > > I was actually talking about more than just entropy. > > > > But nothing is counter-intuitive about entropy, if you realise that > > > the laws of thermodynamics were developed during the heyday of the > > > industrial revolution. > > > Notice, however, that they are not restricted to industrial > > applications. They are laws of physics, which means that, even in the > > most idealized of situations, they still apply. > > As you can see from what I've said above, I do not actually question > any of the laws themselves. Merely the way in which the laws of > physics as a whole are being interpreted and applied to the question. You will find this a useless exercise. Theories and physical descriptions of the universe distinguish themselves from one another by making different predictions about observable phenomena. If you don't have distinguishing predictions, then you don't have a different model. > > The fact is that there is no closed system in which entropy will > increase overall, if energy takes discrete forms and is conserved. > > As I say, the fact that the second law predicts any increase at all in > entropy within closed systems is because it was formulated at a time > when a hypothesis of discrete states of energy, and the means by which > energy is transformed between these states, would not have been known. > Temperature apparently does not have a discrete state, and that is why > someone studying thermodynamics can legitimately observe equilibrium > coming about, and conclude that temperature always reaches > equilibrium. The point is that the known forces of nature apparently > do have the potential to reverse that equilibrium. > > > > Once you have that perspective, it becomes easy > > > to see why ever-increasing entropy was a legitimate interpretation of > > > observations made at the time of its development, in the same way that > > > classical mechanics was a legitimate interpretation of observations > > > made at the time. > > > > That is, I fully understand entropy at an intuitive level - for > > > example I know that the temperature of hot water in a kettle will > > > eventually reach equilibrium with the room temperature (the hot water > > > having given up heat to the room) - but none of this leads me to > > > believe the process is fundamentally irreversible. > > > Whether you believe it or not is not really relevant. What matters is > > whether there is any *evidence* that it is fundamentally reversible. > > This is where observation plays a key role and what separates physics > > from philosophy. > > Science does have a philosophy you know. But it invokes things that philosophy does not, and this is the part you ignore. > > > The moment you believe that the underlying truth of nature is > > something other than what is observed, and that the fundamental truth > > *cannot* be observed, because observations obstruct the truth, then > > you have abandoned science as an investigation and you are just doing > > philosophy. > > It's not a question of what is observed. It is a question of > *interpreting* those observations. See my comment above. > The Sun did not stop rising in the > east and setting in the west with the advent of the heliocentric > model. The point is that people's interpretation of what they were > observing changed. I challenge you to find me a mainstream research > paper that simply states what was observed, and does not also offer a > hypothesis to explain what is observed (i.e. an interpretation). > > Put another way, I've no intention of challenging the observations of > physics, what I am going to do is challenge the interpretation. Again, see my comment above. > > > > > Furthermore, let's get one thing straight: In a confrontation between > > > > experimental observation and intuition, intuition must and always does > > > > lose. > > > > Not at all. For an educated man, the two should be one and the same. > > > Not necessarily! Nature is surprising. We develop mental models that > > are best guesses as to how nature works, and then we TEST that model > > to see if it really describes nature the way we think it does. But > > more often than not, we find that nature is not what we thought it > > was. > > Precisely my view of the matter! Which is why I'm saying for an > *educated* man observation and intuition should be the same - there > should only be dissonance between the two for a short time when > something fundamentally new is observed. Of course, for the ignorant > man, observation will regularly contradict intuition. And you are the one that is complaining about nonintuitive ideas like wormholes, etc. > > > > If a phenomenon is not intuitive, then either the mechanism is not > > > observed enough to develop understanding, or your theory is a > > > nonsense. Clearly, if a mechanism is both regularly observed, and not > > > intuitively understood, then that leaves just one possibility: your > > > theory is wrong. > > > > Of course, what we mean in everyday parlance by "counter-intuitive" is > > > precisely that: your existing theories are wrong. > > > > I seem to remember reading a quote of Bohr's to the effect of: "we > > > don't have to understand it, as long as it works". By which he meant, > > > if the maths work, then we don't have to have any more fundamental > > > understanding of the mechanism. > > > This approach is really not what's taken, though a lot of people use > > it as a provisional approach to be sure that the model tests out > > properly. > > But this approach is not provisional at all. From what I've read it > has become the accepted norm. Incidentally I can't find the exact > quote, but I think it was probably Feynman, not Bohr, who said it. Yes, it was Feynman. But Feynman also contributed to the *physical* understanding of the mathematical model. He didn't abandon it at all, despite your sound bite. > > The physical sciences should not be about coming up with a > mathematical model and seeing if it fits. On the contrary, a mechanism > of action should be conceived first, and then the maths merely used to > describe it. Please do not tell scientists how science should be done. Science is DEFINED by the activity of scientists. > As people have said about economics, a sufficiently > complex algorithm can always be made to fit the existing data, without > necessarily giving any insight at all into the nature of the > variables. Physicists are doing precisely the same, in fitting > (extremely complex) maths to the observations, with no attempt to > describe the physical nature of the variables. > > > Once this is verified to a reasonable degree, THEN the conceptual > > framework is worked out to buttress the model. There's nothing wrong > > with that. It takes a while to readjust a conceptual framework. > > Scientists are humans too, and there are certain deep-seated notions > > that are difficult to dislodge, even when a model clearly says the > > notions are wrong and the model agrees with experiment beautifully. > > I'm afraid I don't see the problem like that. Modern physics seems to > be almost entirely a mathematical model. No, you are quite wrong about that. It is a very sensible PHYSICAL model. > The notion that has been > wrongfully dislodged in modern physics is that idea that mathematical > models have to be described in physical terms, where you can > understand the mechanism of action *mechanically*. Oh, wait a second. If you mean that the universe and all its processes should be reducible to the familiar, macroscopic, time-ordered phenomena exposed to your senses, then I have to draw the line. The universe is much richer than what we once understood with cogs and particles and levers and fluids. Any attempt to reduce all of nature to these rather quaint but limited notions is doomed to failure, simply because nature is more interesting than that. > Every attempt I've > seen to describe modern theories in mechanical terms have left me > utterly unimpressed, and the maths involves a sufficient complexity, > and a sufficient number of arbitrary constants, as to be an obvious > contrivance, force-fitted to the data. > > > > > This doesn't have to do with perspective. It has to do with whether > > > > nature EXHIBITS in EXPERIMENT an asymmetry or not. > > > > This isn't philosophy. It's physics, which is a study of how nature > > > > ACTUALLY BEHAVES, not how we think it ought to behave. > > > > I agree the aim is to ascertain how nature actually behaves, but see > > > my opening statement above for why too little perspective can actually > > > lead one astray from understanding the true nature of things. I find > > > if you observe asymmetry, then you haven't made enough observations, > > > or you haven't made a connection between two apparently unconnected > > > observations. Any true physicist knows (say it with me children!) each > > > and every action has an equal and opposite reaction. That is a > > > statement of symmetry. Each action and counter-action may not occur > > > simultaneously in time, but that's the point: the symmetry is in the > > > relationship *overall*. If an action is observed to occur, then you > > > can be sure that it's counter-action has previously preceded and will > > > eventually follow. > > > I'm not saying there's no symmetry in nature. There's plenty of > > symmetry. But there are also observed asymmetries. And a decent model > > will acknowledge them, rather than insist that symmetry must rule > > everywhere and we are just under some ILLUSION that there's asymmetry > > at a fundamental level. > > I disagree. If you look at the history of science, you find that > everything that was originally held to be asymmetrical, in fact became > symmetrical. I disagree. > And I'm afraid I don't accept that 'this time it's > different' - certainly, that hypothesis would not be consistent with > historical observation. I disagree again. > What we observe from history is that people > each time *say* that it is 'different this time', and each time it > ultimately turns out not to be. > > > > > that is, there are factors that are neglected in the treatment of any > > > > real system. > > > > My view is that the "neglected factors" should be in the > > > implementation, not the idealisation. If there are neglected > > > idealisations in the theory, then the theory is wrong. And while it > > > may be useful when simplicity is desirable for some practical > > > purposes, regard to "practical purposes" should not be a significant > > > consideration in *theoretical* physics. > > > I'm sorry, but the WHOLE POINT of physical models is to learn to what > > degree an idealized model can be applied to this or that situation to > > (adequately) predict the outcomes of those situations. > > I'm afraid I disagree. I make a distinction between what in > engineering is called "tolerance", and what in graphic design might be > called "an idealised model". Tolerance is limited by technical ability > in the real world. Models are limited only by imagination. In other > words, the former problem exists because our engineers' don't have the > technology. The latter problem exists because our theoretical > physicists don't have the imagination (or, more likely, like the > heliocentric model, they are unable to consider the truth without also > rejecting a lot of ideological baggage). I'm afraid you don't understand the reductionist methodology of scientific modeling. Would you like a reference on the methodology of science, something on the philosophy of science perhaps, so that you stop making it up to suit you as you go along? > > > > > which means that a strictly correct treatment would be a one- > > > > off in every case. But the value of science is to aggregate various > > > > real systems so that they can be treated with a common model, to the > > > > extent that the differences can be ignored for the purposes of the > > > > prediction being made. > > > > As I say, there is a difference between theoretical science, and > > > practical science. In practical science, simplifcations are fine. In > > > theoretical science, it isn't. And because theoretical science > > > precedes practical science, if you start treating them as one and the > > > same, your dead in the water. > > > At this point, I just say I believe you're off base. I suspect a hole > > in your training in science and what science does. > > Would you mind telling me something about your background? > > I'm basically a small businessman. I've never studied science > formally. And you're intelligent and interested. However, that is not sufficient. You are missing some essentials. > > > It's a little dodgy for a nonscientist to tell a scientist, "If this > > is what you do and you call it science, then you're doing the wrong > > thing, because science should be about something else." It's like a > > lawyer telling a plumber that what the plumber is doing isn't really > > plumbing and that in the lawyer's opinion, plumbing is about something > > else. > > I like to think it's more a case of the doctor telling the patient > that they are delusional, and the patient saying "no, Doctor, I'm > afraid that's not correct". Of course, I don't want to strain that > analogy to breaking point, but the point is that because that > scientists say they are doing something, and appear to believe what > they say in good faith, does not mean it is actually how science as an > institution works. Most scientists have never actually studied the > sociology or history of their profession. On this, I think it's pretty easy to show that this is NOT the case. Do you need some references? > Indeed the reason we have > social sciences is because the real dynamics of society are often not > explicitly obvious to people, in the same way the workings of the > physical world are not immediately obvious. > > > > > A first-semester physics book has a chapter on 2D kinematics and > > > > projectile motion. With that model, application after application is > > > > drilled into students, even knowing that air drag, air lift, > > > > variations in g, curvature of the earth, rotation of the earth, etc.., > > > > are all being ignored. > > > > Indeed. That's because that course is about training people to > > > implement the theory in practice, not about giving them the education > > > necessary to question existing theories and develop new better ones. > > > I completely disagree. The purpose of doing this is so that students > > know what a model DOES, what is included and excluded in a model and > > why, how models are tested, and how they are proven (by observation) > > to be lacking, and then how to use that evidence to try to infer a > > better one, and then test THAT. > > And why on Earth would they need to be drilled about the myriad > applications of the same theory, and know it off-by-heart, if their > real future role in society is expected to be imagining credible new > theories, and testing them? So they know what makes a good theory good! I think I just said that. If this seems mysterious to you, then I suggest you get some formal training in science to see. > You may say this is necessary in order to > train future theoretical physicists, but I'm afraid I disagree - I > think the real reason is that few if any of them are actually expected > to become theoretical physicists, and on the contrary they will > instead be expected to deploy existing scientific theories in a > practical fashion. No, I'm sorry, but that's not the case. > > > You have this illusion that questioning theories and developing new > > ones is a wholly mental process, like philosophy, separated from > > observation and practical application. Thsi is NOT how science works, > > nor should it be. > > On the contrary. What I'm saying is that often questions are *not* > asked of the theory, or the *philosophy* on which it is necessarily > based. Just observe how much I've become a cat amongst the pigeons > here for suggesting that time is relative. Clearly no one here had > ever seriously considered the idea, despite its obvious synergy with > the theory of relativity, and the potentially compelling fit with all > the other laws of physics. The fact that many people (not you, but > others) on a physics discussion group have been outright abusive at > the suggestion, rather than simply referring me to an experiment that > has falsified the hypothesis, proves surely that the hypothesis of > classical time is not based on observation at all, but merely on a > classical interpretation of what is observed. And because the > classical interpretation was there first, people are loath to even > reconsider it, let alone reject it. > > > > > > > > > OK, then please note the distinction between "yet to be falsified" and > > > > > > > > "unfalsifiable". > > > > > > > > Indeed. Reminds me of a joke actually, that there are only two types > > > > > > > of scientific theory... > > > > > > > And so your problem with this is what? > > > > > > I don't have a problem. I was just acknowledging that I know the > > > > > difference between "unfalsifiable" and "not yet falsified", and then I > > > > > went on to reflect comically on the fact that the only scientific > > > > > theories that will not eventually be falsified are those that are > > > > > unfalsifiable. > > > > > OK, so what does this have to do with whether a theory of multiple > > > > universes is unfalsifiable? > > > > It seems there are experimental tests... > > > > Oh? > > > Yes! This is what I pointed you to. The RESULTS of the tests are not > > back yet, but this doesn't mean that it is unfalsifiABLE, it means > > that it hasn't yet been falsified or confirmed. What we know is that > > the results will tell us one way or the other. > > > It's like the search for the Higgs. We know where the Higgs should be, > > if it's there. This means the Higgs theory is falsifiABLE. If it's > > found where we expect it, then the theory is confirmed. If it's not > > where we expect it, then the theory is falsified. > > Indeed. I don't dispute the point about the Higgs. And if indeed there > is a test for multiple universes (and I'd be very interested to hear > how), Do you need some Google pointers? Since you're a hobbyist, I could suggest a book by a woman at Harvard who wrote it for laypeople for just that purpose. > the question is not whether the theory is falsifiable (it surely > is), but why the theory was ever thought credible enough in the first > place to bother testing. > > > > > > No, and with respect I don't think I want to know, because something > > > > > that includes the "past and future" model of time is bound to confound > > > > > me. > > > > > Well, here's a problem then. > > > > You propose a philosophical statement about time that imposes symmetry > > > > No, I said time is a function of the human mind, not of the material > > > world. > > > Translate this, please, into experimentally confirmable predictions. > > I think you have it backwards. The onus is not on me to show that you > can't navigate time, and that the past exists only in our memories. > The onus is on you to show that you can navigate time, and that the > past and future exist materially. No, I'm sorry. The onus is on the person who presents a new model to use that model to cite predictions that distinguish it from other models. That is how science operates, and with good reason. > > The fact that no one ever has demonstrably navigated time, and the > fact that existing theories suggest it would be paradoxical and in any > event require more than an infinite amount of energy to achieve, > should cause a sensible person to reflect on why the hypothesis seems > to already have universal acceptance of its "obvious" truth. > > Indeed, even the outcome of the twins paradox can be interpreted not > as time travel, but of fundamental physical processes having simply > occurred at a slower rate; as such "time dilation" does not even > require reference to time in order to explain - one can simply say > that the clock ran slower, not that time ran slower. > > > > > and make the claim that it is BETTER than any model that acknowledges > > > > asymmetry of time. But you also acknowledge that your comparison is > > > > hampered by the fact that you don't even understand any model that > > > > acknowledges asymmetry of time, and that moreover you don't even want > > > > to know any more about any model that acknowledges asymmetry of time > > > > because such a model would confound you. > > > > I understand the asymmetric model of time perfectly. It's one I've > > > taken for granted all my life. Until a few weeks ago, when I suddenly > > > realised that relativity doesn't require it, and there is no test for > > > it. > > > You're right, relativity doesn't require it. That doesn't mean that it > > isn't there ANYWAY. > > Oooh! > > > The theory of electromagnetism doesn't require curved spacetime, > > either. But that doesn't mean that it's not curved ANYWAY. > > The question is whether *any* coherent theory requires it. I haven't > heard any explanation yet for why the curvature of spacetime is > distinguishable from forces acting acting on matter in the classical > way in Euclidean space. Because they make different predictions of observable phenomena! You aren't aware of these? > > > > > > > That's nonsense. The forward is accessible to us in a causal manner, > > > > > > the backwards is not. This doesn't render one of them meaningless. Nor > > > > > > does having meaning associated with both imply that we would be able > > > > > > to causally influence the past. > > > > > > My point is that "cause and effect" are an arbitrary classification to > > > > > describe something of meaning to humans. The reason the "past" can > > > > > never be "affected" in a "causal" manner is because, by its very > > > > > definition, cause always precedes effect in the forward-flowing model > > > > > of time. > > > > > On the contrary, cause and effect doesn't imply time ordering. > > > > No and therein lies the contradiction! How on Earth did anyone ever > > > conceive of a model where the effect precedes the cause in time? > > > It's simple. Change state A and that is associated with the > > observation that state B changes. If B precedes A in time, then this > > does not alter the statement that A causes B. > > But this fails to address the real issue, which is that if an > observation is conditional on a future cause, then that either > presupposes that the cause has already happened No, it does NOT. > (thus violating the > idea that the effect came first in time), or it must be the case that > time self-corrects, and therefore erases your memory of the past (and > therefore you would not remember the effect even if it had in fact > happened). I'm afraid you're not seeing what I'm saying. Please reread. > Or a third option is that the existence of the effect > compels the cause to happen, in order to maintain consistency - but in > that event you may as well refer to the effect by its real name: > "cause". > > In any event, I've yet to hear of any experiment that has demonstrated > an effect preceding the cause - and I would genuinely be interested to > discuss such experiments, if indeed any exist. Well, as it turns out, you may be interested in quantum eraser experiments. You can google that. You may also be interested in learning about the Feynman diagrams that include non-strict-time-ordering that are required to correctly predict the anomalous magnetic moment of the muon. > > > > > > > > Of course most people don't accept this notation. They say only that > > > > > > > the astronaut has gone "slower forwards". > > > > > > > > However, on my reading of relativity, it does not actually require an > > > > > > > absolute forward flow of time, relativity merely suggests that events > > > > > > > can move either ahead, or astern, of other events. > > > > > > > No, relativity says nothing of the kind. Perhaps you need some > > > > > > guidance on your reading of relativity. > > > > > > I think perhaps others need reminding about the implications of > > > > > relativity. People just about seem happy with relative positions in > > > > > space. They seem less happy with relative positions in time. > > > > > I think you could use a little better background on what relativity > > > > really says, > > > > You mean I need a better background on what mainstream physicists > > > really say about relativity? > > > Relativity is a theory developed by physicists. If you think > > relativity means something other than what it does mean, then you're > > no longer talking about relativity. You're talking about your notions > > and you're APPROPRIATING the name relativity to tack on to your > > notions. > > No, the point I was making was that by "what relativity says" you > really mean "what mainstream physicists say about relativity". There > is a significant difference between having an idea speak for itself, > and having someone else speak for the idea. > > That is, the theory of relativity developed by physicists speaks for > itself on the question of relative time - there is no problem with it. > What you mean is that I need a better background in something *other* > than relativity, so that I can interpret relativity correctly. But of > course, my point is that it is not relativity that needs to be > questioned, but the background against which it is currently > interpreted. What I'm saying is that you do not understand correctly what relativity actually says.
From: Ste on 1 Jan 2010 10:47
On 31 Dec 2009, 19:59, PD <thedraperfam...(a)gmail.com> wrote: > On Dec 31, 4:20 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > On 30 Dec, 17:39, PD <thedraperfam...(a)gmail.com> wrote: > > > > On Dec 30, 3:32 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > Either the processes occur symmetrically or they don't. > > > > > It's observed that they do not. There is no point in having a > > > > > "theoretical model" that says they are really symmetric after all.. > > > > > But often what appears on casual observation to be "asymmetrical" by > > > > virtue of its complexity, is in fact symmetrical. If a transformation > > > > of energy today only has its re-transformation eons after humans have > > > > ceased to exist, then that would largely explain why "observations" > > > > over a few years appear asymmetrical. > > > > OK, but now you are talking about something that is by definition > > > unfalsifiable, since you are positing something that will erase the > > > observed asymmetry long after humans have ceased to exist to observe > > > it. > > > > Science is about understanding the laws of nature as they can be > > > confirmed by observations and measurements we CAN conduct. > > > > Postulating something that is inconsistent with observations, because > > > you LIKE symmetry better than asymmetry, and then excusing the lack of > > > symmetry by saying that it is by nature unobservable, puts it in the > > > realm of religious faith and not science any longer. > > > > When you can posit your notions in a manner that it produces > > > predictions that can be *tested* by reasonably accessible experiment, > > > then you will have returned to science. > > > I knew you'd say that. But the truth is that what I'm positing about a > > symmetry of fundamental forces *is* a scientific theory, in that it > > can theoretically be tested against the material world. > > Where is the experimental test that distinguishes this theory from the > currently held thinking? More to the point, why is current thinking more legitimate than this theory, if by definition the observations are consistent with either theory? > > Indeed it > > doesn't actually predict anything exotic - it says only that the > > forces of the universe exist in harmony - and in fact wipes away many > > of the exotic predictions or difficult questions of existing theories. > > Well, first of all, I would say it at best does a swap of one exotic > prediction for another. For example, you claim that symmetry will only > be restored long after humans are dead and gone, and so the > experimental test of that appears to be inaccessible. This is not > exotic? I would say it is not exotic in that it doesn't resort to anything but the fundamental mechanisms that we are already able to observe. The only way humans would be able to survive a full run of the whole system would be to exist outside of that system, but of course the real question then is why such an impossibly high burden of proof is being placed on my hypothesis, while the same burden is not placed on existing thinking. > Secondly, nature is no more exotic than what it really is. There is > nothing in current theories that should be taken as "difficult" to > swallow, as long as it matches what is seen in experiment or makes > predictions that can be tested in the foreseeable future. Indeed there was nothing "difficult" about the geocentric model. Except, of course, the model itself. > > It's the same with my relativist interpretation of time. > > I'm sorry, but your interpretation of time is not the relativist > interpretation of time. I've already mentioned some aspects of the > relativist interpretation (fast and future light cones, for example) > which you find hard to swallow. Your interpretation is your own and > needs to have a new label rather than appropriating one reserved for > something else. Well I don't really want to get into a long argument simply about what to call my interpretation. But there is nothing about the light cone model that is time-relative. On the contrary, it implicitly requires the classical model of time in order to understand, and the classical model of time is not a relative model of time. To reillustrate the difference, the classical model of time measures events by reference to their distance from a common past event, not by reference only to the time-separation between the two events being compared. The classical model requires an absolute benchmark (the birth of Jesus, for example), the relative model does not. The light cone model does not work without classical time (and the conversions required for different frames of reference). Personally I would utilise a different model to describe what the light cone model attempts to describe. I would simply draw a sphere of radius r around some point in space, and the radius determines the time interval required for events at the central point to be observed at the periphery (or the other way around). That's a somewhat different model, but it illustrates the same principle, and unlike the light cone model, one can draw the whole "light-globe" model by reference to the 3 dimensions that everyone is familiar with. Of course, I'm happy to discuss the implications of this with you, but I expect the discussion can be moved forward by you actually discussing it, not by telling me that I don't understand and that I need to learn more. > > It's actually > > conceptually simpler, and wipes away the exotic (and generally > > paradoxical) predictions of wormholes, classical time travel, > > singularities, etc. > > What do you think is paradoxical about wormholes and singularities? I should clarify that I refer to "singularities" in their meaningful sense where the laws of physics apparently break down, not just in the sense of "a lot of matter in a small space" - I know in recent years though the meaningful sense has been largely tempered into the trivial sense. Wormholes are paradoxical simply because they suggest movement in space can be achieved without a commensurate amount of acceleration (and therefore without the expected level of energy input). Of course, again, no doubt the concept will be tempered in due course to point out that such a wormhole would require an equal or greater amount of energy than traditional acceleration (thus robbing the concept of all real meaning). > And relativity does not admit classical time travel, and I don't know > where you got the idea it did. I never said relativity did - on the contrary, I've been repeatedly being saying quite the opposite, as you can observe from my previous posts. I have said that existing interpretations of time, that which I am now consistently referring to as "classical time", require a navigable dimension of time in the sense that "going backwards" in time means restoring the universe to a previous state (and, of necessity, observed change implies that time is moving forward). Whereas my relativistic time says that "going backwards" is what happens to the astronaut in the twins paradox, and "going forwards" is what happened to the homebody, even though by classical time both went forwards (because neither returned to a previous state). I'm sure you're sensible enough PD to see the radical differences between those models, and regardless of what you think personally I'm sure you'll accept that most physicists, when they think of time, still necessarily think of time in classical terms, where the past and future continue to exist in some material sense. > > The geocentric model of the heavens, and the reason why people refused > > to discard it despite a simpler model being available, should be > > something taught in every science class. And the reason, as always, is > > political. The geocentric model utterly discredited the idea of the > > Earth being the jewel in the crown of God's creation - and if that was > > false, then *what else* was false about the teachings of the Catholic > > church? > > > Can you think of why fundamental asymmetry in the universe is very > > important to liberal ideology today? > > Oh dear, now you are wandering deep into Crank Zone. Not at all. There is plenty of literature on the subject of how people believe things for ideological reasons, and generally refuse to accept anything that conflicts with their ideology. I quote from a book I'm currently reading (dealing with the approach of historians to their subject) "it is a serious error to suppose that unconsciousness of ideology, or even a complete lack of interest in it, is the same as absence of ideology". > > > > What I would add though about entropy is that there is no evidence > > > > that the entropy of the universe is increasing. > > > > That's actually not the case. There is cosmological evidence that it > > > IS increasing. You didn't know this, I take it. > > > I know I'll find that this "evidence" can interpreted more than one > > way. > > That's the nice thing about experimental evidence. It's usually pretty > unambiguous. Surely you can't be serious? > It's a common misconception among hacks and hobbyists that any > experimental data can be "interpreted" to support any model desired. > (And Ptolemy and Copernicus are used as the neophyte example.) I don't agree that data can be interpreted to support *any* model, but usually a number of models can be conceived to fit the data, at least superficially. And anyway, as Einstein said, "it is the theory that determines what you can observe" - by which of course he did not mean the observation itself changes, only the interpretation of it. > > And although I don't know what specific cosmological evidence you > > refer to, I have of course heard a number of conclusions drawn from > > what has been observed in the cosmos. I've heard for example that > > matter at the edge of the universe is moving outwards at more than the > > speed of light. > > Relative to us, yes. Is there a problem? Yes, insofar as matter is not supposed to be able to accelerate beyond the speed of light. Or have I misunderstood, in that two objects accelerating in diametrically opposite directions at .6c will appear relative to each other to be accelerating at 1.2c? In that case one can see that the maximum *apparent* speed of matter is 2c, but it's actual speed can be limited to c. > > I've heard that energy goes into black holes and never > > comes out. > > Aside from radiation, yes. Is there a problem? Only insofar as the exception of radiation would disprove the hypothesis that nothing ever comes out. > > Etcetera. But let us assume for one moment that matter at > > the edge of the universe is *not* moving outwards at more than the > > speed of light, and let us assume that energy that goes into black > > holes is *not* lost forever. What part of existing theory has to give > > to allow those assumptions to be correct? > > What evidence would support such a proposition? The real scientific question, surely, is what observation is not compatible with it? (Although I take your point that matter can appear to be travelling at more than c without actually doing so.) > Note that the claim about the mass at the edge of the universe is > supported by DATA. I know. That is why I mentioned it. > Note that there are gravitational objects that are absorbing huge > amounts of energy and mass and do not shine, as seen in direct > observation. Agreed. The question, then, is how does the energy come out again? And the answer is EMR. Matter goes in, EMR comes out. > What is the point of diddling with countersuppositions, when the > current suppositions are supported by experimental data? The point is to advance our understanding and simplify our models. If an impossibly high burden of proof is placed on every theory that challenges the incumbent theory, then you become a prisoner of your preconceptions, and commit yourself to adding epicycles forever. Because of course whenever anyone implores science to adopt a conceptually simpler model with aspects that cannot be observed except in the fullness of time, the response comes back simply "our existing model is adequate for what we already observe". And then the question really is why people accept complex models that have a tight fit with existing observations, rather than simple models that fit what already has been observed, and which purport to fit all that will ever be observed? I hope you realise PD that the difference is not between "scientists" and "non-scientists", it's between scientists who insist on only adding to existing models, and scientists who insist on challenging existing models. > > > Entropy is related to the > > > number of available microstates. The energy of a closed system can > > > remain completely constant and the entropy increase nonetheless. > > > I'm afraid I don't agree. > > Then I suggest you take a course in thermodynamics to learn what the > *definition* of entropy is. Let me start with the OED definition then: "A thermodynamic quantity that represents numerically the extent to which a systems thermal energy is unavailable for conversion into mechanical work". The first question is, "unavailable for conversion" by whom? Unavailable for conversion by humans? Or unavailable for conversion by the fundamental forces of nature? > > Clearly there many fundamental phenomena > > that can only exist in discrete states. An electron, for example, > > apparently has a discrete level of charge. If you have a closed system > > in which fundamental forces never tire or wear out, and in which there > > is energy that can only take discrete forms, and in which states can > > only change at a finite speed, then entropy can't increase - you get > > an oscillation of states, or a rotation of states. > > I didn't say there weren't closed systems where entropy didn't stay > constant. Of course you didn't, because that would have contradicted the 2nd law. > What is true is that in closed systems, entropy doesn't DECREASE. > And what is also true is that in many closed systems, entropy DOES > increase. That is false, because you have *never observed a closed system*. > > Like the kinetic balls toy - without friction, the mechanism would > > never tire, because gravity never tires, and the momentum of the balls > > would always be conserved. The only reason the mechanism does tire is > > because it is not a closed system (and in any event the toy is not > > designed to be in balance with all the fundamental forces of nature). > > That's not entirely correct. I don't know what you think is going on > in that system that causes it to wind down. A number of things cause that system to wind down (i.e. lose momentum). Off the top of my head I would say mainly air resistance (i.e. friction) - although I don't discount sound, heat, plastic deformation, chemical change, etc. But I'm willing to be shocked, if you have news for me. > > So to summarise, it is the existence of discrete states, and finite > > velocities, that can lead to observed change in closed systems without > > any increase in entropy. > > > Thinking scientifically I suppose the problem with testing this > > hypothesis is that a closed system is unmeasurable by those outside > > it, and incomprehensible to those within it. In this way, closed > > systems can theoretically exist, but are untestable. > > That's also wrong. > There are two ways this can be done. > One is that the measuring device be INCLUDED in the system, and the > entropy change of that device is included in the closed system sum. But even that requires the measuring device to be loaded with information gleaned from outside the system itself. And then the system must be opened, first to add the measurement device, and then again to gather data from the measuring device. > The other way is to prepare a state and then close the system, let a > process operate, and then open the system and measure its final state. > This can be done in such a way that the end-effects can be accounted > for. But then you didn't measure a closed system. You measured an open system - the system was open at the start when the initial state was set, at at the end when the measurement was taken. A "closed system" that is not closed for all time is not in fact a "closed system" at all. > I'm afraid your lack of experimental experience is impeding you. On the contrary. Your lack of practical imagination is impeding you in understanding just how difficult it is to measure a truly closed system from either within, or without. > Science is not philosophy. I think you'll find scientists have a philosophy. As I said at the beginning, an unconsciousness of, or lack of concern with, ideology is not the same as an absence of ideology. Incidentally are you religious at all? I ask because your model above, where a "closed system" is 'prepared and then closed', its 'internal processes' are run, and then it is 'opened and measured', sounds a lot like the process of biblical creation and final judgment. If that is a view you have sympathy with, then it suffices to say I can fully understand your views. If you aren't religious, then I'd be more interested to hear why you think a "closed system" that is not closed for all time, is a "closed system" at all. > > > > Epicycles only become necessary when > > > > people insist entropy is always increasing. > > > > Why is increasing entropy epicyclic? > > > For the reason first that the 2nd law does not say entropy must > > increase over time. It says entropy in a closed system will either > > remain constant, or increase. > > Yes, I didn't dispute that. > > > Secondly, the law of conservation says > > that energy remains constant. > > Yes, I didn't dispute that either. I didn't mean to imply that you did dispute these. I was just setting my cards out on the table again. > Why is increasing entropy epicyclic again? Increasing entropy isn't the epicycle. Increasing entropy is the false assumption. It is the false assumption that necessitates epicycles in the *whole body of theory*, in order that there can be functional movement around the false assumption. > > If the universe is an open system, > > I didn't say the universe was open. I never said you did, I'm just attempting to give due consideration to all obvious variables in this question. > I just said that the universe is > not the only closed system for the purposes of experimental test. I see. This is clearly one point on which we disagree. I am not aware of any such experimental closed system. At the very least, this closed system would have to exclude the forces of gravity and electromagnetism (note I say "exclude", not "overcome" or "disregard"). Secondly it would have to have been closed, and remain closed, for all time. If no such experimental closed system has been observed, then I'm confused about why you are using an untested and unobserved concept to "prove" the existence of forward-flowing time. > > then the 2nd law doesn't apply - > > and therefore there is no basis on which to assert that entropy is > > increasing in the universe. Also, if the universe is open, then the > > question remains what exists outside of it, and at what level does the > > system become closed (the hypothesis that the material world is > > infinitely open is, obviously, a hypothesis that is not even > > theoretically testable nor intuitively comprehensible). > > > Or, if the universe itself is a closed system[1], then the question is > > whether energy must take discrete forms. If energy does not take > > discrete forms, then the whole place will be just a homogenous, grey, > > moderately-warm mush, for all eternity[2]. > > What? Why? Continuousness does not imply isotropy. Anisotropy does not > imply discreteness. I think you'll find it does. But if you have some examples where there is both continuous-variability and anisotropy, then perhaps we can discuss them. > > > > Another epicycle is the > > > > forward flow of time - it forces us to deal with "time travel", "worm > > > > holes", "cause preceding effect". > > > > What is epicyclic abot any of these? I believe you are overlapping in > > > your mind "epicyclic" and "counterintuitive". > > > Now you put me on the spot, I suppose I'm suggesting that they are > > indeed one and the same. > > Then you have misunderstood the meaning of epicyclic. No, I've explained before about the epicycles in the geocentric model, and how astronomers became exasperated with the ever-increasing complexity and counter-intuitiveness of the model (for example, some stars did not orbit, but simply oscillated in the sky). Thus it is not clear why you would say that I don't understand my own figurative meaning. Perhaps it's more the case that *you* didn't understand my figurative meaning, possibly because you don't know a great deal about the history of the geocentric model, so it isn't obvious to you why I'm using "epicycles" to refer in a broad sense to "the parts of a whole model that has such great complexity that it strains credulity and defies intuitive understanding" - although I should add that the word "epicyclic" has been used more than I would have chosen to use it here simply because you have asked me a number of times why something is epicyclic. That is perhaps my fault though for not realising earlier that you didn't understand what I actually meant by the word. > > Anything that can be rationally understood, > > eventually becomes intuitive with practice. > > I completely agree with that. And there is nothing counterintuitive > about relativity or gravitation or quantum mechanics that isn't > resolved with practice. There is nothing counter-intuitive about gravity or relativity, because it involves concepts we are familiar with in our daily lives. As for quantum mechanics, I think what you mean is that there are some people who know the theory very well. That is not practical intuition. > > And since > > the maths is supposed to be a *description* of the physical world, the > > conclusion one must reach where modern physicists understand their > > mathematical descriptions but not the physical world, is that their > > descriptions do not actually describe the physical world (even in an > > idealised way)! > > The PHYSICAL models describe the physical world, and the mathematical > casting of the physical model is what allows physicists to make > testable predictions. You can have a mathematical model with testable predictions, without a physical model. Heisenberg's uncertainty principle is an example of this. It is non-deterministic, and it doesn't purport to explain why the underlying mechanism cannot be determined. The gas laws are another example where there is a statistical element, but unlike Heisenberg's uncertainty we have an explanation for the underlying mechanism of action of the gas laws. > > > Whether you believe it or not is not really relevant. What matters is > > > whether there is any *evidence* that it is fundamentally reversible. > > > This is where observation plays a key role and what separates physics > > > from philosophy. > > > Science does have a philosophy you know. > > But it invokes things that philosophy does not, and this is the part > you ignore. Such as? > > > > > Furthermore, let's get one thing straight: In a confrontation between > > > > > experimental observation and intuition, intuition must and always does > > > > > lose. > > > > > Not at all. For an educated man, the two should be one and the same.. > > > > Not necessarily! Nature is surprising. We develop mental models that > > > are best guesses as to how nature works, and then we TEST that model > > > to see if it really describes nature the way we think it does. But > > > more often than not, we find that nature is not what we thought it > > > was. > > > Precisely my view of the matter! Which is why I'm saying for an > > *educated* man observation and intuition should be the same - there > > should only be dissonance between the two for a short time when > > something fundamentally new is observed. Of course, for the ignorant > > man, observation will regularly contradict intuition. > > And you are the one that is complaining about nonintuitive ideas like > wormholes, etc. No, I'm complaining about ideas like wormholes (or singularities, classical time, etc.) that *remain* counter-intuitive even after exposure to the concept. Even the twins paradox was immediately reconciled with my intuition when I realised that the astronaut accelerates more - and yet, for hours of searching for information, nowhere did I see such a simple explanation offered, and instead I read all kinds of nonsense about "changing reference frames". I ended up falling back on my own practical intuition that the asymmetry is because a rocket engine does not cause the Earth to accelerate as much as the rocket, and only then did someone here say "oh, yes, you can explain it based on acceleration, but it's easier to explain with the reference frames". And my answer is that it isn't easier at all - the reference frames solution may be a mathematical simplification, but it breaks the link with the physical mechanism. And once I made the link with acceleration, it became easy to understand why changing your position in a gravitational field also causes the same effect. > > The physical sciences should not be about coming up with a > > mathematical model and seeing if it fits. On the contrary, a mechanism > > of action should be conceived first, and then the maths merely used to > > describe it. > > Please do not tell scientists how science should be done. Science is > DEFINED by the activity of scientists. That's strange, I was led to believe earlier that you thought the activity of scientists was defined by science, not the other way around. If science is defined merely as "what scientists do", then that is a bulletproof rejoinder to anyone who points out that what scientists are regularly doing is not at all in accordance with the commonly-apprehended principles of science. > > The notion that has been > > wrongfully dislodged in modern physics is that idea that mathematical > > models have to be described in physical terms, where you can > > understand the mechanism of action *mechanically*. > > Oh, wait a second. If you mean that the universe and all its processes > should be reducible to the familiar, macroscopic, time-ordered > phenomena exposed to your senses, then I have to draw the line. The > universe is much richer than what we once understood with cogs and > particles and levers and fluids. Any attempt to reduce all of nature > to these rather quaint but limited notions is doomed to failure, > simply because nature is more interesting than that. You'd be surprised how much this statement says about you. Science is the investigation of how nature works as a deterministic system. But you think a simple system is a cold system, and you prefer complex adornments to simple efficiency. I can see why you like modern physics! > > > > > that is, there are factors that are neglected in the treatment of any > > > > > real system. > > > > > My view is that the "neglected factors" should be in the > > > > implementation, not the idealisation. If there are neglected > > > > idealisations in the theory, then the theory is wrong. And while it > > > > may be useful when simplicity is desirable for some practical > > > > purposes, regard to "practical purposes" should not be a significant > > > > consideration in *theoretical* physics. > > > > I'm sorry, but the WHOLE POINT of physical models is to learn to what > > > degree an idealized model can be applied to this or that situation to > > > (adequately) predict the outcomes of those situations. > > > I'm afraid I disagree. I make a distinction between what in > > engineering is called "tolerance", and what in graphic design might be > > called "an idealised model". Tolerance is limited by technical ability > > in the real world. Models are limited only by imagination. In other > > words, the former problem exists because our engineers' don't have the > > technology. The latter problem exists because our theoretical > > physicists don't have the imagination (or, more likely, like the > > heliocentric model, they are unable to consider the truth without also > > rejecting a lot of ideological baggage). > > I'm afraid you don't understand the reductionist methodology of > scientific modeling. Would you like a reference on the methodology of > science, something on the philosophy of science perhaps, so that you > stop making it up to suit you as you go along? You couldn't make it up. If you want to discuss the "reductionist methodology of scientific modelling", then do so. I've said my part on this issue above, that there is a difference between a theory whose accuracy is only limited by practical implementation, and a theory whose accuracy is self-limiting - the latter theory is already beyond its conceptual shelf-life (except, perhaps, where it suffices for practical purposes). > > > > > OK, so what does this have to do with whether a theory of multiple > > > > > universes is unfalsifiable? > > > > > It seems there are experimental tests... > > > > > Oh? > > > > Yes! This is what I pointed you to. The RESULTS of the tests are not > > > back yet, but this doesn't mean that it is unfalsifiABLE, it means > > > that it hasn't yet been falsified or confirmed. What we know is that > > > the results will tell us one way or the other. > > > > It's like the search for the Higgs. We know where the Higgs should be, > > > if it's there. This means the Higgs theory is falsifiABLE. If it's > > > found where we expect it, then the theory is confirmed. If it's not > > > where we expect it, then the theory is falsified. > > > Indeed. I don't dispute the point about the Higgs. And if indeed there > > is a test for multiple universes (and I'd be very interested to hear > > how), > > Do you need some Google pointers? > Since you're a hobbyist, I could suggest a book by a woman at Harvard > who wrote it for laypeople for just that purpose. Yes, if you have some links then as I say I'd be interested to read more on the issue. > > > > No, I said time is a function of the human mind, not of the material > > > > world. > > > > Translate this, please, into experimentally confirmable predictions. > > > I think you have it backwards. The onus is not on me to show that you > > can't navigate time, and that the past exists only in our memories. > > The onus is on you to show that you can navigate time, and that the > > past and future exist materially. > > No, I'm sorry. The onus is on the person who presents a new model to > use that model to cite predictions that distinguish it from other > models. That is how science operates, and with good reason. But how does that work when the new model makes *fewer* unverified predictions in some respect than the existing model? My model about relative time simply predicts that time is not navigable, and that "travelling to the past" in the classical sense is as meaningless in the physical world as "going to Hell" - in that it is not a place to which one can navigate by resort to any physical process, if indeed such a place exists materially at all. > > > > > and make the claim that it is BETTER than any model that acknowledges > > > > > asymmetry of time. But you also acknowledge that your comparison is > > > > > hampered by the fact that you don't even understand any model that > > > > > acknowledges asymmetry of time, and that moreover you don't even want > > > > > to know any more about any model that acknowledges asymmetry of time > > > > > because such a model would confound you. > > > > > I understand the asymmetric model of time perfectly. It's one I've > > > > taken for granted all my life. Until a few weeks ago, when I suddenly > > > > realised that relativity doesn't require it, and there is no test for > > > > it. > > > > You're right, relativity doesn't require it. That doesn't mean that it > > > isn't there ANYWAY. > > > Oooh! > > > > The theory of electromagnetism doesn't require curved spacetime, > > > either. But that doesn't mean that it's not curved ANYWAY. > > > The question is whether *any* coherent theory requires it. I haven't > > heard any explanation yet for why the curvature of spacetime is > > distinguishable from forces acting acting on matter in the classical > > way in Euclidean space. > > Because they make different predictions of observable phenomena! You > aren't aware of these? Indeed I'm not aware of any observable phenomena that cannot be trivially described in 3 dimensions. Even the effects of SR can be readily understood in 3 dimensions. Of course I'm willing to be corrected. > > > > > On the contrary, cause and effect doesn't imply time ordering. > > > > > No and therein lies the contradiction! How on Earth did anyone ever > > > > conceive of a model where the effect precedes the cause in time? > > > > It's simple. Change state A and that is associated with the > > > observation that state B changes. If B precedes A in time, then this > > > does not alter the statement that A causes B. > > > But this fails to address the real issue, which is that if an > > observation is conditional on a future cause, then that either > > presupposes that the cause has already happened > > No, it does NOT. > > > (thus violating the > > idea that the effect came first in time), or it must be the case that > > time self-corrects, and therefore erases your memory of the past (and > > therefore you would not remember the effect even if it had in fact > > happened). > > I'm afraid you're not seeing what I'm saying. Please reread. > > > Or a third option is that the existence of the effect > > compels the cause to happen, in order to maintain consistency - but in > > that event you may as well refer to the effect by its real name: > > "cause". > > > In any event, I've yet to hear of any experiment that has demonstrated > > an effect preceding the cause - and I would genuinely be interested to > > discuss such experiments, if indeed any exist. > > Well, as it turns out, you may be interested in quantum eraser > experiments. You can google that. I've studied it again now scrupulously and I don't find anything shocking about it (even though the last page I read - http://www.bottomlayer.com/bottom/kim-scully/kim-scully-web.htm - said as a layman I ought to be). Surely the outcome of the QE experiment is easily understandable if you conceive of there being a sort of EM field (i.e. a potential force, that "charges" space) which is distinct from the photon (i.e. an energy packet causing observable change of state) itself? I know that sounds like going back to the luminiferous aether, but it's surely more physically credible that "action at a distance" or "a particle in two places at once". > You may also be interested in learning about the Feynman diagrams that > include non-strict-time-ordering that are required to correctly > predict the anomalous magnetic moment of the muon. I'm afraid I couldn't make heads nor tails of the concept. |