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| Tags: equations, frames |
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#11
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On Fri, 22 Oct 2004 22:56:09 GMT, "Bill Hobba" wrote:
"Paul Draper" wrote in message . com... "eleaticus" wrote in message ... In various ways matters of frames versus equations have arisen. A. Consider the distance D=vt equation, about the movement of an automobile on the street outside your home. What frames are involved? We can say three: the frame of the observer (you), the street, and the frame of whatever is moving. Yes, your frame and the auto's is the same. Say that the D=0=x location is the nearest corner to you. Should we wish to transform the equation to the viewpoint of the Goodyear blimp overhead, moving at velocity u with respect to you and the street, are we required to ignore the fact that the equation is about the auto versus the street corner and pretend it is about the auto and you? There's a big difference. The 'observer' - meaning the stationary frame - is an imaginary construct in its general usage. If it is the auto versus you the equation is about imaginary observers and physical autos, not about physical autos and the street they are on. If it is auto vs observer then the transform must be about the auto vs the blimp observer and D=vt becomes D'=(u-v)t. If it is auto vs street corner, a correct transform from a physical viewpoint must retain the physical facts of the situation: a car moving relative to a physical object, the street corner, at velocity v. This important difference is extremely imporant in the next case B. Consider the old kinetic energy equation, K = .5mv^2. Here we have only two frames in evidence. The imaginary observer and the non-inertial moving object. As it stands, per my description, the equation doesn't even have the physical standing of the D=vt equation in which I posited a street (corner) as well as the imaginary observer, and the car. Indeed, the equation is in effect meaningless, who cares what the supposed kinetic energy is from the viewpoint of any of the infinities of such observers throughout the universe. There is only one 'object' for which the equation has real meaning: an impact object, an object the moving mass hits. Yes, as it stands the frame of the impact object is at rest with respect to the imaginary observer's frame. Innyhoo. that's the third frame, and the question arises: are we somehow bound to ignore the only kind of frame with respect to which the equation has real meaning? What is the law of physics that says we must play the ass and say it is the imaginary observer to which this object's kinetic energy is relevant. The question has import when we decide to refer the physical facts to another frame. If K=.5mv^2 is at all really about the imaginary observer then surely it is also really about the second imaginary observer, and should transform to K=.5m(u-v)^2. But if K=.5mv^2 is about meaningful physical fact then the v terms is relative to such an impact object and the transform should preserve the relative velocity of the moving object versus the impact object for which the equation is meaningful. Summary. What are equations about in physics, imaginary observers, or real (ie meaningful) physical objects, fields? eleaticus It's an excellent question, one that has to be answered carefully. There is a distinction between an equation and a physical law. Since your title indicates frames, let me remind you that physical laws are what remain invariant in different inertial frames. This is not to say that equations remain invariant. You point out KE, which is not even invariant under a Galilean transformation, let alone Lorentz transformations. But the *conservation* of energy and momentum (the laws) are invariant. Just because there is an equation associated with it doesn't make it a physical law. Very true Paul. The interpretation of the POR requires one to be careful what one means by physical law. For example some have said it has no content - it is in fact a definition of physical law. Such is obviously false as it is required for the derivation of the Lorentz transformations so must have content. Exactly what counts as physical law must be examined on a case by case basis. For example suppose an aether did exist and had detectable consequences. Obviously the laws that govern how objects interact with the aether would be the same in any frame so exactly why would it violate the POR? The answer has to do with the symmetry properties of an inertial frame - an inertial frame is isotropic. The existence of a detectable aether wind breaks isotropy so we are not really dealing with an inertial frame. ... In what observable or measurable sense??? Some people claim that the CBMR provides a way to tell one inertial frame from another in violation of the POR What 'measurable' violation??? - so what is going on with it? The answer is the CBMR can be screened out - Yeah, and so can sound by use of a acoutically damper screen. That doesn't make the air dissapaer. What an absolutely lousy illogicial argument! Just because Tom says it doesn't improve it validity... it is an object contained in a frame and can be gotten rid of. The aether, being, for example, the medium that light is supposed to undulate in, can not be screened out, its very existence is necessary for the laws of nature as we understand them to exist eg we know that light is EM radiation described by Maxwell's equations - so if an aether did exist it would be an intrinsic part of the frame otherwise Maxwell's equations would go down the tube. As eluded to above, waves can be screened in a medium and yet the medium remains. Nuff said... Paul Stowe |
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#12
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"Paul Stowe" wrote in message ... On Fri, 22 Oct 2004 22:56:09 GMT, "Bill Hobba" wrote: "Paul Draper" wrote in message . com... "eleaticus" wrote in message ... In various ways matters of frames versus equations have arisen. A. Consider the distance D=vt equation, about the movement of an automobile on the street outside your home. What frames are involved? We can say three: the frame of the observer (you), the street, and the frame of whatever is moving. Yes, your frame and the auto's is the same. Say that the D=0=x location is the nearest corner to you. Should we wish to transform the equation to the viewpoint of the Goodyear blimp overhead, moving at velocity u with respect to you and the street, are we required to ignore the fact that the equation is about the auto versus the street corner and pretend it is about the auto and you? There's a big difference. The 'observer' - meaning the stationary frame - is an imaginary construct in its general usage. If it is the auto versus you the equation is about imaginary observers and physical autos, not about physical autos and the street they are on. If it is auto vs observer then the transform must be about the auto vs the blimp observer and D=vt becomes D'=(u-v)t. If it is auto vs street corner, a correct transform from a physical viewpoint must retain the physical facts of the situation: a car moving relative to a physical object, the street corner, at velocity v. This important difference is extremely imporant in the next case B. Consider the old kinetic energy equation, K = .5mv^2. Here we have only two frames in evidence. The imaginary observer and the non-inertial moving object. As it stands, per my description, the equation doesn't even have the physical standing of the D=vt equation in which I posited a street (corner) as well as the imaginary observer, and the car. Indeed, the equation is in effect meaningless, who cares what the supposed kinetic energy is from the viewpoint of any of the infinities of such observers throughout the universe. There is only one 'object' for which the equation has real meaning: an impact object, an object the moving mass hits. Yes, as it stands the frame of the impact object is at rest with respect to the imaginary observer's frame. Innyhoo. that's the third frame, and the question arises: are we somehow bound to ignore the only kind of frame with respect to which the equation has real meaning? What is the law of physics that says we must play the ass and say it is the imaginary observer to which this object's kinetic energy is relevant. The question has import when we decide to refer the physical facts to another frame. If K=.5mv^2 is at all really about the imaginary observer then surely it is also really about the second imaginary observer, and should transform to K=.5m(u-v)^2. But if K=.5mv^2 is about meaningful physical fact then the v terms is relative to such an impact object and the transform should preserve the relative velocity of the moving object versus the impact object for which the equation is meaningful. Summary. What are equations about in physics, imaginary observers, or real (ie meaningful) physical objects, fields? eleaticus It's an excellent question, one that has to be answered carefully. There is a distinction between an equation and a physical law. Since your title indicates frames, let me remind you that physical laws are what remain invariant in different inertial frames. This is not to say that equations remain invariant. You point out KE, which is not even invariant under a Galilean transformation, let alone Lorentz transformations. But the *conservation* of energy and momentum (the laws) are invariant. Just because there is an equation associated with it doesn't make it a physical law. Very true Paul. The interpretation of the POR requires one to be careful what one means by physical law. For example some have said it has no content - it is in fact a definition of physical law. Such is obviously false as it is required for the derivation of the Lorentz transformations so must have content. Exactly what counts as physical law must be examined on a case by case basis. For example suppose an aether did exist and had detectable consequences. Obviously the laws that govern how objects interact with the aether would be the same in any frame so exactly why would it violate the POR? The answer has to do with the symmetry properties of an inertial frame - an inertial frame is isotropic. The existence of a detectable aether wind breaks isotropy so we are not really dealing with an inertial frame. ... In what observable or measurable sense??? Please see my supposition - 'For example suppose an aether did exist and had detectable consequences.'. An example would be a positive result on the Trouton-Noble experiment. Some people claim that the CBMR provides a way to tell one inertial frame from another in violation of the POR What 'measurable' violation???] The frequency of the CBMR radiation woul be different is the direction of motion - thus isotropy would be broken. But because the CBMR can be removed (screened out) frames do not have to contain it thus its existence doe not violate the POR - unlike an aether which could not be removed. - so what is going on with it? The answer is the CBMR can be screened out - Yeah, and so can sound by use of a acoutically damper screen. That doesn't make the air dissapaer. What an absolutely lousy illogicial argument! Just because Tom says it doesn't improve it validity... So you are claiming the existence of air is an intrinsic property of frames attached to the earth? Yea right. Bill it is an object contained in a frame and can be gotten rid of. The aether, being, for example, the medium that light is supposed to undulate in, can not be screened out, its very existence is necessary for the laws of nature as we understand them to exist eg we know that light is EM radiation described by Maxwell's equations - so if an aether did exist it would be an intrinsic part of the frame otherwise Maxwell's equations would go down the tube. As eluded to above, waves can be screened in a medium and yet the medium remains. Nuff said... Paul Stowe |
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#13
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Paul Draper wrote:
"eleaticus" wrote in message ... In various ways matters of frames versus equations have arisen. A. Consider the distance D=vt equation, about the movement of an automobile on the street outside your home. What frames are involved? We can say three: the frame of the observer (you), the street, and the frame of whatever is moving. Yes, your frame and the auto's is the same. Say that the D=0=x location is the nearest corner to you. Should we wish to transform the equation to the viewpoint of the Goodyear blimp overhead, moving at velocity u with respect to you and the street, are we required to ignore the fact that the equation is about the auto versus the street corner and pretend it is about the auto and you? There's a big difference. The 'observer' - meaning the stationary frame - is an imaginary construct in its general usage. If it is the auto versus you the equation is about imaginary observers and physical autos, not about physical autos and the street they are on. If it is auto vs observer then the transform must be about the auto vs the blimp observer and D=vt becomes D'=(u-v)t. If it is auto vs street corner, a correct transform from a physical viewpoint must retain the physical facts of the situation: a car moving relative to a physical object, the street corner, at velocity v. This important difference is extremely imporant in the next case B. Consider the old kinetic energy equation, K = .5mv^2. Here we have only two frames in evidence. The imaginary observer and the non-inertial moving object. As it stands, per my description, the equation doesn't even have the physical standing of the D=vt equation in which I posited a street (corner) as well as the imaginary observer, and the car. Indeed, the equation is in effect meaningless, who cares what the supposed kinetic energy is from the viewpoint of any of the infinities of such observers throughout the universe. There is only one 'object' for which the equation has real meaning: an impact object, an object the moving mass hits. Yes, as it stands the frame of the impact object is at rest with respect to the imaginary observer's frame. Innyhoo. that's the third frame, and the question arises: are we somehow bound to ignore the only kind of frame with respect to which the equation has real meaning? What is the law of physics that says we must play the ass and say it is the imaginary observer to which this object's kinetic energy is relevant. The question has import when we decide to refer the physical facts to another frame. If K=.5mv^2 is at all really about the imaginary observer then surely it is also really about the second imaginary observer, and should transform to K=.5m(u-v)^2. But if K=.5mv^2 is about meaningful physical fact then the v terms is relative to such an impact object and the transform should preserve the relative velocity of the moving object versus the impact object for which the equation is meaningful. Summary. What are equations about in physics, imaginary observers, or real (ie meaningful) physical objects, fields? eleaticus It's an excellent question, one that has to be answered carefully. There is a distinction between an equation and a physical law. Since your title indicates frames, let me remind you that physical laws are what remain invariant in different inertial frames. This is not to say that equations remain invariant. You point out KE, which is not even invariant under a Galilean transformation, let alone Lorentz transformations. But the *conservation* of energy and momentum (the laws) are invariant. Just because there is an equation associated with it doesn't make it a physical law. PD Your answer is pearls before swine. Eleaticus, who is such a gutless piece of **** that he won't even put his name on his postings, has had this pointed out to him for years. Until recently, he didn't even respond to replies to his postings. Do you really think that you're going to educate him/her? Help the people who have legitimate questions. Don't waste time on cranks. John Anderson |
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#14
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"Bill Hobba" wrote in message ... "eleaticus" wrote in message . .. Is the v in KE physically meaningful wrt the arbitrary, imaginary observer? No one claimed it was not. They should. It is only by doing so that the one 'experiment' is falsified into more than one experiment. Saying the laws of physics are the same implies the same experiment done under the same conditions will give the same results - not that you have the same experiment when you go to a different frame. Shoot a bullet at a stationary target in an inertial frame and you see the bullet move towards the target. Go to a frame where the bullet is at rest and you see the target move toward the bullet. Two different experiments. What the POR says is the laws of physics that govern the two situations are the same eg F=ma is still true, momentum and energy is still conserved. You switch from KE to F, from v to a. Strange that staying with v would nullify your point. Is the v in KE physically meaningful wrt to an object of impact? Yes it is meaningful - but because it is not the same in different inertial frames it can not be considered a law of nature ie it is not one of those things that govern mechanics regardless of which frame you are in. There is nothing about KE=.5mv that would make it unlawful to consider the velocity to be wrt to the impact object rather than the imaginary observer, but acting as if it is wrt the observer makes it nonsense. Only if it is wrt to an impact object does it make consistent sense and science. WRT the object, the equation is obviously invariant, the point of the whole post! Remember saying the laws of nature are the same is not saying you have exactly the same experiment. Certainly not! IFF you are foolish enough to take an equation about physical fact that is valid only wrt the interaction between two physical objects and say it is about a physical object vs an imaginary object. eleaticus |
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#15
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wrote in message ... Your answer is pearls before swine. Eleaticus, who is such a gutless piece of **** that he won't even put his name on his postings, has had this pointed out to him for years. Until recently, he didn't even respond to replies to his postings. Do you really think that you're going to educate him/her? Help the people who have legitimate questions. Don't waste time on cranks. To quote myself: Focus well on negative 'responses'. Are they vicious ranting? Are the replies actually responsive? Do they rant about gravity, or how Relativity is proved correct a million times each day, or some other 'we are proved right' rave that doesn't deal in details about the debunking done here? It is typically General Relativity or items about the energy and mass of moving objects that are being waved at you, and such items are completely irrelevant to coordinate transformations and invariance.. Just ask them for a list of all the observations that have been made of the shortening (contraction) of moving objects that Special Relativity says always occurs. eleaticus John Anderson |
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#16
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"eleaticus" wrote in message news ![]() "Bill Hobba" wrote in message ... "eleaticus" wrote in message . .. Is the v in KE physically meaningful wrt the arbitrary, imaginary observer? No one claimed it was not. They should. It is only by doing so that the one 'experiment' is falsified into more than one experiment. Your point being? Saying the laws of physics are the same implies the same experiment done under the same conditions will give the same results - not that you have the same experiment when you go to a different frame. Shoot a bullet at a stationary target in an inertial frame and you see the bullet move towards the target. Go to a frame where the bullet is at rest and you see the target move toward the bullet. Two different experiments. What the POR says is the laws of physics that govern the two situations are the same eg F=ma is still true, momentum and energy is still conserved. You switch from KE to F, from v to a. Strange that staying with v would nullify your point. I give examples of laws of nature - the value of KE is not - the form of the equation is. Is the v in KE physically meaningful wrt to an object of impact? Yes it is meaningful - but because it is not the same in different inertial frames it can not be considered a law of nature ie it is not one of those things that govern mechanics regardless of which frame you are in. There is nothing about KE=.5mv that would make it unlawful to consider the velocity to be wrt to the impact object rather than the imaginary observer, but acting as if it is wrt the observer makes it nonsense. That makes no sense. Except for direction a particular KE (for a given mass) implies a particular velocity which can change between frames. Only if it is wrt to an impact object does it make consistent sense and science. I have no idea what you are trying to say - as usual you use words in ways that make no sense. WRT the object, the equation is obviously invariant, the point of the whole post! The above makes no sense - as far as I can give any meaning to what you say wrt to the object means in a frame that the object is at rest hence has zero KE. Remember saying the laws of nature are the same is not saying you have exactly the same experiment. Certainly not! IFF you are foolish enough to take an equation about physical fact that is valid only wrt the interaction between two physical objects and say it is about a physical object vs an imaginary object. What can I say - the above makes no sense just like the rest of your rubbish. Bill eleaticus |
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#17
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"eleaticus" wrote in message .. . "Martin Hogbin" wrote in message ... Are you trying to learn some physics at last? Or will you 'educate' us all? You seem to be missing the fact that y'all (SR-cult cretins) opt for the idiot's side of the question. Just a tiny flicker of hope. Martin Hogbin |
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#18
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"Martin Hogbin" wrote in message ... Just a tiny flicker of hope. Not well fanned by avoiding the principled questions in the thread. Martin Hogbin eleaticus |
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#19
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"eleaticus" wrote in message . .. "Martin Hogbin" wrote in message ... Just a tiny flicker of hope. Not well fanned by avoiding the principled questions in the thread. You never replied to http://groups.google.com/groups?&thr...t01.boi.hp.com So you are stupid or you are a coward. Probably both. Dirk Vdm |
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#20
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"Dirk Van de moortel" wrote in message ... "eleaticus" wrote in message . .. "Martin Hogbin" wrote in message ... Just a tiny flicker of hope. Not well fanned by avoiding the principled questions in the thread. You never replied to http://groups.google.com/groups?&thr...t01.boi.hp.com So you are stupid or you are a coward. Probably both. I should follow slime to their slime pool? When we have both the newsgroup and email before us? eleaticus Dirk Vdm |
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