Questions on world-line
in [Relativity]
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From: Igor on 26 Aug 2006 13:58 kenseto wrote: > "YBM" <ybmess(a)nooos.fr> wrote in message > news:44efa79f$0$19782$636a55ce(a)news.free.fr... > > kenseto a écrit : > > > World line is a path of an object in space traces out by its absolute > > > motion. > > > > Whis this definition, which assumes absolute motion, it is indeed clear > > that worldline => absolute motion. > > > > Note that it is NOT the definition of worldline for the rest of us. > > SO???? It just mean that the rest of you are wrong. :-) That's funny, but there are people in mental institutions all over the world that basically keep saying the same thing.
From: PD on 26 Aug 2006 14:55 kenseto wrote: > "Igor" <thoovler(a)excite.com> wrote in message > news:1156525443.210500.226300(a)75g2000cwc.googlegroups.com... > > > > kenseto wrote: > > > "Igor" <thoovler(a)excite.com> wrote in message > > > news:1156435588.287603.157960(a)p79g2000cwp.googlegroups.com... > > > > > > > > kenseto wrote: > > > > > "Igor" <thoovler(a)excite.com> wrote in message > > > > > news:1156353371.333406.159360(a)i42g2000cwa.googlegroups.com... > > > > > > > > > > > > kenseto wrote: > > > > > > > "Igor" <thoovler(a)excite.com> wrote in message > > > > > > > news:1156349832.759078.175940(a)74g2000cwt.googlegroups.com... > > > > > > > > > > > > > > > > kenseto wrote: > > > > > > > > > "Igor" <thoovler(a)excite.com> wrote in message > > > > > > > > > > news:1156265582.026355.324580(a)p79g2000cwp.googlegroups.com... > > > > > > > > > > > > The worldline is invariant. Motion is relative. That's all there > is > > > > > > to it. Beyond that, I don't really understand what you're even > > > asking. > > > > > > > > > > > What I am asking is: what motion of an object that gives rise to it > > > > > worldline? Is it the object's absolute motion (individual motion)? > If > > > not > > > > > why not? > > > > > > > > > > Ken Seto > > > > > > > > Ask Galileo. This is not just an issue with SR. You might want to > > > > reprase your question as "How can motion in space be relative and > still > > > > have a well-defined trajectory?" > > > > > > > Of course it is an issue with SR. SR claims that there is only relative > > > motion and the fact that each object has its own world line refute this > > > claim. The world line of an object is due to the individual motion of > the > > > object in space. > > > > But Galileo claimed the exact same thing, except with invariant time. > > So it's not strictly a SR thing. Thus, the notion of relative motion > > has been around since the 17th century. So how can you have relative > > motion and still have a well-defined trajectory? > > SO???? Both Galileo and SR failed to recognize This is the part about Ken that I love the best. a) He reads something about physics and thinks he understands what he's read. b) He reads a little further and gets confused. c) He comes to the newsgroup and (backhandedly) tries to find out what's wrong with his understanding by pointing out the confusion that results d) Folks tell him his understanding of what he read in the first place is wrong. e) He says "SO??? Everyone's understanding of these things is wrong. I'm the one that's right." PD > that world line is the result > of absolute motion and relative motion between A abnd B is the vector > components difference of the vector component of A's absolute motion and the > vector component of B's absolute motion along the line joining A and B. > > > It's simple. How the > > motion is described is entirely dependent on the coordinate system, > > hence relative motion, but all inertial observers must see the same > > trajectory. > > > But relative motion is derived from the absolute motions of the interacting > objects. > All inertial observers do not see the same world line for the same object. > > Ken Seto
From: surrealistic-dream on 26 Aug 2006 15:05 Mike wrote: > surrealistic-dream(a)hotmail.com wrote: > > Mike wrote: > > > surrealistic-dream(a)hotmail.com wrote: > > > > Mike wrote: > > > > > Paul B. Andersen wrote: > > > > > > Igor wrote: > > > > > > > surrealistic-dream(a)hotmail.com wrote: > > > > > > >> Not true. SR treats accelerations as absolute, but velocites and > > > > > > >> positions as relative. > > > > > > > > > > > > > > Wrong. There is a Lorentz transformation for acceleration also. > > > > > > > > > > > > No, it's correct. > > > > > > But the acceleration that is absolute is the proper acceleration, > > > > > > that is the acceleration measured in the instant inertial > > > > > > rest frame of the object. It is the acceleration that is > > > > > > measured by an accelerometer. This acceleration is absolute, > > > > > > that is independent of frames of reference. > > > > > > The co-ordinate acceleration is however frame dependent. > > > > > > > > > > The term "absolute" implies a much broader range of possibilities than > > > > > simply "independent of FoR". It is better to call proper acceleration > > > > > an invariant. > > > > > > > > Einstein claimed that he left acceleration as "absolute" in SR (that > > > > is, in his generaltization of Newton's mechanics to include > > > > electrodynamics). Why? well, this is partly semantic and partly > > > > historical and they go together. Historically "absolute motion" of any > > > > kind referred to motion with respect to some physically existing space. > > > > > > I agree. > > > > > > > > > > To Newton, acceleration only made sense in his theory if one could > > > > rely on that kind of motion to be with respect to some space in which > > > > absolute accelerations live. So, of course, Newton took the existence > > > > of inertial frames as absolute. And later, Einstein found the inertial > > > > concept wanting, and he introdcued the so-called Principle of > > > > Equivelence in GR. > > > > > > This has nothing to do with absolute motion, i.e. both concepts are > > > also present in Newtonian mechanics and post-Newtonian formulations. > > > > > > > > > > > Anyway, since you mentioned Mach below, I will address his contribution > > > > to relativity here. It was Mach, contrary to what you claimed below, > > > > who got Einstein to doubt the necessity of founding physics on the > > > > concept of absolute acceleration, meaning accelerations with respect to > > > > some invisible, unidentifiably space. Instead, he suggested that the > > > > inertial properties of matter are totally dependent on the distibution > > > > of matter in the universe. And, since the distribution of matter in the > > > > universe is happenstance, it is not depedent on the existence of some > > > > absolute space. > > > > > > > > > > This is a very narrow interpretation. Mach's idea cannot rule out > > > absolute space. You can still have absolute space and inertia dependent > > > on mass distribution in the universe. > > > > > > > > > > > > > Okay, so what is relative about relativity? This: if the equations of > > > > physics are conceptually founded in some theory on motion with respect > > > > to some absolute space, such as the space in which absolute > > > > accelerations live or the space in which absolute velocities live (rest > > > > space of the ether), then the motion is deemed to be "absolute." But if > > > > the equations of physics are founded on the notion of objects relative > > > > to visible (ponderable) matter, the theory is said to be > > > > "relativistic." Nowadays, physics includes the notion of invisible > > > > matter/energy but such things are still object like (in the same way > > > > that ponderable matter is), not space like in the way the the rest > > > > frame of the ether is. > > > > > > You are confusing Relational theories of spacetime and motion with > > > Relativistic theories. This is a very common mistake. Relativistic > > > theories do not preclude absolute space. Actually, it is now understood > > > that the spacetime of SR and GR is absolute. Relational theories > > > preclude absolute space time but there is no theory at hand which is > > > founded on purely relational spatiotemporal quantities. It is > > > impossible to do it since it is impossible to know the mass > > > distribution function of the universe. Esxpecially when more than 70% > > > (or 90% nobody knows) is ssome dark matter. > > > > > > > > > > > Einstein's main boasting point for SR, was not E = mc^2, but that he > > > > got rid of absolute velocities. And his main boasting point of GR was > > > > not curved spacetime, but that he got rid of absolute accelerations. > > > > > > Neither. This is another common misunderstanding. newtonian Mechanics > > > do not need absolute velocities either. > > > > This incorrect reply you made is typical of every reply you made. > > Newtonian mechanics was NOT a theory of electrodynamics. LET was, and > > LET is the theory Einstein wanted to replace with SR. But LET used > > absolute velocties, but SR did not. > > No, I think you are talking about things you do not understand well. > Neither NM nor LET require absolute velocities to determine state of > motion. Wrong. Whatever you're referring to that you call 'LET' has nothing to do with Lorentz's theories of electrodynamics prior to and including 1904. The 'L' in 'LET' stands for 'Lorentz', by the way. In his theories there was an absolute rest space (of the ether) and any object not moving in the frame has an absolute velocity of zero. Any object moving in the frame has an absolute velocity of v. > The introduction of absolute velocities in these theories is > done solely on the basis of defining the structure of spacetime and > consequently, the metaphysics of these theories. More BS. >Einstein's bold step > was to introduce the invariance of the speed of light in all globally > inertial reference frames. But this has consequences only in the way > observer A determines the motion of observer B and vice versa. > > I never said NM was a theory of electrodynamics. LET does not "use" > absolute velocities, The entire structure of the theory is based on absolute velocities. Just open the book and look at the damn theory yourself! >it postulates them but the way it is formulated in > modern times does not require them to determine state of motion. > Einstein realized th
From: Dirk Van de moortel on 26 Aug 2006 15:09 "PD" <TheDraperFamily(a)gmail.com> wrote in message news:1156618501.614025.186110(a)i42g2000cwa.googlegroups.com... > > kenseto wrote: >> "Igor" <thoovler(a)excite.com> wrote in message >> news:1156525443.210500.226300(a)75g2000cwc.googlegroups.com... >> > >> > kenseto wrote: >> > > "Igor" <thoovler(a)excite.com> wrote in message >> > > news:1156435588.287603.157960(a)p79g2000cwp.googlegroups.com... >> > > > >> > > > kenseto wrote: >> > > > > "Igor" <thoovler(a)excite.com> wrote in message >> > > > > news:1156353371.333406.159360(a)i42g2000cwa.googlegroups.com... >> > > > > > >> > > > > > kenseto wrote: >> > > > > > > "Igor" <thoovler(a)excite.com> wrote in message >> > > > > > > news:1156349832.759078.175940(a)74g2000cwt.googlegroups.com... >> > > > > > > > >> > > > > > > > kenseto wrote: >> > > > > > > > > "Igor" <thoovler(a)excite.com> wrote in message >> > > > > > > > > >> news:1156265582.026355.324580(a)p79g2000cwp.googlegroups.com... >> > > > > > >> > > > > > The worldline is invariant. Motion is relative. That's all there >> is >> > > > > > to it. Beyond that, I don't really understand what you're even >> > > asking. >> > > > > > >> > > > > What I am asking is: what motion of an object that gives rise to it >> > > > > worldline? Is it the object's absolute motion (individual motion)? >> If >> > > not >> > > > > why not? >> > > > > >> > > > > Ken Seto >> > > > >> > > > Ask Galileo. This is not just an issue with SR. You might want to >> > > > reprase your question as "How can motion in space be relative and >> still >> > > > have a well-defined trajectory?" >> > > > >> > > Of course it is an issue with SR. SR claims that there is only relative >> > > motion and the fact that each object has its own world line refute this >> > > claim. The world line of an object is due to the individual motion of >> the >> > > object in space. >> > >> > But Galileo claimed the exact same thing, except with invariant time. >> > So it's not strictly a SR thing. Thus, the notion of relative motion >> > has been around since the 17th century. So how can you have relative >> > motion and still have a well-defined trajectory? >> >> SO???? Both Galileo and SR failed to recognize > > This is the part about Ken that I love the best. > a) He reads something about physics and thinks he understands what he's > read. > b) He reads a little further and gets confused. > c) He comes to the newsgroup and (backhandedly) tries to find out > what's wrong with his understanding by pointing out the confusion that > results > d) Folks tell him his understanding of what he read in the first place > is wrong. > e) He says "SO??? Everyone's understanding of these things is wrong. > I'm the one that's right." > > PD See http://www.webster.com/dictionary/autism Dirk Vdm
From: kenseto on 26 Aug 2006 22:16
"Igor" <thoovler(a)excite.com> wrote in message news:1156614861.712755.257860(a)75g2000cwc.googlegroups.com... > > kenseto wrote: > > "Igor" <thoovler(a)excite.com> wrote in message > > news:1156525443.210500.226300(a)75g2000cwc.googlegroups.com... > > > > > > kenseto wrote: > > > > "Igor" <thoovler(a)excite.com> wrote in message > > > > news:1156435588.287603.157960(a)p79g2000cwp.googlegroups.com... > > > > > > > > > > kenseto wrote: > > > > > > "Igor" <thoovler(a)excite.com> wrote in message > > > > > > news:1156353371.333406.159360(a)i42g2000cwa.googlegroups.com... > > > > > > > > > > > > > > kenseto wrote: > > > > > > > > "Igor" <thoovler(a)excite.com> wrote in message > > > > > > > > news:1156349832.759078.175940(a)74g2000cwt.googlegroups.com... > > > > > > > > > > > > > > > > > > kenseto wrote: > > > > > > > > > > "Igor" <thoovler(a)excite.com> wrote in message > > > > > > > > > > > > news:1156265582.026355.324580(a)p79g2000cwp.googlegroups.com... > > > > > > > > > > > > > > The worldline is invariant. Motion is relative. That's all there > > is > > > > > > > to it. Beyond that, I don't really understand what you're even > > > > asking. > > > > > > > > > > > > > What I am asking is: what motion of an object that gives rise to it > > > > > > worldline? Is it the object's absolute motion (individual motion)? > > If > > > > not > > > > > > why not? > > > > > > > > > > > > Ken Seto > > > > > > > > > > Ask Galileo. This is not just an issue with SR. You might want to > > > > > reprase your question as "How can motion in space be relative and > > still > > > > > have a well-defined trajectory?" > > > > > > > > > Of course it is an issue with SR. SR claims that there is only relative > > > > motion and the fact that each object has its own world line refute this > > > > claim. The world line of an object is due to the individual motion of > > the > > > > object in space. > > > > > > But Galileo claimed the exact same thing, except with invariant time. > > > So it's not strictly a SR thing. Thus, the notion of relative motion > > > has been around since the 17th century. So how can you have relative > > > motion and still have a well-defined trajectory? > > > > SO???? Both Galileo and SR failed to recognize that world line is the result > > of absolute motion and relative motion between A abnd B is the vector > > components difference of the vector component of A's absolute motion and the > > vector component of B's absolute motion along the line joining A and B. > > > > > It's simple. How the > > > motion is described is entirely dependent on the coordinate system, > > > hence relative motion, but all inertial observers must see the same > > > trajectory. > > > > > But relative motion is derived from the absolute motions of the interacting > > objects. > > All inertial observers do not see the same world line for the same object. > > > > Ken Seto > > Not only do all inertial observers see the same world line in SR, all > non-inertial observers see the same world line in GR. What is your proof that all inertial observers see the same world line for the same object?? You assertion doesn't count. If all inertial observers sees the same world line for the same object how come that the coordinates of the same object is observer dependent? >You obviously > don't know what you are talking about. But it's not my problem. I think that it is you who don't know what you are talking about. >You > claim there is absolute motion. How do you get to that? The only way to proof if absolute motion wrt light is by doing the experiments in the following link. http://www.geocities.com/kn_seto/2005Experiment.pdf >Even prior to > SR, most reasonable believers in absolute motion still had it tied down > to relative motion WRT the aether. So?? The newer version of ether theory describes absolute motion as that motion of an object wrt light that is being transmitted by the ether. My ether theory give rise to a new theory of relativity call IRT (Improved Relativity Theory). IRT includes SRT as a subset. However, unlike SRT, the equations of IRT are valid in all environments, including gravity. A descriptiuon of IRT is in the following link: http://www.geocities.com/kn_seto/2995Unification.pdf >How can you believe in absolute > motion when simple everyday experiences can shoot it down? And one > more thing, how you model any such absolute motion mathematically? It > can't be done. Nothing shoots it down.....only the mis-interpretations of the past experimental results. For example, the null result of the MMX can be interpreted as that there is no motion of the apparatus in the horizontal plane of the light rays. If the MMX is performed with the plane of the light rays oriented vertically, non-null results will be obtained. This interpretation is supported by the Pound and Rebka experiments as well as the observed gravitational red shift in the vertical direction. Ken Seto > |