According to 1905 Relativity, a single material point must be always at rest
in [Relativity]
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From: Androcles on 26 May 2010 17:10 <valls(a)icmf.inf.cu> wrote in message news:1585c880-5714-47c1-89e4-943d8647a4cb(a)i31g2000vbt.googlegroups.com... On 25 mayo, 10:46, PD <thedraperfam...(a)gmail.com> wrote: > On May 25, 10:19 am, va...(a)icmf.inf.cu wrote: > > > > > > > On 24 mayo, 07:27, PD <thedraperfam...(a)gmail.com> wrote: > > > > On May 24, 6:13 am, va...(a)icmf.inf.cu wrote: > > > > > On 21 mayo, 10:22, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > On May 21, 6:27 am, va...(a)icmf.inf.cu wrote: > > > > > > > On 20 mayo, 13:09, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > > On May 20, 8:19 am, va...(a)icmf.inf.cu wrote: > > > > > > > > > In his first Relativity paper (30June1905), after declaring > > > > > > > > the ether > > > > > > > > superfluous, Einstein considers a material point at rest. He > > > > > > > > uses a > > > > > > > > system of Cartesian coordinates in which the equations of > > > > > > > > Newtonian > > > > > > > > mechanics and Euclidean geometry hold good. If the massive > > > > > > > > body is > > > > > > > > alone (and then without a Newtonian gravitational force > > > > > > > > acting on it), > > > > > > > > it must remains forever at rest in its own centre of mass > > > > > > > > inertial > > > > > > > > frame. > > > > > > > > Yes. So? > > > > > > > > Every object lives in an infinite multitude of frames. The > > > > > > > ones that > > > > > > > have constant velocity with the frame you just described, plus > > > > > > > this > > > > > > > frame itself, constitutes the set of inertial frames. > > > > > > > If we apply that to the single material point case, the result > > > > > > is an > > > > > > infinite number of inertial frames where the single material > > > > > > point can > > > > > > be moving with any velocity v. > > > > > > Any velocity of magnitude less than c, yes. So? > > > > > > > Once the ether is put out by 1905 > > > > > > Einstein (and with it the Newtonian absolute space and time), > > > > > > can you > > > > > > explain to me with respect to what a single material point can > > > > > > have > > > > > > then a velocity different from zero? > > > > > > A reference frame does not require a material "anchor" object, for > > > > > which that anchor object is at rest in that frame. > > > > > What do you say is totally valid in today Special Relativity, but > > > > not > > > > in 1905 Relativity. See the following references to the 30Jun1905 > > > > text. > > > > Almost at the end of the Introduction: > > > > R1. [The theory to be developed is based like all electrodynamics on > > > > the kinematics of the rigid body, since the assertions of any such > > > > theory have to do with the relationships between rigid bodies > > > > (system > > > > of co-ordinates), clocks, and electromagnetic processes.] > > > > At the beginning of paragraph 3: > > > > R2. [Let us in �stationary� space take two systems of co-ordinates, > > > > i.e. two systems, each of three rigid material lines, perpendicular > > > > to > > > > one another, and issuing from a point.] > > > > In R1 a system of co-ordinates is identified with a rigid body, and > > > > in > > > > R2 (more detailed) with a system of tree rigid material lines. Even > > > > a > > > > single material point must have some mass, imagine tree material > > > > lines. Do you continue thinking that in 1905 Relativity a reference > > > > frame does not require something material to establish the rest? > > > > Yes. Just because Einstein uses a material framework to *explain* his > > > position does not mean that it is essential to the conceptual > > > framework. The idea of reference frames without material anchors > > > preceded Einstein by at least a century. > > > And what? How many centuries preceded Ptolemaic view the Newtonian > > one? > > Taking out the ether with its Newtonian absolute space and absolute > > time is the essence of the Einsteinian relativistic view. > > Yes. > > > In it remain > > only the material bodies themselves to determine inertial frames. > > No. Again, you feel it is essential to anchor a frame to *something* > material for some reason. Thus, if the aether is removed, then to you > it MUST be material bodies. And if loosed from material bodies, then > to you this DEMANDS the aether back again. This is simply wrong. > Reference frames do not need material anchors, period. And they did > not, for a long time preceding Einstein. Newtonian mechanics easily > considered motion in frames in which there was no material object, > including any supposed ether, at rest. > The fact is that all Newtonian mechanics is based in its absolute space and time, the unique privileged inertial frame considered real and true. ============================================== Absolute time, relative frames of reference. Newton knew the frame of reference of the Moon was tied to the frame of reference of the Earth by gravity. THE FACT IS, you are ignorant of even basic physics and a fuckin' liar.
From: valls on 26 May 2010 17:24 On 25 mayo, 14:57, "Sue..." <suzysewns...(a)yahoo.com.au> wrote: > On May 25, 11:19 am, va...(a)icmf.inf.cu wrote: > > > > > > > On 24 mayo, 07:27, PD <thedraperfam...(a)gmail.com> wrote: > > > > On May 24, 6:13 am, va...(a)icmf.inf.cu wrote: > > > > > On 21 mayo, 10:22, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > On May 21, 6:27 am, va...(a)icmf.inf.cu wrote: > > > > > > > On 20 mayo, 13:09, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > > On May 20, 8:19 am, va...(a)icmf.inf.cu wrote: > > > > > > > > > In his first Relativity paper (30June1905), after declaring the ether > > > > > > > > superfluous, Einstein considers a material point at rest. He uses a > > > > > > > > system of Cartesian coordinates in which the equations of Newtonian > > > > > > > > mechanics and Euclidean geometry hold good. If the massive body is > > > > > > > > alone (and then without a Newtonian gravitational force acting on it), > > > > > > > > it must remains forever at rest in its own centre of mass inertial > > > > > > > > frame. > > > > > > > > Yes. So? > > > > > > > > Every object lives in an infinite multitude of frames. The ones that > > > > > > > have constant velocity with the frame you just described, plus this > > > > > > > frame itself, constitutes the set of inertial frames. > > > > > > > If we apply that to the single material point case, the result is an > > > > > > infinite number of inertial frames where the single material point can > > > > > > be moving with any velocity v. > > > > > > Any velocity of magnitude less than c, yes. So? > > > > > > > Once the ether is put out by 1905 > > > > > > Einstein (and with it the Newtonian absolute space and time), can you > > > > > > explain to me with respect to what a single material point can have > > > > > > then a velocity different from zero? > > > > > > A reference frame does not require a material "anchor" object, for > > > > > which that anchor object is at rest in that frame. > > > > > What do you say is totally valid in today Special Relativity, but not > > > > in 1905 Relativity. See the following references to the 30Jun1905 > > > > text. > > > > Almost at the end of the Introduction: > > > > R1. [The theory to be developed is based like all electrodynamics on > > > > the kinematics of the rigid body, since the assertions of any such > > > > theory have to do with the relationships between rigid bodies (system > > > > of co-ordinates), clocks, and electromagnetic processes.] > > > > At the beginning of paragraph 3: > > > > R2. [Let us in stationary space take two systems of co-ordinates, > > > > i.e. two systems, each of three rigid material lines, perpendicular to > > > > one another, and issuing from a point.] > > > > In R1 a system of co-ordinates is identified with a rigid body, and in > > > > R2 (more detailed) with a system of tree rigid material lines. Even a > > > > single material point must have some mass, imagine tree material > > > > lines. Do you continue thinking that in 1905 Relativity a reference > > > > frame does not require something material to establish the rest? > > > > Yes. Just because Einstein uses a material framework to *explain* his > > > position does not mean that it is essential to the conceptual > > > framework. The idea of reference frames without material anchors > > > preceded Einstein by at least a century. > > > And what? How many centuries preceded Ptolemaic view the Newtonian > > one? > > Taking out the ether with its Newtonian absolute space and absolute > > time is the essence of the Einsteinian relativistic view. In it remain > > only the material bodies themselves to determine inertial frames. > > You are free to support the old Newtonian view if you want, but that > > doesnt give you the right to say that in 1905 Relativity a reference > > frame does not require something material. You cant change what 1905 > > Einstein writes, even thinking you that it is something wrong. > > > > > > If that were the case, then for two reference frames to even exist, > > > > > you'd need two objects. For three, you'd need three objects. > > > > > Exactly. See in the previous reference R2 a different material object > > > > for each one of the two different reference systems introduced.> This however, is not the case. A reference frame has a perfectly well- > > > > > defined meaning with or without a material anchor in it. > > > > > A valid assertion in today Special Relativity, but a totally invalid > > > > one in 1905 Relativity. In this thread we are addressing only 1905 > > > > Relativity (see the title). > > > > This, in my opinion, is a boondoggle. > > > I don't see the point of it at all. > > > Relativity is relativity. It is not a *creation*, it is a discovery. > > > When the first sailors navigated to the New World, they drew maps that > > > represented their view of their discovery. Of course, those maps did > > > not at all accurately represent the shape of the Americas. It does > > > absolutely no good to take one of those maps and say, "But this is the > > > America of 1500." It is not. The shape of the continent has not > > > substantively changed since 1500. The America of 1500 is the same as > > > the America of 2010. It's just that how people have described it is a > > > little different from 1500 to 2010. > > > If I am interpreting well, you are suggesting that 1905 Relativity > > contains errors (first sailors making bad America maps) that were > > already corrected in today Special Relativity. And surely you think > > that the need to have material bodies to determine an inertial frame > > is one of these errors. > > 1916 Einstein introduces the word Special to distinguish the > > previous Relativity (denoted SR) from his General Relativity (GR) that > > he is just introducing. But we have here a very strange situation. The > > essence of the new GR is precisely the introduction of material > > (massive) bodies that warp the space-time (without material bodies!) > > introduced by 1907 Minkowski (1907M). Then, 1907M is the one putting > > out the material bodies from 1905 Relativity, conceiving a space-time > > totally independent from them (similar in that to the Newtonian > > absolute space and time, but now with a very strong relationship > > between space and time). Einstein accepts the changes 1907M introduces > > in Relativity and works for years (without success) in the developing > > of a relativistic gravitation. He ends declaring Relativity (the > > modified one by 1907M) not able to address gravitation, developing his > > successful 1916GR gravitation theory. He works then the rest of his > > life trying (without success) to put into accord GR with the rest of > > Physics, a problem that remains open until our days. > > Suppose now that somebody finds the way to explain GR effects (like > > the ones necessary to adjust GPS clocks in the Earths gravitational > > field), but using only 1905 Relativity (Newtonian mechanics, Euclidean > > geometry). Would you consider that a boondoggle? (English is not my > > mother language, and I dont know the meaning of that word). > > > > > > Thus, a single material object lives in not one, but an infinitude of > > > > > reference frames. In one of those inertial reference frames, the > > > > > object happens to be at rest. > > > > > The Earth modelled as a single material point in its centre of mass is > > > > at rest in the GPS ECI System, moving in a monthly almost circular > > > > trajectory around the centre of mass of the Earth-Moon System (CMEM), > > > > and that CMEM is moving in a yearly trajectory around the centre of > > > > mass of the Solar System (CMSS). The CMSS has a velocity of about > > > > 250Km/s in the Galaxy System, etc. Are these systems the ones you have > > > > in mind when talking about infinite ones? > > ================ > > > > > > No, because they aren't inertial, are they? > > > Of course that they are inertial ones, or maybe consider you that an > > inertial frame is only a mathematical entity? The Solar System is the > > more exact real inertial system used by men. And we can make a similar > > remark referring to the GPS ECI. By the way, they are both centre of > > mass inertial systems, supported by huge experimental evidence. > > The earth moves on an elliptical path around the moon. > A surf fisherman can perform gravito-inertial experiments > to detect that motion. (sit still while boots dry) > Hello Sue. Both Earth and Moon are moving in an elliptical path around their common Centre of Mass (CM). By the way, that CM is inside the Earth, but not in the Earths own centre of mass. The Moon seems provoking a sufficient almost equal acceleration in all GPS clocks (the same remark for all the rest of the Universe) to be ignored in the GPS function. With a Moon with a larger mass, surely the inertial system used in GPS would be de Earth-Moon centre of mass. For a future Solar System GPS, its centre of mass inertial frame MUST be used. You get my point? > << Einstein's relativity principle states that: > > All inertial frames are totally equivalent > for the performance of all physical experiments. > > In other words, it is impossible to perform a physical > experiment which differentiates in any fundamental sense > between different inertial frames. By definition, Newton's > laws of motion take the same form in all inertial frames. > Einstein generalized this result in his special theory of > relativity by asserting that all laws of physics take the > same form in all inertial frames. >>http://farside.ph.utexas.edu/teaching/em/lectures/node108.html > That text doesnt correspond to 1905 Relativity, the topic in this thread (surely it corresponds to 1916 Special Relativity). In the GPS ECI inertial frame (used by 1905 Einstein, end of paragraph 4 of the 30June1905 text), it is impossible to make any physical experiment with the Moon or the Sun (or any other body not taken into account when computing the ECI centre of mass). > Sue... > RVHG (Rafael Valls Hidalgo-Gato)
From: Sue... on 26 May 2010 20:23 On May 26, 5:24 pm, va...(a)icmf.inf.cu wrote: [...] > > > ================ > > > > > No, because they aren't inertial, are they? > > > > Of course that they are inertial ones, or maybe consider you that an > > > inertial frame is only a mathematical entity? The Solar System is the > > > more exact real inertial system used by men. And we can make a similar > > > remark referring to the GPS ECI. By the way, they are both centre of > > > mass inertial systems, supported by huge experimental evidence. > > > The earth moves on an elliptical path around the moon. > > A surf fisherman can perform gravito-inertial experiments > > to detect that motion. (sit still while boots dry) > > Hello Sue. > Both Earth and Moon are moving in an elliptical path around their > common Centre of Mass (CM). By the way, that CM is inside the Earth, > but not in the Earths own centre of mass. The Moon seems provoking a > sufficient almost equal acceleration in all GPS clocks (the same > remark for all the rest of the Universe) to be ignored in the GPS > function. With a Moon with a larger mass, surely the inertial system > used in GPS would be de Earth-Moon centre of mass. For a future Solar > System GPS, its centre of mass inertial frame MUST be used. You get my > point? No... Either you have a description for inertial motion or you don't. The example you offered seems in conflict with the principle of relativity. > > > << Einstein's relativity principle states that: > > > All inertial frames are totally equivalent > > for the performance of all physical experiments. > > > In other words, it is impossible to perform a physical > > experiment which differentiates in any fundamental sense > > between different inertial frames. By definition, Newton's > > laws of motion take the same form in all inertial frames. > > Einstein generalized this result in his special theory of > > relativity by asserting that all laws of physics take the > > same form in all inertial frames. >> http://farside.ph.utexas.edu/teaching/em/lectures/node108.html > > That text doesnt correspond to 1905 Relativity, the topic in this > thread (surely it corresponds to 1916 Special Relativity). In the GPS > ECI inertial frame (used by 1905 Einstein, end of paragraph 4 of the > 30June1905 text), it is impossible to make any physical experiment > with the Moon or the Sun (or any other body not taken into account > when computing the ECI centre of mass). Please accept my apologies for interrupting your walk down memory lane with notions that have the benefit of over 100 years of review and experiment. You seem to be saying we can reject the contemporary statement of the principle of relativity and regain something from views of the early 1900s but it is certainly not clear to me what was lost. Sue... > > > Sue... > > RVHG (Rafael Valls Hidalgo-Gato)
From: valls on 27 May 2010 10:08 On 25 mayo, 19:16, Darwin123 <drosen0...(a)yahoo.com> wrote: > On May 25, 5:42 pm, va...(a)icmf.inf.cu wrote: > > > On 21 mayo, 15:00, Darwin123 <drosen0...(a)yahoo.com> wrote:> On May 20, 6:17 pm, va...(a)icmf.inf.cu wrote:> On 20 mayo, 11:57, Darwin123 <drosen0...(a)yahoo.com> wrote:> On May 20, 12:28 pm, va...(a)icmf.inf.cu wrote:> On 20 mayo, 08:50, harald <h...(a)swissonline.ch> wrote:> On May 20, 3:19 pm, va...(a)icmf.inf.cu wrote: > > ANY real inertial frame is an approximate one, only pure mathematical > > concepts can be absolutely exact. > > An inertial frame is a limiting case that can never be achieved > precisely. However, like all limiting cases, it is well defined in > terms of tests. If one has a well defined reference frame, where the > motion of its origin is well defined, then there is a test as too how > close to being an inertial frame. > Einstein started out with "a frame for which the laws of > mechanics applies." There is the inertial frame test. Later on he > revised that to "a frame where the laws of mechanics applies to first > order." > I reading this with a late twentieth century hindsight > interpreted the laws of mechanics as being the laws of motion in > Principia. All the laws of Principia involve forces. Thus, the test of > whether a frame is an inertial frame has to involve forces, or the > accelerations attributed to forces. The "first order" is first order > in velocity divided by speed of light in vacuum. I think it is pretty > clear that the center of mass of the earth can not be precisely the > origin of an inertial frame. This is because there are forces acting > on the earth as a whole system. There are external forces acting on > the entire earth that cause acceleration of the center of mass. > However, there are even greater forces involved on the surface of the > earth. Any clock on the surface of the earth near the equator is going > to undergo far greater external forces than a clock at the center of > the earth. So, in any experiment involving the surface of the earth, > the center of mass can be considered the origin of an inertial frame. > In the 1905 Einstein version of what today is denoted an inertial frame (the one I am interested in this thread), I dont see any reference to the moving of that kind of frame (and much less to its acceleration). He simply denotes stationary frame a reference one in which the equations of Newtonian mechanics hold good (the first order must not be taken into account, it doesnt belong to 1905 Einstein). By the way, the presence of an external force accelerating the centre of mass of some inertial system doesnt affect at all the holding of Newtons laws in it when the same acceleration is shared by all the bodies composing the system. That is the case (with great accuracy) in the GPS ECI and the Solar System, being that a sufficient condition for denoting them inertial frames in the 1905 Einstein sense. > > Anyway, SS and GPS ECI are very > > exact real inertial systems supported by a huge experimental evidence. > > That is a qualitative statement. One could be more quantitative > from the very start of the calculation. Both the center of mass of the > earth and the surface of the earth at the equation are in motion. This > motion is well known from astronomical measurements. The curvature of > these orbits are to first order in v/c caused by centripetal forces. > To first order, gravity can be considered a force. Yes, I know there > is a GR complication that makes gravity different from other forces. > However, this difference won't really be very important in SR. The > gravity of the sun causes the earth to move in an ellipse, the gravity > of the moon causes the earth to wobble in a known way, and the gravity > of the galaxy causes the earth to move in a curve that probably also > resembles ellipse with some wave motion thrown in. All these forces > can be calculated, and make the center of mass different from an > inertial frame point. A clock at the center of the earth will be > subject to all these forces, and hence can't precisely be considered > an inertial clock. The huge GPS experimental evidence is public and very quantitative (I dont understand with what meaning you declare my reference to it as qualitative). In the 1905 Einstein sense, an inertial system can be accelerated as a whole entity. See my previous comment. > Consider a clock on an airplane just above the surface of the > earth. It is subject to the same forces that affect the clock in the > center of the earth. Gravity from the sun, gravity from the moon, and > gravity from the galaxy. However, it is also subject to two additional > force: the force of the seat that holds the clock, and the force of > gravity. The total of the last two forces is the centripetal force on > the clock caused by surface motion. This centripetal acceleration is > huge compared to the centripetal accelerations of the first three > forces (sun, moon, galaxy). So we can ignore these smaller > accelerations on the problem. With respect to the noise in such > experiments, the acceleration caused by sun, moon and galaxy is > negligible. We only have to consider the forces of the seat and earths > gravity on the surface. We can approximate the earths center as the > origin of an inertial frame. However, we know a priori this is an > approximation and we can even give an upper bound to the errors caused > by this approximation.> The Earth surface is NOT approximated as an inertial system in the ECI > > (and also NOT in 1905R). > > I agree. Why do you claim I said otherwise? The earths surface > is not an inertial system in 2010, and was not considered an inertial > system by Einstein in 1905. The center of mass of the earth was > treated like an inertial frame, with respect to suggested clock > experiments on the surface of the earth. The sun, the moon, and the > galaxy are not important for such experiments. The center of mass of > the earth is not an inertial frame. Really sensitive experiments, not > possible yet, would measure the effect of the sun, the moon, and the > galaxy.> Earths surface is moving. I am (almost) sure that you are confused > > about it. The ECI is nothing more that the today denotation of what > > 1905 Einstein uses already. > > I have experience programming computers, an activity where one is > > constantly involved in errors and correcting them. If I am the > > confused one in this point (or in any other), please, dont end until > > convincing me about it. > > Just a minor nit. I made the mistake of thinking the OP was > confused on this issue. I am sorry my reply confused you. However, I > just want you to note. Hypothetically, an experiment may come along > where the annual motion of the earth impacts the final results. In the > experiments so far performed to validate relativity, the annual motion > of the earth is negligible. The noise level is just small enough to > measure the effect of the daily motion, caused by the spin of the > earth. The noise level of the instruments has been far too big to > allow one to measure the effect of the annual motion. > If I were writing a computer program, I would be very careful about > documenting the specific conditions under which the code will be > valid. Basically, I would be concerned at what point my code would > become obsolete. If instruments and techniques come along to measure > the affect of the annual motion on top of the effect of the earths > spin, then the approximation that the CM is the origin of an inertial > frame would be obsolete. > I suggest that you note it, but not to worry about it. Right now, > it is a minor point. The technology makes it trivial. I was answering > another question, which was somewhat ill posed to begin with. > In my last post I address a lot of things considered by me very important ones, but you dont comment the majority of them. I mentioned derivations from 1905R today only explained with GR, noted differences between 1905R and SR, said that rest with respect to itself conveys no information, declared invalid the mutual relative character of the velocity between two entities, said that rest mass measures a total and absolute potential energy, declared GPS a huge experimental evidence supporting 1905R, explained changes in atomic clock owed to gravitation without using GR, changed all your S and S topic (introducing the S+S set), generalized Galileos Principle of Relativity putting out the requirement of a uniform constant velocity, introduced the duality with the external and internal faces of any body, stated the equal acceleration assumption in CM inertial frames, etc. I cant distinguish between you accepting, rejecting, ignoring, non- understanding, still analysing, not reading, or simply not interested in them. RVHG (Rafael Valls Hidalgo-Gato)
From: harald on 27 May 2010 11:52
On May 24, 12:47 pm, va...(a)icmf.inf.cu wrote: > On 21 mayo, 04:35, harald <h...(a)swissonline.ch> wrote: [..] > > > By the way, we are considering here only 1905 Relativity (and > > > I was born long after that epoch). 1905 Einstein can support only 1905 > > > Relativity. > > > Exactly, that is what I referred to. His purpose was to show how: > > > "the same laws of electrodynamics and optics will be valid for all > > frames of reference for which the equations of mechanics hold good" > > > with the clarification: > > > "In order to render our presentation more precise and to distinguish > > this system of co-ordinates *verbally* from others which will be > > introduced hereafter, we call it the ``stationary system.'' " > > And the stationary system is for 1905 Einstein a one in which the > equations of Newtonian mechanics hold good and a time can be > determined applying his clock synchronization procedure, i.e., > according to our previous considerations, a centre of mass inertial > frame corresponding to a body set with at least two bodies.> That is at odds with your statement that: > > > > > > "the moving system must be always part > > > > > of the stationary system, and a stationary system moving with > > > > > respect to a moving system at rest is nothing more that a huge > > > > > absurd [..]. > > What contradiction do you find between that statement and 1905 > Einstein? In SRT we are free to choose which Newtonian coordinate system we call "moving" and which one "stationary"; as they are equally valid for the laws of physics, not one of the two is preferred. The only way in which "mass" is relevant is that it is convenient to choose a high mass object as approximation for a Newtonian reference system. That is at odds with your introduction of "body sets" and your preference for calling certain "centre of mass" systems "stationary" and not "moving". And here below you do it again... Regards, Harald > I can support all what I say using only the 1905 text. As > absolute space and time are out, the space and time used to describe > the movement of any thing must be only the space and time > corresponding to some CM inertial frame, and the moving entity can be > only one body belonging to the body set corresponding to that frame. > As the motion of the CM is totally independent on all the material > points of the body set (a fact derived from Newtons laws), to say > that the stationary system (modelled by a material point in its CM) > is moving with respect to one of the component material points, is > nothing more than a huge absurd (referring to the real example in the > 30June1905 text, the clock at rest in the pole cant be moving with > respect to the moving clock at the equator). > > > Regards, > > Harald > > RVHG (Rafael Valls Hidalgo-Gato) |