A constant speed of light in all reference frames? Surely you can't be serious.
in [Relativity]
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From: Paul Stowe on 11 Mar 2010 23:30 On Mar 11, 7:54 pm, "Inertial" <relativ...(a)rest.com> wrote: > "PaulStowe" <theaether...(a)gmail.com> wrote in message > > news:722fe1d3-ba1d-4439-bffe-eda2ca668f82(a)p3g2000pra.googlegroups.com... > > > > > > > On Mar 10, 8:57 am, PD <thedraperfam...(a)gmail.com> wrote: > >> On Mar 9, 9:41 pm, PaulStowe<theaether...(a)gmail.com> wrote: > > >> > On Mar 8, 8:05 pm, "Inertial" <relativ...(a)rest.com> wrote: > > >> > > "PaulStowe" <theaether...(a)gmail.com> wrote in message > > >> > >news:1132a230-92d9-484a-b0c1-d3a97532cad9(a)z10g2000prh.googlegroups.com... > > >> > > >> >> SR explains it as having to be c due to the geometry of > >> > > >> >> spacetime > > >> > > >> > That's simply a silly idea... > > >> > > >> That you think it is silly is your problem, not that of SR > > >> > > > Something physical may be represented by a geometric description.. > > >> > > And our universe is represented by Minkowski geometry. > > >> > Yes, you can descibe localized behavior with that format. BUT! to do > >> > so you must depend on finite light speed and its physical > >> > independence. Geometry neither predicts. explains, or has a basis for > >> > that. > > >> That's incorrect, Paul. The geometric structure of spacetime imposes > >> both a finite speed of light AND makes it frame-independent. > > >> The geometric structure of spacetime *necessarily* divides pairs of > >> events into three categories: spacelike-separated, timelike-separated, > >> and nullcone-separated. This structure also immediately leads to the > >> result that any wordline that could be traversed by something between > >> timelike-separated events will, in any other inertial reference frame, > >> still be between timelike-separated events. What this means explicitly > >> is that this object can never span two spacelike-separated events. > >> Thus, the universe of events is strictly divided into two completely > >> separated causal domains. The boundary of these domains is the null > >> cone. Since the null cone has a definite slope of space vs time, this > >> imposes a causal speed limit. (This limit does not exist in Euclidean > >> 3D+1D space -- it is a unique feature of the 4D space and its > >> geometry.) > > >> Furthermore, while transformations between inertial frames will shift > >> the slopes between pairs of timelike events (that is, the speed of an > >> object traveling between the two events), the same transformation > >> between pairs of events on the null cone do not change slope. What > >> this means is that any object that can travel between two events on > >> null cone will have the same speed regardless of inertial reference > >> frame. > > >> So you see, the geometric structure DOES imply both a causal speed > >> limit and the invariance of that causal speed limit with choice of > >> inertial reference frame. It just so happens that light appears to be > >> one of the candidate objects that can travel between nullcone- > >> separated events. > > >> If you need to see how the structure does impose those limits > >> formally, I could point you to a reference book or two that derives > >> this unambiguously. > > >> At the time that Einstein proposed special relativity, he did not > >> understand how such a geometric structure could produce those two > >> conclusions as necessary consequences. And so he just posited the > >> invariance of the speed of light as a postulate (or equivalently, > >> demanded that Maxwell's equations obey the principle of relativity). > >> It was only later that the geometric structure was uncovered and it > >> was understood how the light postulate follows directly from this > >> structure. > > >> PD > > > I wasn't going to bother with a reply since we have gone round & round > > on this very point. I find your argument without merit and I'm > > certain that you mind is made up. Why act like kid and continuously > > and say no it ain't, yes it is??? > > > In minkowski math c can be any finite value. > > Indeed it can. But we observe it to have a particular value in our > universe. > > > As Tom Roberts would > > argue the are nearly a infinite number of variations which fit this > > form. > > All equivalent as long as c is finite > > > Thus it's dependent upon c being a 'physical' constant. > > Yes .. it just doesn't really matter that much what particular value it has. > But it does have a particular value in our universe > > > And, > > as GR shows, it not even global. Now why might that be??? The logic > > (actually lack thereof) and thought process is 'in my opinion' silly > > and no one, not in print nor herein has provided any argument that is > > convincing that the math and geometry is NOT! a resultant of physical > > processes rather some magical geometry... > > The geometry models what we find happens physically. I would say that the the observed geometry is an artifact of the physical process(es) that produces it... > Why you insist there > be some physical cause for why space and time is as modeled by Minkowski > geometry, but do not similarly require a physical cause for why it would be > modeled by Euclidean geometry (especially when experimental evidence points > to it NOT being so modeled) sounds rather hypocritical to me. I do not insist that there must be physicality to euclidian geometry. What ever gave you that idea??? Geometry isn't physical, never will be. Geometric form results FROM something that is physical. Euclidian just happens to be the simplest form but the is certainly nothing special or physical about it. Paul Stowe
From: BURT on 11 Mar 2010 23:36 On Mar 11, 8:14 pm, mpc755 <mpc...(a)gmail.com> wrote: > On Mar 11, 9:03 pm, BURT <macromi...(a)yahoo.com> wrote: > > > > > > > On Mar 11, 5:58 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > On Mar 11, 8:57 pm, BURT <macromi...(a)yahoo.com> wrote: > > > > > On Mar 11, 5:54 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > On Mar 11, 4:57 pm, "Peter Webb" > > > > > > <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > > > > > > "PD" <thedraperfam...(a)gmail.com> wrote in message > > > > > > >news:2e16df28-8aaa-4a83-b215-9dae14eb075f(a)g28g2000yqh.googlegroups.com... > > > > > > On Mar 11, 7:37 am, "Peter Webb" > > > > > > > <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > > > > > > > "Ste" <ste_ro...(a)hotmail.com> wrote in message > > > > > > > >news:860a5e85-6231-4eeb-a3a8-f2b25ced173b(a)x12g2000yqx.googlegroups.com... > > > > > > > > > On 11 Mar, 01:58, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > > > > > > > > wrote: > > > > > > > >> "Ste" <ste_ro...(a)hotmail.com> wrote in message > > > > > > > > >> > except for the fairly > > > > > > > >> > obvious explanation that it is the reference clock which is > > > > > > > >> > undergoing > > > > > > > >> > a "real" slowdown. > > > > > > > > >> Or, that you have no idea of what SR predicts, and have completely and > > > > > > > >> falsely assumed that observers see clocks jump ahead when turnaround > > > > > > > >> occurs. > > > > > > > > > I'm merely going off what "experts" here say happens. I didn't say > > > > > > > > there is a "leap ahead". Paul Draper (if I remember correctly) said > > > > > > > > there is a "leap ahead". Now perhaps I misunderstood, but that is what > > > > > > > > was said. > > > > > > > > Perhaps that was what he said. > > > > > > > > But now you know. > > > > > > > > No leap ahead. > > > > > > >http://scope.joemirando.net/faqs/Relativity/SR/TwinParadox/twin_gap.html > > > > > > > This and the supporting links give some of the context here. > > > > > > > ____________________________________ > > > > > > Including the same sort of diagram as on the wiki page, which answers Ste's > > > > > > question, if he could be bothered to look and read. > > > > > > In the Twin Paradox the twin less at rest with respect to the aether > > > > > has their clock tick slower than the other twin. Since the state of > > > > > the aether is determined by its connections with the matter the clock > > > > > of the twin on the Earth tick's faster than the clock associated with > > > > > the twin who leaves and returns to the Earth.- Hide quoted text - > > > > > > - Show quoted text - > > > > > If clocks tick slower then there must be a fastest time rate > > > > corresponding to light rate time. > > > > > Mitch Raemsch > > > > The fastest rate at which a clock ticks is when it is most at rest > > > with respect to the aether.- Hide quoted text - > > > > - Show quoted text - > > > There is gravity slowing of time to take into acount. There are two > > rates in the universe that can slow. > > > Mitch Raemsch > > The rate at which a clock ticks is based upon the aether pressure in > which it exists which is based on its motion with respect to the > aether and the pressure associated with the aether displaced by > massive objects. > > A clock ticks fastest away from massive objects and at rest with > respect to the aether.- Hide quoted text - > > - Show quoted text - Space flow over flowing energy. Mitch Raemsch
From: Inertial on 12 Mar 2010 00:21 "Paul Stowe" <theaetherist(a)gmail.com> wrote in message news:cdc1a1e2-2873-4aa6-a950-c97bab527489(a)k2g2000pro.googlegroups.com... > On Mar 11, 7:54 pm, "Inertial" <relativ...(a)rest.com> wrote: >> "PaulStowe" <theaether...(a)gmail.com> wrote in message >> >> news:722fe1d3-ba1d-4439-bffe-eda2ca668f82(a)p3g2000pra.googlegroups.com... >> >> >> >> >> >> > On Mar 10, 8:57 am, PD <thedraperfam...(a)gmail.com> wrote: >> >> On Mar 9, 9:41 pm, PaulStowe<theaether...(a)gmail.com> wrote: >> >> >> > On Mar 8, 8:05 pm, "Inertial" <relativ...(a)rest.com> wrote: >> >> >> > > "PaulStowe" <theaether...(a)gmail.com> wrote in message >> >> >> > >news:1132a230-92d9-484a-b0c1-d3a97532cad9(a)z10g2000prh.googlegroups.com... >> >> >> > > >> >> SR explains it as having to be c due to the geometry of >> >> > > >> >> spacetime >> >> >> > > >> > That's simply a silly idea... >> >> >> > > >> That you think it is silly is your problem, not that of SR >> >> >> > > > Something physical may be represented by a geometric >> >> > > > description. >> >> >> > > And our universe is represented by Minkowski geometry. >> >> >> > Yes, you can descibe localized behavior with that format. BUT! to >> >> > do >> >> > so you must depend on finite light speed and its physical >> >> > independence. Geometry neither predicts. explains, or has a basis >> >> > for >> >> > that. >> >> >> That's incorrect, Paul. The geometric structure of spacetime imposes >> >> both a finite speed of light AND makes it frame-independent. >> >> >> The geometric structure of spacetime *necessarily* divides pairs of >> >> events into three categories: spacelike-separated, timelike-separated, >> >> and nullcone-separated. This structure also immediately leads to the >> >> result that any wordline that could be traversed by something between >> >> timelike-separated events will, in any other inertial reference frame, >> >> still be between timelike-separated events. What this means explicitly >> >> is that this object can never span two spacelike-separated events. >> >> Thus, the universe of events is strictly divided into two completely >> >> separated causal domains. The boundary of these domains is the null >> >> cone. Since the null cone has a definite slope of space vs time, this >> >> imposes a causal speed limit. (This limit does not exist in Euclidean >> >> 3D+1D space -- it is a unique feature of the 4D space and its >> >> geometry.) >> >> >> Furthermore, while transformations between inertial frames will shift >> >> the slopes between pairs of timelike events (that is, the speed of an >> >> object traveling between the two events), the same transformation >> >> between pairs of events on the null cone do not change slope. What >> >> this means is that any object that can travel between two events on >> >> null cone will have the same speed regardless of inertial reference >> >> frame. >> >> >> So you see, the geometric structure DOES imply both a causal speed >> >> limit and the invariance of that causal speed limit with choice of >> >> inertial reference frame. It just so happens that light appears to be >> >> one of the candidate objects that can travel between nullcone- >> >> separated events. >> >> >> If you need to see how the structure does impose those limits >> >> formally, I could point you to a reference book or two that derives >> >> this unambiguously. >> >> >> At the time that Einstein proposed special relativity, he did not >> >> understand how such a geometric structure could produce those two >> >> conclusions as necessary consequences. And so he just posited the >> >> invariance of the speed of light as a postulate (or equivalently, >> >> demanded that Maxwell's equations obey the principle of relativity). >> >> It was only later that the geometric structure was uncovered and it >> >> was understood how the light postulate follows directly from this >> >> structure. >> >> >> PD >> >> > I wasn't going to bother with a reply since we have gone round & round >> > on this very point. I find your argument without merit and I'm >> > certain that you mind is made up. Why act like kid and continuously >> > and say no it ain't, yes it is??? >> >> > In minkowski math c can be any finite value. >> >> Indeed it can. But we observe it to have a particular value in our >> universe. >> >> > As Tom Roberts would >> > argue the are nearly a infinite number of variations which fit this >> > form. >> >> All equivalent as long as c is finite >> >> > Thus it's dependent upon c being a 'physical' constant. >> >> Yes .. it just doesn't really matter that much what particular value it >> has. >> But it does have a particular value in our universe >> >> > And, >> > as GR shows, it not even global. Now why might that be??? The logic >> > (actually lack thereof) and thought process is 'in my opinion' silly >> > and no one, not in print nor herein has provided any argument that is >> > convincing that the math and geometry is NOT! a resultant of physical >> > processes rather some magical geometry... >> >> The geometry models what we find happens physically. > > I would say that the the observed geometry is an artifact of the > physical process(es) that produces it... >> Why you insist there >> be some physical cause for why space and time is as modeled by Minkowski >> geometry, but do not similarly require a physical cause for why it would >> be >> modeled by Euclidean geometry (especially when experimental evidence >> points >> to it NOT being so modeled) sounds rather hypocritical to me. > > I do not insist that there must be physicality to euclidian geometry. I know .. but you do seem to be insisting that there needs to be one for Minkowski .. that there must be a physical reason for it before you wil accept it. That is hypocritical. > What ever gave you that idea??? Geometry isn't physical, never will > be. Geometric form results FROM something that is physical. > Euclidian just happens to be the simplest form Which experimentally we know is wrong. Minkowski is a far better fit. > but the is certainly > nothing special or physical about it. Then why don't you use Minkowski geometry which is demonstrably a better fit for reality ?? Both geometries are geometries .. They both potentially model reality. Minkowski geometry gets it right, and Euclidean gets it wrong (except at low velocities). So what is your problem with Minkowski geometry as the geometry of reality?
From: G. L. Bradford on 12 Mar 2010 00:43 "Inertial" <relatively(a)rest.com> wrote in message news:4b995b35$0$27864$c3e8da3(a)news.astraweb.com... > > "G. L. Bradford" <glbrad01(a)insightbb.com> wrote in message > news:qJSdnZRY8MdDvgTWnZ2dnUVZ_iydnZ2d(a)insightbb.com... >> >> "Inertial" <relatively(a)rest.com> wrote in message >> news:4b98c72d$0$8803$c3e8da3(a)news.astraweb.com... >>> >>> "G. L. Bradford" <glbrad01(a)insightbb.com> wrote in message >>> news:WaidncSioueeWwXWnZ2dnUVZ_sudnZ2d(a)insightbb.com... >>>> Planet A and planet B are similar planets one light year apart. A ship >>>> leaves planet A for planet B and the length of the voyage is set for >>>> one year, usual for this commuter ship. The month of departure planet A >>>> is Mar 2010. The month of scheduled arrival planet B is Mar 2011. The >>>> ship leaves planet A on time (Mar 2010) and arrives planet B on time >>>> (Mar 2011). >>> >>> So you have a spaceship travelling at the speed of light. Just a tad >>> unrealistic. >>> >>>> If an observer from planet A could observe the ship's arrival at >>>> planet B, what date would the observation of arrival planet B, Mar >>>> 2011, take place? As far as planet A is concerned, as far as the >>>> observer observes and clocks the arrival, the arrival at planet B takes >>>> place, Mar 2012, two years from the date of the ship's departure....and >>>> thus, observed from planet A, two years from the date of departure of >>>> his twin brother. >>>> >>>> The ship goes, and light comes (c). The ship goes farther out, and >>>> light comes from farther out (c). The ship goes even farther out, and >>>> light comes from even farther out (c). The ship goes one light year out >>>> in one year and it takes light one year from the instant of arrival to >>>> communicate the arrival of the ship and brother to the observer >>>> (c).....who notices from the light speed communication that his brother >>>> appears to have aged only one year between Mar 2010 (when he departed >>>> planet A) and Mar 2012 (when he arrived planet B [[per the observation >>>> of that arrival at planet A!]]). His brother APPARENTLY ages only one >>>> year while he definitely ages two during the time period, Mar 2010-Mar >>>> 2012. >>>> >>>> Of course he is smart enough to realize that his brother's apparent >>>> stretching out in space-time observed during the voyage out was nothing >>>> more than an illusion. Particularly when he arrives home apparently in >>>> precisely the same month (Mar 2012) he is observed to have left planet >>>> B (planet B observed, Mar 2011, from planet A, Mar 2012). He is smart >>>> enough to realize that the planet B observed from planet A is the one >>>> that is one year behind the times of the real-time planets A and B, and >>>> that any arrival, and any departure, observed to be happening there >>>> from planet A happened one year ago, making his age one year ago, and >>>> his brother's unobserved age one year ago upon his actual arrival and >>>> departure planet B, the same age. >>>> >>>> The twin brother gets to planet B a year before he is observed to get >>>> to planet B from planet A. The observation of the duration of the >>>> voyage from planet A is a year longer than the actual voyage takes. Yet >>>> it is the actual length of the outbound space voyage, one year, that is >>>> communicated to the observer on planet A in a two year long span of >>>> time where everything concerning the ship, and thus the brother, seems >>>> to slow down (seems to stretch) in the observer's view. The ship, the >>>> brother, and the ship's clock, outran by a full year the ship, the >>>> brother, and the ship's clock, the observer observed. >>>> >>>> Now someone will say that the time observed from planet A, and thus >>>> the stretching that is observed, is the literal physical reality of the >>>> traveler. They have no concept that the traveler's space-time reality >>>> on the spot might be one thing and his space-time relativity to an ever >>>> more distant observer quite another. >>> >>> Of course, you've ignored relativistic effects completely in that (apart >>> from having a spaceship travel at the speed of light) .. so I'm not sure >>> what the point of your post was. >>> >>> >> >> ========================== >> >> The ship didn't travel at the speed of light in its own frame. > > Nothing with mass can travel at c in EVERY inertial frame. It travelled > one light year in a year .. that is the speed of light. Also anything > travelling at c travels at c in EVERY inertial frame. > > How's about you slow your ship down to something that is at least > conceivable. > >> Not by 300,000 kps did it travel at c. > > Eh? What do you think c is? > >> Which just goes to show that you've paid not a bit of attention and >> understood nothing. > > Paying attention to what in particular? > > So you still haven't said what the point of this post was? What point are > you trying to make? > > ====================== Planet B's observer also gives an observed time duration for the voyage of one year....from an initial ship positioning (enroute oncoming) relative to planet B of six light months distance in space rather than one light year. Light speed is c in the ship frame, including all light leaving out from the ship into the universe (including toward planet B). Light speed is c in planet B's frame, including all light it receives from the direction of the oncoming ship. The ship will not be positioned where it actually is between planet A and planet B, either relative to planet A or relative to planet B. Light transmissions to planet A and planet B will not give to either planetary observer its actual relative positions or relative velocities. Light transmissions to planet A has the ship falling far behind in space-time to where it actually is. Space-time expansion is in progress between ship and planet A. When the voyage is finalized planet A is one light year in distance from ship and crew....and planet B. Planet A is then 'non-local' universe (not an inertial frame) to the ship. The ship and planet B are then in the same frame. Planet B is then 'local' universe (the inertial frame) to the ship. Light transmissions to planet B has the ship observably advanced far forward in space, though not in time, of where it actually is. Space-time contraction is in progress between ship and planet B. When the voyage initializes, planet B is one light year in distance from ship and crew.....and planet A. Planet B is then 'non-local' universe (not an inertial frame) to the ship. The ship and planet A are then in the same frame. Planet A is then 'local' universe (the inertial frame) to the ship. While the ship is between them, relatively distant from both, neither of the planets is 'local' to the ship (neither of the planets is an inertial frame to the ship). GLB ======================
From: Inertial on 12 Mar 2010 00:57
"G. L. Bradford" <glbrad01(a)insightbb.com> wrote in message news:auOdnTzdw7jgSQTWnZ2dnUVZ_tSdnZ2d(a)insightbb.com... > > "Inertial" <relatively(a)rest.com> wrote in message > news:4b995b35$0$27864$c3e8da3(a)news.astraweb.com... >> >> "G. L. Bradford" <glbrad01(a)insightbb.com> wrote in message >> news:qJSdnZRY8MdDvgTWnZ2dnUVZ_iydnZ2d(a)insightbb.com... >>> >>> "Inertial" <relatively(a)rest.com> wrote in message >>> news:4b98c72d$0$8803$c3e8da3(a)news.astraweb.com... >>>> >>>> "G. L. Bradford" <glbrad01(a)insightbb.com> wrote in message >>>> news:WaidncSioueeWwXWnZ2dnUVZ_sudnZ2d(a)insightbb.com... >>>>> Planet A and planet B are similar planets one light year apart. A >>>>> ship leaves planet A for planet B and the length of the voyage is set >>>>> for one year, usual for this commuter ship. The month of departure >>>>> planet A is Mar 2010. The month of scheduled arrival planet B is Mar >>>>> 2011. The ship leaves planet A on time (Mar 2010) and arrives planet B >>>>> on time (Mar 2011). >>>> >>>> So you have a spaceship travelling at the speed of light. Just a tad >>>> unrealistic. >>>> >>>>> If an observer from planet A could observe the ship's arrival at >>>>> planet B, what date would the observation of arrival planet B, Mar >>>>> 2011, take place? As far as planet A is concerned, as far as the >>>>> observer observes and clocks the arrival, the arrival at planet B >>>>> takes place, Mar 2012, two years from the date of the ship's >>>>> departure....and thus, observed from planet A, two years from the date >>>>> of departure of his twin brother. >>>>> >>>>> The ship goes, and light comes (c). The ship goes farther out, and >>>>> light comes from farther out (c). The ship goes even farther out, and >>>>> light comes from even farther out (c). The ship goes one light year >>>>> out in one year and it takes light one year from the instant of >>>>> arrival to communicate the arrival of the ship and brother to the >>>>> observer (c).....who notices from the light speed communication that >>>>> his brother appears to have aged only one year between Mar 2010 (when >>>>> he departed planet A) and Mar 2012 (when he arrived planet B [[per the >>>>> observation of that arrival at planet A!]]). His brother APPARENTLY >>>>> ages only one year while he definitely ages two during the time >>>>> period, Mar 2010-Mar 2012. >>>>> >>>>> Of course he is smart enough to realize that his brother's apparent >>>>> stretching out in space-time observed during the voyage out was >>>>> nothing more than an illusion. Particularly when he arrives home >>>>> apparently in precisely the same month (Mar 2012) he is observed to >>>>> have left planet B (planet B observed, Mar 2011, from planet A, Mar >>>>> 2012). He is smart enough to realize that the planet B observed from >>>>> planet A is the one that is one year behind the times of the real-time >>>>> planets A and B, and that any arrival, and any departure, observed to >>>>> be happening there from planet A happened one year ago, making his age >>>>> one year ago, and his brother's unobserved age one year ago upon his >>>>> actual arrival and departure planet B, the same age. >>>>> >>>>> The twin brother gets to planet B a year before he is observed to get >>>>> to planet B from planet A. The observation of the duration of the >>>>> voyage from planet A is a year longer than the actual voyage takes. >>>>> Yet it is the actual length of the outbound space voyage, one year, >>>>> that is communicated to the observer on planet A in a two year long >>>>> span of time where everything concerning the ship, and thus the >>>>> brother, seems to slow down (seems to stretch) in the observer's view. >>>>> The ship, the brother, and the ship's clock, outran by a full year the >>>>> ship, the brother, and the ship's clock, the observer observed. >>>>> >>>>> Now someone will say that the time observed from planet A, and thus >>>>> the stretching that is observed, is the literal physical reality of >>>>> the traveler. They have no concept that the traveler's space-time >>>>> reality on the spot might be one thing and his space-time relativity >>>>> to an ever more distant observer quite another. >>>> >>>> Of course, you've ignored relativistic effects completely in that >>>> (apart from having a spaceship travel at the speed of light) .. so I'm >>>> not sure what the point of your post was. >>>> >>>> >>> >>> ========================== >>> >>> The ship didn't travel at the speed of light in its own frame. >> >> Nothing with mass can travel at c in EVERY inertial frame. It travelled >> one light year in a year .. that is the speed of light. Also anything >> travelling at c travels at c in EVERY inertial frame. >> >> How's about you slow your ship down to something that is at least >> conceivable. >> >>> Not by 300,000 kps did it travel at c. >> >> Eh? What do you think c is? >> >>> Which just goes to show that you've paid not a bit of attention and >>> understood nothing. >> >> Paying attention to what in particular? >> >> So you still haven't said what the point of this post was? What point >> are you trying to make? >> >> > ====================== So .. what point are you trying to make here? > Planet B's observer also gives an observed time duration for the voyage > of one year....from an initial ship positioning (enroute oncoming) > relative to planet B of six light months distance in space rather than one > light year. Hang on .. Planet B will *see* the ship arrive at the same time it leaves, as the ship is travelling at the speed of light as far as planet B is concerned. That observer will calculate the journey took one year though. For the return journey, Planet B will *see* the ship arrive one year after it does, as the light from its arrival back at A takes another year to get back. That observer will calculate the journey took one year though. And vice versa for A > Light speed is c in the ship frame, You can't say that .. because you cannot have something with mass (like a ship) travelling at c. You cannot have an *inertial frame* that is travelling at c relative to another one. So what you say about the ship 'frame' is not going to make any sense. > including all light leaving out from the ship into the universe (including > toward planet B). Yes .. all light is c in all inertial frames. The ship, however, does not have a rest inertial frame. > Light speed is c in planet B's frame, including all light it receives from > the direction of the oncoming ship. The ship will not be positioned where > it actually is between planet A and planet B, > either relative to planet A or relative to planet B. That makes no sense. Of course it is where it is. > Light transmissions to planet A and planet B will not give to either > planetary observer its actual relative positions or relative velocities. Now THAT is correct .. unless they can adjust for known distances etc, which a savy observer would do. > Light transmissions to planet A has the ship falling far behind in > space-time to where it actually is. it is just an illusion > Space-time expansion is in progress between ship and planet A. No .. there is just movement within it .. it isn't expanding > When the voyage is finalized planet A is one light year in distance from > ship and crew....and planet B. Planet A is then 'non-local' universe (not > an inertial frame) to the ship. The ship never had an inertial frame (while travelling) > The ship and planet B are then in the same frame. No .. the whole universe is in EVERY inertial frame. Frames of reference do not segregate the universe into little compartments. They are just different viewpoint for measuring the same events. > Planet B is then 'local' universe (the inertial frame) to the ship. Everything is in every inertial frame > Light transmissions to planet B has the ship observably advanced far > forward in space, though not in time, of where it actually is. Space-time > contraction is in progress between ship and planet B. When the voyage > initializes, planet B is one light year in distance from ship and > crew.....and planet A. Planet B is then 'non-local' universe (not an > inertial frame) to the ship. The ship and planet A are then in the same > frame. Planet A is then 'local' universe (the inertial frame) to the ship. > > While the ship is between them, relatively distant from both, neither of > the planets is 'local' to the ship (neither of the planets is an inertial > frame to the ship). That's all just nonsense. |