A constant speed of light in all reference frames? Surely you can't be serious.
in [Relativity]
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From: G. L. Bradford on 11 Mar 2010 12:09 "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. Not by 300,000 kps did it travel at c. Which just goes to show that you've paid not a bit of attention and understood nothing. GLB ==========================
From: G. L. Bradford on 11 Mar 2010 12:10 "Peter Webb" <webbfamily(a)DIESPAMDIEoptusnet.com.au> wrote in message news:4b98cae0$0$11705$afc38c87(a)news.optusnet.com.au... > > "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. >> > > I think you should lighten up a bit. Photons travel at c, and this is > really just a special case of a more general question. > > The real problem is that looking at what happens at exactly c doesn't > really show the general principle, which is why real world hypothetical > spacecraft travel at 0.99c. But Mr Bradford maybe doesn't know that. > > I do agree however that his post seemed pointless. > > BTW, is you alias Inertial because of SR ? > > ====================== The same goes for you as "Inertial" GLB ======================
From: G. L. Bradford on 11 Mar 2010 12:17 "Androcles" <Headmaster(a)Hogwarts.physics_v> wrote in message news:nO3mn.243839$zD4.168230(a)newsfe19.ams2... > > "G. L. Bradford" <glbrad01(a)insightbb.com> wrote in message > news:WaidncSioueeWwXWnZ2dnUVZ_sudnZ2d(a)insightbb.com... >> Planet A and planet B are similar planets one light year apart. A ship >> leaves planet A for planet B and the length of the voyage is set for one >> year, usual for this commuter ship. > > So the ship travels at one light-year per year, unusual for any type of > ship. ================== Contraction and expansion of space-time. It did no such thing, though that would seem the 'final' result. As I told Inertial, it did not come within 300,000 kps of the speed of light within its own frame. And though its own clock measured a year for the voyage (Mar 2010-Mar 2011), the navigator measured two years for the voyage (Mar 2009-Mar 2011) from the closest most careful observations of the surrounding, enclosing, external universe at large. GLB ==================
From: Androcles on 11 Mar 2010 12:40 "G. L. Bradford" <glbrad01(a)insightbb.com> wrote in message news:UqGdnRHFWJ4kuATWnZ2dnUVZ_omdnZ2d(a)insightbb.com... > > "Androcles" <Headmaster(a)Hogwarts.physics_v> wrote in message > news:nO3mn.243839$zD4.168230(a)newsfe19.ams2... >> >> "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. >> >> So the ship travels at one light-year per year, unusual for any type of >> ship. > > ================== > > Contraction and expansion of space-time. Bwhahahahahahaha! No such animal. > It did no such thing, though that would seem the 'final' result. As I told > Inertial, it did not come within 300,000 kps of the speed of light within > its own frame. Its speed is exactly zero in its own frame, the planets move in its own frame. > And though its own clock measured a year for the voyage (Mar 2010-Mar > 2011), Then the clock was broken or someone forgot to wind it. > the navigator measured two years for the voyage (Mar 2009-Mar 2011) from > the closest most careful observations of the surrounding, enclosing, > external universe at large. It's no good telling Inert anything, the cretin is dead from the neck up.
From: Ste on 11 Mar 2010 15:15
On 11 Mar, 15:12, PD <thedraperfam...(a)gmail.com> wrote: > On Mar 11, 6:43 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > > > On 11 Mar, 01:51, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> > > wrote: > > > > No, perhaps you didn't understand. As I say, this is *not* the twins > > > paradox, because in the twins paradox only *one* twin leaves Earth. > > > > ________________________ > > > Its functionally the same. It is exactly the twins paradox, but with two > > > twins apparently doing exactly the same thing. > > > > Even if you cannot see that, the explanation on the Wikipedia page of the > > > Twins Paradox is trivially adapted for two twins. > > > > I assume that you do not understand the Wikipedia twins paradox page, or > > > else you would know the answers to your questions already. Which parts don't > > > you understand? > > > Let's just go through it step by step Peter, as we have been doing. > > It's pointless spending 10 more postings arguing about how the > > Wikipedia page does or does not answer the question, or how it is or > > is not relevant. As I've just said in a post to Inertial, the only > > analogy between my scenario and the twins paradox is that, in my > > scenario, both twins leave Earth, and both return the same age as each > > other - hence no paradox, and hence bearing no resemblance at all to > > the twins paradox. > > First of all, let's establish what you think is paradoxical at all > about the description of the twins in the twin puzzle. Then let's see > whether this paradox is present in the case you mention. As I understand it, the supposed "paradox" in the twins paradox was that one returned younger than the other. It was, of course, not a paradox at all, but that's besides the point. In our scenario however, we have already agreed that both clocks return to the origin displaying the same time, hence there is no correspondence at all with the twins paradox. |