A constant speed of light in all reference frames? Surely you can't be serious.
in [Relativity]
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From: Ste on 16 Feb 2010 07:59 On 16 Feb, 03:28, mpalenik <markpale...(a)gmail.com> wrote: > On Feb 15, 7:32 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > I can give you a simple example of the rotation I've just described. > > > Accellerate an object. That's a rotation. The only reason people do > > > not recognize it as such is because we can't step back and see the > > > geometry of the 4 dimensional universe. > > > As I said, the real world existed long before geometry. > > You seem to insist that 4 dimensional spacetime is some abstract > philosophical thing when really, it's nothing of the sort. The real > world exists as a 4 dimensional manifold. That's not dependent on > mathematical tricks. You have a four dimensional space. We call one > of those dimensions time. > > You percieve a 3 dimensional world. But you have to realize that's > only your perception and that the universe exists outside of your > perception. No we don't perceive a 3D world. We perceive a 4D world, and have done since the beginning of time (as it were). That's what I'm saying to you: the real world existed long before geometry. And geometry is just a mathematical formalisation of basic concepts that were already physically obvious to anyone who ever considered the issue. > > > It's the same with SR. The fault is your perceptions, not the > > > explanation. > > > No the fault is that you don't (or most probably can't) tailor your > > explanation to the audience. I dare say the next time someone asks for > > a "physical explanation", you'd do better to just say "I don't > > understand relativity in those terms", and then everyone knows where > > they stand. > > I understand relativity in the actual terms of the way the universe > really works. You're looking for something that conforms to your > specific desires, which relativity does not. > > Let's try it this way: what about the picture I drew for you do you > not think could represent physical reality? I never said it didn't *represent* physical reality, at least in some way. But my ability to understand requires me to translate that representation into something physical and concrete. The idea that the representation means anything in itself is just absurd to me. > > > > But "rotation into time" is totally meaningless in the sense that it's > > > > supposed to have any analogy with spatial rotation. It's a bit like > > > > "light follows a groove in space" - the supposed concrete analogy > > > > actually introduces more confusion. > > > > It's not just an analogy, it's a physical reality. Look at the > > > picture I drew you. It means exactly what that picture shows (except > > > in Minkowski spacetime, rather than euclidean). > > > It *represents* something in the real world. It is not physical > > reality itself. At least, it isn't for people like me. > > It represents rotation, just like when I tell you that I rotated a > pole, that also represents a rotation. You just don't understand that > the two things are the same. You insist that they must be different > but in reality, they are not. They don't look quite the same to you > because of your perspective. It's exactly like the flatland example I > gave before. If you have people that live on a little, flat world > sitting in our 3 dimensional space, who can only percieve the things > that exist inside of their little 2 dimensional world, when something > rotates into that third dimension, they'll go "what the heck just > happened? That doesn't look like any rotation I've ever seen." But there is no such thing as a two-dimensional "flatland" in reality. This is much like saying "imagine a place that is not real with people who are not real, and imagine what reality would look like to those people" (which I can only say is unimaginable), and then using this as some sort of proof of a "hidden reality" that is not apparent to people who *are* real. As I say, the four dimensions have been with us since the beginning of time, and people have in one way or another recognised their physical existence since the beginning of time. > > > The picture I made for you wasn't supposed to represent an analogy--it > > > was supposed to represent physical reality (except with a slightly > > > different metric--but we don't need to worry about that just yet). > > > If you don't recognise geometry as being an abstract *representation* > > of the physical world, as opposed to the physical world itself, then > > that is a clear difference in our understandings - and it's a > > philosophical difference which will not be reconcilable. > > It's no more or less geometry that showing you a picture of a pole > that's rotated in our regular 3 dimensional space. It's no more > abstract than that. Why do you insist on calling it something more > abstract than that? The picture I showed you is exactly the same > thing. > > Relable the axes x and y, instead of x and t. Now can you agree that > it's simply a picture of a rotated pole? Now, suddenly if I switch > the axes back to x and t, does it magically become more abstract just > because I changed the labels? No, both are abstract. The difference is that a rotation in the y-axis translates into something quite physically different than a rotation in the t-axis.
From: Peter Webb on 16 Feb 2010 08:53 I never said it didn't *represent* physical reality, at least in some way. But my ability to understand requires me to translate that representation into something physical and concrete. ___________________________ A lot of people have trouble understanding abstract concepts. You shouldn't feel shy about this, but you may take it as a sign that possibly physics is not for you.
From: mpalenik on 16 Feb 2010 08:54 On Feb 16, 7:59 am, Ste <ste_ro...(a)hotmail.com> wrote: > On 16 Feb, 03:28, mpalenik <markpale...(a)gmail.com> wrote: > > > > > > > On Feb 15, 7:32 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > > > > I can give you a simple example of the rotation I've just described.. > > > > Accellerate an object. That's a rotation. The only reason people do > > > > not recognize it as such is because we can't step back and see the > > > > geometry of the 4 dimensional universe. > > > > As I said, the real world existed long before geometry. > > > You seem to insist that 4 dimensional spacetime is some abstract > > philosophical thing when really, it's nothing of the sort. The real > > world exists as a 4 dimensional manifold. That's not dependent on > > mathematical tricks. You have a four dimensional space. We call one > > of those dimensions time. > > > You percieve a 3 dimensional world. But you have to realize that's > > only your perception and that the universe exists outside of your > > perception. > > No we don't perceive a 3D world. We perceive a 4D world, and have done > since the beginning of time (as it were). Which also exists independently of our perceptions. >That's what I'm saying to > you: the real world existed long before geometry. And geometry is just > a mathematical formalisation of basic concepts that were already > physically obvious to anyone who ever considered the issue. This has nothing to do with rotation, which also exists independent of human mathematics. Rotation and orientation are physical things with physical consequences. I also think you might be confusing geometry with coordinate dependent descriptions of geometry. For example, length is a geometric property, which is independent of coordinate descriptions. Length is a property that an object has--i.e. the rod is longer than this other rod. It's not an algebraic or coordinate dependent property. > > > > > It's the same with SR. The fault is your perceptions, not the > > > > explanation. > > > > No the fault is that you don't (or most probably can't) tailor your > > > explanation to the audience. I dare say the next time someone asks for > > > a "physical explanation", you'd do better to just say "I don't > > > understand relativity in those terms", and then everyone knows where > > > they stand. > > > I understand relativity in the actual terms of the way the universe > > really works. You're looking for something that conforms to your > > specific desires, which relativity does not. > > > Let's try it this way: what about the picture I drew for you do you > > not think could represent physical reality? > > I never said it didn't *represent* physical reality, at least in some > way. But my ability to understand requires me to translate that > representation into something physical and concrete. The idea that the > representation means anything in itself is just absurd to me. So, the problem is actually that you find what the picture describes absurd so you reject it off hand, despite the fact that it can be used to recreate every prediction of relativity. There's not that much that needs to be interpreted in that picture. it means exactly what it says it means, literaly--not in some abstract sense. Literally think of a 4 dimensional space with that rotated rod in it. It was not meant as a metaphor. > > > > > > > > > > But "rotation into time" is totally meaningless in the sense that it's > > > > > supposed to have any analogy with spatial rotation. It's a bit like > > > > > "light follows a groove in space" - the supposed concrete analogy > > > > > actually introduces more confusion. > > > > > It's not just an analogy, it's a physical reality. Look at the > > > > picture I drew you. It means exactly what that picture shows (except > > > > in Minkowski spacetime, rather than euclidean). > > > > It *represents* something in the real world. It is not physical > > > reality itself. At least, it isn't for people like me. > > > It represents rotation, just like when I tell you that I rotated a > > pole, that also represents a rotation. You just don't understand that > > the two things are the same. You insist that they must be different > > but in reality, they are not. They don't look quite the same to you > > because of your perspective. It's exactly like the flatland example I > > gave before. If you have people that live on a little, flat world > > sitting in our 3 dimensional space, who can only percieve the things > > that exist inside of their little 2 dimensional world, when something > > rotates into that third dimension, they'll go "what the heck just > > happened? That doesn't look like any rotation I've ever seen." > > But there is no such thing as a two-dimensional "flatland" in reality. > This is much like saying "imagine a place that is not real with people > who are not real, and imagine what reality would look like to those > people" (which I can only say is unimaginable), and then using this as > some sort of proof of a "hidden reality" that is not apparent to > people who *are* real. As I say, the four dimensions have been with us > since the beginning of time, and people have in one way or another > recognised their physical existence since the beginning of time. > I don't think I can get you to visualize a 4 dimensional space, so I took a 3 dimensional slice of 4 dimensions. There's nothing invalid about that. It's like looking at a building from the side and drawing a 2 dimensional profile. In this case, we're looking at the universe by taking a 3 dimensional slice--just a different 3 dimensional slice than the one we're used to looking at. > > > > > > > > The picture I made for you wasn't supposed to represent an analogy--it > > > > was supposed to represent physical reality (except with a slightly > > > > different metric--but we don't need to worry about that just yet). > > > > If you don't recognise geometry as being an abstract *representation* > > > of the physical world, as opposed to the physical world itself, then > > > that is a clear difference in our understandings - and it's a > > > philosophical difference which will not be reconcilable. > > > It's no more or less geometry that showing you a picture of a pole > > that's rotated in our regular 3 dimensional space. It's no more > > abstract than that. Why do you insist on calling it something more > > abstract than that? The picture I showed you is exactly the same > > thing. > > > Relable the axes x and y, instead of x and t. Now can you agree that > > it's simply a picture of a rotated pole? Now, suddenly if I switch > > the axes back to x and t, does it magically become more abstract just > > because I changed the labels? > > No, both are abstract. The difference is that a rotation in the y-axis > translates into something quite physically different than a rotation > in the t-axis. No, it doesn't. Take the picture exactly at face value. There is no metaphor involved--it doesn't translate into anything other than what the picture shows. Your problem is you're looking at the picture and saying, "ok, on x and y, this is a rotation--exactly what it shows in the picture," and then saying "ok, x and t, what does this mean in the real world?" instead of saying, "ok, x and t, this is a rotation-- exactly what it shows in the picture." Do not try to find some hidden layer of interpretation. It is simply a "snapshot" of a 2 dimensional slice of the universe. It doesn't matter what axis we take this slice along. It does not represent anything different.
From: kenseto on 16 Feb 2010 09:13 On Feb 15, 10:32 pm, "Inertial" <relativ...(a)rest.com> wrote: > "kenseto" <kens...(a)erinet.com> wrote in message > > news:65fb4cc2-4dcb-4a03-a564-a5787f7e3550(a)w31g2000yqk.googlegroups.com... > > > > > > > On Feb 15, 5:16 pm, "Inertial" <relativ...(a)rest.com> wrote: > >> "kenseto" <kens...(a)erinet.com> wrote in message > > >>news:65b0b432-ea12-4f62-8dea-14b916d28a20(a)15g2000yqi.googlegroups.com.... > > >> > On Feb 15, 4:06 pm, PD <thedraperfam...(a)gmail.com> wrote: > >> >> On Feb 15, 2:38 pm, kenseto <kens...(a)erinet.com> wrote: > > >> >> > On Feb 15, 12:27 pm, mpalenik <markpale...(a)gmail.com> wrote: > > >> >> > > On Feb 15, 6:54 am, Ste <ste_ro...(a)hotmail.com> wrote: > > >> >> > > > On 14 Feb, 23:46, mpalenik <markpale...(a)gmail.com> wrote: > > >> >> > > > > On Feb 14, 2:03 pm, Ste <ste_ro...(a)hotmail.com> wrote: > > >> >> > > > > > I'm afraid you're easily satisifed Tom. As I say, I'm not > >> >> > > > > > really > >> >> > > > > > interested in learning geometry, or talking about completely > >> >> > > > > > hypothetical "grooves in spacetime". > > >> >> > > > > And as many people have repeatedly tried to explain to you, > >> >> > > > > the > >> >> > > > > answer > >> >> > > > > simply is geometry. When you accellerate, you rotate in > >> >> > > > > spacetime. > >> >> > > > > Why? Because that's what accelleration means. That's what it > >> >> > > > > means > >> >> > > > > to be travelling with a certain velocity with respect to > >> >> > > > > something > >> >> > > > > else. It means that you're both "facing different > >> >> > > > > directions". > >> >> > > > > Every > >> >> > > > > effect predicted by relativity can be explained simply by the > >> >> > > > > fact > >> >> > > > > that two different observers at different speeds are "facing > >> >> > > > > different > >> >> > > > > directions" in spacetime--because that's what it means to be > >> >> > > > > moving > >> >> > > > > with respect to something else. It means that you have a > >> >> > > > > different t > >> >> > > > > and x axis. > > >> >> > > > Mark, if you consider this an answer, then you simply haven't > >> >> > > > understood the question.- Hide quoted text - > > >> >> > > > - Show quoted text - > > >> >> > > And if you think there's more to it than that, then you haven't > >> >> > > understood the answer. The above explains everything about > >> >> > > relativity > >> >> > > and there's no ambiguity when you understand it. > > >> >> > > Going back to the fitting a ladder into a barn analogy, it's like > >> >> > > you > >> >> > > have a ladder to long to fit into the barn, you turn it at an > >> >> > > angle, > >> >> > > and it fits, and then someone starts asking you what "physically" > >> >> > > happened to the ladder. You say "well, it got rotated, so it's > >> >> > > shorter in the horizontal direction". Then the person keeps > >> >> > > demanding > >> >> > > a physical explanation, and you say you just rotated the ladder, > >> >> > > so > >> >> > > it > >> >> > > takes up a bit more space in the vertical and less in the > >> >> > > horizontal > >> >> > > but the total length of the ladder didn't change. > > >> >> > In this case you are not fitting the length of the ladder through a > >> >> > narrow door way. You are fitting a skinny side of the ladder through > >> >> > a > >> >> > wider door way. > >> >> > This is not the same as an 80 ft long material pole can fit into a > >> >> > 40 > >> >> > ft long material barn with both doors close simultaneously. In this > >> >> > case material contraction must occur. That's thee reason why modern > >> >> > interpretation of length contraction in Sr is merely a geometric > >> >> > effect instead of material or physical effect as asserted by the > >> >> > runts of the SRians such as PD and you. > > >> >> "Material" does not mean the same thing as "physical", Ken. > >> >> This has been pointed out even in the common dictionary. > >> >> If you can't let go of your mistakes, Ken, you'll never get off square > >> >> one. > > >> > Physical is material....is one of the definitions in my dictionary. > > >> My dictionary says it is relating to the human body (as opposed to mind > >> or > >> spirit), or involving bodily contact. So if you mean length contraction > >> in > >> SR is not physical because it does not involve human body contact, then > >> I'd > >> agree. > > >> In any case, SR says the all the atoms of a moving rod are closer > >> together > >> (in the frame of a relatively moving observer). ie. that the spatial > >> distance between them (at any given time) is shorter than when the rod is > >> at > >> rest. That sounds 'physically' shorter to me. > > > Hey idiot > > I'm no idiot, as you know. But I'll respond to you anyway. > > > do you realize that you were describing material length > > contraction and not merely geometric projection contraction? > > The geometric projection results in the atoms being closer together in the > frame in which the rod is moving. No...this is wrong. I see you to be shorter from a distance is geometric projection. The atoms in you are not being closer together. > As I said above. The effect of the > geometric projection (rotation) is that the atoms physically get closer. > Geometric operations can have physical results. Like rotating a ladder to > fit through a doorway. Geometric projection has no material or physical effect. When you rotate the x-axis around the time axis the projected x value onto the original non-roatated x-axis is shorter. That is not a physical or material effect. When you said that the atoms get closer together that's is a physical or material effect. > > > If > > material length contraction occur how come from the pole frame point > > of view there is no material length contraction > > There is a unity projection from pole frame to pole frame .. so no change as > a result So from the pole point of view the pole is not able to fit into the barn physically or materially. And at the same time the barn frame observer insisted that the material pole is able to fit into the barn materially or physically. That sound like a contradiction to me. > > > and thus it is not > > able to fit into the barn? > > It fits in the barn in the barn frame at some time in the barn frame. I am afraid that you don't understand SR. SR only claim that the projected length (not the material length or physical length) is able to fit into the barn frame. >There > is no time in the pole frame where that is true. That is due to the > differences in time in those two frames Right the material length is not able to fit into the material barn. Your problem is that you want length contraction to be material or physical instead of accepting the new SR interpretation that length contract is not material or physical. > > > Do you realize that material length > > contraction is frame independent? > > Depends on what you mean by 'length'. What is your definition of the length > of a rod? Length of a meter stick is its physical or material length. There is no physical or material length contraction in my theory. The observer assumes that the light path length of his meter stick is its physical length (1 meter long). He uses this assumed standard and the IRT equations to predict the light path length for a meter stick moving wrt him to be: 1/gamma or (gamma) meters long. The reason for the two prediction is that the observer does not know if the moving stick has a higher or lower light path length. My theory is described in the following link: http://www.modelmechanics.org/2008irt.dtg.pdf Ken Seto
From: BURT on 16 Feb 2010 23:31
On Feb 16, 7:49 pm, BURT <macromi...(a)yahoo.com> wrote: > On Feb 16, 7:22 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > > On Feb 16, 9:26 pm, "Peter Webb" > > > <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > > > > > __________________________________ > > > > > My tabletop is not in a spaceship, and there is no train on the > > > > > spaceship. > > > > > > Here is my question. Lets just take the first half this time: > > > > > > 1. We place two atomic clocks on a tabletop at the centre of a 1 metre > > > > > ruler. We separate them very slowly so they are at either end of the one > > > > > metre ruler. We record the time taken (according to the clocks) for > > > > > light > > > > > to > > > > > travel 1 metre in a vacuum. Will the speed of light measured in this > > > > > manner > > > > > be c or some other value? > > > > > Is the aether at rest with respect to the table top? > > > > > _________________________________ > > > > No. The tabletop is moving at speed of v relative to the ether. > > > > The the tabletop is the train. > > > > __________________________________ > > > No, a tabletop is a tabletop. Its not a train. And you haven't answered my > > > question. Will the speed of light measured in this manner be c or some other > > > value? It is a pretty simple question. Why won't you answer it? > > > How is the tabletop able to move at 'v' with respect to the aether? > > > It's on a train.- Hide quoted text - > > > - Show quoted text - > > Nothing shrinks. There are no flat atoms. The aether is stationary for > space but flows for energy.. > > Mitch Raemsch- Hide quoted text - > > - Show quoted text - Light comes goes in and out of matter while time is flowing. Light order must them be associated with the flow of time. |