Simultaneity of Relativity
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From: PD on 9 Oct 2009 16:21 On Oct 9, 2:33 pm, mpc755 <mpc...(a)gmail.com> wrote: > On Oct 9, 3:26 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Oct 9, 2:04 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > On Oct 9, 2:38 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Oct 9, 12:26 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > > > > That's just it. Whether they are simultaneous or not depends on the > > > > > > > > signals they actually receive at their locations. That is, the > > > > > > > > observers M and M' are not AT the locations A, A', B, B'. They are at > > > > > > > > the places marked M and M'. What they know is what happens where they > > > > > > > > are, and THAT tells them what happens at A, A', B, and B'. They have > > > > > > > > no other way of knowing. > > > > > > > > There are observers at A, A', B and B' and they all have clickers and > > > > > > > they all click their clickers when the pebbles hit the water. It is > > > > > > > determined all four observers hit their clickers at the same time. > > > > > > > How is it determined that they hit their clickers at the same time? > > > > > > What procedure would you need to ensure that? > > > > > > I want you to think about this very carefully... > > > > > > There are observer as close to each contact point between the pebble > > > > > and the water as possible. The length of wire from the clicker to the > > > > > clicker response unit is the same for all observers. > > > > > And the speed of the signal is the same through the wire in both > > > > cases. > > > > > So if the speed in the wire is the same, and the length of the wire is > > > > the same, then you know that the time propagation through the wires > > > > would be the same, right? > > > > > And if this is the case, then you know the following: > > > > 1. If the clicker response unit records signals from the clickers at > > > > the same time, THEN you know that the pebbles landed at the same time. > > > > 2. If the clicker response unit records signals from the clickers at > > > > different times, THEN you know that the pebbles landed at different > > > > times. > > > > > Right? This is how you determine from the clicker and clicker response > > > > system whether the pebbles really landed at the same time or not. > > > > > OK, so here's the situation with the lightning strikes: > > > > You've got ONE lightning strike at one end of the train, and ONE > > > > lightning strike at the other end of the train. > > > > The path length (just like the wire length) from one lightning strike > > > > to the observer M is the same as the path length from the other > > > > lightning strike to the observer M. Equal path lengths, just like > > > > equal wire lengths. > > > > The path length (just like the wire length) from one lightning strike > > > > to the observer M' is the same as the path length from the other > > > > lightning strike to the observer M'. Equal path lengths, just like > > > > equal wire lengths. > > > > And you know the speed of the signal from one lightning strike to M is > > > > the same as the speed of the signal from the other lightning strike to > > > > M. > > > > And you know the speed of the signal from one lightning strike to M' > > > > is the same as the speed of the signal from the other lightning strike > > > > to M'. > > > > > The problem is, in experiment, M says he received the signals at the > > > > same time (clicker case (1)), and M' says he received the signals at > > > > different times (clicker case (2)). > > > > Just like there are four observers at A, A', B, and B' > > > There aren't four observers at A, A', B and B'. > > Read it again! > > You asked me how the pebbles dropped at A, A', B, and B' could be > determined to be simultaneous and I explained how with four observers, > one at each pebble drop. That's fine, but you can also do with the two observers M and M' just as we described. That's all we need. And I've told you what is experimentally observed. > > > > the lightning > > > strikes occur at 4 points. > > > Wow! One lightning strike strikes in two places at once! > > LOL!! > > Yes. When it leaves a mark on the train and on the embankment. This is > two different places. LOL! You are a goofball of large proportions indeed. You can't see that a lightning bolt that strikes at the ONE place where the train and the track meet will leave a mark on both? Do you not even understand what you are reading when you read Einstein's gedanken? > > > > When the light from the lightning strikes > > > reach M and M' are dependent on the medium the light travels through. > > > Especially when it's ONE medium! > > > You're a hoot, you are! > > Water is one medium, but if it is on the train and stationary relative > to the train and water is on the embankment stationary relative to the > embankment, Now, now. How can ONE body of water be stationary relative both to the embankment and the train? Is a lake stationary relative to both the boat and to the shore? Really, are you TRYING to look stupid? > pebbles dropped at A, A', B, and B' will have their > associated waves from A and B reach M and from A' and B' reach M' > simultaneously. > > > > > > > > If the clicks are > > > > > determined to be simultaneous at the clicker response unit, then the > > > > > pebbles each hit the water simultaneously. > >
From: PD on 9 Oct 2009 16:29 On Oct 9, 2:47 pm, mpc755 <mpc...(a)gmail.com> wrote: > On Oct 9, 3:33 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > On Oct 9, 3:26 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > On Oct 9, 2:04 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > On Oct 9, 2:38 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > On Oct 9, 12:26 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > > > > > That's just it. Whether they are simultaneous or not depends on the > > > > > > > > > signals they actually receive at their locations. That is, the > > > > > > > > > observers M and M' are not AT the locations A, A', B, B'. They are at > > > > > > > > > the places marked M and M'. What they know is what happens where they > > > > > > > > > are, and THAT tells them what happens at A, A', B, and B'.. They have > > > > > > > > > no other way of knowing. > > > > > > > > > There are observers at A, A', B and B' and they all have clickers and > > > > > > > > they all click their clickers when the pebbles hit the water. It is > > > > > > > > determined all four observers hit their clickers at the same time. > > > > > > > > How is it determined that they hit their clickers at the same time? > > > > > > > What procedure would you need to ensure that? > > > > > > > I want you to think about this very carefully... > > > > > > > There are observer as close to each contact point between the pebble > > > > > > and the water as possible. The length of wire from the clicker to the > > > > > > clicker response unit is the same for all observers. > > > > > > And the speed of the signal is the same through the wire in both > > > > > cases. > > > > > > So if the speed in the wire is the same, and the length of the wire is > > > > > the same, then you know that the time propagation through the wires > > > > > would be the same, right? > > > > > > And if this is the case, then you know the following: > > > > > 1. If the clicker response unit records signals from the clickers at > > > > > the same time, THEN you know that the pebbles landed at the same time. > > > > > 2. If the clicker response unit records signals from the clickers at > > > > > different times, THEN you know that the pebbles landed at different > > > > > times. > > > > > > Right? This is how you determine from the clicker and clicker response > > > > > system whether the pebbles really landed at the same time or not. > > > > > > OK, so here's the situation with the lightning strikes: > > > > > You've got ONE lightning strike at one end of the train, and ONE > > > > > lightning strike at the other end of the train. > > > > > The path length (just like the wire length) from one lightning strike > > > > > to the observer M is the same as the path length from the other > > > > > lightning strike to the observer M. Equal path lengths, just like > > > > > equal wire lengths. > > > > > The path length (just like the wire length) from one lightning strike > > > > > to the observer M' is the same as the path length from the other > > > > > lightning strike to the observer M'. Equal path lengths, just like > > > > > equal wire lengths. > > > > > And you know the speed of the signal from one lightning strike to M is > > > > > the same as the speed of the signal from the other lightning strike to > > > > > M. > > > > > And you know the speed of the signal from one lightning strike to M' > > > > > is the same as the speed of the signal from the other lightning strike > > > > > to M'. > > > > > > The problem is, in experiment, M says he received the signals at the > > > > > same time (clicker case (1)), and M' says he received the signals at > > > > > different times (clicker case (2)). > > > > > Just like there are four observers at A, A', B, and B' > > > > There aren't four observers at A, A', B and B'. > > > Read it again! > > > You asked me how the pebbles dropped at A, A', B, and B' could be > > determined to be simultaneous and I explained how with four observers, > > one at each pebble drop. > > > > > the lightning > > > > strikes occur at 4 points. > > > > Wow! One lightning strike strikes in two places at once! > > > LOL!! > > > Yes. When it leaves a mark on the train and on the embankment. This is > > two different places. > > > > > When the light from the lightning strikes > > > > reach M and M' are dependent on the medium the light travels through. > > > > Especially when it's ONE medium! > > > > You're a hoot, you are! > > > Water is one medium, but if it is on the train and stationary relative > > to the train and water is on the embankment stationary relative to the > > embankment, pebbles dropped at A, A', B, and B' will have their > > associated waves from A and B reach M and from A' and B' reach M' > > simultaneously. > > Let's see if we can find any common ground. Forget Einstein's Train > Thought Experiment for a second. Nah, that's was the whole point. You were trying to explain what relativity says would happen in the train gedanken and what you say would happen instead. Now you don't want to talk about the train gedanken at all, not to mention what's measured in real experiments that are related to it, using real light. > > We have an embankment that is knee deep in water. The water on the > embankment is stationary relative to the embankment. We have an > enclosed train that is need deep in water. The water on the train is > stationary relative to the train. > > Four pebbles are dropped at A and B on the embankment and A' and B' on > the train. A and B are equi-distant from M and A' and B' are equi- > distant from M'. The distance from A and B to M is the same distance > as A' and B' are to M'. > > The pebbles are dropped simultaneously at A and A'. > > The pebbles are dropped simultaneously at B and B'. > > If the waves from A and B reach M simultaneously, then the waves from > A' and B' reach M' simultaneously.
From: mpc755 on 9 Oct 2009 17:13 On Oct 9, 4:29 pm, PD <thedraperfam...(a)gmail.com> wrote: > On Oct 9, 2:47 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > On Oct 9, 3:33 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > On Oct 9, 3:26 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Oct 9, 2:04 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > On Oct 9, 2:38 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > On Oct 9, 12:26 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > > > > > > That's just it. Whether they are simultaneous or not depends on the > > > > > > > > > > signals they actually receive at their locations. That is, the > > > > > > > > > > observers M and M' are not AT the locations A, A', B, B'. They are at > > > > > > > > > > the places marked M and M'. What they know is what happens where they > > > > > > > > > > are, and THAT tells them what happens at A, A', B, and B'. They have > > > > > > > > > > no other way of knowing. > > > > > > > > > > There are observers at A, A', B and B' and they all have clickers and > > > > > > > > > they all click their clickers when the pebbles hit the water. It is > > > > > > > > > determined all four observers hit their clickers at the same time. > > > > > > > > > How is it determined that they hit their clickers at the same time? > > > > > > > > What procedure would you need to ensure that? > > > > > > > > I want you to think about this very carefully... > > > > > > > > There are observer as close to each contact point between the pebble > > > > > > > and the water as possible. The length of wire from the clicker to the > > > > > > > clicker response unit is the same for all observers. > > > > > > > And the speed of the signal is the same through the wire in both > > > > > > cases. > > > > > > > So if the speed in the wire is the same, and the length of the wire is > > > > > > the same, then you know that the time propagation through the wires > > > > > > would be the same, right? > > > > > > > And if this is the case, then you know the following: > > > > > > 1. If the clicker response unit records signals from the clickers at > > > > > > the same time, THEN you know that the pebbles landed at the same time. > > > > > > 2. If the clicker response unit records signals from the clickers at > > > > > > different times, THEN you know that the pebbles landed at different > > > > > > times. > > > > > > > Right? This is how you determine from the clicker and clicker response > > > > > > system whether the pebbles really landed at the same time or not. > > > > > > > OK, so here's the situation with the lightning strikes: > > > > > > You've got ONE lightning strike at one end of the train, and ONE > > > > > > lightning strike at the other end of the train. > > > > > > The path length (just like the wire length) from one lightning strike > > > > > > to the observer M is the same as the path length from the other > > > > > > lightning strike to the observer M. Equal path lengths, just like > > > > > > equal wire lengths. > > > > > > The path length (just like the wire length) from one lightning strike > > > > > > to the observer M' is the same as the path length from the other > > > > > > lightning strike to the observer M'. Equal path lengths, just like > > > > > > equal wire lengths. > > > > > > And you know the speed of the signal from one lightning strike to M is > > > > > > the same as the speed of the signal from the other lightning strike to > > > > > > M. > > > > > > And you know the speed of the signal from one lightning strike to M' > > > > > > is the same as the speed of the signal from the other lightning strike > > > > > > to M'. > > > > > > > The problem is, in experiment, M says he received the signals at the > > > > > > same time (clicker case (1)), and M' says he received the signals at > > > > > > different times (clicker case (2)). > > > > > > Just like there are four observers at A, A', B, and B' > > > > > There aren't four observers at A, A', B and B'. > > > > Read it again! > > > > You asked me how the pebbles dropped at A, A', B, and B' could be > > > determined to be simultaneous and I explained how with four observers, > > > one at each pebble drop. > > > > > > the lightning > > > > > strikes occur at 4 points. > > > > > Wow! One lightning strike strikes in two places at once! > > > > LOL!! > > > > Yes. When it leaves a mark on the train and on the embankment. This is > > > two different places. > > > > > > When the light from the lightning strikes > > > > > reach M and M' are dependent on the medium the light travels through. > > > > > Especially when it's ONE medium! > > > > > You're a hoot, you are! > > > > Water is one medium, but if it is on the train and stationary relative > > > to the train and water is on the embankment stationary relative to the > > > embankment, pebbles dropped at A, A', B, and B' will have their > > > associated waves from A and B reach M and from A' and B' reach M' > > > simultaneously. > > > Let's see if we can find any common ground. Forget Einstein's Train > > Thought Experiment for a second. > > Nah, that's was the whole point. You were trying to explain what > relativity says would happen in the train gedanken and what you say > would happen instead. > > Now you don't want to talk about the train gedanken at all, not to > mention what's measured in real experiments that are related to it, > using real light. > > > > > We have an embankment that is knee deep in water. The water on the > > embankment is stationary relative to the embankment. We have an > > enclosed train that is need deep in water. The water on the train is > > stationary relative to the train. > > > Four pebbles are dropped at A and B on the embankment and A' and B' on > > the train. A and B are equi-distant from M and A' and B' are equi- > > distant from M'. The distance from A and B to M is the same distance > > as A' and B' are to M'. > > > The pebbles are dropped simultaneously at A and A'. > > > The pebbles are dropped simultaneously at B and B'. > > > If the waves from A and B reach M simultaneously, then the waves from > > A' and B' reach M' simultaneously. > > I'm just pointing out to you what happens if the medium the wave travels through on the embankment is stationary relative to the embankment and the medium the wave travels through on the train is stationary relative to the train. It's an analogy. And if you then take the analogy of a pebble in water and you modify the analogy to be light traveling through water you will come to the same conclusion. If the light waves from A and B reach M simultaneously then the light waves from A' and B' reach M' simultaneously. You then change the medium to be aether instead of water and the same conclusion holds true. If the light waves from A and B reach M simultaneously then the light waves from A' and B' reach M' simultaneously.
From: PD on 9 Oct 2009 17:54 On Oct 9, 4:13 pm, mpc755 <mpc...(a)gmail.com> wrote: > On Oct 9, 4:29 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Oct 9, 2:47 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > On Oct 9, 3:33 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > On Oct 9, 3:26 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > On Oct 9, 2:04 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > > On Oct 9, 2:38 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > > On Oct 9, 12:26 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > > > > > > > That's just it. Whether they are simultaneous or not depends on the > > > > > > > > > > > signals they actually receive at their locations. That is, the > > > > > > > > > > > observers M and M' are not AT the locations A, A', B, B'. They are at > > > > > > > > > > > the places marked M and M'. What they know is what happens where they > > > > > > > > > > > are, and THAT tells them what happens at A, A', B, and B'. They have > > > > > > > > > > > no other way of knowing. > > > > > > > > > > > There are observers at A, A', B and B' and they all have clickers and > > > > > > > > > > they all click their clickers when the pebbles hit the water. It is > > > > > > > > > > determined all four observers hit their clickers at the same time. > > > > > > > > > > How is it determined that they hit their clickers at the same time? > > > > > > > > > What procedure would you need to ensure that? > > > > > > > > > I want you to think about this very carefully... > > > > > > > > > There are observer as close to each contact point between the pebble > > > > > > > > and the water as possible. The length of wire from the clicker to the > > > > > > > > clicker response unit is the same for all observers. > > > > > > > > And the speed of the signal is the same through the wire in both > > > > > > > cases. > > > > > > > > So if the speed in the wire is the same, and the length of the wire is > > > > > > > the same, then you know that the time propagation through the wires > > > > > > > would be the same, right? > > > > > > > > And if this is the case, then you know the following: > > > > > > > 1. If the clicker response unit records signals from the clickers at > > > > > > > the same time, THEN you know that the pebbles landed at the same time. > > > > > > > 2. If the clicker response unit records signals from the clickers at > > > > > > > different times, THEN you know that the pebbles landed at different > > > > > > > times. > > > > > > > > Right? This is how you determine from the clicker and clicker response > > > > > > > system whether the pebbles really landed at the same time or not. > > > > > > > > OK, so here's the situation with the lightning strikes: > > > > > > > You've got ONE lightning strike at one end of the train, and ONE > > > > > > > lightning strike at the other end of the train. > > > > > > > The path length (just like the wire length) from one lightning strike > > > > > > > to the observer M is the same as the path length from the other > > > > > > > lightning strike to the observer M. Equal path lengths, just like > > > > > > > equal wire lengths. > > > > > > > The path length (just like the wire length) from one lightning strike > > > > > > > to the observer M' is the same as the path length from the other > > > > > > > lightning strike to the observer M'. Equal path lengths, just like > > > > > > > equal wire lengths. > > > > > > > And you know the speed of the signal from one lightning strike to M is > > > > > > > the same as the speed of the signal from the other lightning strike to > > > > > > > M. > > > > > > > And you know the speed of the signal from one lightning strike to M' > > > > > > > is the same as the speed of the signal from the other lightning strike > > > > > > > to M'. > > > > > > > > The problem is, in experiment, M says he received the signals at the > > > > > > > same time (clicker case (1)), and M' says he received the signals at > > > > > > > different times (clicker case (2)). > > > > > > > Just like there are four observers at A, A', B, and B' > > > > > > There aren't four observers at A, A', B and B'. > > > > > Read it again! > > > > > You asked me how the pebbles dropped at A, A', B, and B' could be > > > > determined to be simultaneous and I explained how with four observers, > > > > one at each pebble drop. > > > > > > > the lightning > > > > > > strikes occur at 4 points. > > > > > > Wow! One lightning strike strikes in two places at once! > > > > > LOL!! > > > > > Yes. When it leaves a mark on the train and on the embankment. This is > > > > two different places. > > > > > > > When the light from the lightning strikes > > > > > > reach M and M' are dependent on the medium the light travels through. > > > > > > Especially when it's ONE medium! > > > > > > You're a hoot, you are! > > > > > Water is one medium, but if it is on the train and stationary relative > > > > to the train and water is on the embankment stationary relative to the > > > > embankment, pebbles dropped at A, A', B, and B' will have their > > > > associated waves from A and B reach M and from A' and B' reach M' > > > > simultaneously. > > > > Let's see if we can find any common ground. Forget Einstein's Train > > > Thought Experiment for a second. > > > Nah, that's was the whole point. You were trying to explain what > > relativity says would happen in the train gedanken and what you say > > would happen instead. > > > Now you don't want to talk about the train gedanken at all, not to > > mention what's measured in real experiments that are related to it, > > using real light. > > > > We have an embankment that is knee deep in water. The water on the > > > embankment is stationary relative to the embankment. We have an > > > enclosed train that is need deep in water. The water on the train is > > > stationary relative to the train. > > > > Four pebbles are dropped at A and B on the embankment and A' and B' on > > > the train. A and B are equi-distant from M and A' and B' are equi- > > > distant from M'. The distance from A and B to M is the same distance > > > as A' and B' are to M'. > > > > The pebbles are dropped simultaneously at A and A'. > > > > The pebbles are dropped simultaneously at B and B'. > > > > If the waves from A and B reach M simultaneously, then the waves from > > > A' and B' reach M' simultaneously. > > I'm just pointing out to you what happens if the medium the wave > travels through on the embankment is stationary relative to the > embankment and the medium the wave travels through on the train is > stationary relative to the train. It's an analogy. > > And if you then take the analogy of a pebble in water and you modify > the analogy to be light traveling through water you will come to the > same conclusion. > > If the light waves from A and B reach M simultaneously then the light > waves from A' and B' reach M' simultaneously. > > You then change the medium to be aether instead of water and the same > conclusion holds true. > > If the light waves from A and B reach M simultaneously then the light > waves from A' and B' reach M' simultaneously. As I said in the beginning, the train gedanken was designed to explain relativity to people who have a hard time understanding it. It makes a certain class of predictions that can be tested in equivalent experiments. Those predictions match what is actually observed. You have a scenario that has nothing to do with the train gedanken, involving two tanks of water slipping past each other with pebbles dropped in them in four different places. This doesn't make any predictions, as far as I can tell, about what would be measured with light. If you think it does, and it makes predictions other than what relativity says, then I'm afraid the experiments have already ruled your model out. PD
From: PD on 9 Oct 2009 18:14
On Oct 8, 11:49 am, mpc755 <mpc...(a)gmail.com> wrote: > If the aether is stationary relative to the embankment and stationary > relative to the train, this is what will occur in Einstein's train > thought experiment: > > http://www.youtube.com/watch?v=jyWTaXMElUk I think the end result of this discussion, MPC, is that you've never understood what's being said in the Einstein train gedanken. At this point, it might have been effective for you to say, "I guess I don't understand what Einstein was trying to say. Is there anyone that is willing to walk through it with me to explain to me what it's saying?" For some people this is emotionally difficult to do. One recourse for such people is to pretend that they understand what they do not, and to try to invent something they can at least call their own, because they do understand what they invent for themselves. The problem is, this has nothing to do with science, where the value of an idea is determined by how nature really acts, not how intuitive it is in our heads. The right steps are to ask the following: 1. "What is this relativity theory, exactly, and what does it say?" 2. "OK, now that I understand what it claims, what makes you think it's right?" 3. "If there are other claims that have been put forward that are different, how do you know that any of those are not right?" PD |