Re: IRT: A New Theory of Relativity

From: Jesse Mazer (vze2ztqw_at_mail.verizon.net)
Date: 02/01/05 

Date: Tue, 01 Feb 2005 22:39:20 GMT

kenseto wrote:

>"Jesse Mazer" <vze2ztqw@mail.verizon.net> wrote in message
>news:41FC2F54.80901@mail.verizon.net...
>
>
>>kenseto wrote:
>>
>>>>Lorentz may have formulated them this way, but Einstein showed that if
>>>>each observer measures coordinates in terms of rulers and clocks at rest
>>>>relative to himself, and each observer synchronizes his own set of
>>>>clocks based on the assumption that light travels at the same speed in
>>>>all directions in his own frame, then the Lorentz transformation will
>>>>work for *any* two frames, regardless of their velocity relative to the
>>>>ether (which renders the ether superfluous).
>>>>
>>>>
>>>>
>>>>
>>>Einstein also made the same assumption as Lorentz. Otherwise SR wouldn't
>>>
>>>
>say
>
>
>>>that the observer sees all clocks moving wrt to him are running at a
>>>
>>>
>slower
>
>
>>>rate compared to his clock. And that the observer sees all rods moving
>>>
>>>
>wrt
>
>
>>>to him are contracted (this is the same as they have longer light path
>>>lengths).
>>>
>>>
>>>
>>You're wrong. SR does say that *every* inertial observer measures rulers
>>in motion relative to himself to shrink, and measures clocks in motion
>>relative to himself to slow down.
>>
>>
>
>So why I am wrong? You are saying the same thing.
>

No, you are saying that Einstein assumed the observer using the Lorentz
transformations was in a state of rest relative to the ether, I am
saying you are wrong, in SR the Lorentz transformation will work for
transforming between *any* two inertial coordinate systems, even if you
assume both are in motion relative to the ether, or if you are
transforming from the coordinates of an observer in motion relative to
the ether into the coordinates of one at rest relative to the ether.

>
>
>
>>It works out this way because
>>different observers define simultaneity differently.
>>
>>
>
>IRT disagrees with this assertion. This assertion violates the isotropy of
>the speed of light in all inertial frames.
>

No it doesn't. The relativity of simultaneity is based on the assumption
that each observer synchronizes his clocks by assuming light moves the
same speed in all directions in his own frame. If you actually try
plugging numbers into the Lorentz transformation, you'd see that if the
distance/time between two events in one frame is c, then it must also be
c in the other frame, regardless of the spatial positions of the two events.

For example, suppose that in frame A a supernova goes off at position
x=0 light years at time t=0 years, and that light from the nova is
detected by two telescopes--the first is at position x = 1 ly and it
detects the light at time t=1 y, and the second is at position x= -1 ly
and it also detects the light at time t=1 y. You can see that in A's
frame the light moved at a rate of c = 1 ly/y in both directions. So how
will this look in the frame of an observer B moving at v=0.6c relative
to A? The Lorentz transformation equations are:

x'=gamma(x - vt)
t'=gamma(t - vx/c^2)

where gamma = 1/squareroot(1 - v^2/c^2). So, plugging these numbers in:

x=0, t=0 in A's frame converts to x'=0, t'=0 in B's frame.

x=1, t=1 in A's frame converts to x'=1.25(1 - 0.6*1)=0.5, t'=1.25(1 -
0.6*1/1) = 0.5 in B's frame

x=-1, t=1 in A's frame converts to x'=1.25(-1 - 0.6*1)=-2, t'=1.25(1 +
0.6*1/1) = 2 in B's frame.

So in B's frame, the light beam moving right took 0.5 years to reach the
telescope on the right, which was 0.5 light years from the origin of B's
coordinate system at that moment; the light beam moving left took 2
years to reach the telescope on the left, which was 2 light years from
the origin of B's coordinate system at that moment. So, B also saw the
light travelling at a rate of 1 light year/year in both directions,
despite the fact that he did not agree with A that the light beams
reached both telescopes simultaneously.

>
>
>
>>Again, just look at
>>the diagrams of the two ruler/clock systems moving in parallel that I
>>
>>
>made:
>
>
>>http://www.jessemazer.com/images/RulerAFrame.gif
>>http://www.jessemazer.com/images/RulerBFrame.gif
>>
>>
>
>These diagrams assumes rod contraction and time dilation in the moving syate
>m. Clearly this is not correct if the observer who is doing the moving and
>the observed relative motion is due to the observer's motions.
>

No they don't assume that, they can be used to *prove* that. Let's say A
is in a state of absolute rest and B is in a state of absolute motion,
OK? Then if the distance between markings on B's ruler shrinks by 1/2,
and the ticks of B's clocks slow down by 1/2, and B synchronizes his
clocks by assuming light moves at the same speed in both directions in
his frame, then do you agree that
http://www.jessemazer.com/images/RulerAFrame.gif shows which ruler
markings on B will line up with which markings on A at any given time in
A's frame, and what the clock on B's ruler at that marking will read at
the moment they line up?

If so, you can draw the diagram for how things look in B's frame just by
assuming he must get the same answers about what positions/clock
readings on his ruler match up with what positions/clock readings on A's
ruler. For example, if you look at the middle part of the diagram in A's
frame, you see that when the clock at the 0-meter mark on ruler A reads
"1 microsecond", it is lined up with the -519.3-meter mark on ruler B,
and the clock at that mark on ruler B reads "2 microseconds". So do you
agree that when we switch to ruler B's frame, this *must* mean that at a
time of 2 microseconds in B's time coordinate, the -519.3-meter mark on
his ruler must be lined up with the 0-meter mark on ruler A, and the
clock at that mark on ruler A *must* read "1 microsecond"? The only
assumption here is that B defines his own time-coordinate by readints on
his own clocks, and that both frames must agree on local events (ie if a
photo is taken of a particular mark on one ruler passing a particular
mark on another, they can both look at the photo and agree on what the
clock mounted on that mark read at that moment). Just by looking at what
markings/clock readings line up in A's frame, you can construct the
diagram at http://www.jessemazer.com/images/RulerAFrame.gif of what
things look like in B's frame, without making any additional assumptions.

> So what is
>your point? IRT says a rod moving wrt the observer is contracted (or a
>longer light path length) but it also says that a rod moving wrt the
>observer is expanded (or shorter light path length).
>IRT says a cl*** moving wrt the observer is running slower than the
>observer's clock but it also says that a clock moving wrt the observer is
>running fast compared to the observer's clock.
>
>
>>Do you agree that in the first diagram corresponding to ruler A's
>>reference frame, all of ruler B's clocks are ticking at half the correct
>>rate and all the markings on ruler B are squished to half the correct
>>length?
>>
>>
>
>You already assumed this when you make the iagrams so what is your point?
>

No, all I assumed is that if an observer in the A-frame sees a
particular clock of his line up with a particular clock on ruler B at a
particular moment, then whatever the readings on these two clocks as
they pass next to each other, then these same two clocks must also show
the same readings as they pass each other in the B-frame. Do you
disagree with that assumption? Or do you agree with it, but disagree
that http://www.jessemazer.com/images/RulerAFrame.gif shows how things
will line up in the A-frame, even if you assume A is a state of absolute
rest?

>
>
>
>>Do you also agree that in the second diagram corresponding to
>>ruler B's reference frame, all of ruler A's clocks are ticking at half
>>the correct rate and all the markings on ruler A are squished to half
>>the correct length? Do you agree that the way the readings on one
>>ruler/clock system match up to the readings on the other ruler/clock
>>system in these diagrams matches the predictions of the Lorentz transform?
>>
>>
>
>Sure it matches the LT but it is incomplete. Why ? becasue it excludes the
>possibility that it was the observer who is at a higher state of absolute
>motion than the observed frame.
>

Nope, the LT works even if you believe in a state of absolute rest
defined by the ether rest frame, and even if neither observer is at rest
relative to the ether, or even if you want to transform *from* the
coordinates of an observer in motion relative to the ether *to* the
coordinates of one at rest relative to the ether. The only assumptions
needed are:

1. Rulers moving at velocity v relative to the ether shrink by
squareroot(1 - v^2/c^2), and clocks moving at velocity v relative to the
ether extend their ticks by a factor of 1/squareroot(1 - v^2/c^2).

2. In the rest frame of the ether, light travels at c in all directions.

3. All observers, even those in motion relative to the ether,
synchronize spatially separated clocks using the assumption that light
travels at the same speed in all directions *relative to themselves*.

4. Each observer defines their coordinate system in terms of local
readings on a network of rulers and clocks which are at rest relative to
themselves, and with the clocks synchronized using assumption #3

5. observers in different frames must agree on local events, like the
readings on each of their clocks when the two clocks pass right next to
each other.

If all these assumptions hold, you can prove absolutely that the LT will
accurately convert between the coordinate systems of *any* two
observers, regardless of how each one is moving relative to the ether.
Do you need me to show you this proof, or do you accept that this does
follow from these assumptions, but you just disagree with one or more of
the assumptions?

>
>
>>
>>
>>
>>>
>>>Yes. But PoR is valid only because a clock second will have different
>>>universal time content in different state of absolute motion and that the
>>>speed of light is a constant math ratio in all frames as follows:
>>>Light path length of rod (299,792,458m)/the universal time contant for a
>>>clock second co-moving with the rod.
>>>
>>>
>>>
>>I'm asking about how the PoR works in SR, not in your theory. Do you
>>agree that the coordinate system assumed in the Lorentz transformation
>>in SR is not based on "light path length",
>>
>>
>
>It is based on light path length. Why? Because rod contraction is the same
>as longer light path length with the rod remaining at the same physical
>length.
>
>
>
>>but just based on the
>>measurements of rulers and clocks at rest with respect to each observer,
>>with each observer synchronizing his clocks by making the assumption
>>that light travels at the same speed in both directions relative to
>>
>>
>himself?
>
>I don't understand why an observer need to synchronized any clcoks at all.
>All he need is one cl*** to make time interval measurements.
>

Because the point of an observer's own time-coordinate is to label the
moment the event actually happened, not the moment I saw the event. If I
only have one clock, I can only use that clock to find the time I
actually saw light from an event, not the time the event actually
happened. Of course, if I know the distance the event was when it
happened (as measured by a ruler at rest relative to me), I can
*calculate* the time the event happened by dividing this distance by the
speed of light, then subtracting the resulting time interval from the
time when I saw the light from the event. But if I have a network of
synchronized clocks throughout space, I don't need to do any
calculations, I can just look at the reading on the clock of mine which
was right next to the event at the moment it happened. In a way it
doesn't matter which method I use, because both methods will result in
my assigning the same time-coordinate to the event--if you agree that
they both give the same answer, are you willing to assume *for the sake
of the argument* that we use the synchronized-clock method rather than
the (time I saw event) - (distance of event when it happened)/c
calculation?

>
>
>>
>>
>>
>>>
>>>
>>>>How would it invalidate it? If A sees B's clocks running slow, then by
>>>>definition their intrinsic rate cannot be the same.
>>>>
>>>>
>>>>
>>>>
>>>If A sees B's clock is running slow then B cannot see A's cl*** is
>>>
>>>
>running
>
>
>>>slow unless they are running at the same intrsic rate and that what they
>>>
>>>
>see
>
>
>>>is an option illusion.
>>>
>>>
>>>
>>No, the reason both see the other's clocks running slow is that they
>>have different definitions of simultaneity.
>>
>>
>
>In IRT all observers have the same definition of simultaneity. In other
>words simultaneity is absolute but simultaneity for two identical events in
>different frames will occur at a different time interval. Although RoS
>reaches the same end conclusion as IRT but RoS violates the isotropy of the
>speed of light.
>

No it doesn't, see above.

>
>
>
>>Again, look at the diagrams
>>I drew above to see how this works out. For example, in the diagram
>>showing ruler A's frame at
>>http://www.jessemazer.com/images/RulerAFrame.gif , look at the clock on
>>the "-346.2 m" mark on ruler B. You can see that in the top part of the
>>diagram, this clock reads a time t'=1 microsecond and is lined up with a
>>clock on ruler A reading t=0 microseconds; then in the bottom part of
>>the diagram, this clock reads a time of t'=2 microseconds and it's lined
>>up with a clock on ruler A reading t=2 microseconds. So in ruler A's
>>frame, this clock has only ticked forward 1 microsecond while 2
>>microseconds have actually passed according to A's time-coordinates.
>>
>>
>
>All this means is that a micro second in A's frame does not correspond to a
>microsecond in B's frame. However, in terms of absolute time content
>1 microsecond in B's frame=2 microseconds in A's frame.
>

Only if you assume A is in a state of absolute rest! If you assume it is
B who is in a state of absolute rest, then 1 microsecond in B's frame =
1/2 microsecond in A's frame, in terms of absolute time. But either way,
both A and B will *measure* the other one's clock to be ticking at half
the rate of their own clock, even if you believe one of them is making
"inaccurate" measurements in terms of absolute space and time. Again,
this follows from the 5 assumptions I outlined earlier.

>
>
>>But now look at the same situation in ruler B's frame, in the diagram at
>>http://www.jessemazer.com/images/RulerBFrame.gif ...if you look at the
>>same clock on ruler B at "-346.2 m" in the middle and bottom part of the
>>diagram, you again see that when this clock reads t'=1 microsecond, it's
>>lined up with a clock on ruler A that reads t=0 microseconds (the one at
>>the -173.1 m mark on ruler A) and when this clock reads t'=2
>>microseconds, it's lined up with a clock on ruler A that reads t=2
>>microseconds (the one at the 346.2 m mark on ruler A). However, from B's
>>point of view this isn't because the clocks on ruler A are ticking
>>faster, it's just because the clocks on ruler A are out-of-sync--in B's
>>frame, the clock at the 346.2 m mark on ruler A is consistently 0.5
>>microseconds ahead of the clock at the -173.1 m mark on ruler A (look at
>>the top part of the diagram, for example). If you follow each of these
>>clocks from one moment to the next in B's frame, you see that
>>individually they do tick at half the rate of B's clocks, not twice the
>>rate.
>>
>>
>
>All these imaginary situations is pointless. If an observer wants to predict
>the rate of a clock or the length of a rod moving wrt him he uses the LT or
>IRT. The LT is incomplete because it assumes that the observer is at
>absolute rest.
>

Nope, it doesn't. Again, if the 5 assumptions I outlined earlier hold
up, then the LT will work for transforming between the measurements of
any two observers, regardless of their absolute motion.

>>
>>
>>>
>>>
>>>>supernova in 2005 that is 100 light-years away according to rulers at
>>>>rest in my frame, then *if* I assume light travels at the same speed in
>>>>all directions I can say the supernova took place in 1905 according to
>>>>my time-coordinates...but other observers won't agree that light travels
>>>>at the same speed in all directions relative to me in their frame (they
>>>>will see the distance between me and a light beam shrinking faster if I
>>>>am moving towards the source rather than away from it).
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>>>So having a
>>>>series of clocks removes this disagreement between observers, since all
>>>>observers will agree that the clock on my ruler that was next to the
>>>>supernova when it occurred read "1905". Of course, this just leads to a
>>>>different form of disagreement, since other observers won't agree that
>>>>my clock at the location of the supernova is in sync with my clock at my
>>>>own location, but at least it makes the physical meaning of each
>>>>observer's coordinate system completely obvious and unambiguous.
>>>>
>>>>
>>>>
>>>>
>>>Other observer will not agree that the super nova occur at 1905 because
>>>their cl*** second has different universal time content than your clock
>>>second.
>>>
>>>
>>>
>>Other observers will agree that *my* clock which was next to the
>>supernova at the time it happened read "1905".
>>
>>
>
>Sure he uses the LT and his measurements of the supernova to predict what is
>the reading in your clock when the supernova will happen.
>

No, he doesn't need to do any calculations at all, he just looks at a
photo of the supernova as it happened, and observes that in this photo,
the physical clock on my physical ruler which was right next to the
supernova as it happened reads "1905" in the picture.

>
>
>
>>But each observer will
>>have his own series of clocks, and will assign a time-coordinate to the
>>supernova by looking at the reading on the clock in *their own* system
>>which was next to the supernova when it happened. Just by taking a
>>picture of the location of the supernova, and looking at the reading on
>>each observer's clock which was next to it at the moment it happened, I
>>can see what time-coordinate each observer assigns to the
>>supernova--this makes the physical meaning of each observer's
>>coordinate-system completely transparent, as opposed to the case where
>>each observer has to perform some mathematical calculations to figure
>>out the time-coordinate of distant events based on measurements made at
>>other places and times.
>>
>>
>
>You can do all that without calculations using the LT or IRT??
>

Yes, you just look at the actual readings on physical clocks which are
at rest in a given observer's frame, and which the observer has
"synchronized" by assuming light moves at the same speed in all
directions relative to himself (which means that if he is moving
relative to you, then his clocks will look out-of-sync from your point
of view...this is the RoS). Again, Einstein *derived* the LT from
exactly this sort of physical picture, I can provide you with references
if you like.

>
>
>>
>>
>>
>>>The LT or IRT can calculate what each observer will see the super
>>>nova using his own clock.
>>>
>>>
>>>
>>Yes, but this isn't as physically transparent as just looking at the
>>reading on the clock in each observer's system which was right next to
>>the supernova when it happened.
>>
>>
>
>You can read what each clock says next to the supernova without
>calculatations?
>

Sure, just look through your telescope, and at the moment the supernova
occurs, look at what the clock right next to it said at that moment. No
calculations are needed at all for this.

>>>
>>>
>>>>>
>>>>>
>>>>You may believe that there is objective truth about whose clocks are
>>>>*really* running slow and whose rulers have *really* shrunk, but what
>>>>Einstein showed was that even if there is a single ether frame where
>>>>clocks run at the correct rate and rulers read the correct length, as
>>>>long as the ticks of clocks moving at velocity v relative to the ether
>>>>frame are extended by 1/squareroot(1 - v^2/c^2) and rulers shrink by
>>>>squareroot(1 - v^2/c^2), then if each observer assigns coordinates using
>>>>rulers and clocks at rest relative to themselves (and with each observer
>>>>synchronizing clocks by *assuming* light travels at the same speed in
>>>>all directions in their frame, even though this assumption would be
>>>>'objectively' wrong for observers in motion relative to the ether), then
>>>>each observer will *measure* every other observer's clocks to slow down
>>>>and every other observer's rulers to shrink.
>>>>
>>>>
>>>>
>>>>
>>>This is true only if the observer is at rest wrt the ether.
>>>
>>>
>>>
>>No, see above. If each observer synchronizes his clocks based on the
>>assumption that light travels at the same speed in all directions
>>relative to himself (with speed defined in terms of what you called
>>'OWLS' above), then different observers will disagree about
>>simultaneity, and it is this disagreement which allows *every* observer
>>to measure that rulers moving relative to himself shrink, and clocks
>>moving relative to himself slow down.
>>
>>
>
>OWLS has never been measured. It is likely that OWLS is distance dependent.
>

I am not sure exactly what you mean by "OWLS", I was just using that
term because you seemed to be saying earlier that if you measure the
position and time a light beam was emitted and compare to the position
and time it was received, then calculate (distance interval)/(time
interval), this would be an OWLS measurement--was I understanding
correctly?

>>
>>
>>
>>>In real life all
>>>observers are moving in the ether. So some clocks and rods will run
>>>
>>>
>slower
>
>
>>>than the observer's clock and some will run faster than the observer's
>>>cl***.
>>>
>>>
>>>
>>If you believe in ether that may be true "objectively", but it will
>>nevertheless be true that each observer will *measure* all rulers moving
>>relative to himself to shrink and all clocks moving relative to himself
>>to slow down, if they make these measurements in the way that was
>>specified by Einstein (a network of rulers and clocks at rest relative
>>to the observer, with the clocks 'synchronized' using the assumption
>>that light has the same speed in all directions relative to the
>>observer, even if this assumption is 'objectively' wrong).
>>
>>
>
>The problem with Einstein's net work of clocks and rulers is that he assumed
>that these net works are at a state of absolute rest.
>

No he didn't. Again, see my 5 assumptions above, as long as they all
hold then it is absolutely certain that the LT will accurately transform
between the measurements of *any* two observers regardless of their
"absolute motion".

>>
>>
>>>BTW that's the reason why SR is incpomplete. It assumes that the
>>>observer is at rest in the ether because of the PoR postulate says that
>>>
>>>
>all
>
>
>>>frames are equivalent and this enables the observer to assume that he is
>>>
>>>
>at
>
>
>>>rest in the ether.
>>><snip>
>>>
>>>
>>>
>>No it doesn't--you're just not fully understanding the "relativity of
>>simultaneity". Again, examine the diagrams I gave you carefully and you
>>will see how this all works out.
>>
>>
>
>I understand the relativity of simultaneity very well and I understand it is
>based on the bogus assumption that the observer in the train is moving wrt
>light.
>

Only from the track observer's point of view. From the train observer's
point of view, the RoS is a consequence of the fact that light moves at
the same speed in all directions relative to himself, but the observer
on the track is moving wrt light. Either of these points of view is
equally valid and will lead to the same conclusions about the RoS. Thus
the RoS is based on the idea that each observer believes light moving at
the same speed in all directions *relative to himself*.

>
>
>
>>>>>>
>>>>>>
>>>>>IRT is anologous to the LT. In it contains LT as a subset.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>It can't really contain LT as a subset if your procedure for assigning
>>>>coordinates is completely different than those assumed in the derivation
>>>>of the LT. The LT don't use any notion of "light path length", they just
>>>>assign coordinates based on the local readings of rulers and clocks
>>>>which are at rest in that reference frame.
>>>>
>>>>
>>>>
>>>>
>>>IRT does the same thing. The LT does use the notion of light path length.
>>>rod contraction =longer light path length in IRT.
>>>time dilation=a clock seconds contains more universal time in IRT.
>>>
>>>
>>>
>>No, the LT does not use the notion of "light path length". In the LT,
>>the "length" of a moving rod is found just by comparing the position of
>>the back end of the rod and the position of the front end of the rod "at
>>the same moment", with the notion of "the same moment" defined to mean
>>that the reading on the clock at the same position as the back end
>>matches the reading on the clock at the same position as the front end,
>>with the clocks at rest relative to the observer and "synchronized"
>>using the assumption that light travels at the same speed in all
>>directions relative to the observer (so that if a light flash is emitted
>>at the midpoint of two clocks, the clocks should both read the same time
>>when the light beam hits each one). Of course, this "synchronization"
>>procedure guarantees that two clocks which are in-sync in their own rest
>>frame will be out-of-sync when compared with a set of clocks in motion
>>relative to them, so different observers will define simultaneity
>>differently.
>>
>>
>
>When you are using clocks to measure length you are measuring light path
>length.
>

When you measure light-path length, the time when the light is emitted
at one end of the object is *different* from the time when the light is
received on the other end, no? If so, this is different from the
procedure for measuring length I gave above, where you compare the
position of the back end at a given time with the position of the front
end at the *same* time (according to local clocks).

>
>
>>
>>
>>>>But I'm not talking about light path length. I'm talking about what
>>>>happens according to your theory if we try to measure length using the
>>>>same procedure that's assumed in the Lorentz transformations, namely
>>>>looking at the position of each end of the moving rod at a single time,
>>>>according to my own set of clocks and rulers. For example, if the clock
>>>>on the 1-meter mark of my ruler reads "10 seconds" at the moment the
>>>>back end of the moving ruler passes the 1-meter mark, and the clock on
>>>>the 3-meter mark of my ruler also reads "10 seconds" at the moment the
>>>>front end of the ruler passes the 3-meter mark, then using this
>>>>procedure I will say that the length of the moving ruler is 2 meters in
>>>>my own coordinate system.
>>>>
>>>>
>>>>
>>>>
>>>This is not how the current physics measure length.. The current
>>>
>>>
>procedure
>
>
>>>is: you determine the flight time for light to traverse the rod and you
>>>multiply the flight time by the speed of light to get the length of the
>>>
>>>
>rod.
>
>
>>But this is how you are assumed to measure length according to the LT.
>>Of course, you can then prove that if each observer does define length
>>this way, and that if each observer also defines "simultaneity" in the
>>way I've already discussed, then each observer will get exactly the same
>>value for distance/time between the emission of a light beam and its
>>detection. Based on this, you know that each observer is *also* free to
>>define length as (time for light to travel between two ends of an
>>object)*(speed of light), but this will only work for an object which is
>>at rest relative to the observer. It is certainly not true that current
>>physics would define the length of a *moving* object this way,
>>
>>
>
>Length of a moving object is determined by the LT or IRT.
>

You can't define "length" in terms of some abstract mathematical
transformation, you have to define it in purely physical terms, and then
*derive* the transformation from those physical assumptions.

>
>
>>>
>>>
>>>
>>>>
>>>>
>>>>Again, by "equivalent of the Lorentz transforms" I mean what happens
>>>>*if* you assign coordinates using the same physical procedure as is
>>>>assumed in relativity, using the measurements on rulers and synchronized
>>>>clocks at rest in a given frame.
>>>>
>>>>
>>>>
>>>>
>>>I assign corrdinates using the LT or IRT.
>>>
>>>
>>>
>>Again, by "assign coordinates" I'm talking about what physical
>>measurements you must make to determine the coordinates of a given event.
>>
>>
>
>The observer makes measurement with his clock and ruler to determine the
>coordinates of the event and he uses the LT or IRT to transform these
>coordinates to another frame.
>

Again, this would make relativity into an exercise in abstract
mathematical games, not a physical theory. The whole point of the LT is
that they *predict* how measurements made by one observer's physical
ruler-clock system will match up with measurements made by another
observer's system. None of the observers need to know anything about the
LT in advance in order to build these physical measuring systems.

>>
>>
>>
>>
>>>>>>
>>>>>>
>>>>>If the events occur simultaneously while he is at equal distance from
>>>>>
>>>>>
>>>>>
>>>>>
>>>both
>>>
>>>
>>>
>>>
>>>>>events then he will see the events to be simultaneous. That's because
>>>>>
>>>>>
>the
>
>
>>>>>speed of light is isotropic and that the speed of light is independent
>>>>>
>>>>>
>of
>
>
>>>>>the motion of the source or the receiver.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>Yes, if they are simultaneous *in his frame*. But in SR different
>>>>observers' coordinate systems won't agree on whether two events are
>>>>simultaneous.
>>>>
>>>>
>>>>
>>>>
>>>The RoS of SR is bogus. It violate the isotropy of the speed of light in
>>>
>>>
>the
>
>
>>>train.
>>>
>>>
>>>
>>No, the RoS is *based* on the isotropy of the speed of light in each
>>reference frame.
>>
>>
>
>No RoS is not based on the isotropy of the speed of light. In Einstein's
>train example he said that the train observer is runhing toward the light
>front from the front of the train and he is receding away from the light
>front from the back of the train.
>

Only from the point of view of the observer on the track! You could
equally well consider things from the point of view of the observer on
the train--in this frame, it would be the observer on the track who is
moving towards the light emitted at the back of the train and away from
the light emitted at the front of the train. Whichever way you look at
it, you will get exactly the same predictions about how the
train-observer's clocks readings match up with the track-observer's
clock readings at the moment a given pair of clocks pass next to each other.

> Clearly this means that the speed of light
>in the train is not isotropic.
>

In the frame of the track-observer, light moves at the same speed in all
directions relative to himself, but not relative to the observer on the
train. In the frame of the train-observer, light moves at the same speed
in all directions relative to himself, but not relative to the observer
on the track. So, the speed of light is isotropic in each observer's
rest frame.

>
>
>
>>Suppose the observer on the train has two clocks at
>>either end of the train, and flashes a light at the exact midpoint of
>>the train, then "synchronizes" the two clocks so that each clock has the
>>same reading at the moment the light hits it (in other words, he assumes
>>light must take the same amount of time to travel from the midpoint of
>>the train to the clocks on either end, which means he's assuming it
>>travels at the same speed in both directions in the train's rest frame).
>>But from the point of view of the observer on the track, the back end of
>>the train is moving towards the point in space where the flash of light
>>was emitted, while the front end of the train is moving away from it, so
>>if the observer on the track assumes that light travels at the same
>>speed in all directions in *his own* frame, that guarantees that he will
>>see the two clocks of the train-observer to be out-of-sync if the
>>train-observer "synchronizes" them in this way.
>>
>>
>
>The train observer doesn't care what the track observer sees. The train
>observer will conclude that if he emits a pulse of light in both directions
>simultaneously it will hit the ends of the train simultaneously.
>Likewise the track observer doesn't care what the train observer sees. He
>will sees both light pulses hit the ends of the train simultaneously.
>

No, the track observer can't see the light hit both ends simultaneously
or it would violate the isotropy of light in his own frame. In his
frame, the light was emitted from the midpoint of the train, but the
back of the train is moving towards the point where the light was
emitted and the front is moving away from that point, so he must see the
light hit the back end first if light travels at the same speed in both
directions in his own frame.

>
>
>>
>>
>>
>>>Also it leads to the absurd conclusion that the transit time of an
>>>observed rod is different in different directions.
>>>
>>>
>>>
>>No it doesn't.
>>
>>
>
>Yes it does. I suggest that you check with other SRians.
>

What do you mean by "the transit time of an observed rod"? I assumed you
meant a rod which is at rest in the observer's own frame. It's certainly
true that the time for the light to get from one end to another of a rod
which is *moving* in my frame will be different depending on whether the
light was emitted at the front end or the back end, but this is just a
consequence of the fact that I see light going the same speed in both
directions, regardless of the velocity of the source.

>
>
>
>>Again, the RoS is derived from the fact that each
>>observer *assumes* light travels at the same speed in all directions in
>>his own frame, and uses this assumption to synchronize his own clocks.
>>If each observer synchronizes his clocks this way, and if there's at
>>least one frame (the rest frame of the ether, perhaps) where a ruler
>>moving at velocity v will shrink by squareroot(1 - v^2/c^2) and a
>>clock's ticks will extend by 1/squareroot(1 - v^2/c^2), then it is
>>possible to prove mathematically that the Lorentz transformations will
>>work in *all* frames, and that all observers will measure moving rulers
>>to shrink and moving clocks to slow down in exactly the same way. I can
>>show this proof, if you don't believe me.
>>
>>
>
>What is this got to do with my saying that RoS makes the bogus assertion
>that the transit time for a moving rod is different in different directions?
>

Oh, OK, you are talking about a moving rod. But if a light wave moves at
the same speed in both directions in my frame (ie the speed of light is
isotropic in my frame), that means the transit time to get from one end
to another of a rod which is moving in my frame *must* be different
depending on which direction the wave is going. Suppose at time t=0 in
my frame, one end of the rod is at position x=0 and the other is at
position x=L, and the rod is moving in the +x direction with velocity v.
In that case, if a light beam is emitted at position x=0 at time t=0,
and it moves right at velocity c, then it will catch up with the other
end when ct = L + vt, or when t=L/(c-v). On the other hand, if a light
beam is emitted at position x=L at time t=0, and it moves left with
velocity c, then it will catch up with the other end when vt = L - ct,
or when t=L/(c+v). Since c and v are positive, L/(c+v) < L/(c-v), so
clearly the assumption that light moves at speed c in both directions in
my frame *requires* me to believe the transit time for a moving rod is
different in different directions. If the transit time for a moving rod
were the same in both directions in my frame, then the speed of light
could not be isotropic in my frame.

>
>
>>
>>
>>
>>>>Again, this may be how it works in your theory, but I was just talking
>>>>about what would be true if you assign coordinates using ruler/clock
>>>>systems of the type assumed in SR, and if the SR formulas for Lorentz
>>>>contraction and time dilation are correct.
>>>>
>>>>
>>>>
>>>>
>>>This is how it works in both SR and IRT.
>>>
>>>
>>>
>>No, you're misunderstanding SR. If each observer assigns coordinates
>>using the ruler/clock system I've described, then the train observer
>>will indeed assign the two flashes different time-coordinates,
>>
>>
>
>No it doesn't.
>>From the track observer's point of view:
>the time coordinate in the train frame for both flashes =t*gamma
>>From the train observer's point of view:
>The time coordinate in the train for both flashes=t'
>

Wrong, just use the Lorentz transformation! Say that in the track
observer's frame, which we can call frame A, both flashes happen at time
t=0 seconds, and one happens at position x=1 light-second and the other
happens at position x=-1 light-second. Then the light from both will
reach him at t=1 second, at position x=0 light-seconds.

Now, use the lorentz transformation equations to transform the
coordinates of these events into frame B which is moving at v=0.6c
relative in the +x direction in the track observer's frame. In the
track-observer's frame A, the two light-flashes reached his position at
x=0 ls, t=1 s, so in frame B the coordinates of this event would be:
x'=1.25(0 - 0.6*1) = -0.75
t'=1.25(1 - 0.6*0/1) = 1.25

If we assume the train observer was also at the same position at the
moment the two light beams struck the track-observer, then if the
train-observer is at rest in frame B, this must mean his position is
always x'=-0.75 light seconds in this frame.

OK, so now let's figure out the B-coordinates of the flash which took
place at x=1 ls, t=0 s in frame A:

x'=1.25(1 - 0.6*0) = 1.25
t'=1.25(0 - 0.6*1/1) = -0.75

So if the train observer's position was at x=-0.75 ls, then from his
point of view this flash took place at a distance of 2 light seconds
from him. The flash occurred at time t'=-0.75 s, and reached his
position at t'=1.25s, so the time interval between the flash and the
light from the flash reaching him was 2 seconds in frame B where he is
at rest.

Now let's figure out the B-coordinates of the flash which took place at
x=-1 ls, t=0 s in frame A:

x'=1.25(-1 - 0.6*0) = -1.25
t'=1.25(0 - 0.6*(-1)/1) = 0.75

So since the train observer's position was at x=-0.75 ls, this flash
took place at a distance of 0.5 ls from him. The flash occurred at time
t'=0.75 s, 1.5 seconds after the first flash, and reached his position
at t'=1.25 s, so the time interval between the flash and the light from
the flash reaching him was 0.5 seconds in frame B.

So, like I said, the train observer says the flashes occurred at
different times and different distances from himself.

>
>
>
>>and they
>>will have happened at different distances from the origin of his own
>>coordinate system.
>>
>>
>
>This is a bogus assumption. The flashes occurred simultaneously when the
>train observer was at equal distance from both flashes.
>
>
>
>>Just plug some numbers into the Lorentz
>>transformation and you will see that this is true.
>>
>>
>
>The LT does not confirm the validity of the RoS.
>

Of course it does, because if you plug in two events which have the same
time-coordinate but different space coordinates in one frame, then you
will *always* find the same two events have different time-coordinates
in another frame which is in motion relative to the first. Just try
plugging in some numbers into the equations and you will see this is true.

Jesse

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