A constant speed of light in all reference frames? Surely you can't be serious. [Physics]

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From: Bruce Richmond on 10 Mar 2010 21:51

On Mar 10, 11:57 am, PD <thedraperfam...(a)gmail.com> wrote:
> On Mar 9, 9:41 pm, Paul Stowe <theaether...(a)gmail.com> wrote:
>
>
>
>
>
> > On Mar 8, 8:05 pm, "Inertial" <relativ...(a)rest.com> wrote:
>
> > > "Paul Stowe" <theaether...(a)gmail.com> wrote in message
>
> > >news:1132a230-92d9-484a-b0c1-d3a97532cad9(a)z10g2000prh.googlegroups.com....
>
> > > >> >> SR explains it as having to be c due to the geometry of spacetime
>
> > > >> > That's simply a silly idea...
>
> > > >> That you think it is silly is your problem, not that of SR
>
> > > > Something physical may be represented by a geometric description.
>
> > > And our universe is represented by Minkowski geometry.
>
> > Yes, you can descibe localized behavior with that format. BUT! to do
> > so you must depend on finite light speed and its physical
> > independence. Geometry neither predicts. explains, or has a basis for
> > that.
>
> That's incorrect, Paul. The geometric structure of spacetime imposes
> both a finite speed of light AND makes it frame-independent.
>
> The geometric structure of spacetime *necessarily* divides pairs of
> events into three categories: spacelike-separated, timelike-separated,
> and nullcone-separated. This structure also immediately leads to the
> result that any wordline that could be traversed by something between
> timelike-separated events will, in any other inertial reference frame,
> still be between timelike-separated events. What this means explicitly
> is that this object can never span two spacelike-separated events.
> Thus, the universe of events is strictly divided into two completely
> separated causal domains. The boundary of these domains is the null
> cone. Since the null cone has a definite slope of space vs time, this
> imposes a causal speed limit. (This limit does not exist in Euclidean
> 3D+1D space -- it is a unique feature of the 4D space and its
> geometry.)
>
> Furthermore, while transformations between inertial frames will shift
> the slopes between pairs of timelike events (that is, the speed of an
> object traveling between the two events), the same transformation
> between pairs of events on the null cone do not change slope. What
> this means is that any object that can travel between two events on
> null cone will have the same speed regardless of inertial reference
> frame.
>
> So you see, the geometric structure DOES imply both a causal speed
> limit and the invariance of that causal speed limit with choice of
> inertial reference frame. It just so happens that light appears to be
> one of the candidate objects that can travel between nullcone-
> separated events.
>
> If you need to see how the structure does impose those limits
> formally, I could point you to a reference book or two that derives
> this unambiguously.

Please provide the reference.

TIA, Bruce

> At the time that Einstein proposed special relativity, he did not
> understand how such a geometric structure could produce those two
> conclusions as necessary consequences. And so he just posited the
> invariance of the speed of light as a postulate (or equivalently,
> demanded that Maxwell's equations obey the principle of relativity).
> It was only later that the geometric structure was uncovered and it
> was understood how the light postulate follows directly from this
> structure.
>
> PD- Hide quoted text -
>
> - Show quoted text -

From: mpc755 on 10 Mar 2010 22:01

On Mar 10, 8:52 pm, Bruce Richmond <bsr3...(a)my-deja.com> wrote:
> On Mar 10, 8:13 pm, "Peter Webb"
>
> <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote:
> > According to both SR and LET there is no experiment that can reveal
> > which frame is at rest WRT the ether, so there is no way to know which
> > frame is more at rest WRT the ether.
>
> > ______________________
> > Wrong. Only LET has this problem. There is no ether in SR, so the question
> > of its velocity doesn't even arise.
>
> Einstein did not rule out the possibility of an ether, he said that it
> made no difference if there was one, that it was superfluous. If you
> claim my statement is wrong you are claiming there is an experiment
> that can reveal the ether frame.

Another complete misquote of Einstein.

http://en.citizendium.org/wiki/Ether_%28physics%29

'In his 1905 paper Einstein refers to the ether only once:

The introduction of a "luminiferous aether" will prove to be
superfluous inasmuch as the view here to be developed will not require
an "absolutely stationary space" provided with special properties, nor
assign a velocity vector to a point of the empty space in which
electromagnetic processes take place.'

What part of 'inasmuch as the view here to be developed will not
require "an absolutely stationary space"' do you not understand?

Just as you do not understand Einstein's definition of motion you do
not understand what Einstein meant by a superfluous aether.

Einstein's definition of motion requires there to be particles which
can be separately tracked through time.

Einstein's definition of a superfluous aether is one in which it is an
absolutely stationary space.

The aether is displaced by matter. The aether is not at rest when
displaced. The aether 'displaces back'. The pressure associated with
the aether displaced by massive objects is gravity. A moving particle
has an associated aether wave.

"According to the general theory of relativity space without ether is
unthinkable" - Albert Einstein

From: Inertial on 10 Mar 2010 22:02

"Dono." <sa_ge(a)comcast.net> wrote in message
news:5d0b21bd-4696-4e7a-8753-e8e1ac95fc7e(a)t34g2000prm.googlegroups.com...
> On Mar 10, 5:05 pm, "Inertial" <relativ...(a)rest.com> wrote:
>>
>> In LET the 'real' speed of light is anisotropic, because in LET frames of
>> reference are 'really' related by galillean transforms and not lorentz,
>> and
>> it is 'really' simply euclidean geometry and not minkowski.
>>
>
> You are contradicting yourself again.

No .. I am not. I ahve been consistent and correct throughout

> You claimed earlier that LEt
> uses the Lorentz transforms.

yes it does .. on what one measures with the distorted clocks and rulers.

> So, make up your mind.

I have. I have been very clear. Are you having problems following it.
Poor diddums

> Secondly, what is the "REAL" speed of light?

In LET, light has a speed of c in the aether frame. The separation speed of
light and object in the aether frame. According to LET, as reality (as
opposed to what we measure) is Galilean and not Lorentzian, that separation
speed is also the 'real' speed of light in that frame and os is anisproptic.
However, as the clocks and rulers in that frame are distorted by movement
through the aether in such a way that they relate to other frame via lorentz
transforms, we get a measured speed of light in every frame as 'c'.

> As opposed to "UNREAL"?
> Thirdly, I have already told you that , if light speed is anisotropic,
> then the experiments I listed for you invalidate LET. Instantaneously.

And as I have told you, LET says they will be measured as isotropic. And so
every experiment that satisfies SR also satisfies LET.

>> HOWEVER (as I have pointed out every time) LET says that movement through
>> the aether compresses all matter, and slows all processes (which
>> introduces
>> RoS) and so what we MEASURE (observe and experience), with the rulers and
>> clocks that are affected by these distortions, is an isotropic speed of
>> light, and measurements between frames that are related by Lorentz
>> transforms and which are modeled by a minkowski geometry.
>>
>
> No, pathetic imbecile.

I'm neither

> The "compression of rulers", RoS and the "slowing of prcesses" is NOT
> sensitive to the sense of motion,

Yes .. it is .. by Lorentz transforms, jsut as in SR

> so none of this "stuff" that you
> keep repeating can turn anisotropic light speed into isotropic light
> speed.

Yes it does

> Let me give you a simple exercise:

Fine .. though you probably don't understand what you're askign

> 1. In the "aether frame" , according to you, light speed is isotropic
> and equal to c0.

no .. its c. no need to invent another symbol

> 2. In ANY other frame, light speed is anisotropic and equal to:
>
> c=c0+v*cos(theta)

c' = c+v*cos(theta)

so if we chose axes so they are in same direction (theta = 0) we get

c'_real = c+v

that is the 'real' velocity (the one we cannot measure)

> where theta is the angle between the light ray and
> the direction of the semipositive x axis. v is the speed of the frame
> wrt "aether"

That is what it 'really' is according to LET, but not what it is measured to
be.

> Show how LET turns the anisotropic light speed into an isotropic one.

Do you REALLY not know how Lorentz transforms work? Probably not. You can
cite the math, but you don't undertand.

You can simply use velocity composition derived from Lorentz
transforms(which is the same in LET for measured velocities as it is in SR).

In the aether frame, the speed of light is c.

In a frame S' moving at v wrt the aether frame, then you get the measured
velocity of light is:

c' = (c + v) / (1 + vc / c^2)
c' = (c + v) / ((c + v)/c)
c' = c

There you go.

This really is basic stuff .. if measured lengths and time in frames are
related by Lorentz transforms, something with speed measured as c in one
frame will have its speed measured as c in all frames.

From: Inertial on 10 Mar 2010 22:15

"Inertial" <relatively(a)rest.com> wrote in message
news:4b985d3b$0$27829$c3e8da3(a)news.astraweb.com...
>
> "Dono." <sa_ge(a)comcast.net> wrote in message
> news:5d0b21bd-4696-4e7a-8753-e8e1ac95fc7e(a)t34g2000prm.googlegroups.com...
>> On Mar 10, 5:05 pm, "Inertial" <relativ...(a)rest.com> wrote:
>>>
>>> In LET the 'real' speed of light is anisotropic, because in LET frames
>>> of
>>> reference are 'really' related by galillean transforms and not lorentz,
>>> and
>>> it is 'really' simply euclidean geometry and not minkowski.
>>>
>>
>> You are contradicting yourself again.
>
> No .. I am not. I ahve been consistent and correct throughout
>
>> You claimed earlier that LEt
>> uses the Lorentz transforms.
>
> yes it does .. on what one measures with the distorted clocks and rulers.
>
>> So, make up your mind.
>
> I have. I have been very clear. Are you having problems following it.
> Poor diddums
>
>> Secondly, what is the "REAL" speed of light?
>
> In LET, light has a speed of c in the aether frame. The separation speed
> of light and object in the aether frame. According to LET, as reality (as
> opposed to what we measure) is Galilean and not Lorentzian, that
> separation speed is also the 'real' speed of light in that frame and os is
> anisproptic. However, as the clocks and rulers in that frame are distorted
> by movement through the aether in such a way that they relate to other
> frame via lorentz transforms, we get a measured speed of light in every
> frame as 'c'.
>
>> As opposed to "UNREAL"?
>> Thirdly, I have already told you that , if light speed is anisotropic,
>> then the experiments I listed for you invalidate LET. Instantaneously.
>
> And as I have told you, LET says they will be measured as isotropic. And
> so every experiment that satisfies SR also satisfies LET.
>
>>> HOWEVER (as I have pointed out every time) LET says that movement
>>> through
>>> the aether compresses all matter, and slows all processes (which
>>> introduces
>>> RoS) and so what we MEASURE (observe and experience), with the rulers
>>> and
>>> clocks that are affected by these distortions, is an isotropic speed of
>>> light, and measurements between frames that are related by Lorentz
>>> transforms and which are modeled by a minkowski geometry.
>>>
>>
>> No, pathetic imbecile.
>
> I'm neither
>
>> The "compression of rulers", RoS and the "slowing of prcesses" is NOT
>> sensitive to the sense of motion,
>
> Yes .. it is .. by Lorentz transforms, jsut as in SR
>
>> so none of this "stuff" that you
>> keep repeating can turn anisotropic light speed into isotropic light
>> speed.
>
> Yes it does
>
>> Let me give you a simple exercise:
>
> Fine .. though you probably don't understand what you're askign
>
>> 1. In the "aether frame" , according to you, light speed is isotropic
>> and equal to c0.
>
> no .. its c. no need to invent another symbol
>
>> 2. In ANY other frame, light speed is anisotropic and equal to:
>>
>> c=c0+v*cos(theta)
>
> c' = c+v*cos(theta)
>
> so if we chose axes so they are in same direction (theta = 0) we get
>
> c'_real = c+v
>
> that is the 'real' velocity (the one we cannot measure)
>
>> where theta is the angle between the light ray and
>> the direction of the semipositive x axis. v is the speed of the frame
>> wrt "aether"
>
> That is what it 'really' is according to LET, but not what it is measured
> to be.
>
>> Show how LET turns the anisotropic light speed into an isotropic one.
>
> Do you REALLY not know how Lorentz transforms work? Probably not. You
> can cite the math, but you don't undertand.
>
> You can simply use velocity composition derived from Lorentz
> transforms(which is the same in LET for measured velocities as it is in
> SR).
>
> In the aether frame, the speed of light is c.
>
> In a frame S' moving at v wrt the aether frame, then you get the measured
> velocity of light is:
>
> c' = (c + v) / (1 + vc / c^2)
> c' = (c + v) / ((c + v)/c)
> c' = c
>
> There you go.
>
> This really is basic stuff .. if measured lengths and time in frames are
> related by Lorentz transforms, something with speed measured as c in one
> frame will have its speed measured as c in all frames.

I'm waiting now for Dono to backpedal, and say he was not talking about the
LET that the rest of us clearly were (as was obvious from the statements
being made regarding Lorentz transforms), but to Lorentz's earlier work
before he introduced Lorentz transforms (eg where at one stage in 1892 he
only had length contraction postulated).

From: Dono. on 10 Mar 2010 22:24

On Mar 10, 7:02 pm, "Inertial" <relativ...(a)rest.com> wrote:
>
> In a frame S' moving at v wrt the aether frame, then you get the measured
> velocity of light is:
>
> c' = (c + v) / (1 + vc / c^2)
> c' = (c + v) / ((c + v)/c)
> c' = c
>

1.Why would you do such an imbecility?
2.You started with c+v, c-v in the lab frame, cretin. How does your
cretinoid calculation make light speed isotropic in the lab frame? You
"calculated" light speed wrt the "aether" frame, imbecile.
3. Try your cretinism again with c(theta)=c0/(1+v/c0*cos(theta)).
Don't cheat by taking theta=0

> There you go.
>
> This really is basic stuff .. if measured lengths and time in frames are
> related by Lorentz transforms, something with speed measured as c in one
> frame will have its speed measured as c in all frames.