On 03-Aug-23 7:53 pm, Maciej Wozniak wrote:
> On Thursday, 3 August 2023 at 11:06:42 UTC+2, Sylvia Else wrote:
>> On 03-Aug-23 5:19 pm, Maciej Wozniak wrote:
>>> On Thursday, 3 August 2023 at 08:04:23 UTC+2, Sylvia Else wrote:
>>>> On 01-Aug-23 3:12 pm, Maciej Wozniak wrote:
>>>>> On Tuesday, 1 August 2023 at 04:10:22 UTC+2, Sylvia Else wrote:
>>>>>> On 01-Aug-23 11:38 am, Ken Seto wrote:
>>>>>>> On Monday, July 31, 2023 at 8:41:31 PM UTC-4, Sylvia Else wrote:
>>>>>>>> On 01-Aug-23 9:42 am, Ken Seto wrote:
>>>>>>>>> Einstein invented length contraction to make his Postulate P2 constant light speed in all frames viable.
>>>>>>>>> Here's how:
>>>>>>>>> 1. The material length of a meter stick remain constant in all frames.
>>>>>>>>> 2. Einstein invented length contraction without specifyin what is
>>>>>>>>> contracting.
>>>>>>>>> This allowed him to claim that Length contraction along with time dilation
>>>>>>>>> to give him constant light speed in all frames.
>>>>>>>>> The real reason why the speed of light is not constant in all frames is as follows:
>>>>>>>>> 1. The material length of a meter stick remains constant in all frames.
>>>>>>>>> 2. The light-path-length (LPL)...the length that light must travel to cover the material length of a meter stick ....
>>>>>>>>> 3. The LPL of the observer's meter stick is 1meter ...the same as its material
>>>>>>>>> length..
>>>>>>>>> 4. The LPL of a meter moving wrt the observer is predicted to be 1/gamma or gamma.
>>>>>>>>> 5. Einstein assumed that the LPL of the moving meter stick only 1/gamma. and thus all meter stick moving wrt the observer will have LPL 1/gamma. This is wrong. The LPL of a moving meter can be gamma. This means that SR is only half of the story.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>> Indeed, there is no material length contraction. Einstein never said
>>>>>>>> there was.
>>>>>>>
>>>>>>> So what did Einstein said what is contracting? The LPL as I said above?
>>>>>>>>
>>>>>>>> Sylvia.
>>>>>> Relativity is a theoretical model. It tells you what to expect if you do
>>>>>> measurements. That's it.
>>>>>
>>>>> Is it, lady?
>>>>> So, if anyone asked your insdane guru: "an observer
>>>>> moving with c/2 wrt solar system is going to measure
>>>>> a day. What result do you expect in the name of your
>>>>> insane physics?"
>>>>> The answer would be...?
>>>>
>>>> Such questions are ill-framed.
>>>
>>> Isn't Your relativity about predicting the results of measurements?
>>>
>>>> The observer is moving, so their distance
>>>> away from the Earth will vary over the course of day, and the time light
>>>> takes to travel from the Earth to the observer will also vary.
>>>
>>> It doesn't prevent him from measuring the intervals
>>> between the ticks of a clock on Earth, does it? Why
>>> can't he measure a day?
>> Measuring the interval between the ticks of a clock presents exactly the
>> same issues.
>
> And, well, Your relativity doesn't care about them at
> all and is brilliantly predicting the results. Isn't it?

It predicts the result of observing the ticks through a telescope, and
measuring the interval between them. The relativistic Doppler effect
formula gives the answer.

Sylvia.

On Friday, 4 August 2023 at 00:03:50 UTC+2, Sylvia Else wrote:
> On 03-Aug-23 7:53 pm, Maciej Wozniak wrote:
> > On Thursday, 3 August 2023 at 11:06:42 UTC+2, Sylvia Else wrote:
> >> On 03-Aug-23 5:19 pm, Maciej Wozniak wrote:
> >>> On Thursday, 3 August 2023 at 08:04:23 UTC+2, Sylvia Else wrote:
> >>>> On 01-Aug-23 3:12 pm, Maciej Wozniak wrote:
> >>>>> On Tuesday, 1 August 2023 at 04:10:22 UTC+2, Sylvia Else wrote:
> >>>>>> On 01-Aug-23 11:38 am, Ken Seto wrote:
> >>>>>>> On Monday, July 31, 2023 at 8:41:31 PM UTC-4, Sylvia Else wrote:
> >>>>>>>> On 01-Aug-23 9:42 am, Ken Seto wrote:
> >>>>>>>>> Einstein invented length contraction to make his Postulate P2 constant light speed in all frames viable.
> >>>>>>>>> Here's how:
> >>>>>>>>> 1. The material length of a meter stick remain constant in all frames.
> >>>>>>>>> 2. Einstein invented length contraction without specifyin what is
> >>>>>>>>> contracting.
> >>>>>>>>> This allowed him to claim that Length contraction along with time dilation
> >>>>>>>>> to give him constant light speed in all frames.
> >>>>>>>>> The real reason why the speed of light is not constant in all frames is as follows:
> >>>>>>>>> 1. The material length of a meter stick remains constant in all frames.
> >>>>>>>>> 2. The light-path-length (LPL)...the length that light must travel to cover the material length of a meter stick ....
> >>>>>>>>> 3. The LPL of the observer's meter stick is 1meter ...the same as its material
> >>>>>>>>> length..
> >>>>>>>>> 4. The LPL of a meter moving wrt the observer is predicted to be 1/gamma or gamma.
> >>>>>>>>> 5. Einstein assumed that the LPL of the moving meter stick only 1/gamma. and thus all meter stick moving wrt the observer will have LPL 1/gamma. This is wrong. The LPL of a moving meter can be gamma. This means that SR is only half of the story.
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>> Indeed, there is no material length contraction. Einstein never said
> >>>>>>>> there was.
> >>>>>>>
> >>>>>>> So what did Einstein said what is contracting? The LPL as I said above?
> >>>>>>>>
> >>>>>>>> Sylvia.
> >>>>>> Relativity is a theoretical model. It tells you what to expect if you do
> >>>>>> measurements. That's it.
> >>>>>
> >>>>> Is it, lady?
> >>>>> So, if anyone asked your insdane guru: "an observer
> >>>>> moving with c/2 wrt solar system is going to measure
> >>>>> a day. What result do you expect in the name of your
> >>>>> insane physics?"
> >>>>> The answer would be...?
> >>>>
> >>>> Such questions are ill-framed.
> >>>
> >>> Isn't Your relativity about predicting the results of measurements?
> >>>
> >>>> The observer is moving, so their distance
> >>>> away from the Earth will vary over the course of day, and the time light
> >>>> takes to travel from the Earth to the observer will also vary.
> >>>
> >>> It doesn't prevent him from measuring the intervals
> >>> between the ticks of a clock on Earth, does it? Why
> >>> can't he measure a day?
> >> Measuring the interval between the ticks of a clock presents exactly the
> >> same issues.
> >
> > And, well, Your relativity doesn't care about them at
> > all and is brilliantly predicting the results. Isn't it?
> It predicts the result of observing

And the answer of Your insane guru for my question
would be...?

Le 04/08/2023 à 00:03, Sylvia Else a écrit :

> It predicts the result of observing the ticks through a telescope, and
> measuring the interval between them. The relativistic Doppler effect
> formula gives the answer.

> Sylvia.

In current kinematics, there is a longitudinal Doppler effect (for example
the Doppler effect relating to sounds).
But in relativity, it is difficult to speak of a single Doppler effect,
because there are two.
There were also two in classical mechanics, but the second effect is so
weak for low speeds (gamma factor) that it is rightly ignored.
I think (not out of arrogance, but out of love of what is true) that it
would be better on this point to adopt my terminology.
I call longitudinal relativistic effect the effect of the first degree due
to spatial anisochrony (or speed of light).
I call INTERNAL relativistic effect the effect of the second degree linked
to the relativistic factor gamma.
I refute the idea of transverse Doppler effect which leads to confusion.
When I see a rocket arriving at me, its displacement is purely
longitudinal (cosµ=-1).
It therefore has a longitudinal Doppler effect of the first degree.
But it also has a "transverse" Doppler effect as it does not move
transversely in any way. The term therefore seems to me liable to
misinterpretation. I therefore prefer the term INTERNAL Doppler effect.

These two Doppler effects are cumulative.

The object which moves in space will therefore undergo two Doppler effects
and the residual equations will become for the apparent speeds, for the
perceived proper durations, for the perceived lengths, and for the
received wavelengths.
Vapp=Vo/(1+cosµ.Vo/c)
t'=t.(1+cosµ.Vo/c)/sqrt(1-Vo²/c²)
L'=L.sqrt(1-Vo²/c²)/(1+cosµ.Vo/c)
lambda'=lambda.(1+cosµ.Vo/c)/sqrt(1-Vo²/c²)

Notion of relativistic Doppler effects, my love Sylvia.

R.H.