🚀 go-pugleaf

"Wolfgang G. Gasser" <z@z.lol.li> wrote in message
news:ep8ftp$48b$1@atlas.ip-plus.net...
> ::  = Wolfgang G. Gasser in news:ep6cfd$3uk$1@atlas.ip-plus.net :
> :   = harry in news:1169630995_1932@sicinfo3.epfl.ch :
>
> Harry:
> :::   dx' = dx/gamma  (a moving rod appears to contract; thus a really
> :::                    moving rod really contracts)
>
> Wolfgang:
> :: Here also you are a victim of the confusion (resp. fatal error) I'm
> :: dealing with. According to SR,  dx' = dx/gamma  means contraction
> :: of rest-frame distances wrt the moving frame.
>
> Harry:
> : dx = dx'/gamma is valid in S' only. It's an often made mistake ...
>
> Should this be a con trick in order to obfuscate your error above,
> or are you simply confusing dx with dx'?

Sorry, I didn't pay enough attention. Sure, the length dx' of the moving rod 
as measured in its proper frame S' is measured as dx=dx'/gamma in rest frame
S.

> Your just introduced version dx = dx'/gamma actually has the meaning
> you by mistake first attributed to dx' = dx/gamma: a moving rod
> contracts wrt to the rest frame.

Yes.

> This new version dx = dx'/gamma is valid if we assume simultaneity
> in the rest frame S, i.e. dt = 0:
>
>  dx' = gamma * (dx - v*dt)   -->   dx' = dx  * gamma
>                              -->   dx  = dx' / gamma
>
> However, the version we originally have been dealing with,
> dx' = dx/gamma, implies simultaneity in S', i.e. dt' = 0:
>
>  dx = gamma * (dx' + v*dt')  -->   dx  = dx' * gamma
>                              -->   dx' = dx  / gamma

Yes. I thought that you did not understand that point; but obviously that's 
not the issue...

> So S-simultaneity leads to contraction of S' wrt S (or expansion of S
> wrt S') and S'-simultaneity to contraction of S wrt S' (or expansion
> of S' wrt S).

That is the issue, as I explained below. In no inertial system does any 
object appear to be "expanding".

> :: An ether distance of e.g. dx = 1 light-year is contracted to
> :: dx' = l LY / gamma  in the moving-frame.
> :
> : "ether" and "is contracted" are incompatible,
>
> and Lorentz ether theory is therefore inconsistent.

No, there I pointed out to you what in your description is inconsistent.

> Let us assume a twin-paradox

That's really funny: the twin scheme was introduced as example with that 
interpretation of SRT before it became a paradox due to reinterpretation.

> situation where one twin remains at rest
> in the ether whereas the other travels with v = 0.5 c to a point 1 LY
> away from the twin at rest. So an ether distance dx = l LY is passed
> in dt = 2 years.
>
> From time dilation follows that the moving twin does not need 2 years
> proper time to reach the destination but only dt' = 2 Yr / gamma. So,
> if the ether-distance dx from the twin at rest to the destination is
> identical wrt the moving twin (i.e. dx' = dx = 1 LY)

Of course not, why would you think so? I already pointed out to you that you 
your formulation confuses appearance with hidden reality. That is not 
allowed in that interpretation. In every frame one assumes to be in rest; 
which implies that it is the others that are assumed to be moving - by 
convention.

> we get wrt the
> moving twin a proper speed of:
>
>   v'  =  dx' / dt'  =  dx / (dt/gamma)  =  v * gamma.
>
> The only way to get a moving-twin speed of v' = v is the assumption,
> that the ether distance dx = 1 LY contracts by gamma wrt the moving
> twin:
>
>  dx' = dx/gamma   -->   dx'/dt' = (dx/gamma) / (dt/gamma) = v
>
> Time dilation is time expansion. If we combine time dilation with
> length contraction, then velocity as length divided by time obviously
> cannot remain invariant. Therefore we must combine time dilation of
> a moving object with with length expansion of the object (equivalent
> to contraction of the rest frame).

See above: nothing expands.

> : I think that [] you misunderstand what the author of mathpages wrote.
>
> Try again: news:ep2hvi$qli$1@atlas.ip-plus.net
>
> Interestingly the LET-SR confusion, we are dealing with, shows up as
> a different incarnation in the article you've pointed to. There you
> write:
>
>  "Similarly, the clocks will tick at 3/5 of the rate in rest, making
>   one tick 0.6 s of duration. Because this is determined relative to
>   the stationary ether or absolute space, the effects correspond to
>   physical reality."
> http://groups.google.com/group/sci.physics.relativity/msg/9db6b5df54b79f1d
>
> If the clock rate of a moving clock is 3/5 of the rate of rest-frame
> clocks, then one moving-clock cycle does not result in 0.6 sec in the
> rest frame, but in 5/3 sec.

Hmm, it looks like you found a nasty little error. Indeed, one second 
corresponds to 0.6 ticks. Note that the error is only in the intro.

> Imagine simply a transversal light clock
> moving at v = 0.8 c wrt the ether.
>
> Sorry, Wolfgang

Why? Thanks for noticing the error, I'll correct it.
And sorry that due to it, you didn't read on - for then you would not have 
made the mistake above to think that moving observers should apply their 
state of motion inconsistenlty. BTW, you can similarly mess up Newtonian 
mechanics.

Regards,
Harald