Re: How do you Interpret the Lorentz transform

In sci.physics.relativity, Androcles
<Androcles@xxxxxxxxxxx>
wrote
on Sun, 30 Oct 2005 01:22:14 GMT
<afV8f.86054$Ih5.41397@xxxxxxxxxxxxxxxxxxxxxxxxx>:
>
> "The Ghost In The Machine" <ewill@xxxxxxxxxxxxxxxxxxxxxxx> wrote in message news:8r9d33-lmc.ln1@xxxxxxxxxxxxxxxxxxxxxxxxxx
> | In sci.physics.relativity, King Coffee
> | <king.coffee@xxxxxxx>
> | wrote
> | on Sat, 29 Oct 2005 21:52:33 GMT
> | <BaS8f.1264$zb5.177@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>:
> | > Hello,
> | >
> | > I want to determine -- what would observer k observe in the k' reference
> | > frame moving with velocity v, parallel to the x axis and the two coordinate
> | > system origins coincide at t = 0, a strait forward transform.
> | >
> | > I assumed that lighting strikes were observed at -x and x simultaneously in
> | > the k coordinate system, at t = 0.
> | >
> | > So, I have the two observation points (-x, 0) and (x, 0).
> | >
> | > let: A = 1 / sqrt( 1- (v*v)/(c*c)), per Lorentz definition.
> | >
> | > That maps to the coordinate point pairs in the k' system as ( -Ax,
> | > x*v/(c*c) ) and ( Ax, -x*v/c*c) ).
> | >
> | > One of the points have a negative time. That would imply a future interval.
> | > That makes no sense, because the stationary observer k, already received the
> | > photon information at the origin and k' is moving away of the origin, so he
> | > should have already received the information too.
> | >
> | > However, if I assuming -- at t =0, the lighting just struck at -x and x, the
> | > math will probably work out. But than observer k would not have yet observe
> | > the events at t = 0.
> | >
> | > Do coordinate point pair ( x, t) corresponded to the observation of an event
> | > in the k system? I thought propagation delay time was implicit to the
> | > Lorentz Transforms.
> | >
> | > Can you tell me how to use (interpret) the Lorentz Transforms.
> | >
> | > King
> | >
> |
> | At the risk of A****c**s calling me something insulting, allow me. :-)
> | This is more or less the standard solution of how to derive
> | the relationships
> |
> | l/l_0 = sqrt(1-v/c) / sqrt(1+v/c)
> | f/f_0 = sqrt(1+v/c) / sqrt(1-v/c)
> |
> | from the Lorentz
> |
> | x' = (x-vt)/sqrt(1-v^2/c^2)
> | t' = (t-vx/c^2)/sqrt(1-v^2/c^2)
>
> I'd hate to disappoint you, but:
>
> The Lorentz transformation is
> x' = (x-vt) ( a length)
> t' = (t-vx/c^2) (a duration)
> Ref: http://www-groups.dcs.st-and.ac.uk/~history/HistTopics/Special_relativity.html#12
>
> The Einstein transformation is
> xi = x'/sqrt(1-v^2/c^2)
> tau = (t-vx/c^2)/sqrt(1-v^2/c^2) = t* sqrt(1-v^2/c^2)
> Ref: http://www.fourmilab.ch/etexts/einstein/specrel/www/

Lorentz, Hendrik A. Born 1853-07-18, Arnhem, Netherlands.
Died 1928-02-04, Haarlem, Netherlands.

FitzGerald, George Francis. Born 1851-08-03 in Kill-o'-the Grange,
Monkston, Co. Dublin Ireland. Died 1901-02-21 in Dublin, Ireland.

It turns out that the contraction was apparently
originally expressed as a true contraction of the amount
sqrt(1-v^2/c^2) in the direction of motion. This was
in error, of course, and reinterpreted by Einstein in
its modern form, as far as I can tell from very skimpy
research.

http://en.wikipedia.org/wiki/Fitzgerald-Lorentz_contraction

>
> which is cuckoo, and the Ghost transformation
>
> x' = x'/sqrt(1-v^2/c^2) ( a longer length)
> t' = t'/sqrt(1-v^2/c^2) ( a greater duration)
> is as fucking stupid as saying 1 = 2, you fucking ranting lunatic.

Congratulations. You win the "I can't read worth *** award". Your
own reference refers to the equation as being originally written
down by someone named Voigt, who is presumably identified elsewhere;
the Wikipedia has an entry for Voigt, Woldemar, who was a German
physicist, and it turns out he was the first to write the transform,
in some form, a work titled Ã?ber das Doppler'sche Princip in 1887.

Why this became known as the Lorentz transformation is unclear, of
course; all three of Lorentz, Fitzgerald, and Voigt apparently
discovered it independently.

And of course the strawman "Ghost Transform" is cuckoo; I for one would
not use it. You are, of course, free to do as you will.

As for raving lunatics: I for one invite the Esteemed Assembly of
lurkers present to count the number of swear words, as one metric
of lunacy -- or one can merely refer to Dirk's collection of,
erm, snippets.

http://users.pandora.be/vdmoortel/dirk/Physics/ImmortalFumbles.html

>
> Androcles.
>


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