Re: Lorentz transformations - a derivation

From: jem (xxx_at_xxx.xxx)
Date: 01/09/05 

Date: Sun, 09 Jan 2005 08:32:39 -0500

Bill Hobba wrote:
> "jem" <xxx@xxx.xxx> wrote in message
> news:sdSDd.25692$Q%4.10400@fed1read06...

>>Remember this proposed definition? An inertial reference frame is a
>>reference frame in which all stationary standard clocks tick at the same
>>rate.
>
>
> How do you sync those clocks?

It's not necessary to synchronize clocks in order to compare their tick
rates.

  I am pretty sure you will need the assumption
> of space being homogeneous and isotropic to ensure your chosen method is
> valid. When I first read his views on the matter quite some time ago now I
> thought and thought about it and was forced to concede he had a point. For
> example construct a coordinate system from practically rigid rods, sync
> clocks via light (all of which involve further physical assumptions such as
> homogeneity and isotropy of space to ensure the method of syncing works -
> otherwise it is simply a convention that can be challenged - you see posters
> doing it all the time), check if a particle is free then measure its motion.
> If all the previously mentioned problems were not enough the problem now is
> how do you ensure a particle is free? Exactly what does free mean? Does it
> mean if we can not find something in the frame that will not affect its
> motion then it is free? Exactly what is meant by something not affecting
> its motion? - does that apply to forces of acceleration? One might like to
> define an inertial frame by for example the absence of inertial or
> gravitational forces as indicated by accelerometers. But again such a
> definition relies on further physical assumptions based on our intuition
> about force. That seems to be the problem with Newton's first law - one
> really needs further physical assumptions to make it meaningful and those
> assumptions are all based on physical intuition and/or some convention such
> as the Einstein sync procedure. If you do not make these further
> assumptions then you run into the problem that Bilge alludes to 'We define a
> straight line as the path of an inertial object and we define an inertial
> object as one which moves in a straight line' The best way to operationally
> define an inertial frame I think is via the EEP.

The proposed definition says nothing about the motion of particles, free
or otherwise.

Relevant Pages

  • Re: Lorentz transformations - a derivation
    ... >>reference frame in which all stationary standard clocks tick at the same ... > example construct a coordinate system from practically rigid rods, sync ... > doing it all the time), check if a particle is free then measure its motion. ...
    (sci.physics)
  • Re: Einsteins Train Gedanken Re-visited
    ... the one moving with the earth would stay 'still' ... see we need to make it explicit) what do you claim about the clocks ... appropriate speed would keep it in sync. ... frame would then be inertial. ...
    (sci.physics.relativity)
  • Re: Einsteins Train Gedanken Re-visited
    ... the one moving with the earth would stay 'still' ... I thought the whole purpose of this exercise was to get clocks in sync ... frame would then be inertial. ...
    (sci.physics.relativity)
  • Re: Einsteins Train Gedanken Re-visited
    ... the one moving with the earth would stay 'still' ... I thought the whole purpose of this exercise was to get clocks in sync ... frame would then be inertial. ...
    (sci.physics.relativity)
  • Re: Einsteins Train Gedanken Re-visited
    ... >>> Earth itself is accelerating as it travels in its orbit about the ... >> see we need to make it explicit) what do you claim about the clocks as ... appropriate speed would keep it in sync. ... galaxy etc. its pretty much impossible to get a perfectly inertial frame .. ...
    (sci.physics.relativity)