🚀 go-pugleaf

On Apr 30, 6:12 am, bill <cosmo...@optusnet.com.au> wrote:
> On Apr 30, 6:10 pm, "G. L. Bradford" <glbra...@insightbb.com> wrote:
>
> > "bill" <cosmo...@optusnet.com.au> wrote in message
> >   Obviously you think photons of light are cannon balls you can catch up to.
>
> Almost correct (i.e. not cannonballs) but only after we have
> successfully cracked the light barrier which, as Einstein pointed out,
> is a result of SR that is invalidated by the presence of a
> gravitational field.
>
> > To any traveler, no less than any other observer, all light, whether
> > internal or external to it, is locally measured c. The traveler has a body
> > and a complete set of [usual] physics, as does his vessel, and as does his
> > local universe, frame, environment, what have you, and that must include the
> > [usual] physics of light.

==============

>
> Light is only measured by any traveler to be c only in accordance with
> the theory that his rule incurs length contraction and his clock slows
> down when he is moving relatively to the source of that light compared
> to when he was contained in the same RF as the source.

Enjoy your nap Mr. Van Winkle?

http://en.wikipedia.org/wiki/Lorentz_ether_theory

Welcome to the 21st century!

<< where epsilon_0 and mu_0 are physical constants which
can be evaluated by performing two simple experiments
which involve measuring the force of attraction between
two fixed charges and two fixed parallel current carrying
wires. According to the relativity principle, these experiments
must yield the same values for epsilon_0 and mu_0 in all
inertial frames. Thus, the speed of light must be the
same in all inertial frames. >>
http://farside.ph.utexas.edu/teaching/em/lectures/node108.html

>
> According to SR if a source emits a beam of light the front end of
> that beam is moving at c away from the source however if the source
> accelerates in the same direction as a beam of light that it is
> projecting the front end of that beam as well as its constituent
> photons are not moving away from the source at c. Special theory does
> NOT apply to accelerating reference frames!

It barely applies to light because light has no
mass.

<< Einstein's relativity principle states that:

     All inertial frames are totally equivalent
     for the performance of all physical experiments.

In other words, it is impossible to perform a physical
experiment which differentiates in any fundamental sense
between different inertial frames. By definition, Newton's
laws of motion take the same form in all inertial frames.
Einstein generalized[1] this result in his special theory of
relativity by asserting that all laws of physics take the
same form in all inertial frames. >>
http://farside.ph.utexas.edu/teaching/em/lectures/node108.html

No... SR can't say much about light because it substitutes
"stipulations" and "definitions" and specifically
excludes the behaviour of light.

<<There is only one demand to be made of the
definition of simultaneity, namely, that in
every real case it must supply us with an
empirical decision as to whether or not the
conception that has to be defined is fulfilled.
That my definition satisfies this demand is
indisputable. That light requires the same time
to traverse the path A —> M as for the path B —> M
is in reality neither a supposition nor a hypothesis
about the physical nature of light, but a stipulation
which I can make of my own freewill in order
to arrive at a definition of simultaneity.”>>
http://www.bartleby.com/173/8.html

Those things fit nicely on an imaginary axis
however as H. Minkowski demonstrated:

<< the four-dimensional space-time continuum of the
theory of relativity, in its most essential formal
properties, shows a pronounced relationship to the
three-dimensional continuum of Euclidean geometrical space.
In order to give due prominence to this relationship,
however, we must replace the usual time co-ordinate t by
an imaginary magnitude

   sqrt(-1)

ct proportional to it. Under these conditions, the
natural laws satisfying the demands of the (special)
theory of relativity assume mathematical forms, in which
the time co-ordinate plays exactly the same rôle as
the three space co-ordinates. >>
http://www.bartleby.com/173/17.html

>
> >   Light has no rear to run down, overrun, or outrun. Photons of light are
> > not 3-dimensional cannon balls, components, or bubbles or cubes of any kind.
>
> If a light source is illuminated for a brief period of time the end of
> that beam represents 'a rear' that, if we are moving with superluminal
> velocity, can be 'run down' i.e. overtaken.
>
> > They too have no rear to run down, overrun, or outrun. They are
> > 2-dimensional, single-sided (therefore [massless]) entities.
>
> No doubt in your opinion - not in mine which is that individual
> photons of light are 'quantum packages of energy' that are not 2
> dimensional.
>
> >   There is simply no such thing as coming up from behind on something which
> > isn't there from behind. All light and photons you or anything else deals
> > directly in is oncoming light and photons smacking you, or smacking that
> > anything else, as its destination point, not departure point: Every point in
> > the universe deals in light as messengers with messages directly to it, not
> > ever messengers and messages going away because they have no existence to
> > that side (going away). Light (or a photon) doesn't need any infinite speed
> > to keep from ever being overtaken from the rear because, once more, there is
> > no such thing as overtaking what isn't there -- what doesn't exist -- from
> > the rear to be overtaken.
>
> In the 'classical' 'ratification' of time dilation - the light clock -
> that beam is not oncoming light and there are no photons smacking into
> the observer. It IS a purely hypothetical depiction as is mine which
> involves a observer looking at a far distant source that is projecting
> light in both direction none of which is moving toward or smacking
> into him.
>
> >   Sheez what a purely hellish universe it would be if photons were
> > 3-dimensional (...if light was 3-dimensional).
>
> > GLB
>
> > ===================
>
> Beams of light have their own gravitational fields so it follows that
> individual photons also generate gravity which would not be possible
> if they were massless, 2 dimensional entities.

Huh ?

"Beams" are the result of EM coupling structures
(antenna) which interact gravitationally when the
wind blows them down.  :-))

http://www.rp-photonics.com/gaussian_beams.html
http://personal.ee.surrey.ac.uk/Personal/D.Jefferies/antennas.html

Sue...