
On Fri, 17 Mar 2006 14:12:12 0000, "George Dishman" <[email protected]>
wrote:
>
>"Henri Wilson" <HW@..> wrote in message
>news:[email protected]
>> On Tue, 14 Mar 2006 23:38:15 0000, "George Dishman"
>> <[email protected]>
>> wrote:
>>>>>> >> Well I don't accept that spacetime is anything other than a maths
>>>>>> >> convenience.
>>>>>> >> It is certainly interesting to plot various movements in 2D space
>>>>>> >> and
>>>>>> >> 1D
>>>>>> >> time...which can be done fairly easily.
>>>>>> >> y t
>>>>>> >>  /
>>>>>> >>  /
>>>>>> >> /________x
>>>>>> >>
>>>>>> >>
>>>>>> >> 4D can be represented this way too if a series of lines is drawn
>>>>>> >> representing
>>>>>> >> the movement at different TIME coordinates.
>>>>>> >>
>>>>>> >>
>>>>>> >> y z
>>>>>> >>  / ___t1
>>>>>> >>  /__/
>>>>>> >> /________x
>>>>>> >>
>>>>>> >>
>>>>>> >> Alternatively you can try plotting 4D on THESE axes, varying the
>>>>>> >> 'z'
>>>>>> >> instead of
>>>>>> >> 't':
>>>>>> >>
>>>>>> >> y t
>>>>>> >>  /
>>>>>> >>  /
>>>>>> >> /________x
>>>>>> >>
>>>>>> >
>>>>>> >You can but remember the minus sign for t^2 values
>>>>>> >though.
>>>>>>
>>>>>> If I though time went backwards I would give it a  sign.
>>>>>
>>>>>It's not your to choose, and it's "t^2", not "t".
>>>>
>>>> You're confusing this with the maths of SR.
>>>
>>>That's what we are talking about  see above.
>>>
>>>> Einstein uses ict as the time axis,
>>>
>>>Nope, he uses t as the time axis.
>>>
>>>> the imaginary nature denoting
>>>> orthogonality.
>>>
>>>Nope, the negative sign is the change in the
>>>Pythagorean equation produced by the geometry.
>>>
>>>> But of course 'ct' is not TIME at all. It is distance moved by light
>>>> traveling
>>>> at c.
>>>
>>>Nope, it is time expressed in units of metres.
>>>
>>>> 'Spacetime' in not space and time.
>>>
>>>Correct, it is a single 4D manifold. Hey, you
>>>got one right :)
>>
>> It isn't even 4D. It is 3D space but with an extra imaginary spatial axis
>> that
>> denotes the distance light would move at c in unit time.
>
>If you are just going to ignore what I say, there's
>not much point in commenting. The t axis is still
>time, not a distance.
It is 'ct'....definitely distance.
>>>> It is Euclidean space plus a spatial axis based on light movement.
>>>
>>>Back to normal, your showing your ignorance
>>>of SR again Henry.
>>
>> x^2+y^2+z^2ct^2=c.tor^2
>>
>> Think about what that means George.
>>
>> What is the vector c.tor?
>
>It isn't even a vector Henry.
>
>>>>>> >>>Maxwell's Equations require it, Sagnac's experiment
>>>>>> >>>directly supports Einstein's postulate from which it is
>>>>>> >>>logically derived and the MMX, Ives and Stilwell, Hulse
>>>>>> >>>and Taylor and many more confirm its predictions.
>>>>>> >>
>>
>>>>>> >The speed is dx/dt. Maxwell may have conceptualised
>>>>>> >an aether but it isn't in the equations.
>>>>>>
>>>>>> Correct, the speed is dx/dt where x is distance in the aether
>>>>>
>>>>>Don't be stupid Henry, nobody can even prove
>>>>>an aether exists never mind measure distance
>>>>>relative to it.
>>>>
>>>> Correct. There isn't an aether...but SR cannot exist without one.
>>>
>>>Already proven to be a fallacious assertion,
>>>but again irrelevant, x is not "distance in
>>>the aether".
>>
>> It is 'contracted' distance in the aether, as per Lorentz.
>
>Nope, Maxwell's Equations were written years
>before Lorentz got involved.
When Maxwell believed in an aether.
>
>>>>>It doesn't matter anyway, whatever
>>>>>you take for x, the value of dx/dt is the same for
>>>>>all source in Maxwell's Equations so they cannot
>>>>>be used for a Ritzian model. You seem to be having
>>>>>a lot of trouble grasping this simple point.
>>>>
>>>> You seem to be having difficulty in grasping that speed must always have
>>>> a
>>>> reference.
>>>
>>>No, you seem to be having difficulty grasping
>>>that dx/dt has only one value whatever the
>>>reference so light from all sources travels
>>>at the same speed according to the equations.
>>
>> ..and I hope I continue to have difficulty grasping such an impossibility.
>>
>>>> You seem to be having difficulty in grasping the fact that two
>>>> differently
>>>> moving observers
>>>
>>>You seem to be having trouble remembering that
>>>my proof of your error only uses one observer
>>>and two sources, not vice versa.
>>
>> You cannot answr a question by changing the question, George.
>
>Then why are you trying? Stick to my original
>point, one observer and two sources, not multiple
>observers.
The speed at which light travels wrt its source has nothing to do with any
observer. How could it? Light has no idea where it is heading.
Maxwell's 'c' refers to the speed of light emitted in the frame of the
apparatus which measured the constants that produced the answer. The answer in
turn reflects the permittivity and permeability of the apparatus, not those of
completely empty space.
>>>>>They are essential dealing with the units we use.
>>>>>Permittivity deals with the units of capacitance
>>>>>and length:
>>>>>
>>>>> capacitance = permittivity * area / length
>>>>>
>>>>>So the permittivity of a vacuum tells you
>>>>>(in part) how much charge will be held in
>>>>>a vacuum capacitor for a given voltage.
>>>>>
>>>>>It is also the square of the refractive index.
>>>>>
>>>>>Permeability is similar but relates to the
>>>>>magnetic field.
>>>>
>>>> ...and to measure either, one must create a 'field'....an act that
>>>> immediately
>>>> destroys the 'perfect vacuum'.
>>>
>>>No it doesn't since the field doesn't alter
>>>the permittivity or permeability.
>>
>> Oh? So you know what fields are made of do you George?
>
>Keeping to the point, I know what permittivity is.
>
>> Can you explain actionatadistance then? Physically, I mean.
>>
>>>>>> If differently moving observers measure the same values for the
>>>>>> constants, what
>>>>>> does that tell you about light speed?
>>>>>
>>>>>It tells you they will both measure the same
>>>>>speed IF the equations are correct.
>>>>
>>>> ..and IF their instruments contract as per LET.
>>>
>>>Nope, there is no instrument contraction term
>>>in Maxwell's Equations, they are simply not
>>>applicable to a Ritzian model.
>>
>> Sorry George, they are perfectly compatible. They produce the value c for
>> light
>> speed wrt its source.
>
>Learn some basic maths Henry, how to solve
>differential equations and superposition of
>solutions.
Learn some basic logic George. The equations apply to a medium.
>>>>>> Nothing! It might provide a value for the universal constant 'c' but
>>>>>> clearly
>>>>>> light cannot be moving at the same speed wrt both observers.
>>>>>
>>>>>If you think the speeds aren't going to
>>>>>be the same, then you can't use those
>>>>>equations. That was my point.
>>>>
>>>> I don't just THINK they cannot be the saem. They obviously cannot.
>>>
>>>We know from experiment that they are, it is
>>>only your philosophy that conflicts.
>>
>> What experiments George?
>
>See the previous times I've listed them.
Not one is believable.
>
>George
>
HW.
www.users.bigpond.com/hewn/index.htm

