🚀 go-pugleaf

On Thu, 6 May 2010 13:19:16 -0700 (PDT), PD <thedraperfamily@gmail.com> wrote:

>On May 5, 3:47�am, ..@..(Henry Wilson DSc) wrote:
>> On Tue, 27 Apr 2010 03:33:28 -0700 (PDT), "Sue..." <suzysewns...@yahoo.com.au>
>> wrote:
>>
>> >On Apr 27, 12:28�am, Pentcho Valev <pva...@yahoo.com> wrote:
>> >[...]
>>
>> ><< 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. >>
>>
>> Q1) Is there an experiment that shows that differently moving observers at the
>> same point get the same value for e and mu?
>
>Yes. This is commonly done by observing an electric current from two
>different reference frames.
>Since the electric and magnetic fields are related to the current by
>relations involving permittivity and permeability, it is sufficient to
>show that the same relations still work relating the new current to
>the new fields in the other frame.
>
>>
>> Q2) How do you know that the fields involved in above experiments do not
>> actually create the quantities that are being measured.
>
>Then this would significantly alter Maxwell's equations, and the
>solutions would be dramatically different, and they would no longer
>produce predictions that match experiment.
>For example, if you take Gauss' law (one of the relations) and change
>E = E(epsilon_0, r, q) to E = E(epsilon_0(E, B), r, q), so that
>epsilon_0 is now a function of the fields E and B, then solving that
>equation produces different solutions. The fact that the solutions
>taking epsilon_0 to be field-independent work so well gives you solid
>confidence that epsilon_0 is in fact field-independent.
>
>This is a simple exercise that a third-year student will typically do.
>
>>
>> I say that TRULY EMPTY space has zero e or mu.
>
>Well, what most people think of empty space is space devoid of matter.
>Now you may have the notion that space devoid of matter still has
>stuff in it, and it's only because no one has ever been able to remove
>the stuff that they've been able to see that those quantities are
>zero.
>
>What you need to propose is how to make that stuff be removed, so that
>your wild-ass conjecture might conceivably be measured.
>
>Otherwise, it's like proposing that those are the properties of
>peskily persistent angels who refuse to budge.
>

Maxwell devised a way to obtain a value for the universal constant known as
'c'.

It happens that the speed of light wrt its source is also numerically equal to
c.

Henry Wilson...

.......A relativist's IQ = his snipping ability.