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Re: Ectoplasm (Whoops! Typos eh!)

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>   > Meanwhile, other people, not so
>> limited, understand how the speed needs no material reference.




On 11/09/2018 14:54, Keith Stein wrote:
> On 11/09/2018 12:52, Odd Bodkin wrote:
>> Keith Stein <keithstein111@gmail.com> wrote:
>>> On 10/09/2018 20:27, Odd Bodkin wrote:
>>>> Keith Stein <keithstein111@gmail.com> wrote:
>>>>> On 10/09/2018 18:53, Odd Bodkin wrote:
>>>>>> Keith Stein <keithstein111@gmail.com> wrote:
>>>>>>> On 10/09/2018 18:05, Michael Moroney wrote:
>>>>>>>> Keith Stein <keithstein111@gmail.com> writes:
>>>>>>>>
>>>>>>>>> On 10/09/2018 13:07, Michael Moroney wrote:
>>>>>>>>
>>>>>>>>>> The only problem with that is that Maxwell's Equations just
>>>>>>>>>> come up with the speed of light = constant. Never constant
>>>>>>>>>> relative to anything, just the same constant everywhere.
>>>>>>>>>> Part of the motivation for Einstein's SR later, which raised
>>>>>>>>>> the speed of light=c to all inertial observers to a postulate.
>>>>>>>>
>>>>>>>>> Clearly you have never read Maxwell's "Treatise on Electricity
>>>>>>>>> and Magnetism", Michael. If you had you would surely know that
>>>>>>>>> Maxwell did NOT come up with the speed of light = constant, but
>>>>>>>>> rather a speed which depended on the electric permitivity and
>>>>>>>>> magnetic permeability OF THE MEDIUM. Not only did he NOT
>>>>>>>>> introduce the constants epsilon0 and mu0, but it is obvious
>>>>>>>>> that he would have reject such concepts, since the final
>>>>>>>>> chapter of his famous Treatise is headed "A MEDIUM NECESSARY".
>>>>>>>>
>>>>>>>> The modern Maxwell's Equations (modified by Heaviside, Hertz and 
>>>>>>>> others)
>>>>>>>> have two forms: an unwieldy form where you essentially have to 
>>>>>>>> account for
>>>>>>>> every single charge and current but applies to all situations, 
>>>>>>>> and a
>>>>>>>> simpler/integral form where materials of a bulk form have a 
>>>>>>>> displacement
>>>>>>>> field D replacing the electric field E, and the H magnetizing field
>>>>>>>> replacing the magnet field B. The difference between D and E is 
>>>>>>>> D contains
>>>>>>>> a permittivity of a material which is E_r*E_0, and H is B 
>>>>>>>> divided by the
>>>>>>>> magnetic permeability mu of the material, which is mu_r*mu_0.
>>>>>>>>
>>>>>>>> The first form does not involve materials (except as a whole 
>>>>>>>> bunch of
>>>>>>>> charges/currents that have to be accounted for) and produces the 
>>>>>>>> vacuum
>>>>>>>> speed of light c=1/sqrt(mu_0*E_0). The second form can produce 
>>>>>>>> the speed
>>>>>>>> of light in a material with permittivity E_r*E_0 and permeability
>>>>>>>> mu_r*mu_0.
>>>>>>>>
>>>>>>>> Maxwell did not know E_0 and mu_0 individually, but he did know 
>>>>>>>> their
>>>>>>>> product, and noticed that 1/square root of it was very close to 
>>>>>>>> the known
>>>>>>>> speed of light. This is why Maxwell suggested light was 
>>>>>>>> electromagnetic
>>>>>>>> radiation. The product E_0*mu_0 was discovered in an 1855 
>>>>>>>> experiment by
>>>>>>>> Weber and Kohlrausch.
>>>>>>>>
>>>>>>>> In empty space (no charges, no currents, no materials) the first 
>>>>>>>> form is
>>>>>>>> used and E_0*mu_0 is constant, so the speed of light 
>>>>>>>> c=1/sqrt(E_0*mu_0) is
>>>>>>>> also constant.  It does not (cannot) depend on the velocity of 
>>>>>>>> anything
>>>>>>>> since in empty space there is nothing there to move!
>>>>>>>
>>>>>>>
>>>>>>> No one ever measured E_0 or mu_0, Michael, for the very simple 
>>>>>>> reason
>>>>>>> that THERE ISN'T ANY VACUUM. If you measure the appropriate 
>>>>>>> values for
>>>>>>> a low pressure gas then you obtain the velocity of light RELATIVE TO
>>>>>>> THAT LOW PRESSURE GAS. It is really very simple. You make 
>>>>>>> difficulties
>>>>>>> where there aren't any, Michael.
>>>>>>>
>>>>>>> keith stein
>>>>>>>
>>>>>>
>>>>>> Isn’t this like saying no one has measured where absolute 
>>>>>> temperature on
>>>>>> the temperature scale is? There comes a point where you can fit a 
>>>>>> line and
>>>>>> say these are the values of T_0, mu_0, and epsilon_0, because 
>>>>>> we’ve gotten
>>>>>> ever so close and the extrapolation is completely unambiguous.
>>>>>>
>>>>>
>>>>> There is a critical difference between extrapolating to absolute zero,
>>>>> and extrapolating to perfect vacuum. When one extrapolates to (non
>>>>> existent) perfect vacuum one is omitting the "stuff" which defines the
>>>>> frame of reference with which light travels at its characteristic
>>>>> velocity c, and thereby creating non existent difficulties, because a
>>>>> velocity relative to "nothing" is meaningless eh!
>>>>
>>>> But it’s not nothing.
>>>
>>> I assume you mean that "perfect vacuum" is not "nothing",
>>> which is indeed the modern view, i understand. Although
>>> there again Maxwell was there before us. He put it like
>>> this "A vacuum is what is left in a vessel after everything
>>> which can be removed from the vessel has been removed"
>>>
>>>> You are now saying that the ONLY CONCEIVABLE
>>>> reference for the signal speed is a medium. This is of course not true.
>>>
>>> Well i would be equally happy with notion that the speed
>>> of light within a vessel containing a "vacuum" is defined
>>> with reference to that vessel. What to me is inconceivable
>>> is that it could have the same speed with respect to every
>>> thing eh!
>>
>> I think that’s the problem. You’re only able to think of it as a speed in
>> reference to some material thing. And you say that if your imagination is
>> so limited, then it should be for everyone.
> 
> 
> 
> 
> In my limited system, there is
>        NO LIMIT
>        ON SPEED
> Indeed I myself frequently travel
> at speed >> c, in my imagination eh!
> 
> FIRST CLASS
> (AVERAGE SPEED = INFINITE)
> dep. time.................09.00 GMT or whatever
> arr. time.................left as exercise
> for students
> of
> time               eh!
> 
> In 2nd Class
> we will be examining
> DIGITAL SOLUTIONS to
> the one dimensional
> wave equation
> d2 / dx^2 = c^-2 * d2/ dt^2 (corrected)
> 
> How would YOU Solve the above equation
> DIGITALLY.
> 
> It turns out that its very simple,
> since whatever d2 refers to
> it is going to travel at speed c
> ( relative to the local medium )
>       which isn't too shabby
> for 2nd Class eh!
> 
> keith stein

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Ectoplasm xip1415926@gmail.com - 2018-09-08 09:37 -0700
  Re: Ectoplasm Keith Stein <keithstein111@gmail.com> - 2018-09-10 09:51 +0100
    Re: Ectoplasm Keith Stein <keithstein111@gmail.com> - 2018-09-10 10:12 +0100
      Re: Ectoplasm moroney@world.std.spaamtrap.com (Michael Moroney) - 2018-09-10 12:07 +0000
        Re: Ectoplasm Keith Stein <keithstein111@gmail.com> - 2018-09-10 13:32 +0100
          Re: Ectoplasm moroney@world.std.spaamtrap.com (Michael Moroney) - 2018-09-10 17:05 +0000
            Re: Ectoplasm Keith Stein <keithstein111@gmail.com> - 2018-09-10 18:42 +0100
              Re: Ectoplasm Odd Bodkin <bodkinodd@gmail.com> - 2018-09-10 17:53 +0000
                Re: Ectoplasm Keith Stein <keithstein111@gmail.com> - 2018-09-10 19:16 +0100
                Re: Ectoplasm moroney@world.std.spaamtrap.com (Michael Moroney) - 2018-09-10 18:27 +0000
                Re: Ectoplasm "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2018-09-10 12:23 -0700
                Re: Ectoplasm Odd Bodkin <bodkinodd@gmail.com> - 2018-09-10 19:27 +0000
                Re: Ectoplasm Keith Stein <keithstein111@gmail.com> - 2018-09-11 08:16 +0100
                Re: Ectoplasm Odd Bodkin <bodkinodd@gmail.com> - 2018-09-11 11:52 +0000
                Re: Ectoplasm Keith Stein <keithstein111@gmail.com> - 2018-09-11 14:54 +0100
                Re: Ectoplasm (Whoops! Typos eh!) Keith Stein <keithstein111@gmail.com> - 2018-09-11 16:00 +0100
                Re: Ectoplasm (Whoops! Typos eh!) xip1415926@gmail.com - 2018-09-11 08:27 -0700
                Re: Ectoplasm ( and Epistemology and Einstein's Nefarious Practices.) Keith Stein <keithstein111@gmail.com> - 2018-09-11 16:57 +0100
                Re: Ectoplasm Tom Roberts <tjroberts137@sbcglobal.net> - 2018-09-16 08:56 -0500
                Re: Ectoplasm xip1415926@gmail.com - 2018-09-16 12:48 -0700
                Re: Ectoplasm xip1415926@gmail.com - 2018-09-16 13:01 -0700
                Re: Ectoplasm Keith Stein <keithstein111@gmail.com> - 2018-09-17 18:38 +0100
                Re: Ectoplasm moroney@world.std.spaamtrap.com (Michael Moroney) - 2018-09-17 18:04 +0000
                Re: Ectoplasm Tom Roberts <tjroberts137@sbcglobal.net> - 2018-09-17 14:00 -0500
                Re: Ectoplasm "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2018-09-17 20:59 -0700
                Re: Ectoplasm "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2018-09-17 21:16 -0700
                Re: Ectoplasm "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2018-09-23 20:07 -0700
              Re: Ectoplasm moroney@world.std.spaamtrap.com (Michael Moroney) - 2018-09-10 18:16 +0000
                Re: Ectoplasm Keith Stein <keithstein111@gmail.com> - 2018-09-11 07:52 +0100
                Re: Ectoplasm moroney@world.std.spaamtrap.com (Michael Moroney) - 2018-09-11 12:01 +0000
            Re: Ectoplasm Thomas Heger <ttt_heg@web.de> - 2018-09-14 21:16 +0200
              Re: Ectoplasm Thomas Heger <ttt_heg@web.de> - 2018-09-16 20:23 +0200
      Re: Ectoplasm xip1415926@gmail.com - 2018-09-10 07:03 -0700
      Re: Ectoplasm Tom Roberts <tjroberts137@sbcglobal.net> - 2018-09-10 09:39 -0500
        Re: Ectoplasm Keith Stein <keithstein111@gmail.com> - 2018-09-10 16:18 +0100
        Re: Ectoplasm Wilbur Foley <boue@eywffl.uf> - 2018-09-10 17:07 +0000
  Re: Ectoplasm (or History and Foundations of the LT) Keith Stein <keithstein111@gmail.com> - 2018-09-13 16:24 +0100
    Re: Ectoplasm (or History and Foundations of the LT) xip1415926@gmail.com - 2018-09-14 03:45 -0700

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