I'm not at all convinced that the proper intuition of "speed per electric
potential" should be in terms of the "speed of the propagation of electric
potential".

Having said that...

(2012) Experimental measurement of electric field propagation indicates
that it may be instantaneous:

Measuring Propagation Speed of Coulomb Fields
<http://arxiv.org/pdf/1211.2913v1.pdf>
"We have found that, in this case, *the measurements are compatible with
an instantaneous propagation of the field*. We believe that this intriguing
result needs a theoretical explanation in addition to the Feynman
conjecture or the naive hypothesis of instataneous propagation."


(2000) Here is a contradicting experiment showing finite speed:

Coulomb interaction does not spread instantaneously
<http://cds.cern.ch/record/468803/files/0010036.pdf>

The experiment is described which shows that Coulomb interaction spreads
with a limit velocity and thus this kind of interaction cannot be
considered as so called “instantaneous action at a distance”


On Thu, Feb 26, 2015 at 8:23 PM, Foks0904 . <foks0...@gmail.com> wrote:

> I've been thinking on potential fields again myself. So odd to think an
> electrostatic scalar field could travel "instantaneously", but there's some
> argument for it, and seemingly some experimental evidence, and potentials
> are WEIRD. Just look at Ahranov-Bohm Effect.
>
> On Thu, Feb 26, 2015 at 8:38 PM, James Bowery <jabow...@gmail.com> wrote:
>
>> The broad survey of alternate formulations of Maxwell's Law
>> <http://en.wikipedia.org/wiki/Maxwell%27s_equations#Alternative_formulations>
>>  (which
>> I use in preference to "Maxwell's Equation(s)") shows an interesting
>> pattern:
>>
>> In every non-homogeneous formulation, the right hand side shows some
>> expression of the current field times the permeability of free space.
>> Moreover, most of the left hand sides involve the magnetic vector potential.
>>
>> Both sides of these equations have the same physical dimensions as the
>> magnetic vector potential.   By inverting the dimensions of both sides, one
>> may express the critical physical dimension of Maxwell's Law as:
>>
>> velocity per electric potential
>>
>> This has intuitive meaning worth contemplating.
>>
>> Derivation:
>>
>> The vector potential has dimension:
>>
>> momentum per charge
>>
>> In cgs units (gramm = gram as mass as opposed to force in one gravity):
>>
>> gramm*cm/(s*coulomb)
>>
>> The permiability of free space
>> <http://en.wikipedia.org/wiki/Vacuum_permeability> times current has
>> dimension:
>>
>> current electric potential time per (current length)
>>
>> In cgs units:
>>
>> amps*volts*sec/(amps*cm)
>>
>> The amps cancel:
>>
>> volts*sec/cm
>>
>> Subjecting the two sides to a dimensional analysis calculator
>> <http://www.testardi.com/rich/calchemy2/>:
>>
>> gramm*cm/(s*coulomb)?volt*s/cm
>> (gramm * [centi*meter]) / (second * coulomb) ? (volt * second) /
>> (centi*meter)
>> = 1E-7 volt*s/cm
>>
>> In other words, the dimensions of these two units-based expressions
>> match, with only a constant of proportionality difference.
>>
>> Examining the right hand side, the not-so-intuitive ratio "s/cm" has the
>> inverse dimension of velocity, so we can reconsider Maxwell's Law
>> reformulated in terms of a left hand side which is the inverse of the
>> vector potential, and the right hand side which is:
>>
>> (s*coulomb)/(gramm*cm)?(cm/s)/volt
>> (second * coulomb) / (gramm * [centi*meter]) ? ([centi*meter] / second) /
>> volt
>> = 1E7 (cm/s)/volt
>>
>> So we see (cm/s)/volt or velocity per electric potential is not only a
>> relatively intuitive dimension -- it is central to formulations of
>> Maxwell's Law.
>>
>
>

Reply via email to