Le 27/03/2024 à 22:34, Aether Regained a écrit :
> Volney:
>> On 3/25/2024 11:28 AM, Aether Regained wrote:
>>> J. J. Lodder:> LaurenceClarkCrossen <clzb93ynxj@att.net> wrote:
>>>>
>>>>> It is the most ridiculous scientific mistake in history.
>>>>>
>>>>> Einstein took the null result of MMX to disprove the ether.
>>>>
>>>> Wrong, both historicaly and factualy.
>>>>
>>>>> The Lorentz Transformation would make it possible to keep the ether.
>>>>>
>>>>> Einstein kept the LT and discarded the ether.
>>>>
>>>> Wrong. Einstein (and Lorentz with him)
>>>> saw that the aether has no observable properties.
>>>> Lorentz had already seen that to order (v/c)^2,
>>>> and after Einstein 1905 he saw
>>>> that there are no observable effects of an aether to all orders of v/c.
>>
>> In the LET, the aether is undetectable.
>>>>
>>>
>>> There are no observable effects of an aether? What then are the
>>> electromagnetic and gravitational fields, if not observable effects of
>>> an aether?
>>
>> Free space can propagate certain fields such as electromagnetism, with
>> associated constants such as ε₀ and μ₀. The old fashioned luminiferous
>> aether had mechanical properties to propagate light as if it were like
>> sound. Free space properties are not mechanical, and if you want, you
>> could call the ability to propagate electromagnetic fields an aether,
>> but this leads to confusion with the obsolete aether of the 1800s.
>> Einstein explicitly stated that aether had no mechanical properties, so
>> velocity relative to the aether is meaningless. "But this ether may not
>> be thought of as endowed with the quality characteristic of ponderable
>> media, as consisting of parts which may be tracked through time. The
>> idea of motion may not be applied to it."
>
> @Volney, see my reply to Gary Harnagel citing Dirac's 1951 "Is there and
> Aether?", which is cited below too:
>
> The gist is that one can safely let go of this notion due to Einstein
> that the aether may not be conceived as having parts which are in motion.
>
> Dirac 1951: "Is there and Aether?"
> https://doi.org/10.1038/168906a0
> ########################################
>
> In the last century, the idea of a universal and all-pervading aether
> was popular as a foundation on which to build the theory of
> electromagnetic phenomena. The situation was profoundly influenced in
> 1905 by Einstein's discovery of the principle of relativity, leading to
> the requirement of a four-dimensional formulation of all natural laws.
> It was soon found that the existence of an aether could not be fitted in
> with relativity, and since relativity was well established, the aether
> was abandoned.
>
> Physical knowledge has advanced very much since 1905, notably by the
> arrival of quantum mechanics, and the situation has again changed. If
> one re-examines the question in the light of present-day knowledge, one
> finds that the aether is no longer ruled out by relativity, and good
> reasons can now be advanced for postulating an aether.
>
> Let us consider in its simplest form the old argument for showing that
> the existence of an aether is incompatible with relativity. Take a
> region of space-time which is a perfect vacuum, that is, there is no
> matter in it and also no fields. According to the principle of
> relativity, this region must be isotropic in the Lorentz sense—all
> directions within the light-cone must be equivalent to one another.
> According to the ather hypothesis, at each point in the region there
> must be an aether, moving with some velocity, presumably less than the
> velocity of light. This velocity provides a preferred direction within
> the light-cone in space-time, which direction should show itself up in
> suitable experiments. Thus we get a contradiction with the relativistic
> requirement that all directions within the light-cone are equivalent.
>
> This argument is unassailable from the 1905 point of view, but at the
> present time it needs modification, because we have to apply quantum
> mechanics to the aether. The velocity of the aether, like other physical
> variables, is subject to uncertainty relations. For a particular
> physical state the velocity of the aether at a certain point of
> space-time will not usually be a well-defined quantity, but will be
> distributed over various possible values according to a probability law
> obtained by taking the square of the modulus of a wave function. We may
> set up a wave function which makes all values for the velocity of the
> aether equally probable. Such a wave function may well represent the
> perfect vacuum state in accordance with the principle of relativity.
>
> One gets an analogous problem by considering the hydrogen atom with
> neglect of the spins of the electron and proton. From the classical
> picture it would seem to be impossible for this atom to be in a state of
> spherical symmetry. We know experimentally that the hydrogen atom can be
> in a state of spherical symmetry—any spectroscopic S-state is such a
> state —and the quantum theory provides an explanation by allowing
> spherically symmetrical wave functions, each of which makes all
> directions for the line joining electron to proton equally probable.
>
> We thus see that the passage from the classical theory to the quantum
> theory makes drastic alterations in our ideas of symmetry. A thing which
> cannot be symmetrical in the classical model may very well be
> symmetrical after quantization. This provides a means of reconciling the
> disturbance of Lorentz symmetry in space-time produced by the existence
> of an aether with the principle of relativity.
>
> There is one respect in which the analogy of the hydrogen atom is
> imperfect. A state of spherical symmetry of the hydrogen atom is quite a
> proper state—the wave function representing it can be normalized. This
> is not so for the state of Lorentz symmetry of the aether.
>
> Let us assume the four components v_μ of the velocity of the aether at
> any point of space-time commute with one another. Then we can set up a
> representation with the wave functions involving the v's. The four v's
> can be pictured as defining a point on a three-dimensional hyperboloid
> in a four-dimensional space, with the equation :
>
> v₀²-v₁²-v₂²-v₃² = 1, v₀ > 0 (1) [LaTeX: v_0^2 - v_1^2 - v_2^2
> -
> v_3^2 = 1, v_0 > 0]
>
> A wave-function which represents a state for which all aether velocities
> are equally probable must be independent of the v's, so it is a constant
> over the hyperboloid (1). If we form the square of the modulus of this
> wave function and integrate over the three-dimensional surface (1) in a
> Lorentz-invariant manner, which means attaching equal weights to
> elements of the surface which can be transformed into one another by a
> Lorentz transformation, the result will be infinite. Thus this wave
> function cannot be normalized.
>
> The states corresponding to wave functions that can be normalized are
> the only states that can be attained in practice. A state corresponding
> to a wave function which cannot be normalized should be looked upon as a
> theoretical idealization, which can never be actually realized, although
> one can approach indefinitely close to it. Such idealized states are
> very useful in quantum theory, and we could not do without them. For
> example, any state for which there is a particle with a specified
> momentum is of this kind—the wave function cannot be normalized because
> from the uncertainty principle the particle would have to be distributed
> over the whole universe — and such states are needed in collision problems.
>
> We can now see that we may very well have an aether, subject to quantum
> mechanics and conforming to relativity, provided we are willing to
> consider the perfect vacuum as an idealized state, not attainable in
> practice. From the experimental point of view, there does not seem to be
> any objection to this. We must make some profound alterations in our
> theoretical ideas of the vacuum. It is no longer a trivial state, but
> needs elaborate mathematics for its description.
>
> I have recently (Proc. Roy. Soc., [A, 209, 291 (1951)]) put forward a
> new theory of electrodynamics in which the potentials A_μ, are
> restricted by :
>
> A_μA_μ= k², [LaTeX: A_{\mu} A_{\mu} = k^2]
>
> where k is a universal constant. From the continuity of A₀ we see that
> it must always have the same sign and we may take it positive. We can
> then put
>
> k⁻¹A_μ = v_μ (2) [LaTeX: k^{-1} A_{\mu} = v_{\mu}]
>
> and get v's satisfying (1). These v's define a velocity. Its physical
> significance in the theory is that if there is any electric charge it
> must flow with this velocity, and in regions where there is no charge it
> is the velocity with which a small charge would have to flow if it were
> introduced.
>
> We have now the velocity (2) at all points of space-time, playing a
> fundamental part in electrodynamics. It is natural to regard it as the
> velocity of some real physical thing. THUS WITH THE NEW THEORY OF
> ELECTRODYNAMICS WE ARE RATHER FORCED TO HAVE AN AETHER.
>
> (Proc. Roy. Soc., [A, 209, 291 (1951)]): Dirac, P. A. M. (1951). A New
> Classical Theory of Electrons. Proceedings of the Royal Society A:
> Mathematical, Physical and Engineering Sciences, 209(1098), 291–296.
>
> https://doi.org/10.1098/rspa.1951.0204
>
> ########################################