View source for Aether-Theory Clock Retardation vs Special Relativity Time Dilation

{{Infobox paper
| title = Aether-Theory Clock Retardation vs Special Relativity Time Dilation
| url = [http://www.naturalphilosophy.org/pdf/abstracts/abstracts_1098.pdf Link to paper]
| author = [[Joseph Levy]]
| keywords = [[clock retardation]], [[special relativity]], [[aether]], [[Time Dilation]]
| published = 2008
| num_pages = 15
}}

'''Read the full paper''' [http://www.naturalphilosophy.org/pdf/abstracts/abstracts_1098.pdf here]

==Abstract==

Assuming a model of aether non-entrained by the motion of celestial bodies, one can provide a rational explanation of the experimental processes affecting the measurement of time when clocks are in motion. Contrary to special relativity, aether theory does not assume that the time itself is affected by motion; the reading displayed by the moving clocks results from two facts:

# Due to their movement through the aether, they tick at a slower rate than in the aether frame.
# The usual synchronization procedures generate a synchronism discrepancy effect.

These facts give rise to an alteration of the measurement of time which, as we shall show, exactly explains the experimental results. In particular, they enable to solve an apparent paradox that special relativity cannot explain (see chapter 4). When the measurement distortions are corrected, the time proves to be the same in all co-ordinate systems moving away from one another with rectilinear uniform motion. These considerations strongly support the existence of a privileged aether frame. The consequences concern special relativity (SR) as well as general relativity (GR) which is an extension of SR. We should note that Einstein himself became conscious of the necessity of the aether from 1916, in contrast with conventional relativity. Yet the model of aether presented here differs from Einsein's in that it assumes the existence of an aether drift, in agreement with the discoveries of G.F. Smoot and his co-workers listed in Smoot's Nobel Lecture, December 8th 2006. Although it makes reference to previous studies, this text remains self-sufficient.

==Overview==

This paper — an expanded version of arXiv physics/0611077, with a new chapter on reciprocity — sets the relativistic and the Lorentzian accounts of moving clocks side by side on one deliberately simple apparatus: the two-way transit of light along a rod held perpendicular to the direction of motion. [[Joseph Levy]] works throughout with an aether in the [[Hendrik Lorentz|Lorentz]] sense: a privileged frame, not entrained by the motion of celestial bodies, in which the one-way [[Speed of Light|speed of light]] is ''C''. In that picture, time itself is not affected by motion. What happens instead is two separate physical and procedural facts: clocks moving through the aether tick slow, and the standard synchronization procedures introduce a systematic error, the "synchronism discrepancy effect" (SDE) first identified by Prokhovnik. Levy's claim is that these two effects, taken together, reproduce exactly the readings [[Special Relativity]] predicts — so that the experimental record is preserved while its interpretation is reversed.

The departure from the textbook account is therefore not empirical but interpretive, and Levy is explicit about this: "This study does not question the experimental results brought about by relativity theory since... it predicts the same clock readings as SR provided that we use the standard measurement procedures." What he claims to have exposed are ''hidden variables'' — the real speeds ''v''<sub>01</sub>, ''v''<sub>02</sub> of the frames with respect to the aether frame — which the standard procedures conceal, and which reappear the moment the measurement distortions are corrected. He also argues that the aether frame is in principle distinguishable from the others, contrary to the usual claim, and appeals to G.F. Smoot's [[Cosmic Microwave Background]] dipole measurements as evidence of a real "aether drift", noting that Einstein's own 1920 Leyden aether ("the idea of motion may not be applied to this model of aether...") cannot accommodate such a drift.

==The argument==

===The relativistic baseline===

Two frames ''S''<sub>0</sub> and ''S''<sub>1</sub> recede along the ''x''-axis. A light ray leaves a point M fixed in ''S''<sub>1</sub>, travels along a rod ''L'' = MB perpendicular to the ''x''&prime;-axis, reflects at B and returns. In ''S''<sub>1</sub> the two-way transit time is 2''t''<sub>1</sub> = 2''L''/''C''. Viewed from ''S''<sub>0</sub>, the ray goes from A to B to A&prime;, and the Pythagorean relation ''C''<sup>2</sup>''t''<sub>0</sub><sup>2</sup> − ''v''<sub>01</sub><sup>2</sup>''t''<sub>0</sub><sup>2</sup> = ''L''<sup>2</sup> gives ''t''<sub>0</sub> = ''t''<sub>1</sub>/(1 − ''v''<sub>01</sub><sup>2</sup>/''C''<sup>2</sup>)<sup>1/2</sup>. Special relativity reads this as [[Time Dilation]] of time itself.

===Clock retardation in aether theory===

Levy now takes ''S''<sub>0</sub> to be at rest in the aether frame, where the clock reading is unaltered and defines "real time". The same geometry gives the same ''t''<sub>0</sub>, but the interpretation changes: clocks moving at absolute speed ''v'' are ''assumed'' to be retarded by the factor (1 − ''v''<sup>2</sup>/''C''<sup>2</sup>)<sup>1/2</sup> — an assumption Levy says will be "justified a posteriori". The clock in ''S''<sub>1</sub> therefore displays ''t''<sub>1app</sub> = ''L''/''C'', and formula (1), ''t''<sub>0</sub> = ''t''<sub>1app</sub>/(1 − ''v''<sub>01</sub><sup>2</sup>/''C''<sup>2</sup>)<sup>1/2</sup>, has the algebraic shape of the relativistic result while meaning something else entirely: ''t''<sub>1app</sub> is not the true time in ''S''<sub>1</sub> but the reading of a slowed clock. Levy adds a caution that in a preferred-frame theory no real frame is ever perfectly inertial; "inertial" is an approximation valid when absolute speeds are small compared with ''C''.

===Two frames both moving through the aether===

The practical case has ''S''<sub>1</sub> and ''S''<sub>2</sub> both receding from the aether frame ''S''<sub>0</sub>, with the rod fixed in ''S''<sub>2</sub>. Pure clock retardation then gives formula (5), ''t''<sub>1app</sub> = ''t''<sub>2app</sub>(1 − ''v''<sub>01</sub><sup>2</sup>/''C''<sup>2</sup>)<sup>1/2</sup>/(1 − ''v''<sub>02</sub><sup>2</sup>/''C''<sup>2</sup>)<sup>1/2</sup>. To first order this depends on ''both'' the relative speed ''v''<sub>12</sub> ''and'' the absolute speed ''v''<sub>01</sub> — through the combination ''v''<sub>12</sub>(''v''<sub>12</sub> + 2''v''<sub>01</sub>) — whereas the relativistic formula (2) depends on ''v''<sub>12</sub> alone. Levy stresses the consequence: "if clocks were exactly synchronized, there would be an obvious difference between the two theories."

But exact synchronization is not what is done. Measuring a cycle in ''S''<sub>1</sub> requires two spatially separated clocks A and A&prime;, and these must first be synchronized by the Einstein–[[Henri Poincaré|Poincaré]] light-signal method (or by slow clock transport, shown by several authors to be equivalent). Levy derives the resulting error. With ''l''<sub>0</sub> the uncontracted length AA&prime;, [[Length Contraction]] gives the real length ''l'' = ''l''<sub>0</sub>(1 − ''v''<sub>01</sub><sup>2</sup>/''C''<sup>2</sup>)<sup>1/2</sup>, and the one-way real transit times use ''C'' − ''v''<sub>01</sub> and ''C'' + ''v''<sub>01</sub> — "the expression used by Lorentz to explain the Michelson experiment", real speeds being simply additive in this theory. The difference between the true one-way time and half the two-way time is the synchronism discrepancy &Delta;; reduced by clock retardation it becomes &delta; = ''v''<sub>01</sub>''l''<sub>0</sub>/''C''<sup>2</sup>.

Subtracting the SDE from the retarded reading and using ''l'' = 2(''v''<sub>02</sub> − ''v''<sub>01</sub>)''t''<sub>0</sub>, several lines of algebra collapse formula (12) into formula (13), and hence (15): the measured ratio is governed by (1 − ''v''<sub>12app</sub><sup>2</sup>/''C''<sup>2</sup>)<sup>1/2</sup> with the ''apparent'' relative speed ''v''<sub>12app</sub> = (''v''<sub>02</sub> − ''v''<sub>01</sub>)/(1 − ''v''<sub>01</sub>''v''<sub>02</sub>/''C''<sup>2</sup>). Levy points out that this is the relativistic velocity-composition law, here obtained by pushing the Galilean law through the measurement distortions — so its "apparent character is highlighted". He also observes that when ''S''<sub>1</sub> is the aether frame, ''v''<sub>01</sub> = 0 and ''v''<sub>12app</sub> reduces to ''v''<sub>02</sub>: the aether frame is, he argues, theoretically distinguishable after all. Of the coincidence in form he says only: "This surprising result cannot be the effect of chance."

===The reciprocity paradox===

Chapter 4 reverses the arrangement: the rod is now at rest in the aether frame ''S''<sub>0</sub>, and ''S''<sub>1</sub> moves leftward. Relativity, having no preferred frame, must say each clock runs slow relative to the other — a symmetry Levy calls paradoxical, one that "defies logic and cannot be rationally explained if this total equivalence between frames is assumed". In aether theory the asymmetry is real: it is ''S''<sub>1</sub> that moves, so its clocks genuinely tick slow, giving (16), ''t''<sub>1</sub> = ''t''<sub>0</sub>(1 − ''v''<sub>01</sub><sup>2</sup>/''C''<sup>2</sup>)<sup>1/2</sup>. But an observer in ''S''<sub>1</sub> using the E–P procedure finds A&prime; ahead of A by ''v''<sub>01</sub>''l''/''C''<sup>2</sup>(1 − ''v''<sub>01</sub><sup>2</sup>/''C''<sup>2</sup>)<sup>1/2</sup>, and adding this to the retarded reading yields (17), ''t''<sub>1app</sub> = ''t''<sub>0</sub>/(1 − ''v''<sub>01</sub><sup>2</sup>/''C''<sup>2</sup>)<sup>1/2</sup> — the inverse of (16). The apparent symmetry is thus produced, not by nature, but by the synchronization convention. Levy also notes in passing that since the measuring rod in ''S''<sub>1</sub> is contracted in the same ratio as AA&prime;, the length is "erroneously found equal to ''l''<sub>0</sub>" and the light speed erroneously found equal to ''C'' — which is exactly what experiment reports.

==Assessment==

The paper is careful about the one thing this literature most often gets wrong: it does not claim relativity's predictions are false. Levy states plainly that the same clock readings follow from both theories under standard procedures, and his interest is in what the procedures conceal. Within that limited ambition the derivation is clean, the SDE is calculated rather than gestured at, and the reciprocity chapter is the strongest part — the demonstration that the ''same'' preferred-frame model yields (16) for perfectly synchronized clocks and its exact inverse (17) for E–P-synchronized ones is a genuinely instructive piece of bookkeeping, and it makes vivid how much of "reciprocal time dilation" is convention-dependent. The observation that the relativistic velocity-composition law drops out of a Galilean law fed through the measurement distortions is likewise a real result of the algebra, not an assertion.

The difficulties are structural. The clock-retardation factor (1 − ''v''<sup>2</sup>/''C''<sup>2</sup>)<sup>1/2</sup> and the contraction of standards are ''assumed'', not derived; Levy says so, and offers only the ''a posteriori'' justification that the assumption reproduces experiment. But reproducing experiment is precisely what the rival theory does with one postulate fewer, and no dynamical mechanism is proposed by which motion through the aether slows a clock or shortens a rod. The rhetorical move at the centre of the paper — "This surprising result cannot be the effect of chance" — is where an explanation is most needed and least supplied. The standard reply is that the agreement is not chance but structure: Lorentz-covariance makes the preferred frame unobservable identically, so the coincidence is guaranteed rather than remarkable. Levy does not engage that reply.

Two further points weigh against the paper's positive claims. First, its own section 3.2.1 identifies the only place where the theories genuinely diverge — perfectly synchronized clocks, where the reading depends on ''v''<sub>01</sub> as well as ''v''<sub>12</sub> — and Levy concedes the variables "should be difficult to determine experimentally" and the measurement hard to perform. The theory's single discriminating prediction is thus placed beyond reach, which leaves it empirically equivalent to relativity by construction rather than by evidence. Second, the appeal to Smoot's CMB dipole is doing more work than it can bear. The dipole fixes a frame in which the microwave background is isotropic; that is a fact about the distribution of matter and radiation, not about a mechanical medium, and it carries no implication that light propagates at ''C'' only in that frame. The high-precision null results of modern Michelson–Morley descendants and of Kennedy–Thorndike and Ives–Stilwell tests constrain any residual anisotropy far below the ~370 km/s the dipole implies, and Levy's framework survives them only because the same contraction-plus-retardation assumptions are invoked to hide the effect — the very manoeuvre for which the original Lorentz theory was criticised. Finally, the extension to general relativity announced in the abstract is asserted rather than shown; nothing in the paper's fifteen pages treats gravitation at all.

Read as what it is — a demonstration that a Lorentzian aether with retarded clocks and honest accounting for synchronization conventions is observationally indistinguishable from special relativity on this apparatus — the paper is correct and clearly argued. Read as a case that the aether frame has been detected, it overreaches.

==See also==

* [[Joseph Levy]]
* [[Aether]]
* [[Time Dilation]]
* [[Length Contraction]]
* [[Simultaneity]]
* [[Special Relativity]]
* [[Lorentz Transformation]]
* [[Michelson-Morley Experiment]]
* [[Hendrik Lorentz]]
* [[Henri Poincaré]]
* [[Cosmic Microwave Background]]
* [[Reginald T Cahill]]

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