Builder-G · Source catalogue

The PDF is an ADS scan of 19 pages with no embedded text layer (pdftotext returned only the bibcode stamp 1958AuJPh..11..279B); Step 0 later OCR'd all 19 pages. The first Step 1 pass read all 19 pages as images at 110 dpi [read: page images pp.1-19]; this update adds a deep read of pp.5-8 and a direct re-read of OCR pp.14-18. The paper is a response to H. Dingle's 1957 Nature letter, which argued that the clock retardation predicted by special relativity is an absolute effect, so velocity must be absolute and special relativity must be wrong. Builder accepts Dingle's premise (clock retardation depends on absolute velocity) but rejects the conclusion: he argues special relativity itself compels recognition of the causal significance of absolute velocities, and that this is compatible with the relativity principle because absolute velocities cannot be measured by dynamical or electrodynamical experiments. Section I writes the proper time of each clock as integral of (1-u^2/c^2)^(1/2) dt, eq (1)-(3), notes the retardation is an invariant of all observers, and argues that because it depends on the individual speeds u, v in any inertial frame S (not on relative velocity, and not on accelerations), the clocks must be interacting with something universal. He postulates an absolute inertial system S0 (the universe as a whole) and rewrites the same formulas in terms of absolute speeds u0, v0, eq (4)-(5), accepting that u0, v0 cannot be measured. He extends the same argument to relativistic mass and length variations. Section II argues that relativistic electrodynamics has the same form as Maxwell-Lorentz theory, so observed phenomena depend on individual velocities and not just relative ones. He gives approximate force formulas for a magnetic pole and charge (6a, 6b) and for two moving point charges (7, 7a, 7b, 8), showing asymmetry between the cases of the same relative velocity and non-reciprocal forces (Newton's third law fails for the particle pair), which he ascribes to retardation of potentials. He concludes that one only needs to postulate that phenomena are caused by motion relative to an absolute inertial system in accordance with Maxwell-Lorentz equations. [read: page images pp.4-8] Section III argues that the class of inertial frames can be identified only because acceleration is absolute and detectable, so (following Newton and Mach) there must be a unique absolute system interacting with bodies, and that an absolute velocity then exists as well. Section IV defines 'absolute' as relative to the universe (or approximately to the fixed stars), after Poincare, and says absolute velocity is admissible in principle and may be measurable by kinematical means (for example Doppler asymmetry of star light), even though dynamics cannot detect it. Section V rejects Mach's hypothesis (instantaneous action at a distance) and concludes the ether hypothesis is the only tenable alternative; it surveys Einstein's 1905, 1907, 1920 and 1924 statements and Poincare/Lorentz/Eddington/Larmor, and argues that the ether is compatible with and sufficient as a basis for special relativity. Section VI gives the Lorentz-Larmor-FitzGerald argument that a moving clock must slow by (1-v0^2/c^2)^(1/2) when it moves through the ether, with a footnote that length contraction entails the clock slowing (a light-clock argument), and that two clocks leaving and re-meeting differ in elapsed time, the accelerated one lagging. Section VII concludes that the absolute concepts are permissible and have pedagogical and heuristic advantages (relativity of simultaneity, constancy of c and reciprocity are explained as effects of motion through the ether combined with the impossibility of one-way light-speed measurement). References include Dingle 1957 (Nature 179:866), Builder 1957a (The resolution of the clock paradox, Aust. J. Phys. 10:246), Builder 1957b (The clock retardation problem, 10:424), Whittaker 1953, Lorentz 1895, Larmor 1900, Poincare 1904/1908, Einstein 1905/1907/1920/1924, Eddington 1920, Mach 1883, Wiechert 1911. The paper contains no experimental data, no new measurement and no numerical example. [read: page images pp.1-19] Additions from the digests and deep reads. (1) pp.6-7: Builder rejects Einstein's 1905 view (magnet and conductor: observable effect depends only on relative motion) as a fundamental feature; he says (6b) reduces to (6a) for v<<c, fine for laboratory work, but retardation of potentials makes the individual velocities matter [read: p.7 via deep read]. The deep read checked (6b) and (7)-(8) by relativistic transformation: they are correct to O(v^2/c^2), but the (a)/(b) difference is the same system seen in two inertial frames (force is not frame-invariant), and non-reciprocity is field momentum, which Builder never mentions [my calculation, deep read sections 6-7; Griffiths ch.8 recalled, memory medium]. Current-element force formulas are asserted, not printed (p.8). (2) pp.14-15: Mach (1883) himself called a space-filling medium admissible and sufficient and preferred his own hypothesis only as 'expedient provisionally'; Builder quotes Einstein 1905 and 1907 (ether superfluous) and 1920 ('space without ether is unthinkable' in general relativity), stresses that Einstein's 1920 ether differs from Lorentz's (its state is conditioned by matter; it becomes Lorentz's only if its functions are replaced by constants), and cites Einstein's 1924 'Ueber den Aether' and the 1952 appendix to 'Relativity' [read: OCR pp.14-15]. Builder says Einstein had no logical or evidential basis for rejecting the ether in 1905/1907. Eddington 1920 is cited as presenting the theory from an ether-rest frame. (3) p.16: the clock-slowing footnote uses a longitudinal light clock (rod with mirrors) so that length contraction entails clock-rate reduction; Builder says Broad (1923) and others overlooked this when claiming the ether theory needs 'two independent hypotheses' [read: OCR p.16, footnote]. Builder also states that 'true one-way measurements of light velocity are impossible' so only go-and-return averages are measurable (pp.16, 18). He does not name the synchronisation convention; the reviewers' link to Reichenbach/Einstein synchronisation is an inference, not in the text. (4) p.17: if two clocks coincide twice, the one accelerated relative to any inertial frame lags; the experimental support for special relativity is called 'direct evidence for the tenability' of the ether assumption, not proof. (5) p.18: relativity of simultaneity, constancy of c and reciprocity are said to follow from motion relative to the ether plus one-way-speed impossibility; relativistic length, mass and clock changes are 'really-observable' with real causes in motion relative to the ether. (6) p.19: Wiechert, Lodge and Ives named as earlier advocates of absolute concepts. Source gap unchanged: Dingle's letter and Builder's 1957a/1957b papers were not available.

Key claims

• Special relativity's predicted clock retardation, which depends on each clock's individual speed measured in an inertial frame and not on relative velocity or acceleration, requires a causal role for velocity relative to a unique absolute inertial system.
• Accepting a unique absolute inertial system (the universe as a whole, an ether) is compatible with the restricted theory of relativity and with the principle of relativity, because the absolute velocities cannot be measured by dynamical or electrodynamical experiments.
• Relativistic electrodynamics depends on the individual velocities of charges and not only on their relative velocity: the force on a charge differs between a moving-charge and a moving-pole case with the same relative velocity, and Newton's third law fails for moving point charges.
• Absolute acceleration (detectable by dynamical effects) implies the existence of an absolute inertial system and hence absolute velocity, which may in principle be measurable by purely kinematical means such as the Doppler asymmetry of starlight.
• Mach's hypothesis of instantaneous interaction with distant matter must be rejected, leaving the ether hypothesis as the only tenable alternative to explain absolute acceleration.
• A clock moving with speed v0 through the ether slows by the factor (1-v0^2/c^2)^(1/2), which follows from Fitzgerald-Lorentz length contraction of electromagnetically bound bodies, so no second independent hypothesis is needed to explain the Michelson-Morley null result.
• Presenting special relativity in the Lorentz-Poincare ether form removes the conceptual difficulties of simultaneity, reciprocity of length/clock changes and constancy of c, and is pedagogically superior.
• Einstein's 1905 view that the induction effect between a magnet and a conductor depends only on their relative motion must be rejected as a fundamental feature, because retardation of potentials makes the force depend on individual velocities (eq 6a vs 6b; the two agree only for v much less than c).
• Because true one-way measurements of the speed of light are impossible (only go-and-return averages), the constancy of c in all inertial frames, the relativity of simultaneity and the reciprocity of contraction and dilation can all be explained as effects of motion relative to the ether.
• Einstein's 1920 statement that space without ether is unthinkable in general relativity supports the tenability of an ether hypothesis, although Einstein's ether differs from Lorentz's in having its state determined by matter.
• Mach (1883) himself regarded a space-filling medium as admissible and sufficient, and preferred his own hypothesis only as expedient provisionally for lack of evidence.
• Broad's (1923) claim that ether theory needs two independent hypotheses (length contraction and clock slowing) is mistaken, because for a light clock oriented along the motion length contraction entails the clock-rate reduction.

Relevance: This is the only document in the folder and is the whole project: a 1958 mainstream-journal defence of a Lorentz-style ether interpretation of special relativity, written as a rebuttal to Dingle's argument that clock retardation disproves relativity. It is a case of an interpretive ether claim that makes (by Builder's own admission) no observable difference from special relativity. The QE-added points (rejection of the 1905 magnet-and-conductor argument, one-way light speed, Einstein's 1920 ether, Mach's 1883 remark, Broad 1923) are the parts of the paper most useful for teaching.

Mainstream conflict: Partly. The mathematics he uses (time dilation, Lorentz transformations) is standard special relativity and the Lorentz ether theory is empirically equivalent to it, so there is no conflict on predictions. The conflict is interpretive: mainstream physics does not grant a privileged absolute rest frame or causal role to absolute velocity, and treats the ether as superfluous (Occam). His claim that relativistic electrodynamics makes phenomena depend on absolute velocities, and that this is an observable asymmetry, conflicts with the mainstream reading that all inertial frames give identical physics and that the apparent asymmetries (non-reciprocal forces on isolated particle pairs, the force expressions 6b, 7) are frame-dependent descriptions with momentum carried by the fields. The deep read (pp.5-8) checked (6b), (7), (7a), (7b) and (8) and found them correct to O(v^2/c^2) [my calculation]; the asymmetries are frame-description effects and field momentum, not evidence for an absolute frame. His reading of Einstein's 1920 'ether' as supporting him is contestable. [memory: medium]