Operational Light-Speed, Moving Charges, and Synchronization: A Reactive Substrate Theory Perspective

Companion paper in the RST v1.0 sequence (alongside your one-way light-speed post and the thermodynamics paper). This is written in a university-level, research-seminar tone, with plain-text equations for Blogger compatibility.

Abstract

Claims about “what happens near the speed of light” often mix three distinct issues: (i) what can be measured locally, (ii) what depends on clock synchronization conventions, and (iii) what is a genuine dynamical effect in the field equations. Using the popular thought experiment “a charge approaching the speed of light” as an organizing example, this paper separates kinematics from conventions and then states the corresponding reinterpretation in Reactive Substrate Theory (RST). The core result is: the two-way invariant light speed is an operational fact, while the one-way light speed is not empirically accessible without a simultaneity convention; in RST this is reframed as a distinction between signal propagation at c (excitations) and local time-rate/clock structure (substrate state). The same substrate time-rate factor that appears in RST thermodynamics supplies a clean, operational language for synchronization, redshift, and rate comparison across baselines.

1. Motivation: why this topic keeps producing “clickbait physics”

A recurring video trope is: “What if a charged particle goes almost (or exactly) at the speed of light?” (e.g., popular presentations like “What happens when an electric charge approaches the speed of light.”) These pieces are typically compelling because they invoke intuitive imagery (fields getting “flattened,” time “slowing,” forces “compressing”), but they often slide across the boundary between:

Dynamical statements (what Maxwell/Lorentz-covariant electrodynamics predicts), and
Operational statements (what observers can measure with real clocks and synchronization procedures).

RST is useful here because it insists on operational definitions: clocks tick according to local substrate state; signals propagate at a characteristic speed c; and “geometry” is a coarse-grained description of substrate gradients. That stance naturally forces precision about what is measurable vs conventional.

2. The one-way speed of light: what is measurable vs what is definitional

In standard relativity, the experimentally robust invariant is the two-way (round-trip) speed of light. By contrast, any claim about the one-way speed requires comparing distant clocks, and that comparison requires a synchronization convention. Without an agreed simultaneity rule, “one-way time of flight” is underdetermined. This is the conventionality-of-simultaneity point (often parameterized by an epsilon convention). :contentReference[oaicite:0]{index=0}

Operationally:

Two-way measurement:
  send pulse A→B, reflect B→A, use one clock at A.
  Result is convention-independent.

One-way measurement:
  need time stamps at A and B.
  Requires a synchronization prescription to define "simultaneous" across distance.

RST framing (v1.0):

Signals are excitations (e.g., coherence-field disturbances) that propagate at c in the substrate.
Clock rates are substrate-coupled and may vary with local substrate state (your thermodynamics paper already uses this structure).
Therefore: a one-way speed “measurement” is always a joint statement about (i) propagation plus (ii) the chosen cross-baseline clock synchronization rule.

3. What standard electrodynamics actually predicts for a near-c charge

For a point charge in relativistic motion, the electromagnetic potentials and fields are described by the Liénard–Wiechert construction. A key qualitative outcome is that, at high Lorentz factor gamma, the electric field is strongly concentrated into a narrow angular region transverse to the motion (“pancaking”), and radiation from accelerated motion is strongly beamed within an angle ~ 1/gamma. :contentReference[oaicite:1]{index=1}

A useful schematic summary (not a full derivation) is:

Let gamma = 1 / sqrt(1 - v^2/c^2).

Qualitative field structure (constant velocity, far from the charge):
  - Field lines are compressed into a thin transverse region.
  - Longitudinal components are suppressed relative to transverse components.
  - No "infinite shock front" forms for v < c; causality is enforced by retarded-time dependence.

If the charge accelerates:
  - Radiation occurs (Larmor / Liénard formula in relativistic form).
  - Power scales with acceleration squared and relativistic factors.

Radiation by acceleration is not optional: it is a dynamical consequence of Maxwell + relativity. :contentReference[oaicite:2]{index=2} This matters because many popular narratives implicitly treat “approaching c” as if it were merely kinematics, when the physically relevant question is usually: what forces/accelerations are being applied, and what radiation losses and field backreaction accompany them?

4. RST mapping: how the same story is told without changing the observed phenomenology

4.1 Minimal RST kinematics (signals vs state)

RST v1.0 (minimal closure) distinguishes:

Signal channel: propagating excitations (coherence-field disturbances) with characteristic speed c.
State channel: substrate configuration that determines local clock rate (proper time accumulation) and effective “geometry” in the macroscopic limit.

In the same operational spirit used in your thermodynamics paper, define a local time-rate factor:

dτ = α(x,t) dt

with α determined by substrate state (schematically, via the substrate-coupled oscillator frequency model):

ω0^2(x,t) = μ + κ S(x,t)
α(x,t) = sqrt( (μ + κ S(x,t)) / (μ + κ S̄(t)) )

RST interpretation:

Electromagnetic waves remain finite-speed signals in the substrate (propagate at c).
“One-way flight time” across a baseline depends on how τA and τB are related (i.e., the operational synchronization procedure), which in RST is explicitly a statement about substrate-dependent clock rates and the adopted comparison protocol.

4.2 Where the near-c “field pancaking” lives in RST

RST does not need to deny the empirically validated field behavior (e.g., the Liénard–Wiechert picture). Instead it reassigns ontology:

What standard theory calls “Lorentz-covariant field structure” is recast as the behavior of propagating coherence excitations embedded in a substrate whose local time-rate factor defines the operational clock structure.
The “pancaking” remains a kinematic consequence of finite-speed propagation and retarded-time relations; it is not evidence for superluminal influence or for a physically meaningful one-way speed independent of synchronization.

5. Why this connects directly to the one-way light-speed discussion

The one-way light-speed debate is frequently misrepresented as “maybe c is not constant.” The more precise statement is:

The two-way invariant speed is operationally fixed (to very high precision).
The one-way speed cannot be extracted without a simultaneity convention. :contentReference[oaicite:3]{index=3}

RST tightens the language further:

Any baseline comparison is a statement about signal propagation plus clock transport/synchronization.
Clock structure is substrate-dependent (α field), so the operational “time-of-flight” bookkeeping is explicitly tied to local proper time rather than assumed universal coordinate time.

This is not an escape hatch; it is a bookkeeping clarification. It reproduces standard relativity in the homogeneous/weak-gradient limit, and it clarifies what would constitute a genuinely new prediction: not “one-way c differs,” but “a reproducible residual in baseline clock comparison or propagation phase that cannot be absorbed into synchronization plus known relativistic corrections.”

6. What would count as a real, RST-relevant deviation?

Because synchronization conventions can absorb large classes of “one-way” anomalies, the only scientifically meaningful targets are convention-resistant observables, e.g.:

Closed-loop phase observables (interferometry on loops where gauge/sync conventions cancel in the final scalar),
Two-way timing residuals (round-trip comparisons across multiple baselines),
Correlated clock-network residuals that track environmental or gravitational conditions beyond established models.

In RST v1.0 language, these would correspond to detectable structure in α(x,t) and/or substrate–coherence coupling that cannot be re-described as ordinary metric redshift plus known media effects.

7. Appendix A: tie-in to RST thermodynamics (why this is the same “time” problem)

Your thermodynamics paper defined temperature operationally in terms of proper time: temperature encodes the rate at which systems explore accessible microstates per unit τ, with τ determined locally by α(x,t). This light-speed/synchronization paper is the same philosophical move applied to metrology:

Thermodynamics:
  rates, equilibration, and distributions are defined per unit proper time τ.

Metrology / light-speed:
  time-of-flight and "one-way" claims are defined only relative to a clock model;
  in RST the clock model is substrate-coupled and encoded by α(x,t).

Thus, the unifying theme across RST v1.0 papers is:

Signals propagate with finite speed c in the excitation sector.
Rates (clock time, temperature-defined kinetics, synchronization) are substrate-state statements in the α sector.
Empirical contact is made through closed-loop and convention-resistant observables.

References (reader starting points)

Popular prompt example: “What happens when an electric charge approaches the speed of light” (YouTube video page / metadata). :contentReference[oaicite:4]{index=4}
Conventionality of simultaneity / one-way speed of light discussions. :contentReference[oaicite:5]{index=5}
Liénard–Wiechert potentials overview/derivation notes. :contentReference[oaicite:6]{index=6}
Radiation by an accelerating charge (Larmor/Liénard discussions). :contentReference[oaicite:7]{index=7}
Synchrotron radiation beaming angle ~ 1/gamma (relativistic beaming). :contentReference[oaicite:8]{index=8}

Conspiranon