In reference: Addressing the Question: Why is the Speed of Light Always Constant, Regardless of the Observer’s Motion? (Version2) https://www.researchgate.net/post/Addressing_the_Question_Why_is_the_Speed_of_Light_Always_Constant_Regardless_of_the_Observers_Motion_Version-2

Soumendra Nath Thakur

March 21, 2025

The response in question 'C=1/√(ε₀μ₀)', while referencing a well-known electrodynamics relation, does not directly address the core issue. It asserts that the constancy of the speed of light is dictated by the fundamental vacuum properties—ε₀ and μ₀—implying these are absolute and invariant. While this is a widely accepted explanation, it does not sufficiently explain why the speed of light remains constant relative to all observers, which is the focal point of the referenced discussion.

The equation C = 1/√(ε₀μ₀) defines the speed of electromagnetic waves in a given medium but does not inherently provide a causal explanation for why this speed remains invariant to an observer’s motion. The assumption that vacuum properties do not depend on the observer's motion is rooted in Maxwellian electrodynamics but does not establish the fundamental reasoning behind the observed invariance of c across all inertial frames.

In contrast, the referenced discussion seeks to address the deeper question by considering the fundamental mechanics of wave propagation and energy-mass interaction within the spatial medium. It explores whether the underlying framework of physics inherently constrains light’s behaviour in a way that ensures its velocity remains independent of the observer's motion, rather than simply assuming this as an axiom.

If the conventional explanation is taken at face value, it does not account for why all observers, regardless of their motion relative to the source, still measure the same value for c, even when classical mechanics would suggest a relative velocity should emerge. Vacuum properties alone do not provide a mechanistic justification for this phenomenon; instead, a deeper physical reasoning is required, which the discussion aims to provide.

The response, while citing an accepted equation, does not engage with the fundamental issue. It reiterates an empirical result without addressing the underlying physics that enforce the constancy of c beyond the existence of ε₀ and μ₀. In contrast, the discussion presents a more comprehensive framework that moves beyond restating a formula to examining the principles that govern the invariance of light’s speed in motion and interaction.

Comparative Superiority of the Discussion Approach

1. Inclusion of Mass and Gravitational Considerations

- The analysis explicitly incorporates matter mass (Mᴍ), gravitational mass (Mɢ), and negative apparent mass (-Mᵃᵖᵖ), refining the relationship between mass and velocity.

- It extends classical mechanics by integrating Extended Classical Mechanics (ECM) principles, which differentiate gravitational influences on matter mass from the anti-gravitational properties of negative apparent mass.

2. Systematic Treatment of the Observer’s Motion

- Rather than assuming the observer’s speed is negligible, the discussion provides a structured justification for why an observer’s motion (S) does not affect the speed of light (c).

- It introduces the negative measurement framework, which explains why an observer's motion in a gravitational system is insignificant compared to the anti-gravitational motion of photons.

3. Role of Negative Apparent Mass (-Mᵃᵖᵖ) in Light Propagation

- The discussion identifies that photons have zero matter mass Mᴍ = 0 but possess negative apparent mass -Mᵃᵖᵖ, contributing to their anti-gravitational dynamics.

- This distinction clarifies the contrast between the gravitational motion of massive observers and the anti-gravitational motion of massless photons.

4. Planck-Scale Constraints and Universal Limits

- The analysis incorporates Planck length (ℓᴘ) and Planck time (tᴘ) as fundamental constraints on measurable space and time.

- It explains that beyond these limits, conventional space-time interpretations become inadequate, reinforcing why photons are not subject to upper speed limits except through fundamental physical constraints.

5. Quantum Interpretation of Speed and Measurement Systems

- A quantum analogy using ΔS = Δd/Δt is employed, linking the traditional speed equation to the photon’s wavelength-frequency relationship (c = λ f) at the quantum scale.

- This creates a bridge between quantum mechanics, classical mechanics, and ECM without relying on relativistic postulates.

6. Contrasting Gravitational and Anti-Gravitational Reference Frames

- The discussion systematically contrasts the reference frames of massive observers and massless photons.

- It concludes that due to the dominance of the anti-gravitational system (negative measurement framework), an observer’s motion is effectively nullified when compared to the anti-gravitational motion of photons.

Conclusion: Superiority of the Discussion Approach

This discussion presents a more complete resolution to the question of light’s speed invariance by:

- Establishing a mass-energy framework (Mᴍ, -Mᵃᵖᵖ, Mɢ) that accounts for both gravitational and anti-gravitational influences.

- Justifying the observer’s negligible speed not as an assumption, but as a consequence of ECM’s negative measurement framework.

- Clarifying the contrast between gravitational motion (massive observers) and anti-gravitational motion (photons with -Mᵃᵖᵖ).

- Providing a consistent quantum-classical-ECM treatment of speed without dependence on relativistic assumptions.

Thus, this discussion offers a comprehensive resolution to the fundamental question: Why is the speed of light always constant, regardless of the observer’s motion?

Final Consideration

The equation C = 1/√(ε₀μ₀) is a purely electromagnetic definition of light speed derived from Maxwell's equations. It does not incorporate gravitational or antigravitational effects, mass, or negative effective mass, nor does it account for the motion of observers or objects with different masses.

When extended within ECM, the negative effective mass of light must be analysed to determine its role in motion dynamics, particularly in gravitational or antigravitational fields. This approach offers a broader interpretation beyond the classical electromagnetic foundation, providing a more complete understanding of light's speed invariance.