Clarifying the Misconception: ECM Does Not Invoke Physical Negative Mass but Dynamic Mass Equivalents.

April 19, 2025

Dear Dr. Valentyn Nastasenko,

Thank you for your comment. Your statement, “Negative mass only exists in abstract mathematics. It does not exist in real physics,” reflects a crucial concern in foundational physics—one that Extended Classical Mechanics (ECM) has carefully and deliberately addressed by making a distinction between physically real mass and dynamically emergent mass terms, such as negative apparent mass or negative effective mass, which are not "physical negative mass" in the conventional or literal sense.

To clarify:

In Extended Classical Mechanics (ECM), at no point is a physically realizable negative mass postulated. Rather, negative apparent mass (−Mᵃᵖᵖ) arises from the dynamic redistribution of kinetic energy under gravitational influence and motion. It does not signify an exotic substance or particle with negative inertial mass, which would indeed be speculative and lack empirical support.

Similarly, effective mass (Mᵉᶠᶠ) is a composite quantity defined in ECM as:

Mᵉᶠᶠ = Mᴍ + (−Mᵃᵖᵖ)

where:

• Mᴍ is the matter mass (including both ordinary and dark matter), and
• −Mᵃᵖᵖ is the dynamic negative apparent mass arising from the gravitational and kinematic configuration.

This formulation is strictly observational and phenomenological—it is constructed to match and explain cosmological and quantum mechanical behaviour, including light deflection, redshift, and repulsion effects attributed to dark energy.

In fact, negative effective mass is not an invention of ECM. It is empirically supported in observational cosmology, particularly in works such as:

• A.D. Chernin et al., "Dark energy and the structure of the Coma cluster of galaxies," Astronomy and Astrophysics, 553, A101 (2013).

Here, the gravitating effect of dark energy is explicitly modelled as a negative effective mass contribution, denoted as (Mᴅᴇ < 0), resulting from a uniform antigravitational density. This "negative mass" in the cosmological context is not a negative particle mass, but a gravitational term required to reconcile observations of galaxy clusters and cosmic acceleration.

ECM formulates and extends this line of thought by assigning: −Mᵃᵖᵖ to kinetic energy or radiation (e.g., photons), and Interpreting this as the source of antigravitational behaviour in massless particles, particularly under gravitational influence.

This does not violate classical or relativistic principles; rather, it refines them through well-defined, observation-based extensions that remain grounded in Newtonian force dynamics and energy equivalence. The gravitational repulsion observed in phenomena like dark energy becomes natural when modelled through this lens.

Therefore, I respectfully submit that ECM does not introduce or rely upon abstract or unphysical “negative mass,” but rather makes precise distinctions between:

• Intrinsic matter mass (Mᴍ),
• Dynamically derived negative apparent mass (−Mᵃᵖᵖ), and
• Net observable mass (Mᵉᶠᶠ) as it appears in gravitational and inertial contexts.

Your critique is therefore an opportunity to clarify a misidentification: ECM is not invoking exotic or non-physical negative mass, but instead reinterpreting known energetic phenomena (such as the momentum-energy of massless particles and repulsive cosmological expansion) through carefully defined dynamic mass equivalents.

I remain deeply appreciative of your engagement with the subject and welcome further discussion on how ECM models can complement our shared aim of reconciling classical mechanics with the modern observational universe.

Warm regards,

Soumendra Nath Thakur

Framing Force Dynamics in Conventional Massless Particles: The ECM Perspective

ECM Reinterpretation of Photon Mass: Dynamic Negative Apparent Mass vs. Relativistic Rest Mass.

Core Rebuttal to Relativity’s Photon Rest Mass Treatment:

Re-evaluating the Mass Status of Photons in the Context of Particle Definition: Dynamic Particle with Negative Apparent Mass.

Soumendra Nath Thakur 

April 18, 2025

The commonly cited statement—“The photon has no mass, but it is a particle”—raises a fundamental inconsistency when examined through the lens of foundational physical principles.

In the broader framework of physical sciences, the designation of any entity as a “particle” traditionally presumes the presence of either a "real mass" or an "effective mass". Absent such a characteristic, the term “particle” becomes physically ambiguous. This is particularly relevant in advanced frameworks like Extended Classical Mechanics (ECM), which seeks to reconcile and extend classical and relativistic insights.

ECM introduces the concept of negative apparent mass (−Mᵃᵖᵖ), a form of effective mass that corresponds to kinetic energy, particularly in massless or near-massless regimes. Under this interpretation, photons—entities which exhibit kinetic behaviour—are understood to possess dynamic effective mass, even in the absence of rest mass.

Additionally, it is important to distinguish between "rest energy"—associated with "rest mass"—and kinetic energy (KE). which does not equate to rest energy under the relativistic mass-energy relation. This distinction has significant implications for the interpretation of photon behaviour and classification.

Therefore, within the ECM framework, the photon is more accurately described as a dynamic particle with negative apparent mass. This terminology reflects both its energy-based behaviour and its mass-related characteristics in motion.

If a photon were to lose its dynamism (i.e., kinetic expression), it would simultaneously lose the characteristics that define its particle-like behaviour, leading to a loss of existence in that form.

Finally, the term “massless particle,” while common in conventional discourse, may be considered incomplete. A more accurate description would treat the photon's effective mass as less than zero (<0) rather than strictly zero. This nuanced reinterpretation allows for a consistent and complete understanding of the photon's physical nature.