Rest Mass vs. Relativistic Mass

According to Physics, the photon has zero invariant or rest mass. But it has a relativistic mass of hv/c2.

In truth, the rest-mass of any object is always zero. When you are out in space alone with nothing around you, you are at rest because you do not feel any motion. The feeling of motion arises only when there is acceleration. Therefore, we equate “rest” to be same as the state of zero acceleration. 

When a physical object is moving at a “uniform velocity,” its acceleration is zero. Such an object may be considered to be at rest when alone out in space. This is the mathematical, or scientific view. Therefore, when a photon is moving at the uniform speed of light, its acceleration is zero. Scientifically, a photon is always in a state of “rest.”

Inertia is manifested only when an effort is made to change the “uniform velocity” of an object. We call this inertia “mass” in case of matter. We may call this inertia “consistency” in case of a photon. Its measure is hv/c2

This mass, or consistency, is manifested only at the moment of impact, when there is a deceleration. That is when momentum is manifested too. It is interesting to note that Newton used the word “motion” in the sense of momentum.

Physics calls it “relativistic mass.” But this is the mass, or consistency, that is manifested only when there is acceleration or deceleration. It is not manifested under uniform velocity.

This resolves the confusion between “rest-mass” and “relativistic mass.” 

The “rest-mass” of all objects is always zero. And the “relativistic mass” is the same as what we commonly understand to be the inertial mass.


Substance and Consistency

Inertial mass is generally referred to as “mass” in case of matter. We shall refer to the inertial mass as “consistency” in case of light. Therefore, the “relativistic mass” of photon becomes the “consistency of light.”

We shall refer to consistency by the symbol C. Therefore, for light,

C = hv/c2 = (h/c2) v

This means, that the consistency is proportional to the frequency. The proportionality constant h/c2 has the dimensions of [MT] or “mass x time.” Therefore, consistency has the same dimension as mass. Consistency condenses into mass as frequency increases.

Thus, consistency condenses gradually into mass from photon to electron to neutron.

As consistency increases, so does inertia. The two might be considered synonymous. Since, inertia is the property of substance, this puts light in the category of substance.

We may broadly define substance as “anything that is substantial enough to be sensed.” The physical universe is made of substance that we sense with our physical senses. This includes light and not just matter.

We define consistency as the degree of substantiality of substance. It is recognized as density, firmness, or viscosity of the substance. For example, “Honey has higher consistency than water.” 

For “energy substance” consistency is measured per quantum, where quantum is determined by frequency.

For “material substance” consistency is measured by the mass of its elementary particle, such as, proton or neutron. The elementary particle of matter is determined by its smallest discrete inertia.


Consistency of Matter

As light travels from a star to the far reaches of the universe, its consistency remains the same while its intensity decreases. The consistency is determined by frequency, while the intensity is determined by the amplitude of the light wave.

Similarly, as matter breaks down into smaller particles, its consistency remains the same while its amount decreases. The consistency is determined by the mass of a neutron, while the mass of the object is the aggregate of the mass of all the neutron particles in that object.

Therefore, the consistency of matter is “the mass of its core particle.” This takes into account the spectrum of matter. For example, the core particle of a black hole could be more massive than a neutron.

From the view of total mass, the consistencies of Earth and Sun are calculated in Relative Consistencies of Substance as follows:

C” (Earth) =  235.6
C” (Sun) = 256.6

And the relative consistencies are calculated as follows:

Crel (Earth) = 1
Crel (Sun) = 1.089

If we consider the core particle of Earth to be a neutron, then

C (Earth) = 77.6
C (Sun) = 84.5

This means that the core particle of Sun could be heavier than neutron. But this needs to be verified more carefully, since we are using relative velocities for the above calculations.


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  • Chris Thompson  On February 20, 2023 at 10:23 AM

    Considering your example of mass, alone in space, and at constant velocity, would 🤔 we correctly say, that when acted on to create deceleration, that acceleration in the opposite direction is occurring?


  • vinaire  On February 20, 2023 at 10:27 AM

    We have been missing the concept of “substance” scientifically.

    A substance is THAT which is substantial enough to be sensed.

    Matter is not the only substance. Light is a substance too, and so is thought.

    A substance is sensed because it causes an impact. This property of substantialness is called “inertial mass” for matter. We may call it “inertial consistency” for light, and “inertial theta” for thought.


    • Chris Thompson  On February 20, 2023 at 10:40 AM

      Yes. It is easy to see that thought exhibits inertia.

      Liked by 1 person

    • Chris Thompson  On February 21, 2023 at 1:30 AM

      . . . And spatial substance for elbow room.


      • vinaire  On February 21, 2023 at 9:54 AM

        I see “spatial substance” to be the gravitational force. A substance is anything substantial enough to be sensed. We sense the gravitational force through every pore of our body. We find it everywhere like space. The gravitational force forms the very basis of the idea of substance.


  • Chris Thompson  On February 20, 2023 at 10:34 AM

    In your rest-mass example of uniform-motion, would one correctly say that the Earth 🌎 is “at rest?”


    • vinaire  On February 20, 2023 at 10:37 AM

      Yes. Any appearance of motion is due to relativity.

      There is the matter of centripetal acceleration to be sorted out. That is the domain of gravity we still need to understand.

      Liked by 1 person

      • Chris Thompson  On February 20, 2023 at 2:19 PM

        Consider the elliptical orbit. I think that the body in orbit accelerates as it falls closer to the anchoring, master gravity. I think that it decelerates as it passes its closest approach and begins moving farther away. I think it decelelrates until it reaches an equilibrium of the strength of its anchoring gravity equaling it centripetal force. At this point, it begins turning, falling back into the anchoring gravity.

        Is this a correct estimation?

        IF so, to me, each moment of its motion seems natural. Is this motion considered uniform? Or does the body experience reduced relative weight on its fall into the anchoring body and alternately, increased gravity upon its flight away from the anchoring body?

        I see a problem with my example by using gravity. This is not an external force as referred to by Newton, but rather a quality of spacetime. A rocket motor would provide an external force but then my example becomes bogus and not the same question as I began with.


        • vinaire  On February 20, 2023 at 9:20 PM

          I am not ready to tackle gravity yet.


    • vinaire  On February 20, 2023 at 10:57 AM

      According to Newton, Einstein and Motion:

      1. Every physical object has a natural speed in free space that depends on its consistency (mass).
      2. When an object is accelerated from its natural speed with the application of an external force, its consistency decreases by an infinitesimal amount.
      3. When the external force is removed, the acceleration of the object returns to zero. If the object now continues to move at the higher speed, its consistency also stays at the infinitesimally lower value.
      4. If the consistency of the object returns to its original value, then its natural velocity shall also return to its original value.
      5. A physical object can never be accelerated to the speed of light without reducing its mass to consistency of light.

      The above predicts the Higgs Mechanism.


  • vinaire  On February 20, 2023 at 10:35 AM

    Matter is a specific instance of ‘substance’ as defined above. Light and thought are other instances of substance.

    Mass is a specific instance of inertial resistance. Consistency and theta are other instances of inertia.

    This is basic stuff. This is a new look at Newton’s work in the light of the scientific progress made since Newton.


  • vinaire  On February 21, 2023 at 9:56 AM

    I have added the section “SUBSTANCE & CONSISTENCY” to the above document.


  • vinaire  On February 21, 2023 at 10:15 AM

    I have added another section: CONSISTENCY OF MATTER.


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