When mass was chosen to be a third indefinable property of mechanics, it was left unexplained. Much was known about its effects, but, its nature had no history. It is empirical evidence that provides the history of all properties. Since all properties are represented in physics equations only by their units; and, since this is true of the properties of empirical evidence, the histories of the natures of properties must be passed along through their units. It is the units that define what each property is.

The unit of kilogram has no known history because it is an undefined unit. There is no direct link to the units of empirical evidence. There is no path for the kilogram's meaning to be communicated. That lack of meaning created the opportunity for theorists to add their ideas, about what is mass, into the equations of physics. Even the idea that mass is an indefinable property is theoretical. It wasn't learned from empirical evidence that mass is the third indefinable property of mechanics. Force could have been chosen for that role. Mass is an undefined property by arbitrary choice.

The need to make such a choice was due to ignorance about how to define both force and mass in terms of the properties of length and time. As a result of this arbitrary solution to this real dilemma, the equations of physics, which must make use of the undefined mass, become part of the theory that mass is an indefinable property.

If mass and temperature are made into defined properties, along with their units of kilograms and degrees being made into defined units, it removes the opportunity for theorists to inject their imagined ideas into equations. Defining kilograms and degrees leaves no blanks, and therefore, no space for theoretical interventions. The mathematics of fully defined properties, except for the naturally indefinable ones, can then tell us the story about that which empirical evidence is communicating to us.

James A Putnam

Everything we will ever learn about the mechanical operation of the Universe will be revealed to us by empirical evidence. Therefore, we should maintain as direct a dependence as possible on that which empirical evidence is revealing to us. The way in which that direct dependence can be achieved is to define all properties other than those of empirical evidence in the same terms as their empirical evidence is expressed. This applies very strongly to units in particular. It is the units that represent properties in physics equations.

Looking at what empirical evidence tells us about mass, we learn that it is responsible for specific kinds of patterns in changes of velocities of objects with respect to time. That kind of valuable information is not new. What is new is for us to look at what empirical evidence tells us about the units of mass.

The units of acceleration tell us, from the equation f/m=a, that the units of force divided by the units of mass must reduce to the units of acceleration. The 'a' represents the empirical evidence. The ratio of the units of force and mass are tied directly to the units of empirical evidence. Their units, that form this ratio are their empirically revealed units. This ratio ties their empirically revealed units directly to the units of empirical evidence. Their empirically revealed units are defined  units. They are defined as combinations of the units of their empirical evidence.

When mass was declared to be a fundamentally indefinable property with units that were fundamentally indefinable, the direct tie to empirical evidence for leadership was severed. The meaning of the word defined used here follows directly the historically common practice for defining all properties introduced after mass. Force is defined in terms of the already existing properties of mass and acceleration. Energy is defined in terms of the already existing properties of force and length, etc.

By extending this practice to include defining mass, I am connecting the definitions for all properties, now including mass, back to the two properties that pre-exist all others. Those two properties are length and time. Now, there is no break in the development of definitions of properties, or for the definitions of their units, from empirical evidence.

When mass was arbitrarily made the third indefinable property of mechanics, fundamental unity was lost. This loss was due to the lack of direct dependence upon empirical evidence for guidance on how to proceed with the derivations of physics equations. This re-establishment of direct dependence upon that which empirical evidence is revealing to us, re-establishes fundamental unity into the equations of physics.

Hi Christian,

It is important for me to be clear about what I refer to by empirical evidence. Those messages I posted above were poorly written with typos. I didn't realize their condition when I copied them into this discussion. They are improved now. I apologize for this inconvenience. 

The path I chose to develop this work was to begin as an introductory physics text might begin. I know that defining mass by itself is enough to expect radical changes from mainstream theoretical physics. Since the idea is to let the empirical evidence and the math that describes it go where it itself leads, I began with the simple knowledge that initial studies of patterns of accelerations of objects produces f=ma.

There is just one advanced theoretical consideration taken into account. The empirical evidence is represented by a for acceleration. While the acceleration observed is that of an object of matter, the advanced theoretical consideration is that both the existence of the object and its acceleration are learned from our innate ability to find patterns in a storm of wildly mixed photons coming at us from innumerable sources and directions. Our innate ability extends to attaching meanings to those patterns.

Leaving those considerations of innate abilities aside, the advanced idea is that everything we learn is learned from photons. Yet each photon tells us only that a particle of matter underwent an increment of acceleration. For this reason, everything we learn which we call empirical evidence, arrives as information about acceleration. The units of that information consists of meters and seconds only. Therefore, f=ma is telling us correctly that empirical evidence consists of information about acceleration.

The f for force represents cause for the acceleration. We only learn about effects and, therefore, know what cause does but not what cause is. If we are to learn that which empirical evidence is telling us about cause, we must define mass. Then force can be defined and understood to the extent that the nature of mass and object acceleration informs us.

Defining mass is the key to connecting the meanings of empirical evidence to all other properties of mechanics. In other words, the mathematics and properties of mechanics become directly dependent upon that which empirical evidence is revealing to us.

We are either guided empirically to an understanding of mass, or, we never learn what it is. Also, the cause or causes of relativity type of effects, quantum effects, and electromagnetic effects must be revealed and not be theoretically introduced. All of this must happen due to direct dependence upon the leadership provided by empirical evidence and its two units of meters and seconds. 

I have done the work to a large enough extent to argue in favor of the need to define mass, and, also for thermodynamics, the need to define temperature. However, I have found that recognizing the need to define mass and recognizing that mass can be defined because empirical evidence provides guidance on how to proceed, is very difficult to successfully communicate to others. So, instead of asking what temperature is, for example, I ask "Should the units of kilograms and degrees Kelvin be made defined units?"

I do not assume that this is enough said. Please be invited to express your reservations. It is truth that is being sought. 

James A Putnam