A few times in my blogs I have tried to describe an idea that I have (far short of a theory although I sometimes refer to it as that) that gravity is something other than an unexplained pulling force between any two bodies of mass. I'm not a physicist nor am I a mathematician but it seems to me that Einstein pretty much defined matter in terms of energy and some form of movement. His E = m c squared formula is the relationship.
But it seems to me that defining matter as energy divided by the speed of light squared leaves something out, namely force. What is the relationship between matter and force? Unfortunately physics tends to teach that there is a reactionary relationship between the two. Gravity is a force that exists only between two or more pieces of matter. It doesn't exist otherwise. In a hypothetical "empty space" there is no force of gravity.
To me, it seems that matter should be defined in terms of force rather than energy. Energy is the reactionary aspect, not the causal one. Force is the cause. Einstein's formula suggests that all matter is composed of energy. I suggest that all matter is composed instead of force.
Why do I think this? The thing that got me going on this way of thinking is when I realized that the force of gravity in an ideal situation does not depend on either matter or energy in the space between any two bodies of matter. Two balls suspended in an ideal empty space, even at a temperature of absolute zero, would still express the force of gravity just the same as they would in an environment rich in matter and energy. The force of gravity is completely independent of the environment through which it operates.
In other words, there is no rope, no thread, no string made of anything physics is aware of that explains the pull between two pieces of matter. There is no medium known to physics that makes gravity possible. Gravity is just as effective in a complete vacuum of matter and energy as it is in a matter and energy rich space.
If gravity is a pulling force as it is defined to be, it is a pull that needs no string, no rope, no chain, no medium. I am just not OK with this idea. I don't think Einstein was either so I'm not too worried about that fact. Einstein concocted some theory that explains that gravity is the result of the curvature of space, that everything somehow falls towards itself in this curvature. Don't ask me to explain that because it makes no sense at all to me. It's just too complex to be natural. To me, if space is curved it is a result of gravity and not the cause.
What physics and math needs is a formula like Einstein's that expresses mass as a function of force. Physics will never find that formula by imagining force as a reaction of matter and energy. There cannot exist either mass or energy devoid of force so why isn't force the elemental component of their definition? Matter isn't the medium for gravity. Energy isn't the medium for gravity. Force is. But how does it all work? Come on, physics, isn't it about time you tackled this problem?