Is Motion One Of The Three Eternal Properties of Atoms? I.E. Are The Three Properties Shape, Size, and MOTION?

Here is my comment to Patrikios' thought experiment:
Placing the object outside Earth’s gravity would not be enough because then it could be in the Sun's gravity. Placing it outside the Sun’s gravity would still not be enough because then it could be in the gravity of the Milky way.
We might find a point between two galaxies at which the gravitational forces of both galaxies cancel out each other and where the gravity of further away galaxies is too small to be significant for a reasonably long time of observation.
We can define a frame of reference there at which the object would stay at rest once placed there without initial speed in that frame of reference. (There is a logical circle in it because the definition of an inertial frame of reference is that an object without external force keeps moving with its initial speed, i.e. stays at its place if initially at rest.)
If we want to move that object, we need to apply a force to accelerate it. The proportionality constant between force and acceleration is the inertial mass. (I would not call that "potential for movement".)
If we place the object in a gravitational field, the gravitational mass of the object is the proportionality constant between the force on the object and the gravitational field strength.
Gravitational mass and inertial mass are conceptionally different. We have defined our system of measurement units such that both masses are measured in the same units.
In a system, in which the units are not the same, the two types of masses are proportional to each other but not identical, which makes the conceptional difference more obvious. This is an ongoing topic of research into the foreseeable future. Physicists keep designing new experiments to test the proportionality between gravitational mass and inertial mass with ever increasing measurement accuracy.

In a Newtonian universe with absolute space and time and when there is a point in time where there is no motion of that atom in the chosen frame of reference, yes, this would be the case at all other points in time, the atom would never move and would have never moved in the past.
In an Einsteinian universe with only one atom, there would be no references to measure space and time. Therefore, statements like "the atom moves" or "the atom does not move" would have no meaning.

The case of two atoms in an infinite void:
In a Newtonian universe with absolute space and time and when there is a point in time where there is no motion of both atoms and there is a distance between them, both atoms would accelerate from that point in time toward each other, collide, move with decreasing speed back to their points of rest, simultaneously come to rest there and accelerate again toward each other, repeating that cycle all over again into eternity and would have done so in all eternity of the past. (This is the simplest example of an eternal, pulsating universe. Until the discovery of the accelerated expansion, eternal pulsation between big bang and maximum extension was a credible scenario for our universe.)
In an Einsteinian universe, the two atoms would behave similar to the two atoms in a Newtonian universe. The distance between resting points would provide a reference for measuring space in the direction along which the atoms move. The period for one pulsation would provide a reference for measuring time.

There is a caveat: The physics of a universe might depend on what is in it. So, the laws which we know for our universe of maybe 10^89 particles might not apply in a universe with considerably less particles.

Quote from Martin

I agree with the answer from Grok. There is one caveat which I mentioned in one of our Zoom calls. That mass (or energy) produces a gravitational field and curves spacetime is only one of three possibilities and assumes that mass and space exist independently (dualism) but affect each other. The other possibilities are that mass creates space (monism) and that space creates mass (monism). Each of the three possibilities is compatible with observations and the currently best models to explain the observations. Choosing one over the other three possibilities is rather belief akin to religion than knowledge at this time. In practice, publications typically imply dualism like in the quote from Grok.

Thanks Martin and Cassius for your explanations.

Here is how Claude AI helps explain.

Quote

Would the object move on its own in “the void”?
If placed perfectly isolated from all other matter, with zero initial velocity, the object would remain stationary. Gravity is a relational phenomenon — it describes the interaction between masses. A lone object has no “other mass” to attract or be attracted by, so no net gravitational force acts on it. Its own gravitational field exists as a potential, but potential without another mass to interact with produces no movement. So yes, gravity is an inherent potential for interaction that only manifests as force through the presence of another mass.

Is this what “inertial mass” means?
Not quite — this is an important distinction. There are actually two related but conceptually separate properties at play here:
• Gravitational mass is what you’re describing — the property that causes objects to attract one another and be attracted. It’s the “charge” of gravity, analogous to electric charge.
• Inertial mass is resistance to acceleration from any force — it’s the “stubbornness” of matter against changes in motion, regardless of what’s causing that change.

The remarkable and somewhat mysterious fact is that these two quantities are always exactly equal (the equivalence principle), which Einstein built general relativity upon. But they’re conceptually distinct. Your isolated object would have inertial mass even in a universe with no other matter, whereas its gravitational interaction would be zero.

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So as I understand, the constant movement of the smallest indivisible particle (Epicurean atoms) creates the potential for movement by the compound object, but does not mean that all material objects just move without interaction with some relative force from another object. When compound objects do move, it is because of these invisible, natural forces arising between objects, not some divine unnatural force.

In the past I thought laws of nature and natural forces are missing in Epicurean physics.

I searched for them and yes would like partly in this thread see the forces in the „motion of uncuttables“ but maybe also with an extension like an additional attribute(s) for void like curved space-time.

From where for example comes electromagnetic charges for protons ? Maybe from own motion/spin or the quarks in it ( the nowadays „atoms“ / uncuttables next to electrons and phitons ? ).

Or we extend Epicurean physics from atoms and void to fields and void ?

Stoics see in forces and laws of nature their physics confirmed, bit AI says me that even than when seeing energy, fields and information as fundamental, Epicurean physics is more realistic and closer to modern physics ( no intentional, governing Logos ). Exciting discussion.

Is modern physics an extension of Epicurean physics and follows from it ?