The motion of an object relative to you an observer on Earth, is furthermore relative to Earth's motion on which you are resting; and Earth's motion, in turn, is relative to the Sun's around which it is revolving; now through our Milky Way galaxy the motion of that object ends up being relative to the Universe, which in science is expanding or in motion (See Note 1). No matter relativity's accomplishments, the expansion of the Universe is defeating the concept of position.
In gravimotion the concept of position is dismissed, light's absolute speed instead is chosen for reference.
The slower the motion of an object (the closest to light's speed) the stronger the action. Any material object cannot have zero motion (with respect to light), motion and speed (which can mathematically be null) are antagonistic.
Gravimotion's first law
Newston's first law, known as the inertia law: Any object in constant linear motion remains in constant linear motion unless acted upon.
Light rays, and all electromagnetic waves, are moving in constant linear motion and have no mass; constant linear motion needs neither the objects nor their inertia to move along. Gravimotion's first law: Any constant linear motion remains in constant linear motion unless acted upon.
The 2 words object in disappeared; Gravimotion's first law introduces a fundamental fact: constant linear motion is a real entity moving on its own. This moving entity, because real, is alltogether lapsing a duration and occupying a space volume, and given the name motion-volume. Besides having a direction in space, these motion-volumes have a direction along time. The motion-volumes coinciding to light's absolute speed are labeled absolute-motion-volumes.
Gravimotion's concept of motion
In science light is a duality made of 2 incompatibles that are light speed (the wave) and light energy (the particle photon).
In gravimotion, motion is defined as being a massless entity blending both science's idealized forms of speed and energy (Note 2).
Whether moving itself (as light does) or moving material objects, a motion-volume does not involve inertia.
And the slower an object's motion (with respect to light's motion) the higher its energy;
Caution
Considering motion to be ocurring as a real entity, is the farthest that can be from science's Standard Model in which everything is made of particles; beware gravimotion is not part of science.
Besides should you decide to read about gravimotion you might not comprehend this frenchman english writing.
Note 1: Science's accelerated expansion of the Universe is in gravimotion not expanding but occurring as gravity that happens to be accelerated motion in science. Note 2: Even though motion is part of Newton's first law and integral part of Einstein's motion relativity, the word motion is provided no mathematical definition in science; hence the word "idealized", expressing that both speed and energy are actually inappropriate images of motion.