The inertia law or Newton's first law

Any object in the state of rest or in the state of uniform motion, remains at rest or in uniform motion, unless acted upon by an unbalanced force.

The inertia law is in conflict with constant spin

Because it constantly changes direction, a spinning object such as a top or the earth is not in uniform motion.
As such constant spinning is not taken care of by the inertia law, even though it is inertia that maintains constant spinning!

Note that due to friction the spinning of the toy is slowed down and actually not constant. Similarly due to the moon, which causes the tides, Earth’s spin is slowed down through friction of water flows. Friction though, and not inertia, causes the slowing.

Physics solution: create a mathematical duality

In order to comply with nature, physicists created a new law differing from the inertia law!
The new law involves angular speed, angular momentum and rotational inertia!
Clearly the rotational inertia has nothing to do with the inertia law!
Now there are two drastically differing mathematical descriptions of inertia in physics.

The one-ness of inertia in reality

We can only imagine the reality of inertia as being one.
As a matter of fact physicists did not invent a new word to label the inertia that maintains constant spin.
Physicists only gave it the rotational adjective, there is only one inertia in Reality.

First Observation

Because there is only one inertia in reality, physics' duality of interpretation (inertia law / rotational inertia) departs from the unity of Nature.
And because inertia is at the base of all of physics, physics is now based on two differing mathematical pillars, and that seems to compromise the unity of any subsequent buildup no matter how elaborate or clever!

Besides physics' mathematical duality of inertia, there is a much more troubling problem wedged deep within our very concept of inertia!
In our concept of inertia this other concept of ours, which is time plays no role!
In physics, inertia (as well as mass by the way) exists independently of our concept of time!
Yet since Einstein revelations, we know that space and time make one!
Because mass and inertia exist in space, according to Einstein thoughts, mass and inertia should exist in time too!

Second Observation

The absence of time within our concept of inertia prevents us human beings from understanding Nature.
The misinterpretation of inertia, which originates in Newton's inertia law, and which appeared plausible up to Einstein, becomes a liability upon the onset of space-time.

Even though serious, these controversies do not compromise the respect we have for physics

This web-page is based on the belief that the unity of Nature is better described in a united way.
Physics doesn't have to comply with such belief, even while aspiring after a Grand Unified Theory.
The fact of the matter is physics’ mathematical description of reality remains exquisitely accurate.
Yet the abstract interpretations that our brains build-up on top of these mathematics reach definitely a questionable level.

There is at least one other interpretation of inertia that solves these 2 problems!

In that interpretation, called gravimotion, instead of being inert, inertia becomes active within (our human concept of) time as follows.
Because everything is in motion along the expansion of the universe, a fact Newton was not aware of, the state of rest is no doubt fictitious and making abstraction of it, the inertia law can be rewritten:
Any object in the state of uniform motion, remains in uniform motion, unless acted upon by an unbalanced force.
Clearly this law is all about motion, and not at all about inertia!
There is nothing to understand, simply take note of motion when the law is about motion!
In a nutshell:

1. In the gravimotion interpretation of Nature inertia is redesigned as being integral part of motion.
2. And because motion is the only entity on which rests gravimotion interpretation of Nature, physics' dual representation of inertia becomes de facto one in gravimotion!

Gravimotion is a new, unheard of, and spectaculer interpretation of Nature

There is nothing like gravimotion...
The gravimotion mechanism is described in great details in the book pictured on your right.

Once through the book "The Harmony of Reality, in no Time..", physics' concept of inertia will look clumsy and antiquated to you...