$$ Gravity Vs inertia.
Acceleration g has units, m/(sec)^2 ..but inertial units are kg*m^2.
Gravitational constant G has units, m^3/kg/(sec)^2 ..for attraction.
Gravitational impulse is applied per volume, inertial only per area.
Gravitational impulse, centro-symmetric; inertial impulse is linear.
Gravity works automatically at-a-distance ..inertia only by contact.
```Brian.

Joe Fischer wrote: On Wed, RP wrote:
Joe Fischer wrote: [snip]
The concept requires at least _two_ un-needed
forces acting, inertia to make the moon want to follow
a straight path, and gravity, to exert the forces to make
the moon orbit.
And all this with no visible means of accomplishing
it. It is all built on 16th century thinking.

Unless some detectable, yet unknown as of now,
real physical "field" exists, action at a distance is not
possible. And I think the idea of another "field" that
can only be determined by the motion it produces, is
identical in silliness to the aether.

Here's a gedanken for you to ponder: Suppose we find that beyond the
presently visible portion of the universe, that there exists another
layer of matter of much greater thickness than the presently observable
layer or *visible core*, and that wrt that outer layer, on average, the
visible coresic is rotating, in much the same way that a galaxy
rotates wrt the visible core. In such a universe we might find that
when our bucket of of water is stationary wrt the visible fixed stars
(visible background) that a centripetal force acts on the water in the
bucket. By rotating the bucket slowly in the same direction as the outer
layer the centripetal force abates.

Now you want to use a hypothetical universe as
an argument for complexity?

The universe cannot rotate as a whole,

Galaxies do, why not the universe?

as such would have no meaning
unless a fixed aether composed of something other than what we can
detect and observer were introduced, and as we know there is no such
thing,

At least you present some reasonable logic with this.

Having nothing to rotate wrt the universe of matter and fields
thus is the only aether available, and as such anything rotating wrt the
universe is rotating absolutely wrt it.

But that doesn't mean the rest of the universe
causes inertia, and inertia must be an attribute of
the accelerated object, and centrifugal force is
_nothing_ but inertia.

If not for the existence of the
remainder of the matter in the universe, the bucket of water simply
could not spin and no centripetal force should therefore be evident.

Nonsense, even Newton knew the bucket experiment
would not work in the absence of gravity, that is why he
made another thought experiment using two rocks tied
together.

A straight line in space is defined by the metric, which in turn is
structured by the matter in the universe.

Nonsense, it is nonsense simply on the basis
of simplicity, nature must be simple, for the sake
of simplicity.
Simplicity is the most powerful argument that
can be put forth, and any effect of distant matter
on physics here is the most complex concept possible.

The effect of distant
galaxies on the local metric may be small when considered to act
directly, but it is not nonexistent.

The effect of the gravity of the sun is very evident,
but it is not due to an attraction, nor is it due to any
"force" acting. It is the very absence of any force
acting, and the absence of Mach's inertia that makes
the appearance of "a force acting" to produce gravity.

It's effect becomes greater
however as we expand the radius of what we are calling our local space,
up to the point of having sizable effects, such as in the gedanken
above, when applied indirectly to very local, even microscopic effects.

With gravity, which must be identical to inertia,
as the effects of gravity are those of inertia and _nothing_
else (except something matter here is doing), the effect
is an inverse square function, so expanding the radius
is not a good argument.

The angular acceleration of a tossed baseball is greatly influenced by
the Earth's gravity, to a lesser extent by Sun, etc. Our assumed
inertial frame becomes more precisely inertial as we take a broader and
broader perspective of our system, i.e. as we view events from a greater
distance.

We are a considerable distance from the center
of the Milky Way, is that a detectable thing?

The Sun is in turn orbiting the center of the Galaxy, which is
in turn is rotating, and moving through space wrt the greater whole. The
trajectory of the baseball, as viewed from the perimeter of the visible
universe is thus somewhat different than our simplistic perception of it
when considered as only a local sequence of events.

And it all can be explained by local intrinsic
attributes of matter and the simple workings of
nature.

It is also from
the perspective at the perimeter (the state of rest chosen to reflect a
net angular momentum of the universe of precisely zero) that angular
acceleration of the water in the bucket takes on its observed local
characteristics.

Without gravity the water would not stay in the
bucket, or at least without acceleration the water would
not stay in the bucket.
See how simple it is to see that the effects of
gravity are the effects of inertia?
Mach's idea, or even Newton's conjecture of
support for Euclidean space is not simple, therefore
they can be countered on the basis of simplicity for
the sake of simplicity.
Actually, it is idiotic, moronic and bizarre to
argue that distant matter exerts any "forces" or
control over motion or changes in motion here.
For the sake of simplicity!

Though the effect of distant masses may appear to be
insignificant, by the interaction of successive layers of the envelope
with each other locally, an indirect strong influence perpetuates all
the way in to our position here on Earth.

Just the way Newton's attraction of gravity
propagates, but Einstein ditched that nonsense.

The layers are inertially geared together strongly via
local exchanges and weakly via long range interactions.

Gravity is not a long range "interaction", it
is simply the effect of inertia along with something
else which may not be known or considered.

Think about water spinning down a drain and the frictional
exchanges between layers in concentric cross sections. Keep in mind the
inverse square law of force as applied to gravitational and
electromagnetic fields, and thus the local field density is barely
altered directly by distant objects. It will take a small bit of
imagination to understand what I mean by field density.

Not if the "field' can be identified, which would
take a lot of invagination.
The flux density of starlight is easy to detect,
yet it is very small compared to the light of the sun,
but it is not imaginary.

Think in terms of flux density, same thing.

There is nothing about gravity or inertia
that is the same as "flux density".

By analogy, the ambient light energy
density that we experience locally is barely affected by distant
sources, and strongly by local sources, e.g. the Sun.

But it is well studied, and the many factors that
reduce the flux density of light from individual stars
are well understood.

I essentially only reiterating Einstein's own conclusions here.
namely that there is indeed a medium, but it isn't the medium
that was expected.

There is no medium, for the sake of simplicity.

Now here's another thought that might tie it together for you: Given
lorentz/fitzgerald contraction, it follows that if the universe were
more or less uniform in mass distribution wrt some frame of reference,
then in some other frame that approaches c wrt the first, the mass
density of the universe would approach infinity along the line of
motion.

The vast distance between galaxies compared
to the closeness of the stars of the Milky Way makes
your argument baseless.

At c the universe would drop to zero length in the direction of
motion, for that observer.

The view of the observer has nothing to do
with physics, it is part of relativity for other reasons.

That we observe uniformity suggest very
strongly that we are more or less at rest wrt the universe.

If we are not moving relative to the rest of
the universe means we are at rest relative to the
rest of the universe, nothing else.

IOW, when
viewing the bigger picture there is indeed a master frame, namely that
of the universe itself when taken as a whole, and in this observation
there is yet no contradiction to the special theory, which is equivalent
to LET,

A three letter bad word.

which in turn is obviously consistent with the picture just
painted. Some have even argued that LET requires a master frame due to
the acceleration histories of masses within it converging at some point
in the past to a single inertial frame, even though that frame cannot be
discovered conclusively via measurements at this late date in the
universe's history. We can however look at the background anisotropy
(CMBR) and determine that we are in fact in motion wrt the surrounding
whole, though not at an enormous rate.
Richard Perry

What is that an argument for or against?

Physics is simple, the Earth's gravity is a
result of inertia and an attribute of the matter
and energy of the Earth, not of other matter.
Gravity is intimately tied to inertia, and
both must be intrinsic to local matter, for
the sake of simplicity!

This is a valid argument until and unless
some mechanism for distant matter to effect
local physics.
All "forces" involved are imaginary if any
concept of action-at-a-distance are presented.
Gravity is a "fictitious" force, but inertia
is not. And both are attributes of matter "here".

Joe Fischer
Einstein's Mistakes.
Gravity Vs inertia.

$$ Gravity Vs inertia.
Acceleration g has units, m/(sec)^2 ..but inertial units are kg*m^2.
Gravitational constant G has units, m^3/kg/(sec)^2 ..for attraction.
Gravitational impulse is applied per volume, inertial only per area.
Gravitational impulse, centro-symmetric; inertial impulse is linear.
Gravity works automatically at-a-distance ..inertia only by contact.
```Brian.