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Universal Physics Journal
Article I: The Reality of Newton's Inertia
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Author: Ethan Skyler
Publication Date: October 1, 2000
Revision Date: November 14, 2002 |
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Purpose
Isaac Newton made the Classical Mechanics concept
of inertia the widely recognized Physical concept it is today. But in
truth is inertia actually anything real? I have discovered that
when one asks even a single question about the role of inertia
during an event, the reality of inertia's existence immediately becomes shaded
with doubt. My purpose in writing the following article is to answer
the question: "Is inertia real or imaginary?" |
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Article I
In his great work, "Mathematical Principles of Natural
Philosophy", known today more simply as "PRINCIPIA" [1], Isaac Newton
described inertia as the "force of inactivity". He went on to say
that an object maintained its state of rest, or uniform motion (same
state) "by its inertia only." In other words "resting" and "uniformly
moving" objects were viewed by Newton as being equally inactive and
further that this inactivity was being maintained by the force Newton
called "inertia". Thus, according to Newton's description, the object's
"force of inertia" must serve in some manner to prevent activity from
occurring to the object's state of motion if the object's "inactivity" is
to be "maintained". With rest and uniform motion being the inactive
state then a change in motion (acceleration) must be the active state
that challenges the inactivity-maintaining power of the object's
"inertia". Since the activity of acceleration is always caused by an
accelerative force (Newton's LAW I), and further since every accelerative
force always finds support against some other force of equal magnitude
(Newton's LAW III), then it holds that Newton's inertia must be this other
force that reacts in support of the accelerative force which is busy
acting as the cause of the object's accelerational activity. (See
references [2], [3], and [4]).
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(2) But why then did Newton refer to inertia as being a "force of inactivity"? Clearly, any force
that reacts in support for an acceleration-causing action force is itself a
force that is a participant in the activity of acceleration. For certain,
as long as the active acceleration force is present, the object will
continue to accelerate with no end in sight. Therefore, in practice, any
reactive inertia force directed back from the object does nothing to
prevent the acceleration action force from continuing to cause
acceleration for the
object. In fact, it is clear that as long as the acceleration action force
is impressed against the accelerating object, no force of any type is
present that is successful in causing an end to the acceleration and
thereby restoring the object once again to the
non-accelerative inactive state of rest or
uniform motion as Newton predicts is the true role of the
object's inertia. In reality, during an accelerational event, I do not
think there is any
evidence of the presence of any "force of inactivity" that
matches Isaac Newton's description for the role of inertia.
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(3) In my next effort to discover the reality of Newton's inertia, I
propose an experiment in the vacuum of the space between solar systems
whereby a weightless billiard ball is maintaining a constant position
before me, within arm's reach. If Newton's inertia is busy maintaining
this ball's inactive state of motion, then how can it be that even the
slightest push from the tip of a feather will immediately begin causing
the ball to abandon its current state of motion for a new one? I think the answer
is that there is nothing present that prevents the ball from
accelerating away from my location in response to the force applied by the
feather's tip. While it takes an action force to accelerate the ball in
one direction and an oppositely-directed action force to accelerate the
ball in the opposite direction, in the absence of either of these
acceleration action forces, there is no force present at all, nor anything
else, that is busy "maintaining" the ball's inactive state of motion. From
my perspective, the ball before me is in the inactive state of rest. |
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(4) In fact, since it takes the presence of an action force to cause
the billiard ball to accelerate away from its position of inactive rest
before me (Newton's LAW I), in the absence of such an action force, what
should one expect the ball to do in the meantime? Does the inactive
ball not have but one available option? I see that solitary option is
for the ball to continue
waiting in the inactive state of rest until the next acceleration action
force becomes present. If he were asked to consider this event,
Isaac Newton would undoubtedly point to the inactive billiard ball before
me and contend that the presence of the ball's "inertia"
was the reason the ball's inactive state of motion was being
"maintained". I would point back
to Newton that according to his own, perfectly correct LAW I, since it takes an
action force to cause acceleration for the object, the true reason the
billiard ball remains in its inactive state of motion before me is due,
not to his claim of the presence of the ball's supposed "inertia"
but instead, to the absence of an acceleration-causing action
force, as correctly predicted by LAW I.
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(5) Since both Newton and I agree that it takes an
action force to cause acceleration for the billiard ball, then if he were
able to read this discussion he should agree with me that in the absence of such an acceleration-causing action force, the billiard ball has no
other option but to remain in its current inactive state of
rest-motion until such time as the next action force comes along. At
this point it should be clear, even to Newton, that the only condition required for a resting
object to continue resting, indefinitely, is for all action forces to be
either absent or in balance with each other. Clearly "inertia" has no
role to fill in this event regardless of whether the object's state of
motion is active, as when an acceleration/Action force is present,
or inactive as when an acceleration/Action force is absent.
Once again, the role of Isaac Newton's "inertia" is the role of nothing. |
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(6) What then do today's educators teach us
about inertia? Generally inertia is said to be a property of
matter whereby the matter's inertia resists any force causing
a change in its motion. Now, I see the word "resist" as
interchangeable with "oppose" and the phrase "change in its
motion" as interchangeable with "acceleration".
Substituting these
clearer words, we now have matter's inertia opposing any force
causing acceleration for the matter. Since acceleration can only be caused
by an action force (Newton's LAW I) and since any such acceleration/Action force is
always opposed by an equal force (Newton's LAW III), this means that in
order for the matter's inertia to present opposition to the
acceleration/Action
force, it must itself be a force, measurable in pound.force (lb.f)
or the Newton (N). |
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(7) These considerations present a real
problem for the reality of "inertia" which is today professed to not be a
force at all, and not measurable in any distinct units of measure for
"inertia", certainly not in lb.f. or the Newton. Furthermore, the acceleration force
applied by the feather against the weightless billiard ball in deep space
is said to be the only force experienced by the ball's matter. Thus
it is professed in Modern Physics that the acceleration force from the feather
is a "net force" or "single force" or "overall
force" or "unbalanced force" that is predicted
to act upon the ball in the complete absence of an equal and opposite
force affecting the ball's matter. In support of this "net force"
position we are asked to consider that no force is pushing back on the
other side of the ball. Yet what of Newton's LAW III that predicts that,
without exception, every force is
always opposed by an equal force?
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(8) Let us stop for a moment to take
stock on this issue. When the billiard ball is accelerating in one
direction by the acceleration/Action force from the feather,
do you really think the ball's matter is not experiencing an equal force
in the opposite direction? Or do you think, as I, that the bending aside of the
feather's tip is a visual indication of the presence of equal and opposite
forces, one of which is a backward reaction force that is being generated
deep within each component of the matter of the accelerating ball? After
all, how can one possibly push with any force at all against an object,
accelerating or not, that does not push back with an equal force?
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(9) Understand that this backward reaction force from the accelerating billiard ball
that is presented against the feather's tip currently holds a discounted role during this
event. The widely accepted Action/Reaction Force Rule
defines each force of an action/reaction pair of forces as affecting a
different object and therefore neither force is accepted as acting or
reacting to cancel the effect the other force has upon one of the objects.
Based upon this rule, physicists currently ignore the backward reaction
force from the billiard ball because they only accept that it is affecting
the feather. Thus they must think that this reaction force just
suddenly appears at the contact point between the ball and the feather if
they do not accept that it is also present at various lesser magnitudes
throughout the ball's matter. This limited path of logic leads them
to think that there is but one force being experienced by the ball, with
this force being the forward acceleration action force from the feather.
By this logic, today's physicists conclude that the ball is experiencing a forward-directed "net
force" or "unbalanced force" from the feather since, in this frictionless
environment, they do not recognize the presence of any rearward-directed
force that is acting or reacting within the matter of the accelerating
ball. |
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(10) But is this popular "net force" or "unbalanced
force" position, regarding the forces affecting the ball, actually correct? Suppose I use a
second billiard ball that has been previously sliced in two with each flat surface of
each half attached to the opposing ends of a short, large diameter, open-coil compression
spring. Next suppose I set aside the feather and instead apply a
somewhat greater forward-directed acceleration action force with my finger
against the middle of the curved part of the back half of the ball causing
forward-directed acceleration for the back half. This back half will
subsequently apply a
forward-directed acceleration action force that is transferred by the compression spring
to the front half of the ball causing forward-directed acceleration for the
front half. Now, according to Newton's LAW III, (neglecting the matter of the
spring) as much as the back half is pushing forward with an action force
on the ball's front half, the front half is pushing rearward with a
reaction force on the ball's back half. Here I have established the presence of a rearward reaction force upon the back half
of the accelerating ball, as experimentally validated by the visual
reduction in the length of the compression spring between the ball's two
halves. If the front half of the ball is also sliced in half in a
direction parallel to the first slice and another compression spring is
inserted,
another rearward reaction force on another portion of the ball's matter is
also established as being present, and so on until the forward-most atom
of the ball's matter is reached. Even here, as much as the
forward-most atom is accelerated forward by the last of the push of the
acceleration/Action force from my finger, the atom pushes rearward with its own equal and
opposite acceleration/Reaction force. Thus there is no point within the accelerating
billiard ball where the remaining portions of the forward-directed action force
from my finger are not equally opposed by the rearward-directed
reaction forces being transferred rearward from the remaining portions of
the ball's accelerating matter.
Slicing the ball just helps us to see this truth.
Accordingly, the "net force" conclusion regarding the predicted
absence of any rearward-directed forces experienced by any portion of the
ball's matter is a conclusion without merit. The same may be said
for the Action/Reaction Force Rule (see Article
V) for it truly is a
misleading and therefore meritless "rule". I think its continued use
is a hindrance to correctly understanding the true action and reaction
forces present during an object's acceleration.
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(11) Regarding "inertia", at this point in our
discussion,
"inertia" is nothing at all. Since it takes nothing to
maintain a resting object at rest, then there is no role for
"inertia" here. Also if "inertia" is not a real,
measurable, variable, reactive force of support present during the
activity of acceleration, then there is no role during acceleration for
inert "inertia" to fill.[5]
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(12) What then is the truth? It is clear
that Newton's "inertia" is nothing. As nothing,
"inertia" has no role in Physics for nothing is required for an
object observed in the inactive state of rest to remain at rest, forever.
Equally so, if you have trouble recognizing that rest and uniform motion
are the same inactive state, then nothing is required for an object
observed in the inactive state of uniform motion (in a straight line) to
remain in uniform motion, forever. Also, regarding acceleration, while
there are measurable, variable acceleration/Reaction forces present that provide support
for the activity of a measurable, variable acceleration/Action
force, classical mechanic's non-variable, forceless "inertia" is
not one of them, nor is "inertia" one of anything else.
"Inertia" is truly nothing at all. As with the Emperor's fabled
suit of clothes, "inertia" is purely imaginary. |
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(13) Galileo
Galilei, Isaac Newton's predecessor, is often given credit by science authors
as being the first to recognize
"inertia". Now that we recognize the non-reality of
"inertia", one has to wonder if Galileo made the same error as
did Newton. A thorough reading of Galileo's work has not revealed
any evidence that he "discovered"
or named "inertia". Just as in Newton's LAW I, all Galileo did was
note that given the absence of an action force, an object had no choice
but to continue on with its inactive state of rest or uniform motion
unaltered or conserved. In
the words of Professor Stillman Drake, a noted authority
on the life and work of Galileo, "Galileo never asserted any vis
inertiae or "force of inactivity" as Newton did."
In his discussion of the issue, Drake went on to say "Many blame Galileo for his inability to invent inertia-..."
[6]
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(14) Today we understand the truth and are able to credit Galileo
with clear and logical thinking for he long ago recognized that
which has long since been forgotten. The converse of Newton's LAW I
predicts the truth that Galileo understood. If it always takes an impressed
force to change an object's inactive state of motion (rest, uniform motion)
into the active state of acceleration, then as long as such an
impressed action force is absent, no change can possibly occur to the object's
inactive state of motion for the object has no other choice but to
wait in its inactive, default state (rest, uniform motion) until the next
acceleration-causing action force becomes present. I find it curious
that Newton did not recognize the converse of his own LAW I. He
truly did miss this point since he professed in PRINCIPIA in
Definition IV that an object "maintains every new state it acquires
by its inertia only." [4] In other words Newton thought the
presence of "inertia" was required in order for an inactive
object to remain inactive. Instead, the converse of Newton's LAW I predicts the
truth in that the absence of an acceleration action force is the only
requirement that need be met in order for an inactive object to remain
in an inactive, unaccelerated state of motion... forever. |
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(15) A historically significant event occurred when Newton's imaginary "inertia"
was accepted as defined. This misguided effort of Newton's
effectively replaced the most excellent work of Galileo on the matter of establishing the
cause of the continuation of an object's uniform motion. For
centuries Aristotle's position on this matter held firm as he had
predicted that a "mover" was present as the cause of the
continuation of an object's uniform motion. Galileo overturned
Aristotle's unprovable and illogical "mover" when he pointed out
that when no force was present to cause a change in an object's uniform
motion then no change could possible occur. Thus a uniformly moving
object, unable to change its motion by any other technique than with the
presence of an acceleration action force, was left with no other choice
but to continue on in an inactive manner with its uniform motion unchanged
or unaccelerated. Later when
Newton defined "inertia" and wrote that the object
"maintains every new state it acquires by its inertia only", he
breathed new life into Aristotle's abandoned "mover" as he
effectively renamed it "inertia" and predicted that its presence
was the cause of the continuation of an object's uniform motion. In
this manner, Galileo's true work was set aside in favor of Aristotle's
faulty work after having been unwittingly restored and renamed by Isaac Newton. |
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(16) In truth we now recognize that there exists no
cause for the continuation of an object's uniform
motion. Since no cause exists, no true explanation of
cause is necessary or even possible. The object is in
the inactive and causeless default state of rest-motion. It is when the
object is in the active state of acceleration that a forceful cause
becomes present and in need of explanation. Galileo expressed his
recognition of this truth long before Newton's time. Now that we know
the strength of Galileo's enduring genius let us not wait too long before setting
the record straight.
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(17) In honor of Galileo Galilei, The First
Scientist [7], I hereby
propose the banishment of all use of the imaginary term
"inertia" from the writings and discussions of the mechanical
concepts of Universal Physics. Accordingly, non-accelerating objects
and non-accelerating frames of reference shall replace
"inertial" objects and "inertial" frames of reference
while conversely, accelerating objects and accelerating frames of
reference shall replace "non-inertial" objects and
"non-inertial" frames of reference in all true scientific writings.
Ethan Skyler
Author's Photo Gallery
References
[1] Sir Isaac Newton, 1686, 1729, Mathematical Principles of Natural
Philosophy and His System of the World, 1934, 1962, PRINCIPIA, University
of California Press, Berkeley, Los Angeles, London, page 2 - 13.
[2] Newton's LAW I: Every body continues in its state of
rest, or of uniform motion in a right line, unless it is compelled to
change that state by forces impressed upon it.
[3] Newton's LAW III: To every action there is always
opposed an equal reaction: or, the mutual actions of two bodies upon each
other are always equal, and directed to contrary parts.
[4] For a body maintains every new state it acquires
by its inertia only.
[5] Endless hours of discussion with my son, Ryan
Skyler, have helped me to fully develop the "inertia" replacing
concept of matter's acceleration/Reaction force. He was instrumental
in getting me to cease trying to salvage the inert term "inertia" making room
in my mind for its real-world, acceleration/Reaction force replacement. I have yet to find a
keener mind on this subject than Ryan's. I am blessed to have his
brilliance and original insight readily available. His contributions
have influenced the development of many of the concepts of the new science
Universal Physics. We are all in debt to his challenging support.
Thank you, Ryan!
[6] Galileo Galilei, 1638, Two New Sciences
Including Centers of Gravity and Force of Percussion, Translated, with a
New Introduction and Notes, by Stillman Drake, 2nd Edition, Wall &
Thompson, Toronto, page xxxii.
[7] For an excellent presentation and analysis of
the abuse that was heaped, without mercy, upon
Galileo, Our First Scientist, read "The War on Galileo" by
Ronald Bruce Meyer.
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Author's Commentary
One might wonder, with Newton's "inertia" absent, where will we go from here. Well, first of all, understand that the removal of
"inertia" is not the removal of "something" from
Physics, it is the removal of "nothing". It is most
likely that the illusion of "inertia" has been concealing from
our eyes the reality of a solid, practical, logical concept regarding
force that has been
all but ignored up to now.
One thing is for certain. Any science
that embraces an imaginary concept as real and true is in serious trouble,
for nothing that is subsequently based upon the imaginary concept can,
itself, be true. Isaac Newton was confused about the reality of
"inertia". The Modern Physic's version of
"inertia" is no improvement. Continued use of Newton's imaginary
"inertia" has polluted the remaining concepts of Classical
Mechanics. Albert Einstein fared no better for he carried forward
Newton's imaginary "inertia", whole and intact, into the imaginative
thought experiments of Relativistic Mechanics. This simple act of faith on
Einstein's part does not bode well for the future of Relativistic
Mechanics.
Ethan Skyler
Author's Photo Gallery |
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Copyright Notice
Article I "The Reality Of Newton's Inertia" (C) Copyright
2000-2008 by Ethan Skyler. All rights reserved. No portion of
Article I, minus the exceptions noted below, may be copied by any means
without the author's written permission and even then only if the author's
copyright notice is permanently affixed to each approved copy. Requests
for written permission may be directed to Ryan Skyler, Editor, Universal
Physics Journal, 9734 Manitou Place NE, Bainbridge Island, WA, USA.
The author grants each visitor to The
Universal Physics
Journal the right to make one copy of Article I for his or her own
personal archive as long as the author's copyright notice is permanently
affixed to the archive copy.
The Author's Commentary to Article I is
hereby granted by the author, Ethan Skyler, into the realm of the Public
Domain. As such it may be freely copied, in full, or in part, by any
means so long as a reference to the author and this web site address
of http://www.UniversalPhysics.org
are included with each copy.
Click here
to download a copy of Article I "The Reality of Newton's Inertia".
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