"Bill Miller"

So... if Newton is incomplete, as it seems to be, then we need to modify
the rules/formulae. The modification must accomodate retardation, deal
with changes in angular momentum, and handle situations where the starting
and ending masses are not the same!

Who are WE. Must exist the two knowledge. One for students and the second
for adults. The first must be extremely simply and for this reason adults do
not use it. Afer study people (in industry) learn for 40 years and they do
not use textbooks for students. Authors of textbooks need modify the rules
but in direction to make them more simply. Which who launch satellites etc.
have them modified properly.
S*

----------------------------
"Bill Miller" wrote in message
...

"Don Kelly" wrote in message
news:rqU7k.26648$Jx.4753@pd7urf1no...
----------------------------
"Bill Miller" wrote in message
...

"Spaceman" wrote in message
...
Bill Miller wrote:
"Spaceman" wrote in message
. ..
Bill Miller wrote:
For example, for many years, Newton's Law fell into the "Law"
category. Not anymore.

Sorry to quibble Bill,
What law of newtons became not a law anymore?
Perpetual motion designers all over the world would like to know
so they can "break" all of his laws by simply jumping over one.


--
James M Driscoll Jr
Spaceman


Hello Spaceman. No quibble... just an example of how teaching has
not kept pace with reality. Here goes:

One of the fundamental laws of mechanics is Newton's law of action and
reaction, usually stated as : "Whenever a body exerts a force
(action) on a second body, the second body exerts an equal and
opposite force (reaction) on the first body."

Suppose that a stationary mass is located in the gravitational field
of another, distant stationary mass.The two masses exert equal and
opposite forces on each other. (Action and reaction) Let us now
allow one mass to move under the action of the field of the other
mass. ut the second mass, being far away, does not yet "know
that the first mass has moved. (gravity -- like light -- cannot
propagate instantaneously.) The second body continues to experience
the same force as before.

Bill, I am sorry you have been fooled by the described situation
Newtons force theory has to include every object in between
also.
When every action-reaction of the object is considered, it has never
been
wrong.
The example given is "ignoring" action-reaction of all in between
the two objects.

In other words, the forces are now unequal in magnitude and direction
and Newton's action/reaction law no longer holds! Further, this
situation also is in conflict with the very basic law of conservation
of momentum.

Every action/re-action in between have balanced.
Forces have caused "objects that would transfer the force
to transfer to a different direction, and not enough force
was transmitted all the way to cause the re-action you were hoping for.
Newton still holds true if each and every action-reaction is considered
in between.

For a detailed analysis of this, and other Newtonian flaws, please see
Jefimenko's "Causality, Electromagnetic Induction and Gravitation" OR
"Gravitation and Cogravitation."

Again,
This is not a newton flaw, it is a flaw of the understanding of the
newton
law.
Each and every single object in between must be considered.
You can not ignore the action-reactions that take place in between
the two objects like such is being done to come up with
the supposed violation.

Try this one in a much simpler form but almost like the gravity
problem...
Lets use air.
Air between two objects on the ground.
Would the air transfer all the motion of an object
that is 5 ft away from another object?
No, simply because all the force of the action-reactions
are diverted by the air but all action re-action of the air
follows Newton's law very well.
the same holds true for gravity.


BTW, Timo questioned my assertion that F = MA was also "leaky." I
THOUGHT that the above also affected this equation. After further
review... Timo's right... so far!

Action-reaction of Newton law still holds true if
all such action-reactions in between are considered.


I hope this helps!

I hope what I babbled probably too many times just now,
helps you understand that Newton still holds fine and no
problem has occured that Newton has been proven wrong
in such.
(Missing forces is the only way he is ever proven wrong)
and missing forces only proves that someone is not following
Newton the way they really should.

After all any force at all, is a force and not only the ones
Newton haters want to pick are the only forces.


BTW, yes, a glass is simultaneously 20% empty and 80% full, but
entirely too many people (IMNTBHO) ignore the fullness and
concentrate only on the empitiness. And that's kinda sad!

Yes, it is sad..
I always try to think of both sides of the story.
It is much safer to do so also.


I am sorry for babbling but I have never seen Newton's
Laws to be wrong.
and that is why I always follow him and think about each
and every force (action-reaction) that could occur.,,
also if I don't follow such being mechanically minded... I could be
killed.
Newton has saved my life a few times.
I am sure he probably has saved a lot of peoples lives by coming
up with such beautiful laws that have not actually been broken ever.


--
James M Driscoll Jr
Spaceman


I think I understand your point, but in the case that I described, there
is nothing in between the two masses but vacuum. Are you postulating
some special property of vacuum that instantaneously transmits force
vector information from a perturbed mass to a mass in the same field? If
so, I'd like to learn more about that!

If not, then there will be a delay between when a mass is perturbed and
when the perturbation is sensed..And that delay is not explicit in any
of Newton's laws.



Put a bunch of ball bearings in contact with each other in a row. Tap the
first one and not that the last one does not instantaneously react. At
each contact point, assuming the bearings are incompressible there is a
local action/reaction equivalence but the time for this to be transferred
to the end is dependent on the speed of sound in the bearings.
Essentially a travelling wave. No need to go to deep space to see a
delay. Does this make Newtons 3rd law invalid?

GREAT example. Let's think about this.

We hit the first ball. Some time later, the last ball moves.

Newton says: "For every action, there is an equal and opposite reaction."
If this means "instantly," then clearly there is a flaw. Does this mean
that Newton is wrong, or merely incomplete?

Since we routinely use Newton to chart the heavens, launch satellites etc.
etc., it is clear that Newton isn't WRONG. I believe the answer is
"incomplete."

Let's take your line of balls idea a step farther. First, let's assume
that the second ball is slightly out of line with all the others. When we
strike the first ball, it passes the impact on to the second ball slightly
off center. This acts to transfer some of the impact in a straight line,
but also causes it to rotate. This imparts angular momentum to the second
ball -- and subsequent balls. The reaction is not the same as the action!
-----------------
But, at the point of contact the forces are the same whether or not the
impact is dead on. You give some direct force but you also have some spin-on
both balls. You still have conservation of angular momentum. No problem with
Newton there -just consider the forces as vectors. Newton obviously did .
---------


Now let's assume that it has been a while since we have played with our
balls. (Sorry! I couldn't resist!) A thick coating of dust covers all the
balls.

We strike the first ball, and as the traveling wave progresses, it shakes
the dust off of all the other balls. This reduces the mass of each ball.
Again, the reaction is not the same as the action.

So... if Newton is incomplete, as it seems to be, then we need to modify
the rules/formulae. The modification must accomodate retardation, deal
with changes in angular momentum, and handle situations where the starting
and ending masses are not the same!

These issues are important in planetary systems. There, we have distances
that are large WRT the speed of gravity, we have bodies that possess
angular momentum, and (like a comet whose mass changes as it travels by)
bodies whose mass is not constant with time.
------
But then considering only the first dusty ball, the problem becomes not a
two body problem but a multibody problem. Considering all the balls, this is
compounded. The failure is not Newton but in our ability to actually solve
the resultant multibody problem. We don't know the masses or velocities of
the dust particles but they aren't being converted to energy so there is
no change in the total system mass. You can still assume total momentum,
angular and linear is unchanged- even if the final interaction occurs some
time later than the first collision.

--

Don Kelly
remove the X to answer


------------


A gravitostatic model does not work in a gravitodynamic environment.

In the vacuum, we really do not know the propagation method

True

and there are various proposed mechanisms including aether and virtual
phonons and the delay depends on the velocity of light. (or gravity --
they are not necessarily the same, although they SEEM to be)
These all appear to be attempts to cope with mechanical forces at
distances by some essentially fully mechanical coupling. Why?

Because we seem to be worshiping at the shrine of St, Isaac rather than
looking -- as Heaviside did in 1893 (!) -- at the facts.

Do the delays make Newton's law of action/reaction invalid?

Not invalid. Just incomplete.

..After all, this
was developed without consideration of delays. Timo points out the
Heaviside view-all reactions are local. -

True! But all actions are not!

Bill

Don Kelly
remove the X to answer

"Don Kelly" wrote in message
news:Wcl8k.50123$gc5.12925@pd7urf2no...


----------------------------
"Bill Miller" wrote in message
...

"Don Kelly" wrote in message
news:rqU7k.26648$Jx.4753@pd7urf1no...
----------------------------
"Bill Miller" wrote in message
...

"Spaceman" wrote in message
...
Bill Miller wrote:
"Spaceman" wrote in message
. ..
Bill Miller wrote:
For example, for many years, Newton's Law fell into the "Law"
category. Not anymore.

Sorry to quibble Bill,
What law of newtons became not a law anymore?
Perpetual motion designers all over the world would like to know
so they can "break" all of his laws by simply jumping over one.


--
James M Driscoll Jr
Spaceman


Hello Spaceman. No quibble... just an example of how teaching has
not kept pace with reality. Here goes:

One of the fundamental laws of mechanics is Newton's law of action
and
reaction, usually stated as : "Whenever a body exerts a force
(action) on a second body, the second body exerts an equal and
opposite force (reaction) on the first body."

Suppose that a stationary mass is located in the gravitational field
of another, distant stationary mass.The two masses exert equal and
opposite forces on each other. (Action and reaction) Let us now
allow one mass to move under the action of the field of the other
mass. ut the second mass, being far away, does not yet "know
that the first mass has moved. (gravity -- like light -- cannot
propagate instantaneously.) The second body continues to experience
the same force as before.

Bill, I am sorry you have been fooled by the described situation
Newtons force theory has to include every object in between
also.
When every action-reaction of the object is considered, it has never
been
wrong.
The example given is "ignoring" action-reaction of all in between
the two objects.

In other words, the forces are now unequal in magnitude and direction
and Newton's action/reaction law no longer holds! Further, this
situation also is in conflict with the very basic law of conservation
of momentum.

Every action/re-action in between have balanced.
Forces have caused "objects that would transfer the force
to transfer to a different direction, and not enough force
was transmitted all the way to cause the re-action you were hoping
for.
Newton still holds true if each and every action-reaction is
considered
in between.

For a detailed analysis of this, and other Newtonian flaws, please
see
Jefimenko's "Causality, Electromagnetic Induction and Gravitation" OR
"Gravitation and Cogravitation."

Again,
This is not a newton flaw, it is a flaw of the understanding of the
newton
law.
Each and every single object in between must be considered.
You can not ignore the action-reactions that take place in between
the two objects like such is being done to come up with
the supposed violation.

Try this one in a much simpler form but almost like the gravity
problem...
Lets use air.
Air between two objects on the ground.
Would the air transfer all the motion of an object
that is 5 ft away from another object?
No, simply because all the force of the action-reactions
are diverted by the air but all action re-action of the air
follows Newton's law very well.
the same holds true for gravity.


BTW, Timo questioned my assertion that F = MA was also "leaky." I
THOUGHT that the above also affected this equation. After further
review... Timo's right... so far!

Action-reaction of Newton law still holds true if
all such action-reactions in between are considered.


I hope this helps!

I hope what I babbled probably too many times just now,
helps you understand that Newton still holds fine and no
problem has occured that Newton has been proven wrong
in such.
(Missing forces is the only way he is ever proven wrong)
and missing forces only proves that someone is not following
Newton the way they really should.

After all any force at all, is a force and not only the ones
Newton haters want to pick are the only forces.


BTW, yes, a glass is simultaneously 20% empty and 80% full, but
entirely too many people (IMNTBHO) ignore the fullness and
concentrate only on the empitiness. And that's kinda sad!

Yes, it is sad..
I always try to think of both sides of the story.
It is much safer to do so also.


I am sorry for babbling but I have never seen Newton's
Laws to be wrong.
and that is why I always follow him and think about each
and every force (action-reaction) that could occur.,,
also if I don't follow such being mechanically minded... I could be
killed.
Newton has saved my life a few times.
I am sure he probably has saved a lot of peoples lives by coming
up with such beautiful laws that have not actually been broken ever.


--
James M Driscoll Jr
Spaceman


I think I understand your point, but in the case that I described,
there is nothing in between the two masses but vacuum. Are you
postulating some special property of vacuum that instantaneously
transmits force vector information from a perturbed mass to a mass in
the same field? If so, I'd like to learn more about that!

If not, then there will be a delay between when a mass is perturbed and
when the perturbation is sensed..And that delay is not explicit in any
of Newton's laws.



Put a bunch of ball bearings in contact with each other in a row. Tap
the first one and not that the last one does not instantaneously react.
At each contact point, assuming the bearings are incompressible there is
a local action/reaction equivalence but the time for this to be
transferred to the end is dependent on the speed of sound in the
bearings. Essentially a travelling wave. No need to go to deep space to
see a delay. Does this make Newtons 3rd law invalid?

GREAT example. Let's think about this.

We hit the first ball. Some time later, the last ball moves.

Newton says: "For every action, there is an equal and opposite reaction."
If this means "instantly," then clearly there is a flaw. Does this mean
that Newton is wrong, or merely incomplete?

Since we routinely use Newton to chart the heavens, launch satellites
etc. etc., it is clear that Newton isn't WRONG. I believe the answer is
"incomplete."

Let's take your line of balls idea a step farther. First, let's assume
that the second ball is slightly out of line with all the others. When we
strike the first ball, it passes the impact on to the second ball
slightly off center. This acts to transfer some of the impact in a
straight line, but also causes it to rotate. This imparts angular
momentum to the second ball -- and subsequent balls. The reaction is not
the same as the action!
-----------------
But, at the point of contact the forces are the same whether or not the
impact is dead on. You give some direct force but you also have some
spin-on both balls. You still have conservation of angular momentum. No
problem with Newton there -just consider the forces as vectors. Newton
obviously did .
---------


Now let's assume that it has been a while since we have played with our
balls. (Sorry! I couldn't resist!) A thick coating of dust covers all the
balls.

We strike the first ball, and as the traveling wave progresses, it shakes
the dust off of all the other balls. This reduces the mass of each ball.
Again, the reaction is not the same as the action.

So... if Newton is incomplete, as it seems to be, then we need to modify
the rules/formulae. The modification must accomodate retardation, deal
with changes in angular momentum, and handle situations where the
starting and ending masses are not the same!

These issues are important in planetary systems. There, we have distances
that are large WRT the speed of gravity, we have bodies that possess
angular momentum, and (like a comet whose mass changes as it travels by)
bodies whose mass is not constant with time.
------
But then considering only the first dusty ball, the problem becomes not a
two body problem but a multibody problem. Considering all the balls, this
is compounded. The failure is not Newton but in our ability to actually
solve the resultant multibody problem. We don't know the masses or
velocities of the dust particles but they aren't being converted to
energy so there is no change in the total system mass. You can still
assume total momentum, angular and linear is unchanged- even if the final
interaction occurs some time later than the first collision.

--

Don Kelly
remove the X to answer


------------


A gravitostatic model does not work in a gravitodynamic environment.

In the vacuum, we really do not know the propagation method

True

and there are various proposed mechanisms including aether and virtual
phonons and the delay depends on the velocity of light. (or gravity --
they are not necessarily the same, although they SEEM to be)
These all appear to be attempts to cope with mechanical forces at
distances by some essentially fully mechanical coupling. Why?

Because we seem to be worshiping at the shrine of St, Isaac rather than
looking -- as Heaviside did in 1893 (!) -- at the facts.

Do the delays make Newton's law of action/reaction invalid?

Not invalid. Just incomplete.

..After all, this
was developed without consideration of delays. Timo points out the
Heaviside view-all reactions are local. -

True! But all actions are not!

Bill

Don Kelly
remove the X to answer

Don & Spaceman

Don's ball exercise was an excellent ANALOGY but it does not represent an
EXAMPLE of the issues that I raised. I will cheerfully concede that the
dynamics of balls clicking together represents known (almost high-school
level) interactions between materials whose proprties are (or can be) well
known..

What is of interest to me is what happens when these "balls" are in space
and their only interaction is via gravity. In this case, we have to resort
to the concept of force fields.

(Please! let us not re-open the silly discussion about the "reality" of
fields.)

In my example, we have two masses separated by a distance. We wiggle one
mass. MUCH later the effect is felt by the other mass. During that time
perid, the law of action and reaction does not hold.

There are other examples:

If one calculates the forces between a charged particle moving on the x axis
and a particle moving along the z axis, we find the forces are unequal. (
Breitenburger "Magnetic Interaction betwen Charged Particles" A J Ph. 36,
505-515 1968 & Scanio, "Conservation of Momentum in electrodynamics... " A J
Ph. 43, 258-260, 1975)

Also, if a charge moves past a magnetic dipole, the forces are unequal.
(Portis, "Electromagnetic Fields, Sources and Media" John Wiley & Sons
1978, pp 390-392)

There are others. See Ch 4 of Jefimenko's "Causality..." book for some more.

This is not surprising. Newton's theory of gravitation is based on the
Gravitational Force Law, F = G(M1M2)/r sq.

This is a STATICS law. There is no provision for time dependency, whether it
be location, velocity (linear or otherwise) nor of mass. Also, like Coulomb,
it has an obvious flaw in that it "blows up" as
r -- 0. Or do we just "normalize" this away as some would have us do with
Coulomb?

We do not (slavishly) attempt to apply Coulomb's Law to Electrodynamic
situations. Why should we do so with Newton?

Let's douse the candles and incense at Isaac's shrine and recognize that his
is a great theory, or "law" if you wish..

It is incomplete.

Bill

Bill Miller wrote:
Don & Spaceman

Don's ball exercise was an excellent ANALOGY but it does not
represent an EXAMPLE of the issues that I raised. I will cheerfully
concede that the dynamics of balls clicking together represents known
(almost high-school level) interactions between materials whose
proprties are (or can be) well known..

What is of interest to me is what happens when these "balls" are in
space and their only interaction is via gravity. In this case, we
have to resort to the concept of force fields.

(Please! let us not re-open the silly discussion about the "reality"
of fields.)

In my example, we have two masses separated by a distance. We wiggle
one mass. MUCH later the effect is felt by the other mass. During
that time perid, the law of action and reaction does not hold.

Actually it does, but like I said,
to think Newtonian, you would have to have an aether of some sort
"a medium of the transference of the force".
I do agree there will not be an instant reaction between any two object
and a newtonian force would need that to be "complete".
But still, the basic of the newton equation still hold
(barring the instant motion thing)
Each and every " ball" be it so tiny would account
for the motion occuring.
It also is of course an immense amount of math of each and every
action/re-action.


There are other examples:

If one calculates the forces between a charged particle moving on the
x axis and a particle moving along the z axis, we find the forces are
unequal. ( Breitenburger "Magnetic Interaction betwen Charged
Particles" A J Ph. 36, 505-515 1968 & Scanio, "Conservation of
Momentum in electrodynamics... " A J Ph. 43, 258-260, 1975)

Such non balance of the forces is simply "a missing a force"
that is ignored and thrown into the "anti-newton evidence" folder.


Also, if a charge moves past a magnetic dipole, the forces are
unequal. (Portis, "Electromagnetic Fields, Sources and Media" John
Wiley & Sons 1978, pp 390-392)

Ditto again.
If they looked for the force instead of just dismissing the missing force
as a newton fault, they may actually find it instead of using "math"
as a cause instead.
math is not a cause.
At least not in the Universe I know.



There are others. See Ch 4 of Jefimenko's "Causality..." book for
some more.

This is not surprising. Newton's theory of gravitation is based on the
Gravitational Force Law, F = G(M1M2)/r sq.

This is a STATICS law. There is no provision for time dependency,
whether it be location, velocity (linear or otherwise) nor of mass.
Also, like Coulomb, it has an obvious flaw in that it "blows up" as
r -- 0. Or do we just "normalize" this away as some would have us
do with Coulomb?

We do not (slavishly) attempt to apply Coulomb's Law to Electrodynamic
situations. Why should we do so with Newton?

Let's douse the candles and incense at Isaac's shrine and recognize
that his is a great theory, or "law" if you wish..

It is incomplete.

I agree, but it is only incomplete in the "timing" of the action/reaction.
With proper timing and newtonian force laws and the actual finding
of each and every force,
Newtons force laws hold fine but are missing the timing equation
of such force transference.


And the biggest factor of timing with a newtonian/eculidian world,
would be to use "absolute" timing.
nothing relative at all.
Relative timing is non standard, if you read my post about that.
"The standard of time and identical clocks"
I am sure you would agree.


--
James M Driscoll Jr
Spaceman

"Spaceman" wrote in message

Bill Miller wrote:
Don & Spaceman

Don's ball exercise was an excellent ANALOGY but it does not
represent an EXAMPLE of the issues that I raised. I will cheerfully
concede that the dynamics of balls clicking together represents known
(almost high-school level) interactions between materials whose
proprties are (or can be) well known..

What is of interest to me is what happens when these "balls" are in
space and their only interaction is via gravity. In this case, we
have to resort to the concept of force fields.

(Please! let us not re-open the silly discussion about the "reality"
of fields.)

In my example, we have two masses separated by a distance. We wiggle
one mass. MUCH later the effect is felt by the other mass. During
that time perid, the law of action and reaction does not hold.

Actually it does, but like I said,
to think Newtonian, you would have to have an aether of some sort
"a medium of the transference of the force".

Give us the required stiffness (bulk modulus) of this
medium in order for the speed of interaction to be as
high as it is measured to be -- the speed of light.
Then tell us how anything material could ever move
through such a medium, let alone frictionlessly. After
that you can explain how such a medium would not be
dispersive for light.

Greg Neill wrote:
Give us the required stiffness (bulk modulus) of this
medium in order for the speed of interaction to be as
high as it is measured to be -- the speed of light.
Then tell us how anything material could ever move
through such a medium, let alone frictionlessly. After
that you can explain how such a medium would not be
dispersive for light.

Hmm?
It would seem that it all would match a photons everything.
so it must just be full of photons or even smaller stuff.
Of course, you would only have to find a true "mass"
and size of such photons or even smaller stuff to finish
the aether theory correctly.
But of course,
such is beyond what a rubber ruler person could even think of
being so brainwashed about a 0 mass photon to begin with.


--
James M Driscoll Jr
Spaceman

"Spaceman" wrote in message

Greg Neill wrote:
Give us the required stiffness (bulk modulus) of this
medium in order for the speed of interaction to be as
high as it is measured to be -- the speed of light.
Then tell us how anything material could ever move
through such a medium, let alone frictionlessly. After
that you can explain how such a medium would not be
dispersive for light.

Hmm?
It would seem that it all would match a photons everything.
so it must just be full of photons or even smaller stuff.

If that were true then gravity could be shielded by the
simple expedient of interposing a blind (shades of
cavorite!), and planets would slow in their orbits due to
frictional effects (a photon bath provides a form of
friction to bodies moving in it).

Of course, you would only have to find a true "mass"
and size of such photons or even smaller stuff to finish
the aether theory correctly.

Oh is that all? Suppose you take a stab at specifying the
material properties of the bulk aether then, being
careful that they correspond to the physical requirements.
I'm not saying specify the particles it's made of (you can
if you want though) but rather the measurable bulk
qualities of the aether.

But of course,
such is beyond what a rubber ruler person could even think of
being so brainwashed about a 0 mass photon to begin with.

Forget Relativity in this case. The aether was a failure
of classical physics (which you would know if you had
read any science history).

There are no consistent set of properties that can be
assigned to an aether that will not be self contradictory
or empirically impossible.

Greg Neill wrote:
If that were true then gravity could be shielded by the
simple expedient of interposing a blind (shades of
cavorite!), and planets would slow in their orbits due to
frictional effects (a photon bath provides a form of
friction to bodies moving in it).

You must be forgetting the smaller stuff.
Figures.
Only gigantic swelled brains can ignore the tiny stuff.
LOL

--
James M Driscoll Jr
Spaceman

"Timo A. Nieminen" wrote in message
...
On Mon, 23 Jun 2008, Bill Miller wrote:


"Timo A. Nieminen" wrote in message
...
On Sat, 21 Jun 2008, Bill Miller wrote:

snip

Correct. And as long as the interaction is of a contact nature, then
eveything is OK. But when there is a delay between the action and the
reaction, then *for that delay period* momentum is not conserved. But we
know that momentum MUST be conserved, so we must look at Newton with an
eye
to modifying it to deal with what amounts to a time dependency.

This is not a new idea. We have long recognized, for EM that electrostaic
representations break down when time dependency is present.

Heaviside suggested this in 1893 but never took it all the way to its
logical conclusion.

Heaviside's Maxwellian gravitation? There is no modification of Newton's
laws of motion in it. Newton's law of universal gravitation, describing
gravitational forces as interactions between distant bodies, is replaced
by a field theory, wherein all interactions are local - body interacts
with local field, not body with distant body.

You must be looking at a different copy of Heaviside's 1893 article. In it,
he clearly (to me at least) understood concepts of time-dependancy, the
gravitational equivalent of the Poynting Vector (that he claimed partial
credit for) and others. I agree that he did NOT deal with retardation.
Neither did/does Maxwell!

This "action at a distance" has always been an Achilles Heel.

It is resolved, I believe by understanding and applying Causality. We need
to understand that if two events occur at the same time, neither can cause
the other. Instead, at least one must be caused by some other (hidden)
event.

Recognition of this simple concept would, as one example, have stopped
generations of instructors from teaching their students that E causes H and
H causes E. It would have also stopped generations of mathematical
physicists from publishing articles in peer-reviewed publications that
"proved" that E causes H or vice versa. And it would have stopped
generations of experimental physicists from spending countless hours and
dollars in building apparatus to measure the non-existent H between the
plates of capacitors.

If I have understood your position on this, Timo, it is that the teaching of
this is expeditious & that once one gets to the PG leve, the "true facts"
are revealed and everything is fine.

That leaves hordes of non PG students still believing this rubbish. And it
begs the question of why, in UG classes, the instructors don't say
*something* about how theses two parameters don't cause each other, but that
they always appear simultaneously. I suspect its because the instructors
don't know it!

Is there a single UG EM textbook that correctly categorizes the relationship
between E and H? Even ONE?

Bill takes a deep breath, steps down from the soap box, and shuffles away
from the small crowd of mostly disinterested onlookers. A nondescript brown
dog sniffs the box suspiciously, turns sidewise and lifts its leg.

Newton 1 and 2 are pretty much just definititions of inertial motion and
force, while Newton 3 is (as above) conservation of momentum. How can these
be modified sensibly?

I'd say that looking at Causality and incorporating what we learn into new
expressions that include factors tor time variation of position and for
timevariation of mass would get the job done. Naturally, any such additions
must obey conservation of momentum AND must reduce to the original form when
time dependancy is absent.

Yes, if we consider two masses as above (or two electric charges) to be
interacting with each other, we have exactly the problem you point out.

Does this mean Newton 3 is wrong? Does this mean momentum is not
conserved? I would say that it means that we simply don't have a
situation
where there are two objects interacting at a distance, but two objects
each interacting with a field. Perhaps the interaction really is as
described by field theory, a local interaction between field and body,
and
we should throw away the classical mechanics idea of interaction at a
distance rather than Newton 3.
That's one way of dealing with it. I believe that a better way would be
to
recognize that Newton's work is not applicable to time dependency. That's
no
different, conceptually, from Maxwell's expansion of Ampere's Law to
include
The rate of Change Of E field in order to deal with magnetic fields in a
time-dependent environment.

I think it is different conceptually. One is a conservation law, and the
other describes a limited set of experimental observations.

It is true that gravity is a whole bunch of orders of magnitude more
difficult to deal with experimentally than EM. Building planetary objects,
setting them rotating, and zapping them past one another is way beyond our
experimental capability.

BUT, we have a handy set of "toys" in our own night sky. And there we have
an interesting set of pre-made experiments already in process. Like, maybe,
does our model explain why the rotational speed of the Sun at the equator is
different from the speed at the poles? Or does it provide some insights into
Mercury's (supposedly) residual precession? Does it support or deny the
existence of black holes? Does it provide some insight into the "missing
mass of the universe" question? What might it say about gravitational waves?
Does it provide a definitive explanation of the process wherein potential
energy is converted into kinetic energy by a falling body? Does it explain
why EM beams are deflected by gravity?

But that's a lotta work. Doing it wrong is a lot easier!

Cheers, Bill

"Bill Miller" wrote in message
...
|
| "Timo A. Nieminen" wrote in message
| ...
| On Mon, 23 Jun 2008, Bill Miller wrote:
|
|
| "Timo A. Nieminen" wrote in message
| ...
| On Sat, 21 Jun 2008, Bill Miller wrote:
|
| snip
|
| Correct. And as long as the interaction is of a contact nature, then
| eveything is OK. But when there is a delay between the action and the
| reaction, then *for that delay period* momentum is not conserved. But
we
| know that momentum MUST be conserved, so we must look at Newton with an
| eye
| to modifying it to deal with what amounts to a time dependency.
|
| This is not a new idea. We have long recognized, for EM that
electrostaic
| representations break down when time dependency is present.
|
| Heaviside suggested this in 1893 but never took it all the way to its
| logical conclusion.
|
| Heaviside's Maxwellian gravitation? There is no modification of Newton's
| laws of motion in it. Newton's law of universal gravitation, describing
| gravitational forces as interactions between distant bodies, is replaced
| by a field theory, wherein all interactions are local - body interacts
| with local field, not body with distant body.
|
| You must be looking at a different copy of Heaviside's 1893 article. In
it,
| he clearly (to me at least) understood concepts of time-dependancy, the
| gravitational equivalent of the Poynting Vector (that he claimed partial
| credit for) and others. I agree that he did NOT deal with retardation.
| Neither did/does Maxwell!
|
| This "action at a distance" has always been an Achilles Heel.
|
| It is resolved, I believe by understanding and applying Causality. We need
| to understand that if two events occur at the same time, neither can cause
| the other. Instead, at least one must be caused by some other (hidden)
| event.
|
| Recognition of this simple concept would, as one example, have stopped
| generations of instructors from teaching their students that E causes H
and
| H causes E.


You mean this magnet turns on only when the operator throws a switch
because it is a simultaneous but independent event?
http://www.global-b2b-network.com/di...ctromagnet.jpg

I must say that is a very simple concept - from an extremely simple mind,
****head.

*plonk*