On Wed, 12 Jan 2005, Jesse Mazer wrote:

His math seems to be incorrect

The maths is correct (barring typos I didn't notice). The final result is
certainly correct.

it's better to analyze this problem
using the full Lorentz transformations.

Why? You only use the Lorentz transformations when changing reference
frames. Apart from the initial Lorentz transformation to find the lengths
of the 2 arms in the moving frame from the lengths measured in the rest
frame, there is need to change reference frames at all.

But, carry on. Remember that the aim of the exercise is to find the
difference in round-trip times for light in the two tubes.

--
Timo Nieminen - Home page: http://www.physics.uq.edu.au/people/nieminen/
Shrine to Spirits: http://www.users.bigpond.com/timo_nieminen/spirits.html

Androcles wrote:

"Jesse Mazer" wrote in message
...


Creighton Hogg wrote:



On Wed, 12 Jan 2005, Jesse Mazer wrote:




Androcles wrote:




"Jesse Mazer" wrote in message
...




Androcles wrote:





"Jesse Mazer" wrote in message
...





Androcles wrote:






"Jesse Mazer" wrote in message
. ..






Androcles wrote:







In a reference frame in which the apparatus is stationary, x
and y don't
change as the apparatus is rotated (assuming x and y are the
arm-lengths).







Exactly. So you prove nothing. However, Einstein's postulate
is
"light is always propagated in empty space with a definite
velocity
c which is independent of the state of motion of the emitting
body"
Reference :
http://www.fourmilab.ch/etexts/einstein/specrel/www/

The Earth is moving in the empty space, which is the reference
frame.
Are you trying to deliberately obfuscate the problem?







Empty space doesn't have a particular reference frame in
Einstein's theory.






Then light will be source dependent.
Androcles.








Nope, not according to the laws of electromagnetism.





Which one? Gauss, Faraday or Ampere?
Androcles.





The fact that the speed of light is independent of the source can
only be derived using all of Maxwell's laws.




When you can read a graph, we'll discuss it. Until then, it's a
waste of time.
Androcles.




I can read your graphs, but with no descriptions of what is being
measured, I don't know what they mean. For example, on the graph you
posted at
http://www.androc1es.pwp.blueyonder....r/00918-ck.gif one
axis measures time and the other measures "m", which I would guess is
meters--but what is it that is being measured in meters? Without
context, a graph like that is meaningless--if you are willing to
explain the context, I will try to address it.

In the meantime, regardless of what that graph shows, it doesn't
change the fact that you have not addressed the issue that Maxwell's
laws are all based on experiments with electricity and magnetism that
are extremely well-confirmed, and which don't involve light at all;
once you have these laws, you can show mathematically that together
they imply the velocity of electromagnetic waves is always
1/squareroot(epsilon_0*mu_0), and that this "coincidentally" happens
to match the observed speed of light very accurately, even though the
experiments to determine epsilon_0 and mu_0 have nothing to do with
light.



Not to be a jerk, but epsilon_0 and mu_0 are really an artifact of
using SI units and wouldn't have shown up Back in The Day.




OK, but they did have terms for the permittivity and permeability of
the vacuum back in the day--whatever symbols they would have used,
just put them in place of epsilon_0 and mu_0 in the above paragraph
and the argument is unchanged.

Jesse



So you DO believe in aether, then, because those are the very properties
that
define it.
Androcles.





No they aren't. They are just constants that have to be included in
order to express the relationship between, say, the total charge
enclosed in a volume and the total electric flux passing through the
surface. That's just Gauss' law, which you said earlier you believed
in--see the description he

http://hyperphysics.phy-astr.gsu.edu...maxeq2.html#c1

The value of the permittivity is just determined by experiment, in order
to get the units to come out right. You don't have to believe anything
about what permittivity "means" in order to use the equation to make
predictions about various experiments. No mainstream physicists believe
in the aether today, but they still make use of the same equation.

And again, the experiments needed to determine the correct value of this
constant have nothing to do with measuring the speed of light. So it's
quite a "coincidence" that when you calculate the speed of
electromagnetic waves based on the permittivity and the permeability, it
comes out equal to the experimentally-determined speed of light, no? And
the same laws which imply the speed of electromagnetic waves is equal to
1/squareroot(permeability*permittivity) also imply the speed of
electromagnetic waves is independent of the source. So there's really no
plausible way around the conclusion that light is just the kind of
electromagnetic wave predicted by Maxwell's equations, and that its
speed must therefore be independent of the source's velocity.

Jesse

Timo Nieminen wrote:

On Wed, 12 Jan 2005, Jesse Mazer wrote:



His math seems to be incorrect



The maths is correct (barring typos I didn't notice). The final result is
certainly correct.


Well, I didn't look at what he was trying to calculate very closely, I
just assumed he was calculating the time in two different frames. Maybe
I was mislead by Androcles' response though, since he suggested that
since you didn't get c for the velocity this conflicted with
relativity--if he was actually calculating something like the "closing
velocity" rather than the velocity of light in a particular reference
frame, then my assumption was wrong, in which case I'll take your word
for it that his final result was the correct one.

Jesse

On Wed, 12 Jan 2005, Jesse Mazer wrote:

Timo Nieminen wrote:
On Wed, 12 Jan 2005, Jesse Mazer wrote:

His math seems to be incorrect

The maths is correct (barring typos I didn't notice). The final result is
certainly correct.

Well, I didn't look at what he was trying to calculate very closely, I
just assumed he was calculating the time in two different frames.

Actually, the simplest way to do the calculation is in the rest frame.
Light pulses sent at t = 0 return at t = T in both arms. Have both
detectors at the same value of x (and thus x'), so that the pulse launch
can be simultaneous in both frames. Lorentz transformation trivially shows
round trip time is the same in both arms in the moving frame.

OTOH, given that Androcles flatly rejected a rest frame calculation as an
analysis of the problem, I don't think he'd have accepted that.

Maybe
I was mislead by Androcles' response though, since he suggested that
since you didn't get c for the velocity this conflicted with
relativity--if he was actually calculating something like the "closing
velocity" rather than the velocity of light in a particular reference
frame, then my assumption was wrong, in which case I'll take your word
for it that his final result was the correct one.

Well, the speed c-v that he objected to my use of was exactly the speed at
which the light pulse closes with the moving mirror.

But what would you expect? Do you really think Androcles would have
admitted being wrong?

--
Timo Nieminen - Home page: http://www.physics.uq.edu.au/people/nieminen/
Shrine to Spirits: http://www.users.bigpond.com/timo_nieminen/spirits.html

Androcles wrote:

"Jesse Mazer" wrote in message
...


Androcles wrote:



"Jesse Mazer" wrote in message
...



Androcles wrote:




"Jesse Mazer" wrote in message
...




Androcles wrote:





"Jesse Mazer" wrote in message
...





Androcles wrote:






In a reference frame in which the apparatus is stationary, x
and y don't
change as the apparatus is rotated (assuming x and y are the
arm-lengths).






Exactly. So you prove nothing. However, Einstein's postulate is
"light is always propagated in empty space with a definite
velocity
c which is independent of the state of motion of the emitting
body"
Reference :
http://www.fourmilab.ch/etexts/einstein/specrel/www/

The Earth is moving in the empty space, which is the reference
frame.
Are you trying to deliberately obfuscate the problem?






Empty space doesn't have a particular reference frame in
Einstein's theory.





Then light will be source dependent.
Androcles.







Nope, not according to the laws of electromagnetism.




Which one? Gauss, Faraday or Ampere?
Androcles.




The fact that the speed of light is independent of the source can
only be derived using all of Maxwell's laws.



When you can read a graph, we'll discuss it. Until then, it's a waste
of time.
Androcles.



I can read your graphs, but with no descriptions of what is being
measured, I don't know what they mean. For example, on the graph you
posted at
http://www.androc1es.pwp.blueyonder....r/00918-ck.gif one
axis measures time and the other measures "m", which I would guess is
meters--but what is it that is being measured in meters? Without
context, a graph like that is meaningless--if you are willing to
explain the context, I will try to address it.



'm' is magnitude (actually, apparent magnitude). The definition of
magnitude
http://liftoff.msfc.nasa.gov/academy/universe/MAG.HTML

"When astronomers began to accurately measure the brightness of stars
using instruments, it was found that each magnitude is about 2.5 times
brighter than the next greater magnitude. This means a difference in
magnitudes of 5 units (from magnitude 1 to magnitude 6, for example)
corresponds to a change in brightness of 100 times."

You are seeing a change of 16-9 = 7 magnitudes.
This is AFTER the brightness was first noticed and measurement began.
The curve you see is typical of recurrent novae, although no two are
identical.


Ok, so the graph shows the variation in magnitude of a recurrent nova.
Note that astronomers already have a theory about why this occurs:

http://antwrp.gsfc.nasa.gov/apod/ap970925.html

What happens when a thermonuclear blast occurs on the surface of a
white dwarf star? Over the years astronomers have watched (at a safe
distance ...) as, 6,000 light years from Earth in the southern
constellation Pyxis, a binary star known as T Pyxidis repeatedly
produces these fearsome explosions. This Hubble Space Telescope image
of Nova T Pyx captures what appear to be blobs rather than the
expected shells of material expanding from this interacting star
system. Like other binary star systems which produce nova outbursts, T
Pyx is composed of a dense white dwarf and a close companion star. An
outburst occurs when the temperature and density of the sea of matter
dumped from the companion onto the surface of the white dwarf reach
the nuclear flash point for Hydrogen. While material is violently
blown off, the white dwarf itself is not disrupted and soon begins to
accumulate more matter from its companion, repeating the cataclysm a
few years later.


Can your theory make more accurate quantitative predictions about the
variations in brightness of a particular recurrant nova than this
theory? Can you predict the exact magnitude of successive variations in
advance, for example? If your theory can't make accurate predictions
that no other theory can, then you can hardly expect physicists to throw
out Maxwell's laws, which each have a mountain of experimental evidence
to support them, in favor of your theory.


So... we are looking at light that has travelled a huge distance.

What is going on, that this curve should be typical?

What do you think would happen if I mounted a machine gun on a carousel
or Ferris wheel, kept it aimed in your direction, just like the seats on
a Ferris
wheel, and proceeded to pepper a steel shield you were hiding behind, a
couple
of miles away. Bullets from the bottom of the wheel would travel the 3
miles
at c+ v.sin(phi) = muzzle velocity + tangential velocity of the wheel,
taking
time (say) 3 miles/(1000 - 5) mph = 0.003015 hours, or 10.85 seconds.
Bullets from the top of the wheel take 3 miles/(1000+5)mph = 10.75
seconds.
Not much difference in the rate of arrirval, is there?
What about from 300 miles away? 1085 seconds and 1075 seconds, right?
Suppose it takes 10 seconds for the wheel to turn the gun from the
bottom
to the top, then the time of arrival of bullets from the top is
1075+ 10 seconds = 1085, exactly the time of arrival of bullets
from the bottom. So your shield is hit by two bullets at the same
instant,
one from the bottom and one from the top. Actually, you are also hit
by all the bullets in between as well. Now, it is a lot of work
calculating
1,000,000 bullets, I think you'll agree, so that task is best left to a
computer.
Not only that, but the ferris wheel isn't a wheel at all, it is an
ellipse. Much
more calculation, right?
But that's what computers are for, so why not do it right?
And YOU can take advantage of one, because you have one.
All you need is the program. I've even written it for you, and its FREE!
You can specify the parameters of
Distance,
Period
Eccentricity
Semimajor Axis
Yaw
Pitch
Roll
and how many bullets to fire,
and it will plot the arrival of the bullets as a function of time.
Then you can toddle off to the library, find some nice curves
that some kind astronomers have drawn for you but do not
themselves understand the reason for, and recreate those curves
on the computer screen, as I have done.


Are the bullets from the machine gun supposed to be analogous to the
photons from the star orbiting the nova? If it's just the orbiting star
that's responsible for the variation in magnitude, why don't we see the
same degree of variation in magnitude in binary systems where the main
star hasn't gone nova?


Now, If Maxwell had had a computer and a program like mine,
he would still have agreed with Gauss and Faraday. But he would
not be saying there was any aether. He would have been saying
the speed of light in the vacuum of space is constant with respect
to the source at the time of emission.


No he wouldn't, because he'd know that each of the laws individually
(Gauss' laws for electricity and magnetism, Faraday's law, and Ampere's
law) are well-supported by experiment, and that together they *must*
imply that the speed of electromagnetic waves is independent of the
velocity of the source. To accept each law individually but deny this
conclusion is like accepting that A=B and B=C and C=D but denying that A=D.

So, which of Maxwell's laws do you want to throw out?





In the meantime, regardless of what that graph shows, it doesn't
change the fact that you have not addressed the issue that Maxwell's
laws are all based on experiments with electricity and magnetism that
are extremely well-confirmed, and which don't involve light at all;



I don't need to. I have the data and I have the model. It is up to
Maxwell
(or you) to make his laws fit reality, instead of guessing.
You won't have to change very much, just the error band that all your
extremely well-confirmed experiments have shown to within the limits
of experimental error.


There is no known way you can make a slight modification to Maxwell's
laws and get the prediction that electromagnetic waves have a velocity
that's dependent on the source--if you discover such a way, you should
publish it. And again, each one of those laws has a huge amount of
experimental evidence to support it individually.






Once you have these laws, you can show mathematically that together
they imply the velocity of electromagnetic waves is always
1/squareroot(epsilon_0*mu_0), and that this "coincidentally" happens
to match the observed speed of light very accurately, even though the
experiments to determine epsilon_0 and mu_0 have nothing to do with
light.



You are right. "Coincidently". Actually, contrived.


"Contrived"? How can it be "contrived" when the values for permittivity
and permeability were measured *before* anyone thought there would be a
connection with the speed of light, and using techniques that have
nothing to do with light? Only after both the values of these constants
and all four of Maxwell's equations had been discovered did Maxwell
realize that the laws implied electromagnetic waves would always travel
with a velocity that came out very close to c. Since both the equations
and the values were already known, there was no way he could have
fiddled with them in order to insure it would work out this way, it was
a complete surprise.


What is the speed of
sound in a vacuum? What is the volume of a gas at zero degrees Kelvin?
Just extrapolate, easy enough. Trouble is, there is no sound in a
vacuum.
There are no gases at zero Kelvin. That doesn't matter to you, though.
You believe the vacuum of space has the identical properties of aether,
the equations say so


No, I simply believe that all of Maxwell's equations give correct
predictions about the electric and magnetic force in all known
situations involving macroscopic charged objects. Do you disagree? If
so, which of the four laws do you think don't give the right predictions?

and it has been experimentally confirmed.
What has been experimentally confirmed, old son, is that the speed
of light in a vacuum is source dependent, billions of times by thousands
of stars.
And YOU are walking around with you head in a book instead of
looking up, telling me I'm wrong, your book says so. I'm looking
at REAL data, EMPIRICAL data


Data which can be easily explained by an alternate theory, without
throwing out existing equations that have mountains of REAL and
EMPIRICAL data supporting them. Do you want me to explain all the REAL
and EMPIRICAL experiments which can be done to test each of Maxwell's,
or do you agree that there's a lot of evidence for them, even if you
hold out faith that somehow we will be able to modify them in a way that
still agrees with these experiments but that no longer predicts the
velocity of electromagnetic waves is independent of source velocity?

Jesse

"Timo Nieminen" wrote in message
news:Pine.LNX.4.50.0501130759240.18481-100000@localhost...
On Wed, 12 Jan 2005, Androcles wrote:

"Timo Nieminen" wrote:
On Wed, 12 Jan 2005, Androcles wrote:

I will now give the proof.
I place two identical evacuated tubes at right angles, with
mirrors
and
with
sources and detectors of light.
When the light reaches a detector, it turns off the source.
When NO light reaches the detector, it turns the source on.
The path length can be any reasonable one.
I connect the outputs of the detectors to an up/down counter, one
for
up
and the other for down. I calibrate the tube lengths until there
is
no
count.
I now have MMX, electronic version and air free.


Since your original assertion was specific to MMX, I'll first deal
with
the actual MMX. Then your modified experiment.

I rotate the apparatus 90 degrees and what happens? NO count
happens.
Acording to SR, and there being velocity as the Earth moves and
rotates
x' = (x-vt)/ sqrt(1-v^2/c^2)
y' = y.
So, x' does not equal y'.

Why would you want to analyse the experiment using a reference
frame
moving wrt the Earth?

Simple, really.
If you analyse it from a frame that is at rest, you prove nothing at
all.
Hence we analyze from a relatively moving frame. Get your telescope
out and watch the fringe shifts from a plane if you like. As you look
at Michelson's light, you'll notice it is doppler-shifted. Stay at
rest
and
you won't.

Your modified version makes Doppler shifts irrelvant - you can ignore
the
wavelength and frequency, and only the speed matters.

Exactly. Well done. To use Einstein's own words, the "tip of the ray".
Nobody is really interested on the following wave train, but that was
all
Michelson had.


Analysing it in a frame where it at rest proves everything that is
required.

Of course it does. The tip of the ray is travelling at c relative
to the source.


An analysis using any theory that is compatible with
the PoR allows us to use any reference frame.

There you are, then. You've answered your own question.

No, I haven't. The analysis is _simplest_ in the rest frame. The
question
was why not use that rest frame?

Define "rest frame". To Einstein and Michelson it meant the rest of the
Universe, with the Earth in motion about to the sun. Of course
Michelson
and Einstein didn't know the Milky Way was a galaxy back then, galaxies
were called "nebulae", meaning clouds. The sun was still the centre of
the Universe. It was the Earth's motion through the "rest frame" that
was being
used by MMX to find the speed of light in the "rest frame".

"together with the unsuccessful attempts to discover any motion
of the earth relatively to the ``light medium,'' suggest that the
phenomena
of electrodynamics as well as of mechanics possess no properties
corresponding to the idea of absolute rest."....
"We will raise this conjecture (the purport of which will hereafter be
called the "Principle of Relativity'') to the status of a postulate,
and also introduce
another postulate, which is only apparently IRRECONCILABLE
with the former, namely, that light is always propagated in empty space
with a definite velocity c which is independent of the state of motion
of the emitting body." Einstein.
Now, what rest frame was he talking about, and why does he suggest
his second postulate is irreconcilable with the first?
I'll tell you why. Because it is, that's why.



The frame in which the
apparatus is stationary allows the simplest analysis, so why not
use
it?

Because It doesn't prove anything.

It gives a simpler analysis, and gives the same result as the moving
frame
analysis.

The simplest analysis is the rest frame, I agree. But that is c constant
with respect the source (which it is) and SR has nothing to do with
the result. It cannot resolve the case of a different rest frame,
although
that is the claim. The FAQ is babbling about MMX being evidence
for SR, and it simply isn't.




Are you trying to deliberately obfuscate the problem?

No, but you are by deliberately taking out v.

It gives a simpler analysis, and gives the same result as the moving
frame
analysis. So why not take out v?

Then you prove nothing.



In a reference frame in which the apparatus is stationary, x and y
don't
change as the apparatus is rotated (assuming x and y are the
arm-lengths).

Exactly. So you prove nothing.

No, it proves that any theory compatible with the PoR predicts a null
result.

I'll ask you the same question I asked Roberts, which he snipped as
irrelevant verbiage.
Roberts:

Standard and well-known derivations of the Lorentz transform are
based on the following assumptions/postulates/techniques:
1. The Principle of Relativity (Einstein's version)


Androcles:
Which one do we use?
Is it
a) "But the ray moves relatively to the initial point of k, when
measured
in the stationary system, with the velocity c-v..."
or
b) "It follows, further, that the velocity of light c cannot be altered
by composition with a velocity less than that of light.
For this case we obtain V = (c+w)/(1+w/c) = c."


Roberts:
[... irrelevant verbiage]

It is Einstein's irrelevant verbiage, not mine.

So which PoR are YOU talking about, a) or b)?




No frequency shifts, since there is no relative motion, no
wavelengths shifts, so no change after rotation.

Do you dispute this?

Yes.

You dispute that there are no frequency shift in the rest frame of the
apparatus due to rotation?

Don't be a ****ing smart arse. I've given my reasons.



How about that! Galilei-invariant emission theories predict no
frequency
shift, SR predicts no frequency shift.

SR does nothing of the kind, as I've explained.




Do note that the question was "Do you dispute this?", not would
Michelson
or Maxwell have disputed this. It's well-known that the null result
was
surprising.

Yes, it was surprising, because Michelson anticipating finding c-v in
one arm
and c in the other, and it didn't happen. That would produce fringe
shift.
Your problem is that you cannot analyze the matter with modern
equipment,
you are still living in 1893.
You babble about the speed being invarant and then make use of c-v.



The speed of flight in both tubes is c (invariant),
and the tubes are of different lengths.
Therefore a count will occur, the x (up) count exceeding the count
of
the
(y) down counter.

In a reference frame in which the MMX apparatus is moving, yes,
according
to SR, there is a length contraction. The length contraction
applies
equally to the wavelength in the contracted arm, so the length as
measured
in wavelengths along the arm remains exactly the same.

That has nothing to do with the *speed* of light. Speed is defined as
distance/time. The distance along the contracted arm is less that
the distance along the transverse arm.

Irrelevant for this analysis of the original MMX. And, yes, speed is
distance/time (for straight-line motion at a constant speed, as we
have
here). You do realise that the distance in that expression is the
distance
that the light pulse travels? You do realise that this distance is
longer
(or shorter, depending on direction) than the length of the tube? You
do
realise that the far end of the tube moves while the light pulse is on
its
way?

How much you contract the
wavelength of the light to cram in the same count of wavelenghts
along
the contracted arm is completely irrelevant. Time is the same in
both
arms.
The distances are different. You've change the *speed* of light.
SR says that is illegal. This is why the electronic MMX has an
advantage
over the original. It doesn't care about the wavelength, the light is
pulsed
and only pulses are counted.

The above (as noted earlier) relates to the actual MMX, which looks
for a
change in the optical pathlengths.

Cant handle a modern version?


The ratio of the wavelength to the arm length is the most relevant
thing.
I see you have no reply of substance.

What have I to reply to?
I've eliminated your wavelength issue, why bring it up?
You have nothing of substance to say of my electronic version, just
whine about the old one, and you have nothing of substance to say
about that, either, smart arse.



Damnly, my frank, I don't give a dear about the wavelength. I'm using
pulses.
[cut]
Cut? Nothing of substance to say? Frightens you, does it?

[Replace]
"You are deliberately obfuscating. The solution you've just
given is for the speed of light being source dependent. I could make
my light tubes become sound tubes and still get a null result. I'm
applying a velocity of the earth through the empty space from a
moving source and supposing that the speed of the light is
independent of the source."

You had to cut that, because it is true and you know it.
It's back in your face, smart-arse.

[cut]
(because you are dishonest)
Androcles.

"Jesse Mazer" wrote in message
...


Androcles wrote:

"Jesse Mazer" wrote in message
...

Creighton Hogg wrote:


On Wed, 12 Jan 2005, Jesse Mazer wrote:



Androcles wrote:



"Jesse Mazer" wrote in message
...



Androcles wrote:




"Jesse Mazer" wrote in message
.. .




Androcles wrote:





"Jesse Mazer" wrote in message
.. .





Androcles wrote:






In a reference frame in which the apparatus is stationary,
x and y don't
change as the apparatus is rotated (assuming x and y are
the
arm-lengths).






Exactly. So you prove nothing. However, Einstein's
postulate is
"light is always propagated in empty space with a definite
velocity
c which is independent of the state of motion of the
emitting body"
Reference :
http://www.fourmilab.ch/etexts/einstein/specrel/www/

The Earth is moving in the empty space, which is the
reference frame.
Are you trying to deliberately obfuscate the problem?






Empty space doesn't have a particular reference frame in
Einstein's theory.





Then light will be source dependent.
Androcles.







Nope, not according to the laws of electromagnetism.




Which one? Gauss, Faraday or Ampere?
Androcles.




The fact that the speed of light is independent of the source can
only be derived using all of Maxwell's laws.



When you can read a graph, we'll discuss it. Until then, it's a
waste of time.
Androcles.



I can read your graphs, but with no descriptions of what is being
measured, I don't know what they mean. For example, on the graph
you posted at
http://www.androc1es.pwp.blueyonder....r/00918-ck.gif
one axis measures time and the other measures "m", which I would
guess is meters--but what is it that is being measured in meters?
Without context, a graph like that is meaningless--if you are
willing to explain the context, I will try to address it.

In the meantime, regardless of what that graph shows, it doesn't
change the fact that you have not addressed the issue that
Maxwell's laws are all based on experiments with electricity and
magnetism that are extremely well-confirmed, and which don't
involve light at all; once you have these laws, you can show
mathematically that together they imply the velocity of
electromagnetic waves is always 1/squareroot(epsilon_0*mu_0), and
that this "coincidentally" happens to match the observed speed of
light very accurately, even though the experiments to determine
epsilon_0 and mu_0 have nothing to do with light.


Not to be a jerk, but epsilon_0 and mu_0 are really an artifact of
using SI units and wouldn't have shown up Back in The Day.



OK, but they did have terms for the permittivity and permeability of
the vacuum back in the day--whatever symbols they would have used,
just put them in place of epsilon_0 and mu_0 in the above paragraph
and the argument is unchanged.

Jesse


So you DO believe in aether, then, because those are the very
properties that
define it.
Androcles.




No they aren't. They are just constants that have to be included in
order to express the relationship between, say, the total charge
enclosed in a volume and the total electric flux passing through the
surface. That's just Gauss' law, which you said earlier you believed
in--see the description he

http://hyperphysics.phy-astr.gsu.edu...maxeq2.html#c1

The magnetic constant m0 = 4p x 10-7 T m/A
is not a property. It is a unit conversion, and total bull****
to claim c = 1/sqrt( a couple of constants) as if they were properties.
It is your claim that c is invariant, and use Maxwell's equations
as the basis.
I think you speak with forked tongue, you have not said c is
relative to.





The value of the permittivity is just determined by experiment, in
order to get the units to come out right. You don't have to believe
anything about what permittivity "means" in order to use the equation
to make predictions about various experiments. No mainstream
physicists believe in the aether today, but they still make use of the
same equation.

As long as c is source dependent in a vacuum, that is permissible.
But YOU are claiming it to be invariant, and saying Maxwell's laws
make it so. They do not.



And again, the experiments needed to determine the correct value of
this constant have nothing to do with measuring the speed of light. So
it's quite a "coincidence" that when you calculate the speed of
electromagnetic waves based on the permittivity and the permeability,
it comes out equal to the experimentally-determined speed of light,
no?

Experimentally determined *relative to the source*. There is no such
thing as the speed of light, ALL speeds are relative to something.
Name the experiment that tested the speed of light when the source
was in motion.


And the same laws which imply the speed of electromagnetic waves is
equal to 1/squareroot(permeability*permittivity) also imply the speed
of electromagnetic waves is independent of the source.

Prove it. Name the experiment that you say there are so many of that
measured the speed of light independent of the source.


So there's really no plausible way around the conclusion that light is
just the kind of electromagnetic wave predicted by Maxwell's
equations, and that its speed must therefore be independent of the
source's velocity.

Prove it.
Androcles.

Androcles wrote:

Define "rest frame". To Einstein and Michelson it meant the rest of the
Universe, with the Earth in motion about to the sun. Of course
Michelson
and Einstein didn't know the Milky Way was a galaxy back then, galaxies
were called "nebulae", meaning clouds. The sun was still the centre of
the Universe. It was the Earth's motion through the "rest frame" that
was being
used by MMX to find the speed of light in the "rest frame".

When Einstein used the words "rest frame" he just meant "the frame in
which a given observer is at rest". For example, if I drive by you at 60
mph relative to the ground, in my rest frame it is the car which is at
rest and you who are moving backwards at 60 mph. The concept of each
observer having a rest frame is used in Newtonian mechanics as well.

Michelson-Morely thought there was a special frame, the rest frame of
the aether, in which light travelled at the same speed in all
directions. But Einstein didn't believe that, of course--he thought that
light travelled at the same speed in all directions in *every*
observer's rest frame.

So when Timo said "The analysis is _simplest_ in the rest frame", I
think he just meant the rest frame of the apparatus, not some
universally special reference frame.

Jesse

"Timo Nieminen" wrote in message
news:Pine.LNX.4.50.0501130933070.18650-100000@localhost...

Well, the speed c-v that he objected to my use of was exactly the
speed at
which the light pulse closes with the moving mirror.

But what would you expect? Do you really think Androcles would have
admitted being wrong?

No, I will not, because I'm not wrong.
(c-v) is not equal to 1/sqrt(epsilon0 * mu0), which are constants
and the basis of Mazer's argument that Maxwell's laws apply.
Therefore c-v is not permitted in SR, which says c = (c-v)/(1-v/c)

SR does NOT explain MMX, and source dependency does.
Source dependency also explains cepheids as quite ordinary stars,
recurrent novae as ordinary stars, flare stars as ordinary stars
and changes the orbital parameters of eclipsing variables, which
if the source independency model is used would rip apart from
tidal forces in a mere century.
NOBODY has ever measured the speed of light from a moving
source in the vacuum of space. That is about to change.
Androcles.

On Thu, 13 Jan 2005, Androcles wrote:

"Timo Nieminen" wrote:
On Wed, 12 Jan 2005, Androcles wrote:
"Timo Nieminen" wrote:
On Wed, 12 Jan 2005, Androcles wrote:

I will now give the proof.
I place two identical evacuated tubes at right angles, with
mirrors
and
with
sources and detectors of light.
When the light reaches a detector, it turns off the source.
When NO light reaches the detector, it turns the source on.
The path length can be any reasonable one.
I connect the outputs of the detectors to an up/down counter, one
for
up
and the other for down. I calibrate the tube lengths until there
is
no
count.
I now have MMX, electronic version and air free.

Since your original assertion was specific to MMX, I'll first deal
with
the actual MMX. Then your modified experiment.

I rotate the apparatus 90 degrees and what happens? NO count
happens.
Acording to SR, and there being velocity as the Earth moves and
rotates
x' = (x-vt)/ sqrt(1-v^2/c^2)
y' = y.
So, x' does not equal y'.

Why would you want to analyse the experiment using a reference
frame
moving wrt the Earth?

Simple, really.
If you analyse it from a frame that is at rest, you prove nothing at
all.
Hence we analyze from a relatively moving frame. Get your telescope
out and watch the fringe shifts from a plane if you like. As you look
at Michelson's light, you'll notice it is doppler-shifted. Stay at
rest
and
you won't.

Your modified version makes Doppler shifts irrelvant - you can ignore
the
wavelength and frequency, and only the speed matters.

Exactly. Well done. To use Einstein's own words, the "tip of the ray".
Nobody is really interested on the following wave train, but that was
all
Michelson had.

So why bring up Doppler shifts? If you knew they were irrelevant, why
introduce them into the discussion?

Analysing it in a frame where it at rest proves everything that is
required.

Of course it does. The tip of the ray is travelling at c relative
to the source.

So, you agree that the rest-frame analysis proves everything that is
required?

An analysis using any theory that is compatible with
the PoR allows us to use any reference frame.

There you are, then. You've answered your own question.

No, I haven't. The analysis is _simplest_ in the rest frame. The
question
was why not use that rest frame?

Define "rest frame".

A reference frame where the MMX apparatus is at rest.

To Einstein and Michelson it meant the rest of the
Universe, with the Earth in motion about to the sun.

Perhaps to Michelson. Not to Einstein.

"together with the unsuccessful attempts to discover any motion
of the earth relatively to the ``light medium,'' suggest that the
phenomena
of electrodynamics as well as of mechanics possess no properties
corresponding to the idea of absolute rest."....
"We will raise this conjecture (the purport of which will hereafter be
called the "Principle of Relativity'') to the status of a postulate,
and also introduce
another postulate, which is only apparently IRRECONCILABLE
with the former, namely, that light is always propagated in empty space
with a definite velocity c which is independent of the state of motion
of the emitting body." Einstein.
Now, what rest frame was he talking about, and why does he suggest
his second postulate is irreconcilable with the first?
I'll tell you why. Because it is, that's why.

So, a diversion away from the analysis of MMX. Is this to distract from
your lack of refutation?

Where do you think he talked about a rest frame in your quote above?
Einstein points out that experiment suggests that there is _no absolute
rest frame_.

Secondly, he clearly states that the light postulate is only _apparently_
irreconcilable with the PoR. You do know what "apparently" means, don't
you?

You do know that SR is a reconciliation of the two (the PoR and the light
postulate)?

You have stated repeatedly that you think that Einstein's derivation of
the Lorentz transformations was in error. (As an aside, mostly for any
other reader, I'll note that in a previous discussion with you, it became
clear very quickly that your objections to Einstein's derivations were
based on a misunderstanding of Einstein's derivation. It also became clear
very quickly that you were not going to correct that misunderstanding.)
Now, as you should know as a matter of basic logic, even if Einstein's
derivation was in error (which it wasn't), that would not necessarily mean
that Einstein's result was wrong.

About a week ago, I posted a non-Einsteinian derivation of the Lorentz
transformations. You want to bring up "incompatibilities" between the PoR
and the light postulate, perhaps that's a better place. It's really quite
irrelevant to our discussion here of your original assertion that SR does
not predict a null result for MMX.

Note that even the correctness of SR is irrelevant to a discussion of
whether SR predicts a null or non-null result for MMX.

The fact that you introduce irrelevant diversions into the discussion,
while failing to address the issue at hand strongly suggests that you are
simply trying to divert attention away from the demolition of your
original claim.

The frame in which the
apparatus is stationary allows the simplest analysis, so why not
use
it?

Because It doesn't prove anything.

It gives a simpler analysis, and gives the same result as the moving
frame
analysis.

The simplest analysis is the rest frame, I agree. But that is c constant
with respect the source (which it is) and SR has nothing to do with
the result. It cannot resolve the case of a different rest frame,
although
that is the claim. The FAQ is babbling about MMX being evidence
for SR, and it simply isn't.

MMX is evidence for the PoR. The PoR is a postulate of SR. To that extent,
it is evidence. Or are you really trying to claim that MMX is _not_
evidence for the PoR?

Are you trying to deliberately obfuscate the problem?

No, but you are by deliberately taking out v.

It gives a simpler analysis, and gives the same result as the moving
frame
analysis. So why not take out v?

Then you prove nothing.

SR can be applied in the rest frame. You claimed that SR predicts a
non-null result. An SR analysis in the rest frame clearly predicts a null
result. SR being fully compatible with the PoR, it being a postulate of
the theory, also predicts a null result in moving frames as a simple
consequence of this.

Everything required is proved.

In a reference frame in which the apparatus is stationary, x and y
don't
change as the apparatus is rotated (assuming x and y are the
arm-lengths).

Exactly. So you prove nothing.

No, it proves that any theory compatible with the PoR predicts a null
result.

I'll ask you the same question I asked Roberts, which he snipped as
irrelevant verbiage.

So, another diversion away from the analysis of MMX. Is this to distract
from your lack of refutation?

Roberts:

Standard and well-known derivations of the Lorentz transform are
based on the following assumptions/postulates/techniques:
1. The Principle of Relativity (Einstein's version)


Androcles:
Which one do we use?
Is it
a) "But the ray moves relatively to the initial point of k, when
measured
in the stationary system, with the velocity c-v..."
or
b) "It follows, further, that the velocity of light c cannot be altered
by composition with a velocity less than that of light.
For this case we obtain V = (c+w)/(1+w/c) = c."


Roberts:
[... irrelevant verbiage]

It is Einstein's irrelevant verbiage, not mine.

So which PoR are YOU talking about, a) or b)?

Since neither is the PoR, or really has anything to do with the PoR, I
must agree with Roberts' assessment as "irrelevant verbiage".

Do you mean to say that you don't know what the PoR is?

Einstein's statement of the PoR was:

" ... the same laws of electrodynamics and optics will be valid for all
frames of reference for which the equations of mechanics hold good."

No frequency shifts, since there is no relative motion, no
wavelengths shifts, so no change after rotation.

Do you dispute this?

Yes.

You dispute that there are no frequency shift in the rest frame of the
apparatus due to rotation?

Don't be a ****ing smart arse. I've given my reasons.

You're the one who said that you dispute it. I stated that there are no
frequency shifts due to rotation in the rest frame, you disputed it. Does
that mean that you claim there are frequency shifts?

What can it mean that you choose to swear and dodge the question instead
of actually answering it?

How about that! Galilei-invariant emission theories predict no
frequency
shift, SR predicts no frequency shift.

SR does nothing of the kind, as I've explained.

So, you're claiming that SR predicts a frequency shift in the rest frame
due to rotation? How about that, I can learn new things from you every
day!

Do note that the question was "Do you dispute this?", not would
Michelson
or Maxwell have disputed this. It's well-known that the null result
was
surprising.

Yes, it was surprising, because Michelson anticipating finding c-v in
one arm
and c in the other, and it didn't happen. That would produce fringe
shift.
Your problem is that you cannot analyze the matter with modern
equipment,
you are still living in 1893.

In 1893 (Why 1893? Why not 1887?) your electronic version wouldn't be
feasible. You're the one who introduced modern equipment.

The above (as noted earlier) relates to the actual MMX, which looks
for a
change in the optical pathlengths.

Cant handle a modern version?

Sure I can. And did after dealing with the original MMX. You can't handle
the original MMX?

The ratio of the wavelength to the arm length is the most relevant
thing.
I see you have no reply of substance.

What have I to reply to?
I've eliminated your wavelength issue, why bring it up?

Your original claim was regarding the original MMX. What do you have
against an analysis of the original MMX, other than your inability to
refute the analysis?

You have nothing of substance to say of my electronic version, just
whine about the old one, and you have nothing of substance to say
about that, either, smart arse.

Resorting to insults, I see. You still haven't managed even at attempt at
refutation of my analysis of the original MMX.

Your only attempt at refutation of the analysis of your modified MMX was:

[moved from where it was out of context to where it's actually relevant:]
You babble about the speed being invarant and then make use of c-v.

Are you really saying that, as measured in the moving frame, if the light
pulse travels at a speed c towards a mirror moving away from the source at
speed v, it _isn't_ approaching it at c-v?

Can you give a simple "yes" or "no" as your answer?

You do know that according to the PoR, the laws of mechanics hold in all
inertial frames. The moving frame being an inertial frame, Galilean
kinematics are all that is needed. Are you really claiming that Galileo
was wrong?

In any case, even if you are saying that Galilean kinematics is wrong, SR
says that Galilean kinematics work perfectly well in all inertial frames.
Since the issue at hand is whether SR predicts a null or non-null result
for MMX, your disagreement with Galileo is irrelevant.

Damnly, my frank, I don't give a dear about the wavelength. I'm using
pulses.
[cut]
Cut? Nothing of substance to say? Frightens you, does it?

[Replace]
"You are deliberately obfuscating. The solution you've just
given is for the speed of light being source dependent. I could make
my light tubes become sound tubes and still get a null result. I'm
applying a velocity of the earth through the empty space from a
moving source and supposing that the speed of the light is
independent of the source."

You had to cut that, because it is true and you know it.
It's back in your face, smart-arse.

Do note that I've been saying all along that emission theories and
fully-dragged ether theories also predict a null result.

Above you are simply agreeing with me. Does that really need further
comment?

--
Timo Nieminen - Home page: http://www.physics.uq.edu.au/people/nieminen/
Shrine to Spirits: http://www.users.bigpond.com/timo_nieminen/spirits.html