EINSTEIN RELATIVITY: THE UNAMBIGUOUS AMBIGUITY

Every generation has its Albert Einstein and the Albert Einstein of
our generation is undoubtedly Tom Roberts:

http://groups.google.com/group/sci.p...6f54853449465?
http://groups.google.com/group/sci.p...90046b3bff4c1?

The Albert Einstein of our generation once informed the group
sci.physics.relativity about the inherent ambiguity of Einstein's
theory:

http://groups.google.com/group/sci.p...0c6f27f1d6be1?
Tom Roberts: "As I keep stressing: in an accelerated system (like a
rotating disk), geometry is INHERENTLY AMBIGUOUS. You can get whatever
answer you want by defining differently what you mean by
"circumference of the rotating disk"."

Briefly, the problem under discussion was as follows. By the end of
Chapter 23 in his "Relativity" Einstein claims that measuring rods
laid out along the rim of a rotating disc are Lorentz contracted
whereas those laid out along the radius are not and therefore the
ratio of the circumference and the diameter, as judged by a non-
rotating observer, is no longer pi. The problem is usually referred to
as the Ehrenfest paradox and has four solutions:

1. Ehrenfest: The ratio is smaller than pi.

2. Einstein: The ratio is greater than pi.

3. M. Strauss (Int.J.Theor.Phys. 11, 107, 1974): The ratio is equal to
pi.

4. The rest of the scientific world: Who cares.

Clearly Tom Roberts, the Albert Einstein of our generation, is
absolutely right: there can be nothing more ambiguous than this. So my
initial intention was to call this message:

EINSTEIN RELATIVITY: AN AMBIGUITY

Then I realized that, despite the ambiguity discovered by Tom Roberts,
the final results in Chapter 23 - that the rotating clock runs slow by
a factor of 1/gamma and that the ratio circumference/diameter is
greater than pi - were used by Einstein in a quite unambiguous manner
and proved very important for the development of relativity. So I
decided to call my message

EINSTEIN RELATIVITY: THE UNAMBIGUOUS AMBIGUITY

Of course I could also have called it

EINSTEIN RELATIVITY: THE AMBIGUOUS UNAMBIGUITY

Pentcho Valev

Pentcho Valev wrote:
Every generation has its Albert Einstein and the Albert Einstein of
our generation is undoubtedly Tom Roberts:

http://groups.google.com/group/sci.p...6f54853449465?
http://groups.google.com/group/sci.p...90046b3bff4c1?

The Albert Einstein of our generation once informed the group
sci.physics.relativity about the inherent ambiguity of Einstein's
theory:

http://groups.google.com/group/sci.p...0c6f27f1d6be1?
Tom Roberts: "As I keep stressing: in an accelerated system (like a
rotating disk), geometry is INHERENTLY AMBIGUOUS. You can get whatever
answer you want by defining differently what you mean by
"circumference of the rotating disk"."

Briefly, the problem under discussion was as follows. By the end of
Chapter 23 in his "Relativity" Einstein claims that measuring rods
laid out along the rim of a rotating disc are Lorentz contracted
whereas those laid out along the radius are not and therefore the
ratio of the circumference and the diameter, as judged by a non-
rotating observer, is no longer pi. The problem is usually referred to
as the Ehrenfest paradox and has four solutions:

1. Ehrenfest: The ratio is smaller than pi.

2. Einstein: The ratio is greater than pi.

3. M. Strauss (Int.J.Theor.Phys. 11, 107, 1974): The ratio is equal to
pi.

4. The rest of the scientific world: Who cares.

Clearly Tom Roberts, the Albert Einstein of our generation, is
absolutely right: there can be nothing more ambiguous than this. So my
initial intention was to call this message:

EINSTEIN RELATIVITY: AN AMBIGUITY

Then I realized that, despite the ambiguity discovered by Tom Roberts,
the final results in Chapter 23 - that the rotating clock runs slow by
a factor of 1/gamma and that the ratio circumference/diameter is
greater than pi - were used by Einstein in a quite unambiguous manner
and proved very important for the development of relativity. So I
decided to call my message

EINSTEIN RELATIVITY: THE UNAMBIGUOUS AMBIGUITY

Of course I could also have called it

EINSTEIN RELATIVITY: THE AMBIGUOUS UNAMBIGUITY

Nice examples of unambiguous ambiguity are the cases where a
relativity hypnotist has written a text based on some hypnotic
principles and then another hypnotist updates the text by using
different hypnotic principles. The following patchwork created by
relativity hypnotists Philip Gibbs and Steve Carlip can be regarded as
a paradigm of unambiguous ambiguity:

http://math.ucr.edu/home/baez/physic..._of_light.html

"Is c, the speed of light in vacuum, constant? At the 1983 Conference
Generale des Poids et Mesures, the following SI (Systeme
International) definition of the metre was adopted: The metre is the
length of the path travelled by light in vacuum during a time interval
of 1/299 792 458 of a second. This defines the speed of light in
vacuum to be exactly 299,792,458 m/s. This provides a very short
answer to the question "Is c constant": Yes, c is constant by
definition!"

"The SI definition makes certain assumptions about the laws of
physics. For example, they assume that the particle of light, the
photon, is massless. If the photon had a small rest mass, the SI
definition of the metre would become meaningless because the speed of
light would change as a function of its wavelength....Any such
possible photon rest mass is certainly too small to have any practical
significance for the definition of the metre in the foreseeable
future, but it cannot be shown to be exactly zero--even though
currently accepted theories indicate that it is. If it wasn't zero,
the speed of light would not be constant; but from a theoretical point
of view we would then take c to be the upper limit of the speed of
light in vacuum so that we can continue to ask whether c is constant."

"....it is nonsense to say that the speed of light is now constant
just because the SI definitions of units define its numerical value to
be constant."

"Another assumption on the laws of physics made by the SI definition
of the metre is that the theory of relativity is correct."

"It is a basic postulate of the theory of relativity that the speed of
light is constant. This can be broken down into two parts: The speed
of light is independent of the motion of the observer. The speed of
light does not vary with time or place."

"Einstein then argued that those transformations should be understood
as changes of space and time rather than of physical objects...."

"Einstein went on to discover a more general theory of relativity
which explained gravity in terms of curved spacetime, and he talked
about the speed of light changing in this new theory. In the 1920
book "Relativity: the special and general theory" he wrote: . . .
according to the general theory of relativity, the law of the
constancy of the velocity of light in vacuo, which constitutes one of
the two fundamental assumptions in the special theory of relativity
[. . .] cannot claim any unlimited validity. A curvature of rays of
light can only take place when the velocity of propagation of light
varies with position. Since Einstein talks of velocity (a vector
quantity: speed with direction) rather than speed alone, it is not
clear that he meant the speed will change, but the reference to
special relativity suggests that he did mean so."

"This interpretation is perfectly valid and makes good physical sense,
but a more modern interpretation is that the speed of light is
constant in general relativity."

"The problem here comes from the fact that speed is a coordinate-
dependent quantity, and is therefore somewhat ambiguous. To determine
speed (distance moved/time taken) you must first choose some standards
of distance and time, and different choices can give different
answers. This is already true in special relativity: if you measure
the speed of light in an accelerating reference frame, the answer
will, in general, differ from c."

"In this passage, Einstein is not talking about a freely falling
frame, but rather about a frame at rest relative to a source of
gravity. In such a frame, the speed of light can differ from c,
basically because of the effect of gravity (spacetime curvature) on
clocks and rulers."

"If general relativity is correct, then the constancy of the speed of
light in inertial frames is a tautology from the geometry of
spacetime."

"Finally, we come to the conclusion that the speed of light is not
only observed to be constant; in the light of well tested theories of
physics, it does not even make any sense to say that it varies."

Pentcho Valev

In epsilon, a linear shift of the discrete time domain shows the inverse of
gamma as the effective value. Epsilon being the relative connection in
relative states and interjections.

Patrick Ashley Meuser"-Bianca"
Cyberneticist
"Pentcho Valev" wrote in message
oups.com...

Pentcho Valev wrote:
Every generation has its Albert Einstein and the Albert Einstein of
our generation is undoubtedly Tom Roberts:

http://groups.google.com/group/sci.p...6f54853449465?
http://groups.google.com/group/sci.p...90046b3bff4c1?

The Albert Einstein of our generation once informed the group
sci.physics.relativity about the inherent ambiguity of Einstein's
theory:

http://groups.google.com/group/sci.p...0c6f27f1d6be1?
Tom Roberts: "As I keep stressing: in an accelerated system (like a
rotating disk), geometry is INHERENTLY AMBIGUOUS. You can get whatever
answer you want by defining differently what you mean by
"circumference of the rotating disk"."

Briefly, the problem under discussion was as follows. By the end of
Chapter 23 in his "Relativity" Einstein claims that measuring rods
laid out along the rim of a rotating disc are Lorentz contracted
whereas those laid out along the radius are not and therefore the
ratio of the circumference and the diameter, as judged by a non-
rotating observer, is no longer pi. The problem is usually referred to
as the Ehrenfest paradox and has four solutions:

1. Ehrenfest: The ratio is smaller than pi.

2. Einstein: The ratio is greater than pi.

3. M. Strauss (Int.J.Theor.Phys. 11, 107, 1974): The ratio is equal to
pi.

4. The rest of the scientific world: Who cares.

Clearly Tom Roberts, the Albert Einstein of our generation, is
absolutely right: there can be nothing more ambiguous than this. So my
initial intention was to call this message:

EINSTEIN RELATIVITY: AN AMBIGUITY

Then I realized that, despite the ambiguity discovered by Tom Roberts,
the final results in Chapter 23 - that the rotating clock runs slow by
a factor of 1/gamma and that the ratio circumference/diameter is
greater than pi - were used by Einstein in a quite unambiguous manner
and proved very important for the development of relativity. So I
decided to call my message

EINSTEIN RELATIVITY: THE UNAMBIGUOUS AMBIGUITY

Of course I could also have called it

EINSTEIN RELATIVITY: THE AMBIGUOUS UNAMBIGUITY

Nice examples of unambiguous ambiguity are the cases where a
relativity hypnotist has written a text based on some hypnotic
principles and then another hypnotist updates the text by using
different hypnotic principles. The following patchwork created by
relativity hypnotists Philip Gibbs and Steve Carlip can be regarded as
a paradigm of unambiguous ambiguity:

http://math.ucr.edu/home/baez/physic..._of_light.html

"Is c, the speed of light in vacuum, constant? At the 1983 Conference
Generale des Poids et Mesures, the following SI (Systeme
International) definition of the metre was adopted: The metre is the
length of the path travelled by light in vacuum during a time interval
of 1/299 792 458 of a second. This defines the speed of light in
vacuum to be exactly 299,792,458 m/s. This provides a very short
answer to the question "Is c constant": Yes, c is constant by
definition!"

"The SI definition makes certain assumptions about the laws of
physics. For example, they assume that the particle of light, the
photon, is massless. If the photon had a small rest mass, the SI
definition of the metre would become meaningless because the speed of
light would change as a function of its wavelength....Any such
possible photon rest mass is certainly too small to have any practical
significance for the definition of the metre in the foreseeable
future, but it cannot be shown to be exactly zero--even though
currently accepted theories indicate that it is. If it wasn't zero,
the speed of light would not be constant; but from a theoretical point
of view we would then take c to be the upper limit of the speed of
light in vacuum so that we can continue to ask whether c is constant."

"....it is nonsense to say that the speed of light is now constant
just because the SI definitions of units define its numerical value to
be constant."

"Another assumption on the laws of physics made by the SI definition
of the metre is that the theory of relativity is correct."

"It is a basic postulate of the theory of relativity that the speed of
light is constant. This can be broken down into two parts: The speed
of light is independent of the motion of the observer. The speed of
light does not vary with time or place."

"Einstein then argued that those transformations should be understood
as changes of space and time rather than of physical objects...."

"Einstein went on to discover a more general theory of relativity
which explained gravity in terms of curved spacetime, and he talked
about the speed of light changing in this new theory. In the 1920
book "Relativity: the special and general theory" he wrote: . . .
according to the general theory of relativity, the law of the
constancy of the velocity of light in vacuo, which constitutes one of
the two fundamental assumptions in the special theory of relativity
[. . .] cannot claim any unlimited validity. A curvature of rays of
light can only take place when the velocity of propagation of light
varies with position. Since Einstein talks of velocity (a vector
quantity: speed with direction) rather than speed alone, it is not
clear that he meant the speed will change, but the reference to
special relativity suggests that he did mean so."

"This interpretation is perfectly valid and makes good physical sense,
but a more modern interpretation is that the speed of light is
constant in general relativity."

"The problem here comes from the fact that speed is a coordinate-
dependent quantity, and is therefore somewhat ambiguous. To determine
speed (distance moved/time taken) you must first choose some standards
of distance and time, and different choices can give different
answers. This is already true in special relativity: if you measure
the speed of light in an accelerating reference frame, the answer
will, in general, differ from c."

"In this passage, Einstein is not talking about a freely falling
frame, but rather about a frame at rest relative to a source of
gravity. In such a frame, the speed of light can differ from c,
basically because of the effect of gravity (spacetime curvature) on
clocks and rulers."

"If general relativity is correct, then the constancy of the speed of
light in inertial frames is a tautology from the geometry of
spacetime."

"Finally, we come to the conclusion that the speed of light is not
only observed to be constant; in the light of well tested theories of
physics, it does not even make any sense to say that it varies."

Pentcho Valev

A few more examples of unambiguous ambiguity:

http://groups.google.com/group/sci.p...d7baf4ffcae461
On February 23, 1994, Hartmut Frommert wrote in sci.physics:

Though the natural constant "c" which is usually called the vacuum light
velocity (or speed) can only be changed by re-definition of units (as any
conversion factor), the (actual) speed of (the propagation of) light
(photons !) is NOT constant, e.g. in a gravitational field (see any textbook
on elementary General Relativity).

JOHN BAEZ replied: "This is darn misleading. THE SPEED OF LIGHT IS
CONSTANT IN GR, it's just that the spacetime the light is moving
around in is a bit wiggly. Of course, one *could* think of it the way
you suggest, but one would have to say, not just that the speed of
light was different in a "gravitational field," but that all other
laws of physics were different too, in a fairly complicated manner."

http://www.pitt.edu/~jdnorton/papers...UP_TimesNR.pdf "What Can
We Learn about the Ontology of Space and Time from the Theory of
Relativity?", John D. Norton: "IN GENERAL RELATIVITY THERE IS NO
COMPARABLE SENSE OF THE CONSTANCY OF THE SPEED OF LIGHT. The constancy
of the speed of light is a consequence of the perfect homogeneity of
spacetime presumed in special relativity. There is a special velocity
at each event; homogeneity forces it to be the same velocity
everywhere. We lose that homogeneity in the transition to general
relativity and with it we lose the constancy of the speed of light.
Such was Einstein's conclusion at the earliest moments of his
preparation for general relativity. ALREADY IN 1907, A MERE TWO YEARS
AFTER THE COMPLETION OF THE SPECIAL THEORY, HE HAD CONCLUDED THAT THE
SPEED OF LIGHT IS VARIABLE IN THE PRESENCE OF A GRAVITATIONAL FIELD;
indeed, he concluded, the variable speed of light can be used as a
gravitational potential."

http://www.ias.ac.in/jarch/jaa/20/91-101%20.pdf John Stachel: "At
first Einstein looked for a scalar generalization of Newtons theory,
based on the gravitational potential. By the middle of 1912, he had
worked out what he regarded as a satisfactory theory for the case of a
static gravitational field. He developed a field equation for the
gravitational potential, which he identified in this case with a
VARIABLE SPEED OF LIGHT c(x,y,z) INSTEAD OF THE CONSTANT SPEED OF THE
SPECIAL THEORY..."

In Oceania (where we all live) it makes no sense to ask "Is the speed
of light REALLY variable?" for the same reason for which it makes no
sense to ask "Do two and two REALLY make four?". It only makes sense
to ask: "What do Einstein's criminal cult (the Party) say about the
speed of light?":

http://www.online-literature.com/orwell/1984/ George Orwell "1984":
"In the end the Party would announce that two and two made five, and
you would have to believe it. It was inevitable that they should make
that claim sooner or later: the logic of their position demanded it.
Not merely the validity of experience, but the very existence of
external reality, was tacitly denied by their philosophy. The heresy
of heresies was common sense. And what was terrifying was not that
they would kill you for thinking otherwise, but that they might be
right. For, after all, how do we know that two and two make four? Or
that the force of gravity works? Or that the past is unchangeable? If
both the past and the external world exist only in the mind, and if
the mind itself is controllable what then?"

Pentcho Valev