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The Measurement of Contraction



 
 
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  #1  
Old February 8th 08 posted to sci.physics.relativity
Peri of Pera
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Posts: 352
Default The Measurement of Contraction

The Measurement of Contraction

The theory of relativity is presented as one that cannot be understood
by most people. This aura of complexity and difficulty is maintained
by using ambiguity and vagueness in describing and defining the theory
and defending it with even more ambiguity and vagueness against logic.
But what is it really? Stripped of all esoteric language it simply
means that physical objects (we may call them frames) that are capable
of motion (cars, trains, planes, the earth, planets, stars) will
shrink along the axis parallel to the motion and have their clocks
slow down. The effects are in proportion to the velocity of the object
and are called length contraction and time dilation. They can be
calculated using the transformation formulas that are the substance of
the Lorentz contraction hypothesis. But as the tools of measurement
(rulers, clocks) are also adjusted relative to the speed, any change
in metres and clock rates will not be noticed by anyone measuring
length or time in his environment (the local frame). Regardless of the
velocity of the local frame, things measured within the local frame by
local frame occupants always have the same size and the local frame
time always flows at the same rate.

However, the supporters of the relativity theories (both SR and LET)
have introduced the concepts of observed frame and observer frame. If
an observed frame and an observer frame travel at different speeds, it
is claimed that any contraction and dilation affecting the observed
object can be measured by an observer in the observer frame. A
procedure of measurement which will lead to 'the visibility of
contraction' is described in a textbook (Resnick, Introduction to
Special Relativity, 1968) as:

"An observer is an INFINITE set of recording clocks distributed
throughout space, AT REST and synchronized with respect to one
another. The space time co-ordinates of an event (x,y,z,t) are
recorded by the clock at the location (x,y,z) of the event at the time
(t) it occurs. Measurements thus recorded throughout space time (we
might call them local measurements) are then available to be PICKED UP
and ANALYSED by an EXPERIMENTER who collects the measurements made in
this way. Each inertial frame is IMAGINED to have such a set of
recording clocks, or such an observer. The relations between the space-
time co-ordinates of a physical event measured by one OBSERVER (S) and
the space-time co-ordinates of the same physical event measured by
another OBSERVER (S') are the equations of transformation".

Resnick uses the terms INFINITE, AT REST, PICKED UP, ANALYSED,
EXPERIMENTER, OBSERVER (S) and OBSERVER (S'). While the phraseology
may not prevent calculating contraction according to the Lorentz
formulas with a pencil on a piece of paper, it can surely never be
done in the field. It is a smokescreen to support the illusion that
contraction is a physical reality.

But let us ask questions about such a measurement. Event 1 is the
recording of location A of one end of a rod in space at time t by
observers S and S'. Event 2 is the recording of location B of the
other end of the rod also at time t by the same observers. The
experimenter picks up and analyses the four space time co-ordinates
made by the two observers. Will the answer be the contracted length of
the rod? How will the movement of the two observers relative to the
rod disclose the contracted length of the rod and not a distorted view
of it? How are optical, communicative and angular aspects included in
the measurement? What single fixed co-ordinate system is common to
both observers or is it only relative to observer S or observer S'?
How will the experimenter establish that the times t of the two
observers are simultaneous given that SR imposes a whole set of ifs
and buts on simultaneity? How will any difference in the speed the
observed object, S and S' be taken into account?

It all can be done on paper making assumptions but not as a real test.
The more ardent supporters of the contraction hypothesis assert that
proof is not required. Their argument is that to 'make predictions' is
sufficient or they will do the calculations manually and if these are
rejected or ignored by anyone, they accuse him of being incapable of
the maths and he should study the subject to understand the theory.
With understanding they mean accepting it without reservation. It is
the approach of all monotheistic religions which ostracise all non-
believers, excommunicate them, vilify them, and ultimately stone or
burn them. In this NG it is automatically practised against any member
who dares to reject SR or even question it.

Peter Riedt


Ads
  #2  
Old February 8th 08 posted to sci.physics.relativity
Jeckyl
external usenet poster
 
Posts: 8,421
Default The Measurement of Contraction

"Peri of Pera" wrote in message
...
The Measurement of Contraction

The theory of relativity is presented as one that cannot be understood
by most people.


Not 'cannot', just 'is difficult'

This aura of complexity and difficulty is maintained
by using ambiguity and vagueness in describing and defining the theory


No .. the theory is very clear and precise .. however, some popularisation
of it are vague and ambiguous, because they use colloquial terms that the
layman is more familiar with, and those terms are vague and ambiguous.

and defending it with even more ambiguity and vagueness against logic.


There is nothing illogical about SR

But what is it really? Stripped of all esoteric language it simply
means that physical objects (we may call them frames) that are capable
of motion (cars, trains, planes, the earth, planets, stars) will
shrink along the axis parallel to the motion and have their clocks
slow down.


No .. nothing happens to the object .. it can't do. Someone moving quickly
past you does not change you. But something happens to how they are
measured by things that move relative to them

The effects are in proportion to the velocity of the object


No .. they are not in propoertion at all.

and are called length contraction and time dilation.


You missed relativity or simultaneity .. so many people do, yet it is
probably the most important effect

They can be
calculated using the transformation formulas that are the substance of
the Lorentz contraction hypothesis.


Why not just say "Lorentx transforms"

But as the tools of measurement
(rulers, clocks) are also adjusted relative to the speed,


Now you are talking LET, not SR. LET is the one that claim physical
shrinking and an absolute frame of reference and aboslute velocities etc
(its a bit like what KenSteo talks about, only LET is self-consistent)

any change
in metres and clock rates will not be noticed by anyone measuring
length or time in his environment (the local frame). Regardless of the
velocity of the local frame, things measured within the local frame by
local frame occupants always have the same size and the local frame
time always flows at the same rate.


Again, the above is not SR

However, the supporters of the relativity theories (both SR and LET)
have introduced the concepts of observed frame and observer frame.


Well, derr .. there isn't much physics able to be done if there is no
observer !!

If
an observed frame and an observer frame travel at different speeds, it
is claimed that any contraction and dilation affecting the observed
object can be measured by an observer in the observer frame.


There is no contraction and dilation in the observed object in SR .. there
is only a measurement of it from the observer frame.

A
procedure of measurement which will lead to 'the visibility of
contraction' is described in a textbook (Resnick, Introduction to
Special Relativity, 1968) as:

"An observer is an INFINITE set of recording clocks distributed
throughout space, AT REST and synchronized with respect to one
another. The space time co-ordinates of an event (x,y,z,t) are
recorded by the clock at the location (x,y,z) of the event at the time
(t) it occurs. Measurements thus recorded throughout space time (we
might call them local measurements) are then available to be PICKED UP
and ANALYSED by an EXPERIMENTER who collects the measurements made in
this way. Each inertial frame is IMAGINED to have such a set of
recording clocks, or such an observer. The relations between the space-
time co-ordinates of a physical event measured by one OBSERVER (S) and
the space-time co-ordinates of the same physical event measured by
another OBSERVER (S') are the equations of transformation".

Resnick uses the terms INFINITE, AT REST, PICKED UP, ANALYSED,
EXPERIMENTER, OBSERVER (S) and OBSERVER (S').


So?

While the phraseology
may not prevent calculating contraction according to the Lorentz
formulas with a pencil on a piece of paper, it can surely never be
done in the field.


We measure and calculate the positions, speeds, and lengths of moving
objects all the time .. what are you alking about?

It is a smokescreen to support the illusion that
contraction is a physical reality.


It isn't in SR. In LET it is a physical reality that we cannot measure
(which is rather pointless)

But let us ask questions about such a measurement. Event 1 is the
recording of location A of one end of a rod in space at time t by
observers S and S'. Event 2 is the recording of location B of the
other end of the rod also at time t by the same observers.


Yes .. that is what length is. The thing is, time t for S and time t for S'
are not simultaneous

The
experimenter picks up and analyses the four space time co-ordinates
made by the two observers. Will the answer be the contracted length of
the rod?


The rod isn't contracted (in SR) .. but he will see possible different
measured lengths by the two observers, depending on the relative velocities
of them compare to the rod. In LET the situation is the same, excpe that
the rod is said to possibly be contracted due to its absolute motion in the
ether, but what the observers observe is the same in either case.

How will the movement of the two observers relative to the
rod disclose the contracted length of the rod and not a distorted view
of it?


There is no contracted length in SR, and it won't disclose the contracted
lenth in LET (you cannot determine what the contracted length is in LET)

How are optical, communicative and angular aspects included in
the measurement?


When we talk about what we the length of the rod is for the two observers to
be here, we make adjustments for those things .. ie it is what we measure
after tkaing into account the possible differences in transit time for
light, aberation etc etc..

What single fixed co-ordinate system is common to
both observers or is it only relative to observer S or observer S'?


It is relative. In LET there is an unknown absolute ether system of
coordinates, but that doesn't really make any difference.

How will the experimenter establish that the times t of the two
observers are simultaneous


They aren't

given that SR imposes a whole set of ifs
and buts on simultaneity? How will any difference in the speed the
observed object, S and S' be taken into account?


In what way 'taken into account' .. the observers measure what they measure.
If you want to do some calculation using Lorentx transforms back to the
frame of the rod itself, then you get that the rod is the length of the rod
... but what I assume you are actually interested in is the length of the rod
in the frames S and S' .. ite how much space the rod takes up at a given
time in those two frames respectively

It all can be done on paper making assumptions but not as a real test.


No .. it can be done as a real test.

The more ardent supporters of the contraction hypothesis assert that
proof is not required.


We have experiments that indicate length contraction. It is more difficult
to measure as we need to get something up to very high speeds and measure
its length .. and that is tricky to do.

Their argument is that to 'make predictions' is
sufficient or they will do the calculations manually and if these are
rejected or ignored by anyone, they accuse him of being incapable of
the maths and he should study the subject to understand the theory.


Noone argues that.

With understanding they mean accepting it without reservation. It is
the approach of all monotheistic religions which ostracise all non-
believers, excommunicate them, vilify them, and ultimately stone or
burn them. In this NG it is automatically practised against any member
who dares to reject SR or even question it.


Nonsense


  #3  
Old February 8th 08 posted to sci.physics.relativity
rotchm@gmail.com
external usenet poster
 
Posts: 635
Default The Measurement of Contraction

On Feb 7, 8:04*pm, Peri of Pera wrote:
The Measurement of Contraction

The theory of relativity is presented as one that cannot be understood
by most people.


Unfortunately that is how it is often presented.

This aura of complexity and difficulty is maintained
by using ambiguity and vagueness in describing and defining the theory


Quite true. I often wondered why they would present the theory in such
a vague and confusing way, when it can be simply presented w/o
vagueness and confusions. Rare are the SR books which are well
presented.

I have come to the conclusion that SR authors are either clueless
about relativity and thus remain vague in its descriptions or that
those authors are just really bad pedagogists.

I am not saying that SR is wrong and I tend to say the opposite.
But I do say that SR is badly represented or described. If relativity
authors really wanted to, they can introduce SR
in simple terms well accessible to highschool students. But then SR
would loose all of its "mystery" and relativist would no longer be
viewed as "brilliant".

  #4  
Old February 8th 08 posted to sci.physics.relativity
harry
external usenet poster
 
Posts: 1,450
Default The Measurement of Contraction


"Peri of Pera" wrote in message
...
The Measurement of Contraction

The theory of relativity is presented as one that cannot be understood
by most people. This aura of complexity and difficulty is maintained
by using ambiguity and vagueness in describing and defining the theory
and defending it with even more ambiguity and vagueness against logic.
But what is it really? Stripped of all esoteric language it simply
means that physical objects (we may call them frames) that are capable
of motion (cars, trains, planes, the earth, planets, stars) will
shrink along the axis parallel to the motion and have their clocks
slow down. The effects are in proportion to the velocity of the object
and are called length contraction and time dilation. They can be
calculated using the transformation formulas that are the substance of
the Lorentz contraction hypothesis.


Note: the transformation formulas do much more than that: they also account
for time dilation and define relativity of simultaneity.

But as the tools of measurement
(rulers, clocks) are also adjusted relative to the speed, any change
in metres and clock rates will not be noticed by anyone measuring
length or time in his environment (the local frame). Regardless of the
velocity of the local frame, things measured within the local frame by
local frame occupants always have the same size and the local frame
time always flows at the same rate.


That is roughly the way Lorentz formulated the theory, and also close to
Einstein's earliest formulation. Presented like that, it's indeed rather
easy to understand.

However, the supporters of the relativity theories (both SR and LET)
have introduced the concepts of observed frame and observer frame.


"Observer frame" or "Local frame", what does it matter?! As long as one
knows what is meant. It becomes less good when next "observer frame" is
replaced by "observer": due to such jargon, all too many people fall in the
trap of confusing inertial coordinate system procedures with
quantum-mechanical "observer" effects.

If
an observed frame and an observer frame travel at different speeds, it
is claimed that any contraction and dilation affecting the observed
object can be measured by an observer in the observer frame. A
procedure of measurement which will lead to 'the visibility of
contraction' is described in a textbook (Resnick, Introduction to
Special Relativity, 1968) as:

"An observer is an INFINITE set of recording clocks distributed
throughout space, AT REST and synchronized with respect to one
another. The space time co-ordinates of an event (x,y,z,t) are
recorded by the clock at the location (x,y,z) of the event at the time
(t) it occurs. Measurements thus recorded throughout space time (we
might call them local measurements) are then available to be PICKED UP
and ANALYSED by an EXPERIMENTER who collects the measurements made in
this way. Each inertial frame is IMAGINED to have such a set of
recording clocks, or such an observer. The relations between the space-
time co-ordinates of a physical event measured by one OBSERVER (S) and
the space-time co-ordinates of the same physical event measured by
another OBSERVER (S') are the equations of transformation".

Resnick uses the terms INFINITE, AT REST, PICKED UP, ANALYSED,
EXPERIMENTER, OBSERVER (S) and OBSERVER (S'). While the phraseology
may not prevent calculating contraction according to the Lorentz
formulas with a pencil on a piece of paper, it can surely never be
done in the field. It is a smokescreen to support the illusion that
contraction is a physical reality.


What do you mean with "physical reality"?

But let us ask questions about such a measurement. Event 1 is the
recording of location A of one end of a rod in space at time t by
observers S and S'. Event 2 is the recording of location B of the
other end of the rod also at time t by the same observers. The
experimenter picks up and analyses the four space time co-ordinates
made by the two observers. Will the answer be the contracted length of
the rod?


In principle, yes. In practice it's hard to test length contraction directly
because of the difficulty of creating high-speed extended objects and as the
effect is not cumulative. It's different however with time dilation which is
regularly measured.

How will the movement of the two observers relative to the
rod disclose the contracted length of the rod and not a distorted view
of it? How are optical, communicative and angular aspects included in
the measurement? What single fixed co-ordinate system is common to
both observers or is it only relative to observer S or observer S'?


??? "observer S" *is* a co-ordinate system.

How will the experimenter establish that the times t of the two
observers are simultaneous given that SR imposes a whole set of ifs
and buts on simultaneity?


It is *defined* as simultaneous. If the PoR is correct then more cannot be
done, if that is what you mean.

How will any difference in the speed the
observed object, S and S' be taken into account?


??? S and S' *are* the co-ordinate systems.

It all can be done on paper making assumptions but not as a real test.
The more ardent supporters of the contraction hypothesis assert that
proof is not required. Their argument is that to 'make predictions' is
sufficient or they will do the calculations manually and if these are
rejected or ignored by anyone, they accuse him of being incapable of
the maths and he should study the subject to understand the theory.
With understanding they mean accepting it without reservation.


Certainly not. :-))
Instead, when taking into account every imagined possibility, no other
reasonable option remains.

It is
the approach of all monotheistic religions which ostracise all non-
believers, excommunicate them, vilify them, and ultimately stone or
burn them. In this NG it is automatically practised against any member
who dares to reject SR or even question it.


No problem with questioning it - that's science! However, be prepared to
receive answers. :-)

Harald


  #5  
Old February 8th 08 posted to sci.physics.relativity
Dirk Van de moortel
external usenet poster
 
Posts: 15,039
Default The Measurement of Contraction


"Peri of Pera" wrote in message ...
The Measurement of Contraction


[snip]

But let us ask questions about such a measurement. Event 1 is the
recording of location A of one end of a rod in space at time t by
observers S and S'.


This is wrong already.
First you decide in whose coordinate system the rod is
at rest. Let's assume that this is S. So for S' the rod is
moving, so S' must make sure he measures the events
simultaneously - otherwise he is just daft.

Event1 is something that happens on one end of a rod
at time t1' according to observer S'.
According to observer S who is at rest w.r.t. the rod,
this happens at some time t1.
According to S' the spatial coordinate of this event is x1'.
According to S the spatial coordinate of this event is x1

Event 2 is the recording of location B of the
other end of the rod also at time t by the same observers.


Wrong again
Event2 is something that happens on the other end of the rod
at the same time t2' = t1' according to the same observer S'.
According to observer S who is at rest w.r.t. the rod,
this happens at some time t2.
According to S' the spatial coordinate of this event is x2'.
According to S the spatial coordinate of this event is x2

If S' is to measure the lenght of the rod, he must make sure that
t1' = t2' ,
so he can *DEFINE* the "coordinate length" as
L' = | x1' - x2' |

For S the times t1 and t2 don't matter since he is at rest
w.r.t. the rod, so he *DEFINES* the "proper length" as
L = | x1 - x2 |

The
experimenter picks up and analyses the four space time co-ordinates
made by the two observers.


I have counted 8 space time co-ordinates, two of which must
be identical: t1' = t2'.

Will the answer be the contracted length of
the rod? How will the movement of the two observers relative to the
rod disclose the contracted length of the rod and not a distorted view
of it?


If you do it correctly, you will get
L' = L / gamma
which says that the coordinate lenght is contracted w.r.t. to
the proper length.

How are optical, communicative and angular aspects included in
the measurement?


For both observers the times and the distance of events
are recorded by sending light signals to the events. This
has been explained to you before. See if you can find
how it is done.
In the one dimensional case there are no angles involved.

What single fixed co-ordinate system is common to
both observers


none.

or is it only relative to observer S or observer S'?
How will the experimenter establish that the times t of the two
observers are simultaneous given that SR imposes a whole set of ifs
and buts on simultaneity?


See above.

How will any difference in the speed the
observed object, S and S' be taken into account?


See above.


It all can be done on paper making assumptions but not as a real test.


Indeed, this particular test never has been done.
We also never dropped you from a high tower to test whether
you will indeed fall.

The more ardent supporters of the contraction hypothesis assert that
proof is not required.


I don't think that you need a proof for your falling down
from a high tower either.

Their argument is that to 'make predictions' is
sufficient or they will do the calculations manually and if these are
rejected or ignored by anyone,


They should also be consistent with all other experiments
which *have* been conducted (and which, by the way, are generally
ignored by most people on this forum)

they accuse him of being incapable of
the maths and he should study the subject to understand the theory.
With understanding they mean accepting it without reservation. It is
the approach of all monotheistic religions which ostracise all non-
believers, excommunicate them, vilify them, and ultimately stone or
burn them. In this NG it is automatically practised against any member
who dares to reject SR or even question it.


No, rest assured, on this NG these people are not stoned or burned.
We just have a good laugh over them, and we use them for practice
for when we have to explain to our kids. Thanks for that. It has worked
superbly!

Dirk Vdm

  #6  
Old February 8th 08 posted to sci.physics.relativity
Bryan Olson
external usenet poster
 
Posts: 831
Default The Measurement of Contraction

Peri of Pera (Peter Riedt) wrote:
The Measurement of Contraction

The theory of relativity is presented as one that cannot be understood
by most people.


That's called "projecting".

This aura of complexity and difficulty is maintained
by using ambiguity and vagueness in describing and defining the theory
and defending it with even more ambiguity and vagueness against logic.
But what is it really? Stripped of all esoteric language it simply
means that physical objects (we may call them frames) that are capable
of motion (cars, trains, planes, the earth, planets, stars) will
shrink along the axis parallel to the motion and have their clocks
slow down. The effects are in proportion to the velocity of the object
and are called length contraction and time dilation.


The "shrink" and dilation are not proportional to the velocity.
Peter, you've seen the formula for Lorentz "gamma". How you could
possibly think it's proportional to velocity?

SR is precise. Peter Riedt just doesn't know what the words mean,
not even words he uses.


--
--Bryan

  #7  
Old February 8th 08 posted to sci.physics.relativity
alen
external usenet poster
 
Posts: 705
Default The Measurement of Contraction

On Feb 8, 12:04*pm, Peri of Pera wrote:
The Measurement of Contraction


[...]

But let us ask questions about such a measurement. Event 1 is the
recording of location A of one end of a rod in space at time t by
observers S and S'. Event 2 is the recording of *location B of the
other end of the rod also at time t by the same observers. The
experimenter picks up and analyses the four space time co-ordinates
made by the two observers. Will the answer be the contracted length of
the rod? How will the movement of the two observers relative to the
rod disclose the contracted length of the rod and not a distorted view
of it? How are optical, communicative and angular aspects included in
the measurement? What single fixed co-ordinate system is common to
both observers or is it only relative to observer S or observer S'?
How will the experimenter establish that the times t of the two
observers are simultaneous given that SR imposes a whole set of ifs
and buts on simultaneity? How will any difference in the speed the
observed object, S and S' be taken into account?

It all can be done on paper making assumptions but not as a real test.
The more ardent supporters of the contraction hypothesis assert that
proof is not required. Their argument is that to 'make predictions' is
sufficient or they will do the calculations manually and if these are
rejected or ignored by anyone, they accuse him of being incapable of
the maths and he should study the subject to understand the theory.
With understanding they mean accepting it without reservation. It is
the approach of all monotheistic religions which ostracise all non-
believers, excommunicate them, vilify them, and ultimately stone or
burn them. In this NG it is automatically practised against any member
who dares to reject SR or even question it.

Peter Riedt


One cannot really be surprised if SR appears to people
to be not well or clearly explained. It is in the peculiar
situation of something that is largely correct, and looks
like it could be completely correct, but is actually partly
wrong. In a situation like this, the most brilliant people
can explain it in all ways ad nauseum, and point to the
right final results but, somehow, the mind is always left
partially unsatisfied.

Why? I think that it is like the case of a room with
obstacles in it. No matter how people show you how
you can move about the room, you are always at least
slightly irritated and dissatisfied with the obstacles that
never get out of the way. They can tell you that they are
not obstacles, and you can easily move around them,
but you are not, and never can be persuaded.

A perfectly true theory will be experienced as something
of clarity, with everything manifestly in order, and in its
place. A theory hiding a subtle falsehood, however small,
however, will never give such an experience, and people
will therefore be forever questioning it and feeling perplexed,
even when they cannot put their finger on what it is about
the theory that seems unsatisfactory.

Such is the case with SR

Alen


  #8  
Old February 8th 08 posted to sci.physics.relativity
Dirk Van de moortel
external usenet poster
 
Posts: 15,039
Default The Measurement of Contraction


"Alen" wrote in message ...

[snip]

One cannot really be surprised if SR appears to


less gifted

people
to be not well or clearly explained. It is in the peculiar
situation of something that is largely correct, and looks
like it could be completely correct, but is


in the eyes of less gifted people

actually partly
wrong. In a situation like this, the most brilliant people
can explain it in all ways ad nauseum, and point to the
right final results but, somehow, the


less gifted

mind is always left
partially unsatisfied.

Why? I think that it is like the case of a room with
obstacles in it. No matter how people show you how
you can move about the room, you are always at least
slightly irritated and dissatisfied with the obstacles that
never get out of the way. They can tell you that they are
not obstacles, and you can easily move around them,
but you are not, and never can be persuaded.

A perfectly true theory will be experienced as something
of clarity, with everything manifestly in order, and in its
place. A theory hiding a subtle falsehood, however small,
however, will never give such an experience, and people
will therefore be forever questioning it and feeling perplexed,
even when they cannot put their finger on what it is about
the theory that seems unsatisfactory.

Such is the case with


your and most crackpot's understanding of

SR


Severy less gifted

Alen


Dirk Vdm

  #9  
Old February 8th 08 posted to sci.physics.relativity
wugi
external usenet poster
 
Posts: 45
Default The Measurement of Contraction

"jeckyl" :
"Peri of Pera" :
The Measurement of Contraction

The theory of relativity is presented as one that cannot be understood
by most people.


Not 'cannot', just 'is difficult'


Restricting oneself to the usual algebraic axiomatics and the establishment
of Lorentz transforms, I had the opposite problem: it seemed too simple, yet
it evaded our intuition...

This aura of complexity and difficulty is maintained
by using ambiguity and vagueness in describing and defining the theory


No .. the theory is very clear and precise .. however, some popularisation
of it are vague and ambiguous, because they use colloquial terms that the
layman is more familiar with, and those terms are vague and ambiguous.

and defending it with even more ambiguity and vagueness against logic.


There is nothing illogical about SR


.... so I once decided to have a go at a truly intuitive approach of its
axiomatics. In my case (and I take it, in many people's that would mean:
geometry and graphic rendering.

But what is it really? Stripped of all esoteric language it simply
means that physical objects (we may call them frames) that are capable
of motion (cars, trains, planes, the earth, planets, stars) will
shrink along the axis parallel to the motion and have their clocks
slow down.


No .. nothing happens to the object .. it can't do. Someone moving

quickly
past you does not change you. But something happens to how they are
measured by things that move relative to them

The effects are in proportion to the velocity of the object


No .. they are not in propoertion at all.

and are called length contraction and time dilation.


You missed relativity or simultaneity .. so many people do, yet it is
probably the most important effect


Agreed. A result of an "isotropy of = equality of light clocks" axiom (*),
easily taken for granted in a rest frame, but a real hypothesis when
realising that there is no such thing as an all round rest frame...
(*) actually my axiom 4 in the page below, under "MySRT".
See also axiom 5 and comments following:
"
Axiom 4, put to comparison between different inertial systems, yields
differential simultaneity.

Axioms 4 and 5 yield length contraction and time dilation.

Another result is the constancy of light speed, as a common feature of all
light clocks, their isotropy meaning same light time for same distance, but
being aware of what 'distance' means in different systems.



Actually, understanding the properties of light clocks, and their role as
basic gauge tools for measuring length and time in any system, with any
ruler and clock equipment, is my cornerstone for an intuitive and
geometrical understanding of SRT. The Michelson-Morley experiment may with
hindsight be re-interpreted as an attempt to prove light clocks not being
true (isotropic) clocks !

"

SRT made easy, intuitive, geometrically and logically satisfactory:
http://home.scarlet.be/~pin12499/paratwin.htm
SRT in my QBasic pages with some graphic examples:
http://home.scarlet.be/~pin12499/qbRelaty.html

guido


  #10  
Old February 8th 08 posted to sci.physics.relativity
wugi
external usenet poster
 
Posts: 45
Default The Measurement of Contraction


:
The Measurement of Contraction


The theory of relativity is presented as one that cannot be understood

by most people.


Unfortunately that is how it is often presented.


This aura of complexity and difficulty is maintained

by using ambiguity and vagueness in describing and defining the theory


Quite true. I often wondered why they would present the theory in such

a vague and confusing way, when it can be simply presented w/o
vagueness and confusions. Rare are the SR books which are well
presented.

I have come to the conclusion that SR authors are either clueless

about relativity and thus remain vague in its descriptions or that
those authors are just really bad pedagogists.

I am not saying that SR is wrong and I tend to say the opposite.

But I do say that SR is badly represented or described. If relativity
authors really wanted to, they can introduce SR
in simple terms well accessible to highschool students. But then SR
would loose all of its "mystery" and relativist would no longer be
viewed as "brilliant".

guido:
Let's see if you don't find my approach perhaps less vague, clueless,
confusing (if a bit messy, yes:-), mysterious :
SRT made easy, intuitive, geometrically and logically satisfactory:
http://home.scarlet.be/~pin12499/paratwin.htm
SRT in my QBasic pages with some graphic examples:
http://home.scarlet.be/~pin12499/qbRelaty.html

guido



 




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