"wugi" wrote in message
...
| "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...

Go a step further.
Intuition says believe what you see and intuition says velocities add.
One conflicts with the other, don't rely on intuition.
If you believe what you see then this pencil broken:
http://hyperphysics.phy-astr.gsu.edu...ic/brokpen.jpg

If you use GR to calculate the time on Earth vs the time on the Moon
http://en.wikipedia.org/wiki/Gravita..._time_dilation

tf = 1,000,000 years
gravitational constant G = 6.673E-11 m^3 kg^-1 s^-2
Mass of Earth = 5.9736E+24 kg
r = 385000 km (distance to Moon)
c = 299792.458 km/sec

t0 = 994222.168323667

An observer on Earth measures the Moon making ~6 more
orbits around the Sun in a thousand years, as prophesied
by Einstein. You'd think someone would notice by now.

Einstein's pathetic mathematics isn't just counter-intuitive, it's
"believe what you see" crap.

"wugi" wrote in message
...
|
| :
| 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:

There is no mystery to bull****.
'we establish by definition that the "time" required by
light to travel from A to B equals the "time" it requires
to travel from B to A' because I SAY SO. -- Rabbi Albert Einstein
http://www.androcles01.pwp.blueyonde...rt/tAB=tBA.gif

4 = 12 according to the cretin Einstein.

"Androcles" wrote in message
. uk...

"wugi" wrote in message
...
| "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...

Go a step further.
Intuition says believe what you see and intuition says velocities add.

SR gives you the same answers that we see in everyday life .. so
(intuitively) SR is just as right regarding what most of us see of the world
most of the time.

One conflicts with the other, don't rely on intuition.

But when we look at things with greater velocities, we see that velocities
do not just add as vectors when we change frames of reference. We see a
constant speed of light despite source speed. WE see time dilating. SR
describes better what we do see.

Intuition says believe what we see .. and we see SR works better.

"Androcles" wrote in message
news
There is no mystery to bull****.
'we establish by definition that the "time" required by
light to travel from A to B equals the "time" it requires
to travel from B to A' because I SAY SO. -- Rabbi Albert Einstein
http://www.androcles01.pwp.blueyonde...rt/tAB=tBA.gif

That diagrams does NOT describe what the statement shows. The A and B in
that are fixed points in a frame of reference .. not moving ones . You've
been told repeatedly, and keep showing your misreprentations. that is
called dishonesty .. that makes you a liar and a fraud just like Henri
Wilson.

On Feb 8, 3:56*pm, "wugi" wrote:
"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- Hide quoted text -

- Show quoted text -

xxein: I wouldn't even have to url to know it is incomplete.

"wugi" wrote in message
...
SRT made easy, intuitive, geometrically and logically satisfactory:
http://home.scarlet.be/~pin12499/paratwin.htm

The presentation there seems to make it harder, unintuitive and an
incoherent mess. Nice that you've tried, but I think you've failed.

On Feb 8, 4:42*am, "harry" wrote:
"Peri of Pera" wrote in ...

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.

xxein: Hi, Harry. Standard explanation, but what about the
unobserved physic where a subjectively measured relativeness doesn't
matter? What is the explanation/description for that?


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.

... as a relative method of measurement.


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.

C'mon Harry. Qm "observers' just localize it more. It's all the same
frame vs. frame. All qm does is focus more intensely and lose gravity
as a more macro part of the physic.






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.

So is the observer S'. They are different. What defines the physic
for this difference (and not just their relative difference)?

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.

Poo. I define the PoR as a subjective collection of observation (made
into a physical theory) of measureable relationships with no
underlying physical atributes. There is no common thread that unites
the micro to the macro (try gravity) despite the current tries. But I
did mention to you, some time ago, that I was doing it.


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.

Yeaaaay. So what unites them in the underlying physic?

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.

The "TR hmm" is in order here. You will say that cavemen cannot make
computers. WHY NOT???


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. :-)

You seem to believe that you have all the answers already and that no
more are needed or to be considered. Did I get that right?


Harald- Hide quoted text -

- Show quoted text -

On Feb 8, 9:25 am, "jeckyl" wrote:
"Peri of Pera" wrote in ...

The Measurement of Contraction

Jecko,
Your version of SR is a very strange one.

I said: 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.

You replied: 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.

Einstein writes in 1916 (Relativity: The Special and General Theory,
Chapter 16): "The contraction of moving bodies follows from the two
fundamental principles of the theory". This statement by AE is
unqualified. It does not assume as you do that something happens to
moving bodies because they are measured by things that move relative
to them. Utter nonsense. Don't try to re-interpret SR in order to
defend it and study it before you lecture on it.
Peter Riedt

On Feb 8, 6:23*pm, "Dirk Van de moortel" dirkvandemoor...@ThankS-NO-
SperM.hotmail.com wrote:
"Peri of Pera" wrote in ...

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

Dirk,
thank you for your comments which will help me somewhat. However, the
point I am trying to make is that contraction has not (as you
agreed)and can not be made visible by any procedure because it does
not eventuate in nature but is only a hypothetical mathematical
exercise. It all started with the misunderstood MMX and Lorentz's
attempt to explain the null result by conjecture.
Peter Riedt

On Feb 9, 4:49*am, "Dirk Van de moortel" dirkvandemoor...@ThankS-NO-
SperM.hotmail.com wrote:
"Alen" wrote in ...

[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

I suppose you must persuade yourself of that.
After all, where would you be if you had to think that
I, or any of the others, was actually gifted? In an
unthinkable quandary, probably! No! It MUST never
be possible that any of us could be 'gifted'!

But the other side of the coin is that the supposedly
gifted are able to blind themselves with their own
cleverness, so that they are not able to see past
the brilliance of their own mental constructs, even
if they are wrong.

Gifted or not, I can see perfectly well what is the
reason for a hyperbolic spacetime, and what it is
supposed to achieve, but I can also see that it is
a conceptual hogs breakfast, as someone else
remarked, and can never actually work as a
physical reality!

Alen