Hi,
I am not a physics, just an amateur. However, I treat myself as a
logician, so the paradoxes are in my interest. After I read the
discussions about the special relativity(SR) and twin's paradox,
believe that it can not be resolved within SR. The defenders of SR
claims that there is an asymmetry in the conditions of the twins and so
there is no paradox. However, one can easily think of an experiment in
which the twins are in symmetric conditions.

Let A B are the twins and C is a third observer. The twins move away
from the earth in opposite directions and C remains rest on the earth.
Assume their clock is synchronized just before the movement. After
accelaration twins continue to their journey in a constant speed. After
some time they return back and land on the earth. Let from the C's
point of view, the twins all accelarate at the same time and with the
same amount. The only difference between the twins is that they travel
in opposite directions. After returning back they compare their
clocks. If SR is true, according to C, the twins clock will slow down
with the same amount and their clocks must be the same. On the other
hand, according to the twin A, twin B's clock must be slow down and not
the same with his/her clock. The same thing is true for twin B. Of
course there can be only one result. However, according to SR, three
observer comes out with three different results.

For just objections relating to accelarations: the accelaration times
of the twins can be made arbitrararily smaller according to the
duration in which the twins travel at a constant speed, so their
affects can be vanished without a significant error.

Lokman Kolukisa

wrote in message
oups.com...
| Hi,
| I am not a physics, just an amateur. However, I treat myself as a
| logician, so the paradoxes are in my interest. After I read the
| discussions about the special relativity(SR) and twin's paradox,
| believe that it can not be resolved within SR. The defenders of SR
| claims that there is an asymmetry in the conditions of the twins and so
| there is no paradox. However, one can easily think of an experiment in
| which the twins are in symmetric conditions.
|
| Let A B are the twins and C is a third observer. The twins move away
| from the earth in opposite directions and C remains rest on the earth.
| Assume their clock is synchronized just before the movement. After
| accelaration twins continue to their journey in a constant speed. After
| some time they return back and land on the earth. Let from the C's
| point of view, the twins all accelarate at the same time and with the
| same amount. The only difference between the twins is that they travel
| in opposite directions. After returning back they compare their
| clocks. If SR is true, according to C, the twins clock will slow down
| with the same amount and their clocks must be the same. On the other
| hand, according to the twin A, twin B's clock must be slow down and not
| the same with his/her clock. The same thing is true for twin B. Of
| course there can be only one result. However, according to SR, three
| observer comes out with three different results.
|
| For just objections relating to accelarations: the accelaration times
| of the twins can be made arbitrararily smaller according to the
| duration in which the twins travel at a constant speed, so their
| affects can be vanished without a significant error.
|
| Lokman Kolukisa

yawn
http://www.androcles01.pwp.blueyonde...ket/Rocket.htm
http://www.androcles01.pwp.blueyonde...mart/Smart.htm

Dear lkoluk2003:

wrote in message
oups.com...
....
Let A B are the twins and C is a third observer. The twins
move away from the earth in opposite directions and C
remains rest on the earth. Assume their clock is
synchronized just before the movement. After
accelaration twins continue to their journey in a constant
speed. After some time they return back and land on the
earth. Let from the C's point of view, the twins all
accelarate at the same time and with the same amount.
The only difference between the twins is that they travel
in opposite directions. After returning back they
compare their clocks. If SR is true,

"true" is not part of science. "what is observed, within our
ability to measure" is part of science.

according to C, the twins clock will slow down with the
same amount and their clocks must be the same. On
the other hand, according to the twin A, twin B's clock
must be slow down and not the same with his/her
clock. The same thing is true for twin B. Of course
there can be only one result. However, according to
SR, three observer comes out with three different
results.

If you did the math, observer A sees observer B's clock go very
slowly on A's outbound, continue slowly for some time with A
inbound (since B's start-of-return doesn't reach A until later)
then sees B's clock rate increase until it meets A at Earth, with
net 0 difference at Earth.

So three observers in a symmetric situation yields two results,
because only two unique paths are described.

It is the words that trick your common sense, not the facts. Use
the math.

David A. Smith

wrote:
Hi,
I am not a physics, just an amateur. However, I treat myself as a
logician, so the paradoxes are in my interest. After I read the
discussions about the special relativity(SR) and twin's paradox,
believe that it can not be resolved within SR. The defenders of SR
claims that there is an asymmetry in the conditions of the twins and so
there is no paradox. However, one can easily think of an experiment in
which the twins are in symmetric conditions.

Let A B are the twins and C is a third observer. The twins move away
from the earth in opposite directions and C remains rest on the earth.
Assume their clock is synchronized just before the movement. After
accelaration twins continue to their journey in a constant speed. After
some time they return back and land on the earth. Let from the C's
point of view, the twins all accelarate at the same time and with the
same amount. The only difference between the twins is that they travel
in opposite directions. After returning back they compare their
clocks. If SR is true, according to C, the twins clock will slow down

No... SR doesn't say clocks slow, it says they *appear* to slow
to a remote observer.

http://www.bartleby.com/173/12.html



Abstract
Einstein addressed the twin paradox in special relativity
in a relatively unknown, unusual and rarely cited paper
written in 1918, in the form of a dialogue between a
critic and a relativist. Contrary to most textbook versions
of the resolution, Einstein admitted that the special
relativistic time dilation was symmetric for the twins,
and he had to invoke, asymmetrically, the general relativistic
gravitational time dilation during the brief periods
of acceleration to justify the asymmetrical aging.
Notably, Einstein did not use any argument related to
simultaneity or Doppler shift in his analysis. I discuss
Einstein's resolution and several conceptual issues
that arise. It is concluded that Einstein's resolution using
gravitational time dilation suffers from logical and
physical flaws, and gives incorrect answers in a general
setting. The counter examples imply the need to reconsider
many issues related to the comparison of transported
clocks. The failure of the accepted views and
resolutions is traced to the fact that the special relativity
principle formulated originally for physics in empty
space is not valid in the matter-filled universe.

C. S. Unnikrishnan
Gravitation Group,
Tata Institute of Fundamental Research,
Homi Bhabha Road, Mumbai 400 005, India
http://www.iisc.ernet.in/currsci/dec252005/2009.pdf
-----

Sue...


with the same amount and their clocks must be the same. On the other
hand, according to the twin A, twin B's clock must be slow down and not
the same with his/her clock. The same thing is true for twin B. Of
course there can be only one result. However, according to SR, three
observer comes out with three different results.

For just objections relating to accelarations: the accelaration times
of the twins can be made arbitrararily smaller according to the
duration in which the twins travel at a constant speed, so their
affects can be vanished without a significant error.

Lokman Kolukisa

wrote in message
oups.com...
Hi,
I am not a physics, just an amateur. However, I treat myself as a
logician, so the paradoxes are in my interest. After I read the
discussions about the special relativity(SR) and twin's paradox,
believe that it can not be resolved within SR. The defenders of SR
claims that there is an asymmetry in the conditions of the twins and so
there is no paradox. However, one can easily think of an experiment in
which the twins are in symmetric conditions.

Let A B are the twins and C is a third observer. The twins move away
from the earth in opposite directions and C remains rest on the earth.
Assume their clock is synchronized just before the movement. After
accelaration twins continue to their journey in a constant speed. After
some time they return back and land on the earth. Let from the C's
point of view, the twins all accelarate at the same time and with the
same amount. The only difference between the twins is that they travel
in opposite directions. After returning back they compare their
clocks. If SR is true, according to C, the twins clock will slow down
with the same amount and their clocks must be the same. On the other
hand, according to the twin A, twin B's clock must be slow down and not
the same with his/her clock. The same thing is true for twin B. Of
course there can be only one result. However, according to SR, three
observer comes out with three different results.

For just objections relating to accelarations: the accelaration times
of the twins can be made arbitrararily smaller according to the
duration in which the twins travel at a constant speed, so their
affects can be vanished without a significant error.

Lokman Kolukisa

The SR math that you used (the symmetry) is valid in inertial frames only.
Twins A and B did not stay in inertial frames. The correct calculations
yield a single result. In short, you can pick any inertial frame you like
(say of observer A at the first half journey, or C, or any inertial observer
D); either you stick to such a frame for your calculation (and you will get
the same result as with any other inertial frame) or you use several
inertial reference frames and switch between them. Then you must correct for
that switch between reference frames with a Lorentz transformation; and
again the result is the same. Such is the property of the Lorentz
transformations. Mathematics can't be disproved with logic.

Harald

N:dlzc D:aol T:com (dlzc) wrote:
Dear lkoluk2003:

wrote in message
oups.com...
...
Let A B are the twins and C is a third observer. The twins
move away from the earth in opposite directions and C
remains rest on the earth. Assume their clock is
synchronized just before the movement. After
accelaration twins continue to their journey in a constant
speed. After some time they return back and land on the
earth. Let from the C's point of view, the twins all
accelarate at the same time and with the same amount.
The only difference between the twins is that they travel
in opposite directions. After returning back they
compare their clocks. If SR is true,

"true" is not part of science. "what is observed, within our
ability to measure" is part of science.

according to C, the twins clock will slow down with the
same amount and their clocks must be the same. On
the other hand, according to the twin A, twin B's clock
must be slow down and not the same with his/her
clock. The same thing is true for twin B. Of course
there can be only one result. However, according to
SR, three observer comes out with three different
results.

If you did the math, observer A sees observer B's clock go very
slowly on A's outbound, continue slowly for some time with A
inbound (since B's start-of-return doesn't reach A until later)
then sees B's clock rate increase until it meets A at Earth, with
net 0 difference at Earth.

So three observers in a symmetric situation yields two results,
because only two unique paths are described.

It is the words that trick your common sense, not the facts. Use
the math.

David A. Smith

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tick-faries and their teeth are so sharp they can gnaw through
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the wire. )


Sue...

wrote:
Hi,
I am not a physics, just an amateur. However, I treat myself as a
logician, so the paradoxes are in my interest. After I read the
discussions about the special relativity(SR) and twin's paradox,
believe that it can not be resolved within SR. The defenders of SR
claims that there is an asymmetry in the conditions of the twins and so
there is no paradox. However, one can easily think of an experiment in
which the twins are in symmetric conditions.

Since you have chosen the reference frame of C to be your reference,
use that frame to calculate the elapsed time for A and B. No problem.
If your calculations don't all agree, post your calculations and I will
point out where the error lies.

Let A B are the twins and C is a third observer. The twins move away
from the earth in opposite directions and C remains rest on the earth.
Assume their clock is synchronized just before the movement. After
accelaration twins continue to their journey in a constant speed. After
some time they return back and land on the earth. Let from the C's
point of view, the twins all accelarate at the same time and with the
same amount. The only difference between the twins is that they travel
in opposite directions. After returning back they compare their
clocks. If SR is true, according to C, the twins clock will slow down
with the same amount and their clocks must be the same. On the other
hand, according to the twin A, twin B's clock must be slow down and not
the same with his/her clock. The same thing is true for twin B. Of
course there can be only one result. However, according to SR, three
observer comes out with three different results.

For just objections relating to accelarations: the accelaration times
of the twins can be made arbitrararily smaller according to the
duration in which the twins travel at a constant speed, so their
affects can be vanished without a significant error.

Wrong. A finite Lorentz transform is an infinite product of
infnitesimal Lorentz transforms, just like a finite rotation by
some angle is an infinite product of infinitesimal rotations. If
you applied your same argument to a rotation, you would conclude
that making a left turn (or any turn) is impossible for exactly
the same reason.

wrote:
Hi,
I am not a physics, just an amateur. However, I treat myself as a
logician, so the paradoxes are in my interest. After I read the
discussions about the special relativity(SR) and twin's paradox,
believe that it can not be resolved within SR.

Then you either haven't studied SR. Don't try to evaluate a theory
unless you really know what it says.

Paul Cardinale

wrote:
Hi,
I am not a physics, just an amateur. However, I treat myself as a
logician, so the paradoxes are in my interest. After I read the
discussions about the special relativity(SR) and twin's paradox,
believe that it can not be resolved within SR. The defenders of SR
claims that there is an asymmetry in the conditions of the twins and so
there is no paradox. However, one can easily think of an experiment in
which the twins are in symmetric conditions.

The so-called twin paradox was never actually a paradox. If you don't
understand SR, it can continue to appear to be one however. But both
twins agree that the twin who did the frame changing has aged less
since he has the shorter invariant world line.

wrote in message oups.com...
Hi,
I am not a physics, just an amateur. However, I treat myself as a
logician, so the paradoxes are in my interest. After I read the
discussions about the special relativity(SR) and twin's paradox,
believe that it can not be resolved within SR. The defenders of SR
claims that there is an asymmetry in the conditions of the twins and so
there is no paradox. However, one can easily think of an experiment in
which the twins are in symmetric conditions.

Let A B are the twins and C is a third observer. The twins move away
from the earth in opposite directions and C remains rest on the earth.
Assume their clock is synchronized just before the movement. After
accelaration twins continue to their journey in a constant speed. After
some time they return back and land on the earth. Let from the C's
point of view, the twins all accelarate at the same time and with the
same amount. The only difference between the twins is that they travel
in opposite directions. After returning back they compare their
clocks. If SR is true, according to C, the twins clock will slow down
with the same amount and their clocks must be the same.

Correct.

On the other
hand, according to the twin A, twin B's clock must be slow down and not
the same with his/her clock.

Wrong! SR predicts that both twins' clocks will show the same time in
the symmetrical case you describe.

As others have pointed out, you must understand a theory before
you criticise it.

Martin Hogbin