IS LENGTH CONTRACTION MERELY A GEOMETRICAL PROJECTION?
Pentcho Valev
sci.physics.relativity:
http://groups.google.com/group/sci.physics.relativity/msg/737d548d1bf664b4
>
> If you are thinking of "length contraction" in SR, then you are
> confused. That does not affect any object, it is merely a
> geometrical projection between relatively moving frames.
>
> Tom Roberts
Then explain this, Honest Roberts (the quotations below act like the
face of Medusa the Gorgon - on seeing them, Roberts gets petrified and
never replies):
http://math.ucr.edu/home/baez/physics/Relativity/SR/barn_pole.html
"These are the props. You own a barn, 40m long, with automatic doors
at either end, that can be opened and closed simultaneously by a
switch. You also have a pole, 80m long, which of course won't fit in
the barn. Now someone takes the pole and tries to run (at nearly the
speed of light) through the barn with the pole horizontal. Special
Relativity (SR) says that a moving object is contracted in the
direction of motion: this is called the Lorentz Contraction. So, if
the pole is set in motion lengthwise, then it will contract in the
reference frame of a stationary observer.....So, as the pole passes
through the barn, there is an instant when it is completely within the
barn. At that instant, you close both doors simultaneously, with your
switch. Of course, you open them again pretty quickly, but at least
momentarily you had the contracted pole shut up in your barn. The
runner emerges from the far door unscathed.....If the doors are kept
shut the rod will obviously smash into the barn door at one end. If
the door withstands this the leading end of the rod will come to rest
in the frame of reference of the stationary observer. There can be no
such thing as a rigid rod in relativity so the trailing end will not
stop immediately and the rod will be compressed beyond the amount it
was Lorentz contracted. If it does not explode under the strain and it
is sufficiently elastic it will come to rest and start to spring back
to its natural shape but since it is too big for the barn the other
end is now going to crash into the back door and the rod will be
trapped IN A COMPRESSED STATE inside the barn."
http://www.quebecscience.qc.ca/Revolutions
Stéphane Durand: "Pour mieux comprendre le phénomène de ralentissement
du temps, il est préférable d'aborder un autre phénomène tout aussi
paradoxal: la contraction des longueurs. Car la vitesse affecte non
seulement l'écoulement du temps, mais aussi la longueur des objets.
Ainsi, une fusée en mouvement apparaît plus courte que lorsqu'elle est
au repos. Là aussi, plus la vitesse est grande, plus la contraction
est importante. Et, comme pour le temps, les effets ne deviennent
considérables qu'à des vitesses proches de celle de la lumière. Dans
la vie de tous les jours, cette contraction est imperceptible.
Cependant, si une fusée de 100 m passait devant nous à une vitesse
proche de celle de la lumière, elle pourrait sembler ne mesurer que 50
m, ou même moins. Bien sûr, la question qui vient tout de suite à
l'esprit est: «Cette contraction n'est-elle qu'une illusion?» Il
semble tout à fait incroyable que le simple mouvement puisse comprimer
un objet aussi rigide qu'une fusée. Et pourtant, la contraction est
réelle... mais SANS COMPRESSION physique de l'objet! Ainsi, une fusée
de 100 m passant à toute vitesse dans un tunnel de 60 m pourrait être
entièrement contenue dans ce tunnel pendant une fraction de seconde,
durant laquelle il serait possible de fermer des portes aux deux
bouts! La fusée est donc réellement plus courte. Pourtant, il n'y a
PAS DE COMPRESSION matérielle ou physique de l'engin."
http://www.parabola.unsw.edu.au/vol35_no1/vol35_no1_2.pdf
Parabola Volume 35, Issue 1 (1999)
LENGTH AND RELATIVITY by John Steele
"The Pole in the Barn Paradox. Now we know about length contraction,
we can invent some amusing uses of it. Suppose you want to fit a 20m
pole into a 10m barn. If the pole were moving fast enough, then length
contraction means it would be short enough. (...) Now comes the
paradox. According to your friend who is going to slam the barn doors
shut just as the end of the pole goes in, the pole is 10m long, and
therefore it fits. However as far as you are concerned, the pole is
still 20m long but the barn is now only 5m long: length contraction
must work both ways by the first postulate. How can you fit this 20m
pole into a 5m barn? This paradox is apparently due to Wolfgang
Rindler of the University of Texas at Dallas. Of course the key to
this is relativity of simultaneity. Your friend sees the front end of
the pole hit the back wall of the barn at the same time as the doors
are closed, but you (and the pole) do not see things this way. You are
standing still and see a 5m long barn coming towards you at some
shockingly high speed. When the back of the barn hits the front of the
pole (and takes the front of the pole with it), the back end of the
pole must still be at rest. It cannot 'know' about the crash at the
front, because the shock wave travelling along the pole telling it
about the crash travels at some finite speed. The front of the barn
has only 15m to go to get to the back of the pole, but the shock wave
has to travel the whole length of the pole, namely 20m. The speed of
the barn is such that even if this shock wave travelled at the speed
of light, it would not get to the back of the pole before the front of
the barn did. Hence in both frames of reference, the pole fits inside
the barn (and will presumably shatter when the doors are closed)."
Pentcho Valev
pva...@yahoo.com
PD
> On Aug 26, 3:39 pm, Tom Roberts<tjroberts...@sbcglobal.net> wrote in
> sci.physics.relativity:
>
> http://groups.google.com/group/sci.physics.relativity/msg/737d548d1bf664b4
>>
>> If you are thinking of "length contraction" in SR, then you are
>> confused. That does not affect any object, it is merely a
>> geometrical projection between relatively moving frames.
>>
>> Tom Roberts
>
> Then explain this, Honest Roberts (the quotations below act like the
> face of Medusa the Gorgon - on seeing them, Roberts gets petrified and
> never replies):
Explain what? What is quoted below reflect exactly what Tom said. Do you
not understand that? And if you DON'T understand it, whose problem is that?
>
> http://math.ucr.edu/home/baez/physics/Relativity/SR/barn_pole.html
>
> http://www.quebecscience.qc.ca/Revolutions
>
> http://www.parabola.unsw.edu.au/vol35_no1/vol35_no1_2.pdf
>
> Pentcho Valev
> pva...@yahoo.com
Francoise Garros
>IS LENGTH CONTRACTION MERELY A GEOMETRICAL >PROJECTION?
much more than that, is a natural impossibility !!!
good bye
Pentcho Valev
> On 8/26/2011 10:17 AM, Pentcho Valev wrote:
>
> > On Aug 26, 3:39 pm, Tom Roberts<tjroberts...@sbcglobal.net> wrote in
> > sci.physics.relativity:
>
>
> >> If you are thinking of "length contraction" in SR, then you are
> >> confused. That does not affect any object, it is merely a
> >> geometrical projection between relatively moving frames.
>
> >> Tom Roberts
>
> > Then explain this, Honest Roberts (the quotations below act like the
> > face of Medusa the Gorgon - on seeing them, Roberts gets petrified and
> > never replies):
>
> Explain what? What is quoted below reflect exactly what Tom said.
Really? Would he confirm that an 80m object can safely be trapped
inside a 40m container so that Einsteiniana's zombies can circle
around singing "Divine Einstein" and "Yes we all believe in
relativity, relativity, relativity"? I am not so sure.
Pentcho Valev
pva...@yahoo.com
papa...@gmail.com
It sure can!!. And the reason is quite simple and should be
understandable to even those ignorant nuts and crackpots of this
group. Being trapped inside a barn involves to have the object inside
two closed doors. In other words, the front of the pole is approaching
a closed door and the back of the pole is receding from a closed back
door. But, those two events are simultaneous in one frame of reference
(the one of the 40 m barn) while they are not simultaneous in the
other frame of reference (the one of the pole). So the observer at the
barn sees the pole moving through the barn doors at high speed and,
for a very brief period of time, the length contracted pole perfectly
fits within the barn with both doors closed, while the pole observer
sees the front door close and open first, just before the pole is
going into the door, and later he sees the back door closing and
opening, just after the back of the pole went through the back door.
Francoise Garros
>
> > On Aug 26, 3:39 pm, Tom Roberts<tjroberts...@sbcglobal.net> wrote in
> > sci.physics.relativity:
>
>
> >> If you are thinking of "length contraction" in SR, then you are
> >> confused. That does not affect any object, it is merely a
> >> geometrical projection between relatively moving frames.
>
> >> Tom Roberts
>
>
>
> >http://www.quebecscience.qc.ca/Revolutions
>
> >http://www.parabola.unsw.edu.au/vol35_no1/vol35_no1_2.pdf
>
> > Pentcho Valev
> > pva...@yahoo.com
>
> > Then explain this, Honest Roberts (the quotations below act like the
> > face of Medusa the Gorgon - on seeing them, Roberts gets petrified and
> > never replies):
>
> Explain what? What is quoted below reflect exactly what Tom said. Do you
> not understand that? And if you DON'T understand it, whose problem is that?
is not only a geometrical projection, a lot
of self-styled contractors dont understand this
all relation in between the objects must be
length contracted, which is all physics,
including entropy !!!
PD
What do you mean by "safely trapped"? What you can do is *briefly* close
a 40 m container so that a rapidly moving 80 m object is between the
walls of that container without touching any wall of the container. Of
course, the object is moving inside so you have to open it up before it
hits the side of the container.
If you leave the container closed so that the object is in fact trapped,
then this will mean that you will change the rapidly moving 80 m object
from moving to stopped, which does of course affect its length, because
the Lorentz contraction is observed for a *moving* object, not a
stationary object.
I would think this would be common sense, Pentcho. Are you admitting
that you don't have a lick of common sense?
>
> Pentcho Valev
> pva...@yahoo.com
Pentcho Valev
> What do you mean by "safely trapped"? What you can do is *briefly* close
> a 40 m container so that a rapidly moving 80 m object is between the
> walls of that container without touching any wall of the container. Of
> course, the object is moving inside so you have to open it up before it
> hits the side of the container.
> If you leave the container closed so that the object is in fact trapped,
> then this will mean that you will change the rapidly moving 80 m object
> from moving to stopped, which does of course affect its length, because
> the Lorentz contraction is observed for a *moving* object, not a
> stationary object.
Don't forget that all along Einsteiniana's zombies (initially in the
frame of the container) are circling around singing "Divine Einstein"
and "Yes we all believe in relativity, relativity, relativity". This
is extremely important - if they did not sing, the 80m object would
not be trapped inside the 40m container. Then, as zombies realize that
the long object is SAFELY trapped inside the short container, the
ecstasy gets uncontrollable - zombies tumble to the floor, start
tearing their clothes and go into convulsions.
Pentcho Valev
pva...@yahoo.com
PD
I take it that the part about applying common sense to what "safely
trapped" means eluded you. This doesn't surprise me at all, Pentcho --
it's right up your alley. As soon as somebody points out that you don't
have enough common sense not to use the laces on the left shoe to tie
the right shoe, you start blubbering about dancing, singing,
clothes-rending, convulsing zombies. That way, at least, the attention
will no longer be on your tangled feet, right?
wugi
>> Really? Would he confirm that an 80m object can safely be trapped
>> inside a 40m container so that Einsteiniana's zombies can circle
>> around singing "Divine Einstein" and "Yes we all believe in
>> relativity, relativity, relativity"? I am not so sure.
>
> It sure can!!. And the reason is quite simple and should be
> understandable to even those ignorant nuts and crackpots of this
> group. Being trapped inside a barn involves to have the object inside
> two closed doors. In other words, the front of the pole is approaching
> a closed door and the back of the pole is receding from a closed back
> door. But, those two events are simultaneous in one frame of reference
> (the one of the 40 m barn) while they are not simultaneous in the
> other frame of reference (the one of the pole). So the observer at the
> barn sees the pole moving through the barn doors at high speed and,
> for a very brief period of time, the length contracted pole perfectly
> fits within the barn with both doors closed, while the pole observer
> sees the front door close and open first, just before the pole is
> going into the door, and later he sees the back door closing and
> opening, just after the back of the pole went through the back door.
Nicely worded, stressing the (non-)simultaneity of two compared events, a
relativistic affair.
It's also easily shown graphically, eg
http://home.scarlet.be/~pin12499/MySRT/LorentzObjects.PNG
discussed on my page
http://home.scarlet.be/~pin12499/paratwin.htm
Of course all this remains futile for permanently tripping alumni like PV
:-o)
Guido
Tom Roberts
> Then explain this, Honest Roberts (the quotations below act like the
> face of Medusa the Gorgon - on seeing them, Roberts gets petrified and
> never replies):
Wow! You sure have delusions of grandeur!
I generally don't respond to you, not because I am "petrified", but because
there's no point -- you have never shown any understanding of relativity, nor
any desire or ability to learn, so why should I bother trying to teach you when
you have demonstrated a complete inability to learn anything?
"Stupid is as stupid does", and that's how you act around here.
> http://math.ucr.edu/home/baez/physics/Relativity/SR/barn_pole.html
> [... 40 meter barn, 80 meter pole, gamma factor > 2]
That is a more complicated situation than necessary, so let me simplify it,
because this physical situation is better and the essence of the paradox is
retained (even sharpened, IMHO). We assume the doors can open or close
instantaneously (unrealistic, but this is just a gedanken).
The pole has a proper length of 80 meters, and the barn has a proper length of
40 meters; their relative motion has a gamma greater than 2 (4 is used in the
drawings below). Let the downstream (DS) door of the barn start closed and the
upstream (US) door start open. The pole enters the (open) US door which closes
as soon as the back end of the pole passes by. The (closed) DS door opens just
before the front end of the pole hits it. Because the gamma factor is greater
than 2, both doors are closed for a brief time period WHEN OBSERVED
SIMULTANEOUSLY IN THE BARN FRAME.
In the barn frame, the moving pole is measured to be less than 40 meters long,
which means when both ends are observed SIMULTANEOUSLY IN THE BARN FRAME the
distance between the observed points is less than 40 meters. That means that
while moving it can briefly fit inside the barn with both doors closed (i.e.
both are closed SIMULTANEOUSLY IN THE BARN FRAME). After the DS door opens the
pole just sails away. In the barn frame the US door closes before the DS door opens.
In the pole frame things look considerably different. The barn is measured to be
less than 20 meters long, which means that when both ends are observed
SIMULTANEOUSLY IN THE POLE FRAME the distance between observations is less than
20 meters. As the barn approaches the pole, the US door is open and the DS door
is closed. The barn surrounds the front of the pole, and just before the front
end hits the DS door, that door opens. At this instant in the pole frame (i.e.
observed SIMULTANEOUSLY IN THE POLE FRAME) the US door is still open, and is
less than 1/2 of the way along the pole. Now the barn passes along the pole with
both doors open. When the US door has passed the back end of the pole, the US
door closes. At this instant in the pole frame, the DS door is less than 1/2 of
the length of the pole from the back end of the pole (i.e. observed
SIMULTANEOUSLY IN THE POLE FRAME). After the US door closes the barn just sails
away. In the pole frame the DS door opens before the US door closes.
ASCII art (use fixed-width font). pole is ..., barn is --- for walls and | for
closed doors, open doors are blanks (as is empty space). Scale is 4 columns = 20
meters; gamma = 4; "->" indicates motion at start and end.
BARN FRAME start:
--------
.... -> |
--------
BARN FRAME US door closes:
--------
|.... |
--------
BARN FRAME pole center and barn center coincide:
--------
| .... |
--------
BARN FRAME DS door opens:
--------
| ....
--------
BARN FRAME End:
--------
| .... ->
--------
POLE FRAME Start:
----
................ <- |
----
POLE FRAME DS door opens:
----
................
----
POLE FRAME pole center and barn center coincide:
----
................
----
POLE FRAME US door closes:
----
|................
----
POLE FRAME End:
----
<- | ................
----
So there is no contradiction, and both frame agree the pole will get through the
barn, even though both doors of the barn were closed for a brief time period
SIMULTANEOUSLY IN THE BARN FRAME. But both doors are never closed SIMULTANEOUSLY
IN THE POLE FRAME.
As you can see, the difference in simultaneity between the frames is an
essential aspect of this. "Length contraction" is NOT sufficient to describe
this. The relativity of simultaneity resolves the paradox, because the order of
doors opening and closing are DIFFERENT in the two frames.
Yes, "length contraction" IS geometrical projection. Observing the endpoints of
the pole simultaneously in the barn frame PROJECTS the ends of the pole onto the
x coordinate of the barn frame (motion is along x). It should be clear that to
measure the length of a moving object you must mark both ends simultaneously in
your frame and measure the distance between the marks -- nothing else could be
called a measurement of the moving object's length in this frame (some aspect of
its motion would be included in the measurement).
Tom Roberts
Alen
> On Aug 26, 3:39 pm, Tom Roberts <tjroberts...@sbcglobal.net> wrote in
> sci.physics.relativity:
>
Since we are dealing with Minkowski spacetime, we don't
have to bother about opening the barn doors at all. The
pole is on a completely different spatial axis in spacetime
to that of the barn. Obviously, the pole will go straight
through the barn doors without even touching them, since,
in spacetime, it is not ever in the same spatial location as
the barn. So there is no need to go the expense of constructing
super-instantaneous door opening mechanisms :)
Alen
Pentcho Valev
have devised camouflages the fact that YOU AVOID COMMENTING ON THE
CASE WHERE THE DOORS REMAIN PERMANENTLY CLOSED and the long object
permanently trapped inside the short container? Let me refer you again
to the texts that act like the face of Medusa the Gorgon:
http://math.ucr.edu/home/baez/physics/Relativity/SR/barn_pole.html
"If the door withstands this the leading end of the rod will come to
rest in the frame of reference of the stationary observer. There can
be no such thing as a rigid rod in relativity so the trailing end will
not stop immediately and the rod will be compressed beyond the amount
it was Lorentz contracted. If it does not explode under the strain and
it is sufficiently elastic it will come to rest and start to spring
back to its natural shape but since it is too big for the barn the
other end is now going to crash into the back door and the rod will be
trapped IN A COMPRESSED STATE inside the barn."
http://www.parabola.unsw.edu.au/vol35_no1/vol35_no1_2.pdf
Parabola Volume 35, Issue 1 (1999)
LENGTH AND RELATIVITY by John Steele
"Hence in both frames of reference, the pole fits inside the barn (and
will presumably shatter when the doors are closed)."
Pentcho Valev
pva...@yahoo.com
On Aug 27, 5:39 am, Tom Roberts <tjroberts...@sbcglobal.net> wrote in
sci.physics.relativity:
Androcles
"Tom Roberts" <tjrobe...@sbcglobal.net> wrote in message
news:RMKdnYHTLsK...@giganews.com...
There is only one door, you deluded stupid fuck.
"Stupid is as stupid does", and that's how you act around here.
Moreover, the back of the barn is at x = 40 metres in proper barn
coordinates,
the front of the barn is at 0 in proper barn coordinates,
the proper length of the proper pole is x' = (x-vt) = 80 independent of time
in proper pole coordinates because you said so and
xi = x'/sqrt(1-v^2/c^2) = 160 metres in proper barn coordinates.
Because
160 = 80/0.5
the proper pole doesn't fit in the proper barn in proper barn coordinates.
"Stupid is as stupid does", and that's how you act around here.
Wow! You sure have delusions of grandeur but you are fucking hopeless
at proper arithmetic!
You won't answer ME, though, you squirming worm.
-- Androcles
shuba
> Since we are dealing with Minkowski spacetime, we don't
> have to bother about opening the barn doors at all. The
> pole is on a completely different spatial axis in spacetime
> to that of the barn. Obviously, the pole will go straight
> through the barn doors without even touching them, since,
> in spacetime, it is not ever in the same spatial location as
> the barn. So there is no need to go the expense of constructing
> super-instantaneous door opening mechanisms :)
Just because you may be pretending to be an uninformed crank,
it does not follow that you are not in fact an uninformed crank.
---Tim Shuba---
set...@att.net
You are playing with words....the gedanken specified that the doors
close simultaneouly briefly while the pole is inside the barn...and
they open immediately to allow the pole pass through the barn. This
action is absolute and the pole observer cannot claim that the doors
didn't close simultaneously.
Ken Seto
set...@att.net
ROTFLOL....you just say anything to fit your bogus SR theory.....do
you know that relativity of simultaneity violates the isotropy of the
speed of light in all frames???
- Hide quoted text -
>
> - Show quoted text -
papa...@gmail.com
I do know that you don´t have the slightest idea of what the following
terms mean:
-relativity of simultaneity
-isotropy
-speed of light
-frames
Also, you don´t know what "violates" mean.
So your comments have, of course, no value whatsoever.
PD
>
> Since we are dealing with Minkowski spacetime, we don't
> have to bother about opening the barn doors at all. The
> pole is on a completely different spatial axis in spacetime
> to that of the barn. Obviously, the pole will go straight
> through the barn doors without even touching them, since,
> in spacetime, it is not ever in the same spatial location as
> the barn. So there is no need to go the expense of constructing
> super-instantaneous door opening mechanisms :)
Nicely done. That made no sense whatsoever. If you were attempting to
describe the situation in relativistic terms, you've just demonstrated
that you have absolutely no understanding of those terms at all.
("completely different spatial axis" indeed!) If you are making up
your own poetry about it, then this would be in line with other word
salad you've tossed before.
PD
> Honest Roberts, do you really believe that the lengthy red herring you
> have devised camouflages the fact that YOU AVOID COMMENTING ON THE
> CASE WHERE THE DOORS REMAIN PERMANENTLY CLOSED and the long object
> permanently trapped inside the short container? Let me refer you again
> to the texts that act like the face of Medusa the Gorgon:
>
What comment are you awaiting? In the case where the doors remain
closed, then there is a collision. This is predicted by common sense
as well as relativity.
If you thought that relativity says you can nestle an 80 m object
inside a 40 m enclosure safely and permanently, then I'm afraid you've
simply not paid attention to what relativity actually says, Pentcho.
papa...@gmail.com
> Honest Roberts, do you really believe that the lengthy red herring you
> have devised camouflages the fact that YOU AVOID COMMENTING ON THE
> CASE WHERE THE DOORS REMAIN PERMANENTLY CLOSED and the long object
> permanently trapped inside the short container? Let me refer you again
> to the texts that act like the face of Medusa the Gorgon:
>
You have to be a total moron (hey...wait...you are indeed a total
moron!!) to think that an object moving at a significant percentage of
the speed of light, with respect to the container, can be miraculously
be stopped down (can you calculate the energy involved?).
But, again, you are totally unable to discuss the very fine
demonstration provided by Tom.
Alen
Still, it would be nice if some Minkowski spacetime
expert were to explain to us the mechanism by which
the pole's shortened perspective in the barn frame is
able to physically collide with the barn door, just as
the pole at its proper length would if it were travelling
at an infinitesimal velocity in the barn. It would need to
be explained why the foreshortened perspective of the
pole in the barn frame has no affect on the physics
of the collision between the pole and the barn??
Alen
Sam Wormley
> ROTFLOL....you just say anything to fit your bogus SR theory.....do
> you know that relativity of simultaneity violates the isotropy of the
> speed of light in all frames???
setoken doesn't understand the relativity of simultaneity. There is
nothing wrong special relativity!
See: "Student understanding of time in special relativity:
simultaneity and reference frames".
Rachel E. Scherr, Peter S. Shaffer, and Stamatis Vokos
Department of Physics, University of Washington, Seattle, WA
This article reports on an investigation of student understanding
of the concept of time in special relativity. A series of research
tasks are discussed that illustrate, step-by-step, how student
reasoning of fundamental concepts of relativity was probed. The
results indicate that after standard instruction students at all
academic levels have serious difficulties with the relativity of
simultaneity and with the role of observers in inertial reference
frames. Evidence is presented that suggests many students construct
a conceptual framework in which the ideas of absolute simultaneity
and the relativity of simultaneity harmoniously co-exist.
See: http://arxiv.org/pdf/physics/0207109
VII. CONCLUSION
"This investigation has identified widespread difficulties that
students have with the definition of the time of an event and the
role of intelligent observers. After instruction, more than 2/3 of
physics undergraduates and 1/3 of graduate students in physics are
unable to apply the construct of a reference frame in determining
whether or not two events are simultaneous. Many students interpret
the phrase “relativity of simultaneity” as implying that the
simultaneity of events is determined by an observer on the basis of
the reception of light signals. They often attribute the relativity
of simultaneity to the difference in signal travel time for different
observers. In this way, they reconcile statements of the relativity
of simultaneity with a belief in absolute simultaneity and fail to
confront the startling ideas of special relativity".
Androcles
"Sam Wormley" <swor...@gmail.com> wrote in message
news:Mr2dnSkfeoO4iMTT...@mchsi.com...
| On 8/27/11 8:05 AM, set...@att.net wrote:
| > ROTFLOL....you just say anything to fit your bogus SR theory.....do
| > you know that relativity of simultaneity violates the isotropy of the
| > speed of light in all frames???
|
| setoken doesn't understand the relativity of simultaneity. There is
| nothing wrong special relativity!
The babbling bullshitting wormlet doesn't understand mathematics. There is
everything wrong (with) special relativity!
Immortalist
> On Aug 26, 3:39 pm, Tom Roberts <tjroberts...@sbcglobal.net> wrote in
> sci.physics.relativity:
>
>
>
>
> > If you are thinking of "length contraction" in SR, then you are
> > confused. That does not affect any object, it is merely a
> > geometrical projection between relatively moving frames.
>
> > Tom Roberts
>
> Then explain this, Honest Roberts (the quotations below act like the
> face of Medusa the Gorgon - on seeing them, Roberts gets petrified and
> never replies):
>
This problem is very similar to the ancient Greek philosopher Zeno's
paradox of motion. But instead space and time are reversed as frames
of reference. The measurement frame can be discrete but the discrete
units of measurement change without any discretness in relation to to
the changes in what is measured.
Here a modern version of the paradox;
Suppose a very fast runner—such as mythical Atalanta—needs to run for
the bus. Clearly before she reaches the bus stop she must run half-
way, as Aristotle says. There's no problem there; supposing a constant
motion it will take her 1/2 the time to run half-way there and 1/2 the
time to run the rest of the way. Now she must also run half-way to the
half-way point—i.e., a 1/4 of the total distance—before she reaches
the half-way point, but again she is left with a finite number of
finite lengths to run, and plenty of time to do it. And before she
reaches 1/4 of the way she must reach 1/2 of 1/4 = 1/8 of the way; and
before that a 1/16; and so on. There is no problem at any finite point
in this series, but what if the halving is carried out infinitely many
times? The resulting series contains no first distance to run, for any
possible first distance could be divided in half, and hence would not
be first after all. However it does contain a final distance, namely
1/2 of the way; and a penultimate distance, 1/4 of the way; and a
third to last distance, 1/8 of the way; and so on. Thus the series of
distances that Atalanta is required to run is: …, then 1/16 of the
way, then 1/8 of the way, then 1/4 of the way, and finally 1/2 of the
way (of course we are not suggesting that she stops at the end of each
segment and then starts running at the beginning of the next—we are
thinking of her continuous run being composed of such parts). And now
there is a problem, for this description of her run has her travelling
an infinite number of finite distances, which, Zeno would have us
conclude, must take an infinite time, which is to say it is never
completed. And since the argument does not depend on the distance or
who or what the mover is, it follows that no finite distance can ever
be traveled, which is to say that all motion is impossible. (Note that
the paradox could easily be generated in the other direction so that
Atalanta must first run half way, then half the remaining way, then
half of that and so on, so that she must run the following endless
sequence of fractions of the total distance: 1/2, then 1/4, then 1/8,
then ….) ...
...(One) response—given by Aristotle himself—is to point out that as
we divide the distances run, we should also divide the total time
taken: there is 1/2 the time for the final 1/2, a 1/4 of the time for
the previous 1/4, an 1/8 of the time for the 1/8 of the run and so on.
Thus each fractional distance has just the right fraction of the
finite total time for Atalanta to complete it, and thus the distance
can be completed in a finite time. Aristotle felt that this reply
should satisfy Zeno, however he also realized (Physics, 263a15) that
it could not be the end of the matter. For now we are saying that the
time Atalanta takes to reach the bus stop is composed of an infinite
number of finite pieces —…, 1/8, 1/4, and 1/2 of the total time—and
isn't that an infinite time?
Of course, one could again claim that some infinite sums have finite
totals, and in particular that the sum of these pieces is 1 × the
total time, which is of course finite (and again a complete solution
would demand a rigorous account of infinite summation, like Cauchy's).
However, Aristotle did not make such a move. Instead he drew a sharp
distinction between what he termed a ‘continuous’ line and a line
divided into parts. Consider a simple division of a line into two: on
the one hand there is the undivided line, and on the other the line
with a mid-point selected as the boundary of the two halves. Aristotle
claims that these are two distinct things: and that the latter is only
‘potentially’ derivable from the former. Next, Aristotle takes the
common-sense view that time is like a geometric line, and considers
the time it takes to complete the run. We can again distinguish the
two cases: there is the continuous interval from start to finish, and
there is the interval divided into Zeno's infinity of half-runs. The
former is ‘potentially infinite’ in the sense that it could be divided
into the latter ‘actual infinity’. Here's the crucial step: Aristotle
thinks that since these intervals are geometrically distinct they must
be physically distinct. But how could that be? He claims that the
runner must do something at the end of each half-run to make it
distinct from the next: she must stop, making the run itself
discontinuous. (It's not clear why some other action wouldn't suffice
to divide the interval.) Then Aristotle's full answer to the paradox
is that the question of whether the infinite series of runs is
possible or not is ambiguous: the potentially infinite series of
halves in a continuous run is possible, while an actual infinity of
discontinuous half runs is not—Zeno does identify an impossibility,
but it does not describe the usual way of running down tracks!
http://plato.stanford.edu/entries/paradox-zeno/
Cantor thought that the order properties of infinite series are much
more elaborate than those of finite series. Any way of arranging the
numbers 1, 2 and 3 gives a series in the same pattern, for instance,
but there are many distinct ways to order the natural numbers: 1, 2,
3, … for instance. Or … ,3, 2, 1. Or … ,4, 2, 1, 3, 5, … . Or 2, 3, 4,
… ,1, which is just the same kind of series as the positions an object
must go through. Thus the theory of the transfinites treats not just
‘cardinal’ numbers—which depend only on how many things there are—but
also ‘ordinal’ numbers which depend further on how the things are
arranged. Since the ordinals are standardly taken to be mathematically
legitimate numbers, and since the series of points an object must pass
has an ordinal number, we shall take it that the series is
mathematically legitimate.
PD
Whaaaaaat?
Let me see if I can parse what it is you're asking.
Are you asking how it is the fast pole can NOT hit the barn door when
a slow pole would?
Let's first of all be clear on what the situation described really is.
Initially, both the front and rear doors of the barn are OPEN.
The front of the pole then enters the barn, passing first the OPEN
front door of the barn, and it is approaching the OPEN rear door of
the barn. The front of the pole is inside the barn and at this moment
the rear of the pole is outside the barn.
BEFORE the front of the pole passes through the OPEN rear door of the
barn to be outside the barn again, the rear of the pole passes through
the OPEN front door of the barn. At this moment the front of the pole
AND the rear of the pole are both inside the barn, though the pole is
still moving toward the back door of the barn.
The statement that is made is that, at least for some very short
period of time, you could now close both barn doors, with both ends of
the pole inside. Of course, you'd have to OPEN the doors again to
prevent a collision, but at least for some short, finite time, you
could have both doors prior to any collision.
Is this much clear so far?
Of course, if you then LEAVE the barn doors closed, there will soon be
a collision.
OK, so let's return back to the case where we're going to NOT leave
the barn doors closed and ask how it is that the above can happen? The
answer is simple. In the reference frame in which the barn is at rest,
the barn is 40 m long and the pole is 30 m long. Of COURSE it fits
between the doors. Even a slow 30 m pole would fit. Heck, even a
stationary 30 m pole would fit.
"But wait!" you say "I thought it was an 80 m pole!" No, not in the
reference frame in which the barn is at rest. In that frame, the pole
IS 30 m long. Period, end of story. It is NOT an 80 m pole in this
frame. It is an 80 m pole in a completely DIFFERENT frame, the one
where the pole is at rest and the barn is moving. In THAT frame, the
pole is 80 m long and the barn is 15 m long. But there the physical
description of what happens between the pole and the barn is
completely different. There are still no collisions with the doors,
but for different reasons. (Hint: The principle of relativity does NOT
say that the accounting of events must be the same in all inertial
frames. If you thought it did, fix that. The principle of relativity
just says that the laws of physics are the same in all inertial
frames, NOT the description of the events, not the shape of the
trajectories, not even the *sequence* of events.)
Tom Roberts
> Roberts, do you really believe that the lengthy red herring you
> have devised camouflages the fact that YOU AVOID COMMENTING ON THE
> CASE WHERE THE DOORS REMAIN PERMANENTLY CLOSED and the long object
> permanently trapped inside the short container?
I avoid that because nobody knows what would happen -- it requires knowledge of
material properties in a regime that is OUTRAGEOUSLY far removed from any
experience we have. The simplified version I described captures the essence of
the pole and barn paradox without introducing the red herring you concentrate
on: material properties of doors and pole.
It is QUITE clear to me that it is utterly impossible to stop a macroscopic
object moving ~0.9c within a few meters -- the energy density required is TRULY
ENORMOUS [#], and VASTLY beyond what any known material could withstand. And
it's silly to assume this, even in a gedanken.
[#] the kinetic energy of a 10 kilogram pole moving with gamma=4
FAR exceeds all of the hydrogen bombs ever detonated. And you
want to contain all that energy in the doors of a barn.
Yes, it is also impossible to construct doors that open and close
instantaneously, but that is not really essential to the paradox, because one
could omit the doors completely and just observe the locations of the pole ends.
Dishonest Valev, it is necessary to have some knowledge of the subject, so you
can distinguish what is essential from what is not. The material properties of
pole and barn are not. The instantaneous doors are not. The impossibility of
getting a macroscopic object to move so fast is not. But the relationships
between frames and the relativity of simultaneity are essential.
Tom Roberts
Tom Roberts
> the gedanken specified that the doors
> close simultaneouly briefly while the pole is inside the barn...and
> they open immediately to allow the pole pass through the barn. This
> action is absolute and the pole observer cannot claim that the doors
> didn't close simultaneously.
That may be so in the dream world of your imagination. I was discussing a
gedanken IN SPECIAL RELATIVITY. In SR, in this original (IMHO flawed) version of
the gedanken, the pole observer DOES observe that the doors didn't close
simultaneously.
BTW the experiments supporting SR imply that there is a high likelihood that if
such a situation could be implemented in the world we inhabit, the results would
be as SR predicts. IMHO the likelihood of this ever being realized is nil.
Tom Roberts
xxein
> Pentcho Valev wrote:
> > Then explain this, Honest Roberts (the quotations below act like the
> > face of Medusa the Gorgon - on seeing them, Roberts gets petrified and
> > never replies):
>
> Wow! You sure have delusions of grandeur!
>
> I generally don't respond to you, not because I am "petrified", but because
> there's no point -- you have never shown any understanding of relativity, nor
> any desire or ability to learn, so why should I bother trying to teach you when
> you have demonstrated a complete inability to learn anything?
>
> "Stupid is as stupid does", and that's how you act around here.
xxein: Tom, Tom, Tom. You should know by now that the 'physic', the
measure of it and the illusion of it are not the same thing. The
'physic' is not the 'physics'. I remember you preaching that very
point.
>
> >http://math.ucr.edu/home/baez/physics/Relativity/SR/barn_pole.html
> > [... 40 meter barn, 80 meter pole, gamma factor > 2]
>
> That is a more complicated situation than necessary, so let me simplify it,
> because this physical situation is better and the essence of the paradox is
> retained (even sharpened, IMHO). We assume the doors can open or close
> instantaneously (unrealistic, but this is just a gedanken).
>
xxein: Given.
> The pole has a proper length of 80 meters, and the barn has a proper length of
> 40 meters; their relative motion has a gamma greater than 2 (4 is used in the
> drawings below). Let the downstream (DS) door of the barn start closed and the
> upstream (US) door start open. The pole enters the (open) US door which closes
> as soon as the back end of the pole passes by. The (closed) DS door opens just
> before the front end of the pole hits it. Because the gamma factor is greater
> than 2, both doors are closed for a brief time period WHEN OBSERVED
> SIMULTANEOUSLY IN THE BARN FRAME.
>
xxein: Let, let, let what? Why that? Both doors can be open all the
time. But to have doors that close (instantly) and simultaneously is
easy. Put a trigger on the center of the length of the pole and
another at the center of the barn. But this is not ideal yet. You
would have to know the relative velocity of the pole to allow you to
calculate the time needed for the barn switch to communicate with the
doors. So you would have to move the barn switch backward along the
pole's path accordingly. And that means you cannot use a simple
light signal to operate them. You'd have to use equal length optical
cables or predetermine it in another way. Btw. V(pole) must be >.
866025403784439 x c and the barn would have to be 0v. Otherwise, any
calculations must be wrt velocity addition. Good luck with that. But
doing that requires you to assume the barn actually has 0v. Hardly
likely on a rotating planet with gravity. But the good side is that
the barn velocity is miniscule in comparison.
> In the barn frame, the moving pole is measured to be less than 40 meters long,
> which means when both ends are observed SIMULTANEOUSLY IN THE BARN FRAME the
> distance between the observed points is less than 40 meters. That means that
> while moving it can briefly fit inside the barn with both doors closed (i.e.
> both are closed SIMULTANEOUSLY IN THE BARN FRAME). After the DS door opens the
> pole just sails away. In the barn frame the US door closes before the DS door opens.
>
xxein: Your SR speculation.
> In the pole frame things look considerably different. The barn is measured to be
> less than 20 meters long, which means that when both ends are observed
> SIMULTANEOUSLY IN THE POLE FRAME the distance between observations is less than
> 20 meters. As the barn approaches the pole, the US door is open and the DS door
> is closed. The barn surrounds the front of the pole, and just before the front
> end hits the DS door, that door opens. At this instant in the pole frame (i.e.
> observed SIMULTANEOUSLY IN THE POLE FRAME) the US door is still open, and is
> less than 1/2 of the way along the pole. Now the barn passes along the pole with
> both doors open. When the US door has passed the back end of the pole, the US
> door closes. At this instant in the pole frame, the DS door is less than 1/2 of
> the length of the pole from the back end of the pole (i.e. observed
> SIMULTANEOUSLY IN THE POLE FRAME). After the US door closes the barn just sails
> away. In the pole frame the DS door opens before the US door closes.
>
xxein: Yes. Looks differently. Measures differently. Get a clue.
Balance the physic between addition of velocities and a constant c
measured by two-way. Can't you understand that math can describe
anything you tell it to do?
xxein: Only a false conception of the reality of the physic.
>
> So there is no contradiction, and both frame agree the pole will get through the
> barn, even though both doors of the barn were closed for a brief time period
> SIMULTANEOUSLY IN THE BARN FRAME. But both doors are never closed SIMULTANEOUSLY
> IN THE POLE FRAME.
>
xxein: True. There is no contradiction in the act of enclosing an
80m pole in a 40m barn. Now. Did the pole frame fit and not crash
into the doors? And I add the same instantaneous opening of the doors
(say within a femtosecond) of them closing.
> As you can see, the difference in simultaneity between the frames is an
> essential aspect of this. "Length contraction" is NOT sufficient to describe
> this. The relativity of simultaneity resolves the paradox, because the order of
> doors opening and closing are DIFFERENT in the two frames.
>
xxein: You do not even know how to figure out relativity of a
measurement. Show me that gamma^2 is not time dilation x physical
length contraction.
> Yes, "length contraction" IS geometrical projection. Observing the endpoints of
> the pole simultaneously in the barn frame PROJECTS the ends of the pole onto the
> x coordinate of the barn frame (motion is along x). It should be clear that to
> measure the length of a moving object you must mark both ends simultaneously in
> your frame and measure the distance between the marks -- nothing else could be
> called a measurement of the moving object's length in this frame (some aspect of
> its motion would be included in the measurement).
>
xxein: The barn and the pole are both physical objects. Each has a
velocity. Again. Get a clue of the 'physic' instead of following a
belief of the 'physics'. Geez. I've already disected SR-GR by/in
1990. I have never met any theory that can prove mine wrong. I can
disect 'them' too.
I've let this 'ride' for a long time. I'm not xxein for nothing
though, despite your limited understanding. You can outmath me but
you cannot outlogic me.
Go play god with your captured math minions. I shouldn't care, but
apparently I do. Someday, when I feel motivated enough, I'll publish
a macro-theory that will knock the socks off any macro-theorist and
lead to redefining Q theories (with gravity).
Have a nice day being intolerent to anything logical.
> Tom Roberts
xxein
> > Then explain this, Honest Roberts (the quotations below act like the
> > face of Medusa the Gorgon - on seeing them, Roberts gets petrified and
> > never replies):
>
> Wow! You sure have delusions of grandeur!
>
> I generally don't respond to you, not because I am "petrified", but because
> there's no point -- you have never shown any understanding of relativity, nor
> any desire or ability to learn, so why should I bother trying to teach you when
> you have demonstrated a complete inability to learn anything?
>
> "Stupid is as stupid does", and that's how you act around here.
xxein: Tom, Tom, Tom. You should know by now that the 'physic', the
measure of it and the illusion of it are not the same thing. The
'physic' is not the 'physics'. I remember you preaching that very
point.
>
> >http://math.ucr.edu/home/baez/physics/Relativity/SR/barn_pole.html
> > [... 40 meter barn, 80 meter pole, gamma factor > 2]
>
> That is a more complicated situation than necessary, so let me simplify it,
> because this physical situation is better and the essence of the paradox is
> retained (even sharpened, IMHO). We assume the doors can open or close
> instantaneously (unrealistic, but this is just a gedanken).
>
xxein: Given.
> The pole has a proper length of 80 meters, and the barn has a proper length of
> 40 meters; their relative motion has a gamma greater than 2 (4 is used in the
> drawings below). Let the downstream (DS) door of the barn start closed and the
> upstream (US) door start open. The pole enters the (open) US door which closes
> as soon as the back end of the pole passes by. The (closed) DS door opens just
> before the front end of the pole hits it. Because the gamma factor is greater
> than 2, both doors are closed for a brief time period WHEN OBSERVED
> SIMULTANEOUSLY IN THE BARN FRAME.
>
xxein: Let, let, let what? Why that? Both doors can be open all the
time. But to have doors that close (instantly) and simultaneously is
easy. Put a trigger on the center of the length of the pole and
another at the center of the barn. But this is not ideal yet. You
would have to know the relative velocity of the pole to allow you to
calculate the time needed for the barn switch to communicate with the
doors. So you would have to move the barn switch backward along the
pole's path accordingly. And that means you cannot use a simple
light signal to operate them. You'd have to use equal length optical
cables or predetermine it in another way. Btw. V(pole) must be >.
866025403784439 x c and the barn would have to be 0v. Otherwise, any
calculations must be wrt velocity addition. Good luck with that. But
doing that requires you to assume the barn actually has 0v. Hardly
likely on a rotating planet with gravity. But the good side is that
the barn velocity is miniscule in comparison.
> In the barn frame, the moving pole is measured to be less than 40 meters long,
> which means when both ends are observed SIMULTANEOUSLY IN THE BARN FRAME the
> distance between the observed points is less than 40 meters. That means that
> while moving it can briefly fit inside the barn with both doors closed (i.e.
> both are closed SIMULTANEOUSLY IN THE BARN FRAME). After the DS door opens the
> pole just sails away. In the barn frame the US door closes before the DS door opens.
>
xxein: Your SR speculation.
> In the pole frame things look considerably different. The barn is measured to be
> less than 20 meters long, which means that when both ends are observed
> SIMULTANEOUSLY IN THE POLE FRAME the distance between observations is less than
> 20 meters. As the barn approaches the pole, the US door is open and the DS door
> is closed. The barn surrounds the front of the pole, and just before the front
> end hits the DS door, that door opens. At this instant in the pole frame (i.e.
> observed SIMULTANEOUSLY IN THE POLE FRAME) the US door is still open, and is
> less than 1/2 of the way along the pole. Now the barn passes along the pole with
> both doors open. When the US door has passed the back end of the pole, the US
> door closes. At this instant in the pole frame, the DS door is less than 1/2 of
> the length of the pole from the back end of the pole (i.e. observed
> SIMULTANEOUSLY IN THE POLE FRAME). After the US door closes the barn just sails
> away. In the pole frame the DS door opens before the US door closes.
>
xxein: Yes. Looks differently. Measures differently. Get a clue.
Balance the physic between addition of velocities and a constant c
measured by two-way. Can't you understand that math can describe
anything you tell it to do?
> ASCII art (use fixed-width font). pole is ..., barn is --- for walls and | for
xxein: Only a false conception of the reality of the physic.
>
> So there is no contradiction, and both frame agree the pole will get through the
> barn, even though both doors of the barn were closed for a brief time period
> SIMULTANEOUSLY IN THE BARN FRAME. But both doors are never closed SIMULTANEOUSLY
> IN THE POLE FRAME.
>
xxein: True. There is no contradiction in the act of enclosing an
80m pole in a 40m barn. Now. Did the pole frame fit and not crash
into the doors? And I add the same instantaneous opening of the doors
(say within a femtosecond) of them closing.
> As you can see, the difference in simultaneity between the frames is an
> essential aspect of this. "Length contraction" is NOT sufficient to describe
> this. The relativity of simultaneity resolves the paradox, because the order of
> doors opening and closing are DIFFERENT in the two frames.
>
xxein: You do not even know how to figure out relativity of a
measurement. Show me that gamma^2 is not time dilation x physical
length contraction.
> Yes, "length contraction" IS geometrical projection. Observing the endpoints of
> the pole simultaneously in the barn frame PROJECTS the ends of the pole onto the
> x coordinate of the barn frame (motion is along x). It should be clear that to
> measure the length of a moving object you must mark both ends simultaneously in
> your frame and measure the distance between the marks -- nothing else could be
> called a measurement of the moving object's length in this frame (some aspect of
> its motion would be included in the measurement).
>
xxein: The barn and the pole are both physical objects. Each has a
hanson
xxein: Given.
xxein: Your SR speculation.
> Tom Roberts
hanson
xxein: Given.
xxein: Your SR speculation.
> Tom Roberts
Michael Moroney
>On 27 ago, 10:05, seto...@att.net wrote:
[snip crap]
>I do know that you don't have the slightest idea of what the following
>terms mean:
>-relativity of simultaneity
>-isotropy
>-speed of light
>-frames
>Also, you don't know what "violates" mean.
>So your comments have, of course, no value whatsoever.
Seto routinely redefines common terms to meet his own definitions then
starts arguments because he's arguing from his own misguided definitions
and everyone else is using the normal definition.
Alen
No - you don't see what I am asking. Your description
of how the pole fits in the barn, etc. is not a question
I am asking - I know how that works.
{...}
> The principle of relativity
> just says that the laws of physics are the same in all inertial
> frames, NOT the description of the events, not the shape of the
> trajectories, not even the *sequence* of events.
It may SAY the laws of physics are the same,
but we need to see how this can work in reality.
Postulating they are the same is not the same as
explaining how this works in terms of the two
versions of the pole. I explain as follows:
We have a foreshortened version of the pole,
simultaneous along its length, in the barn frame -
also the original, proper length pole, not simultaneous
along its length, in the barn frame. Is the shortened
version, in the barn frame, a real, physical pole, able
to collide with a barn door, or just a barn frame view of
the pole, without any physical reality in the barn frame?
If it is a physical pole, and the full length pole is also
a physical pole, are there two physical versions of the
pole, one simultaneously in the barn frame, and one
not simultaneously in the barn frame?
How are these two versions of the pole supposed to
relate to one another physically?
Alen
Pentcho Valev
sci.physics.relativity:
Correct, Honest Roberts:
Conditional 1: If Einstein's 1905 constant-speed-of-light postulate is
true, arbitrarily long objects can, IN PRINCIPLE, be trapped inside
arbitrarily short containers and therefore length contraction is NOT
merely a geometrical projection.
Additional unessential assumptions concerning the form and the
properties of object and container allows us to elaborate:
Conditional 2: If Einstein's 1905 constant-speed-of-light postulate is
true, the volume of the long object can, IN PRINCIPLE, be reduced
arbitrarily.
I hope you accept the above conditionals, Honest Roberts. It is up to
any reader to judge the consequent absurd and reject the antecedent,
or to judge the consequent extremely reasonable and sing, with
abandon, "Divine Einstein" and "Yes we all believe in relativity,
relativity, relativity".
Pentcho Valev
pva...@yahoo.com
Tom Roberts
> Conditional 1: If Einstein's 1905 constant-speed-of-light postulate is
> true, arbitrarily long objects can, IN PRINCIPLE, be trapped inside
> arbitrarily short containers and therefore length contraction is NOT
> merely a geometrical projection.
You need to learn logic, and geometry, and relativity. Your conclusion is false.
Geometrical projection can explain fast-moving long objects trapped briefly
inside a short container, just as it explains carrying a long ladder through a
narrow doorway.
> Conditional 2: If Einstein's 1905 constant-speed-of-light postulate is
> true, the volume of the long object can, IN PRINCIPLE, be reduced
> arbitrarily.
When you say "volume of the object", those words implicitly refer TO THE OBJECT,
and not to some other, arbitrarily moving observer. The "length contraction" of
SR does not affect the object itself, it merely affects how OTHER observers
measure the object when they PROJECT it onto their own coordinates. So your
words do not reflect what the theory actually says -- you MUST mention the other
observer doing the measurement of the object's volume. If you would make
ACCURATE and CORRECT statements, the apparent absurdities would disappear.
You need to learn logic. And you need to learn what relativity ACTUALLY SAYS.
And you need to be MUCH more precise in your statements.
Tom Roberts
set...@att.net
> seto...@att.net wrote:
> > the gedanken specified that the doors
> > close simultaneouly briefly while the pole is inside the barn...and
> > they open immediately to allow the pole pass through the barn. This
> > action is absolute and the pole observer cannot claim that the doors
> > didn't close simultaneously.
>
> That may be so in the dream world of your imagination.
It is not in the dream world of my imagination. It is what the word
simultaneous means. When the barn frame observer claims that the pole
can be trapped into the shorter barn briefly then the pole must be
contracted physically (materially) for his claim to be true.
Aetherist
{snip...}
>BARN FRAME US door closes:
>
> --------
> |.... |
> --------
>
>BARN FRAME pole center and barn center coincide:
>
> --------
> | .... |
> --------
I have some questions,
1. Is the pole solid & substantive?
2. Are the doors solid & substantive?
3. If we had a high speed camara set up and it took a pricture would it
show this? (The pole inside the barn with both doors closed?
4. If all of the above is this instant 'an event'
5. Finally, if all of the above are true how can the below also be 'true'
since even with relative simultaniety it is the apparent order of 'events'
not the events that are affected. If indeed at some instant both doors
as physically closed with the pole physically in the barn as evidenced
but 'a measurement' (the photo of the event) what is the physical
reality?
>So there is no contradiction, and both frame agree the pole will get through the
>barn, even though both doors of the barn were closed for a brief time period
>SIMULTANEOUSLY IN THE BARN FRAME. But both doors are never closed SIMULTANEOUSLY
>IN THE POLE FRAME.
>
>As you can see, the difference in simultaneity between the frames is an
>essential aspect of this. "Length contraction" is NOT sufficient to describe
>this. The relativity of simultaneity resolves the paradox, because the order of
>doors opening and closing are DIFFERENT in the two frames.
>
>
>
hanson
>
>
>
> Pentcho Valev wrote:
>> Conditional 1: If Einstein's 1905 constant-speed-of-light postulate is
>> true, arbitrarily long objects can, IN PRINCIPLE, be trapped inside
>> arbitrarily short containers and therefore length contraction is NOT
>> merely a geometrical projection.
>
> Pentcho, You need to learn..... <snip crap>
>
> Pentcho Valev wrote:
>> Conditional 2: If Einstein's 1905 constant-speed-of-light postulate is
>> true, the volume of the long object can, IN PRINCIPLE, be reduced
>> arbitrarily.
>
> Pentcho, You need to learn logic.
>
.... You, Roberts, like all other Einstein Dingleberries,
do always resort to your papal edicts, that folks who
have seen and realized the uselessness & fallacies
of Relativity, should revert and "learn" to become
believers in your relativity cult again . ...
>
It's you and your Rel Cult Pharisees who do "need to
learn", see and realize that:
====== SR is short for STUPID RANT and ======
====== GR is just a GULLIBLE RECITAL ======
Stop proselytizing your silly & useless Rel-crap, which
you only know from hear-say, but with which you never
ever had any experience, personally, during your entire
career & much less in your own life!... Thanks for the
laughs though,Tom. .... ahahahaha... ahahahahanson
Pentcho Valev
sci.physics.relativity:
> Pentcho Valev wrote:
> > Conditional 1: If Einstein's 1905 constant-speed-of-light postulate is
> > true, arbitrarily long objects can, IN PRINCIPLE, be trapped inside
> > arbitrarily short containers and therefore length contraction is NOT
> > merely a geometrical projection.
>
> You need to learn logic, and geometry, and relativity. Your conclusion is false.
> Geometrical projection can explain fast-moving long objects trapped briefly
> inside a short container, just as it explains carrying a long ladder through a
> narrow doorway.
But cannot explain long objects trapped PERMANENTLY inside a short
container, and according to Einsteinians cleverer than you, this
PERMANENT trapping is a valid consequence of Einstein's 1905 constant-
speed-of-light postulate:
http://math.ucr.edu/home/baez/physics/Relativity/SR/barn_pole.html
"If the door withstands this the leading end of the rod will come to
rest in the frame of reference of the stationary observer. There can
be no such thing as a rigid rod in relativity so the trailing end will
not stop immediately and the rod will be compressed beyond the amount
it was Lorentz contracted. If it does not explode under the strain and
it is sufficiently elastic it will come to rest and start to spring
back to its natural shape but since it is too big for the barn the
other end is now going to crash into the back door and the rod will be
trapped IN A COMPRESSED STATE inside the barn."
http://www.parabola.unsw.edu.au/vol35_no1/vol35_no1_2.pdf
Parabola Volume 35, Issue 1 (1999)
LENGTH AND RELATIVITY by John Steele
"Hence in both frames of reference, the pole fits inside the barn (and
will presumably shatter when the doors are closed)."
Therefore, Honest Roberts, according to special relativity, length
contraction is NOT merely a geometrical projection.
Pentcho Valev
pva...@yahoo.com
Tom Roberts
> On Aug 28, 4:14 pm, Tom Roberts <tjroberts...@sbcglobal.net> wrote in
> sci.physics.relativity:
>> Geometrical projection can explain fast-moving long objects trapped briefly
>> inside a short container, just as it explains carrying a long ladder through a
>> narrow doorway.
>
> But cannot explain long objects trapped PERMANENTLY inside a short
> container,
You are supposed to read what I write. That is not within the domain of SR, and
to discuss that one needs more physical theory than just SR -- one needs to
model the material properties of the objects involved. None of your quotes
bother to do that, and neither do you yourself.
Goodbye.
Tom Roberts
Pentcho Valev
PD
> On Fri, 26 Aug 2011 22:39:42 -0500, Tom Roberts<tjrobe...@sbcglobal.net> wrote:
>
> {snip...}
>
>> BARN FRAME US door closes:
>>
>> --------
>> |.... |
>> --------
>>
>> BARN FRAME pole center and barn center coincide:
>>
>> --------
>> | .... |
>> --------
>
> I have some questions,
>
> 1. Is the pole solid& substantive?
Yes.
> 2. Are the doors solid& substantive?
Yes.
> 3. If we had a high speed camara set up and it took a pricture would it
> show this? (The pole inside the barn with both doors closed?
Yes, if it is positioned properly and is at rest with respect to the
barn. Note however you don't need to have a camera. All that you need is
the lack of impact of the pole on the doors.
> 4. If all of the above is this instant 'an event'
NO. That's not what an event is. It's important to learn what this word
means to a physicist. An event is something that happens at a specific
*location* and *time*. By asking about things at different locations at
the same time (in this frame), you are asking about an assemblage of events.
> 5. Finally, if all of the above are true how can the below also be 'true'
> since even with relative simultaniety it is the apparent order of 'events'
> not the events that are affected. If indeed at some instant both doors
> as physically closed with the pole physically in the barn as evidenced
> but 'a measurement' (the photo of the event) what is the physical
> reality?
The physical reality is that there are four events you can look at:
1. Where and when the front barn door is closed.
2. Where and when the rear barn door is closed.
3. Where and when the front of the pole is between the two barn doors.
4. Where and when the rear of the pole is between the two barn doors.
and there is also the confirmable observation that
5. There are no impact marks on either barn door after the whole shebang.
6. There are no impact marks on the pole after the whole shebang.
The physical reality is that in the reference frame in which the barn is
at rest, you can choose a time where the "whens" for all four events
above are the same. The physical reality is that the "whens" for those
four events in the reference frame in which the pole is at rest will all
be different.
There is no underlying reality where there is a definitive order of
events, and the others are just "apparent" orders.
PD
Then perhaps you should ASK what it means. There is an available
explanation, you know. What it means is that the laws of physics
relevant to the system can be written in the same mathematical form,
though the values of the variables in that common form may change.
To give you a simple example, if you drop a penny from the window of a
car, its path will be described completely differently, depending on the
reference frame. In the rest frame of the car, the penny falls
vertically downward in a straight line. In the rest frame of the road,
the penny falls in a parabolic trajectory starting with purely
horizontal motion. The values of the velocities throughout the flight,
but in magnitude and direction are completely different in the two
reference frames. But BOTH descriptions of the trajectory are solutions
of the *identical* laws of physics, which are the ones that apply to
simple projectile motion.
There are no "parallel realities" here. There is no "reality in one
frame and phantasm in the other". The penny doesn't become real in one
frame and imaginary in the other. There are not two versions of the
penny that have to be related to each other. There is ONE penny, ONE
falling trajectory, ONE set of laws, and (at least) two descriptions of
that trajectory depending on the reference frame.
If you have a philosophical problem with this, then you need to go back
to Galilean/Newtonian physics first and resolve it before attempting
special relativity.
Alen
This is a Clayton's explanation (an explanation which
you have when you're not having an explanation)
On the one hand we have a pole, which is short
enough to fit in the barn, as being a spacetime
perspective of the full length pole (i.e. viewed at an
angle). Yet, if the barn door isn't opened, this
'perspective' of the full length pole will physically
crash through the door, just like a physical pole.
This is obviously nothing like an angled view of a
pole in ordinary space, which does not have any
such kind of shortened physical reality.
If we say that there is no physical shortened pole,
and only the angled pole is passing through the barn,
then, in this case, any location along the pole could
possibly strike the door, rather than only the front of
it (just like any part of a long ladder carried through a
door could strike the doorpost). In fact, only the front
of the pole can ever strike the door.
So, either way, we don't have any real explanation as
to what is supposed to be happening.
This kind of thing is really why, a long time ago, I gave
up on the perspective-type explanation for length
contraction (and time dilation). One day I thought
"maybe this whole perspective-type approach is
not the answer at all - perhaps there is some entirely
different mechanism that is producing these effects"
So this became the end of Minkowski spacetime for me!
Alen
PD
No, no, no, Alen.
You are confusing things here.
You have heard the word "rotation" and "geometric effect" and have
therefore surmised that the explanation of the barn-pole problem is a
*rotation through space*, JUST LIKE turning a ladder. This is why you're
wondering why turning the pole just doesn't make the pole go sideways in
the door.
A boost (the transformation from one inertial reference frame to
another) is NOT a rotation through space. It is ANALOGOUS TO a rotation
through space.
"But what does that even MEAN?" I can hear you holler. "I can
*visualize* a rotation through space. I can take two tips of an object
and turn them around about an axis. I can *see* that in my mind. So what
should I *see* in my mind if you're talking about this thing that is
LIKE a rotation."
Here is where you have to step back and look at it with a *different*
set of eyes. The analog is *mathematical*.
In a spatial rotation, I would ask you *visualize* it by using these
equations:
x' = (x*cos(theta) - y*sin(theta))
y' = (x*sin(theta) + y*cos(theta))
where theta is the thing that represents the difference between the two
reference frames. We can then learn some useful things from this. What
we learn is that the *physical* properties del(x) and del(y) are
definitely measurable but depend on the reference frames. That is,
del(x) won't be the same as del(x') and del(y) won't be the same as
del(y'), and this does not mean that anything happened to the object
spanning del(x) a del(y). It is *purely* an artifact of choice of
reference frame.
Now for boosts between inertial reference frames, there is an
*analogous* thing going on -- not identical -- and some *analogous*
things can be gleaned. Visualize the boost as this:
x' = (x*cosh(phi) - t*sinh(phi))
t' = (-x*sinh(phi) + t*cosh(phi))
Compare this with above so that you can see that it is LIKE a rotation.
But it is not a spatial rotation because a) you are using hyperbolic
trig functions, not trig functions, b) you are mixing space and time
coordinates, not two different space coordinates, c) there is a sign
difference. But still many of the same conclusions apply as before about
del(x) and del(t).
phi by the way isn't an angle, but it does represent the difference
between the two frames. It is phi = ln[gamma*(1+beta)].
"This still doesn't help me," you complain, "because I want to visualize
this kind of 'rotation' of the pole in the same way I can visualize a
spatial rotation of a pole as swinging the ends around an axis."
Sorry, can't help you there. As I said, you have to use a *different
kind* of visualization, a different set of eyes, one that can look at
the equations and extract meaning from those equations. This is what Tom
Roberts is doing mentally when he describes this as being a geometric
effect, *something like* turning a ladder in a doorway. It is NOT a
spatial rotation, but mathematically it has a lot of properties that are
analogous to a spatial rotation.
Alen
Applying this to a real, physical pole just
makes no sense to me. I much prefer my
alternative explanation, as something I can
believe in as physically possible.
Alen
PD
>>
>> "This still doesn't help me," you complain, "because I want to visualize
>> this kind of 'rotation' of the pole in the same way I can visualize a
>> spatial rotation of a pole as swinging the ends around an axis."
>> Sorry, can't help you there. As I said, you have to use a *different
>> kind* of visualization, a different set of eyes, one that can look at
>> the equations and extract meaning from those equations. This is what Tom
>> Roberts is doing mentally when he describes this as being a geometric
>> effect, *something like* turning a ladder in a doorway. It is NOT a
>> spatial rotation, but mathematically it has a lot of properties that are
>> analogous to a spatial rotation.
>
> Applying this to a real, physical pole just
> makes no sense to me. I much prefer my
> alternative explanation, as something I can
> believe in as physically possible.
What is physically possible is determined SOLELY in science by whether
the quantitative predictions of a model agree with what is measured.
There is NO prior requirement -- and I cannot stress this enough: NO
prior requirement -- that the model make intuitive sense or appeal to
some "believably possible" aesthetic. That sensibility comes AFTER the
acknowledgment of the success of the model.
Tom Roberts
> But cannot explain long objects trapped PERMANENTLY inside a short
NOTHING can "explain" that, because it will not and can not happen. As I pointed
out before, the energy densities required are trillions of times larger than
anything remotely feasible.
As I said several times, this is IRRELEVANT to the issues of SR brought up by
the pole and barn paradox. The fact that you obsess over the irrelevancies
indicates how little you understand about SR.
Tom Roberts
PD
What's going on here is fairly transparent. Pentcho has relativistic
contraction confused with mechanical compression.
When he sees that *in principle* a very fast moving object can be given
as small a volume as one would like, and hence as high a density as one
would like, he splutters that this is impossible because mechanical
compression has a limit before damage occurs.
Then in the barn-pole puzzle he sees that length contraction allows you
to *briefly* close both barn doors at the same time, and he is imagining
that if you can mechanically compress something that way, then surely it
would fit inside the barn *permanently*, not just briefly.
He has the two things hopelessly confused.
Pentcho Valev
sci.physics.relativity:
Here we go again. Honest Roberts, yesterday I called your attention to
the fact that "long objects trapped PERMANENTLY inside a short
container" is an example taught by Einsteiniana's priests:
http://math.ucr.edu/home/baez/physics/Relativity/SR/barn_pole.html
"If the door withstands this the leading end of the rod will come to
rest in the frame of reference of the stationary observer. There can
be no such thing as a rigid rod in relativity so the trailing end will
not stop immediately and the rod will be compressed beyond the amount
it was Lorentz contracted. If it does not explode under the strain and
it is sufficiently elastic it will come to rest and start to spring
back to its natural shape but since it is too big for the barn the
other end is now going to crash into the back door and the rod will be
trapped IN A COMPRESSED STATE inside the barn."
http://www.parabola.unsw.edu.au/vol35_no1/vol35_no1_2.pdf
Parabola Volume 35, Issue 1 (1999)
LENGTH AND RELATIVITY by John Steele
"Hence in both frames of reference, the pole fits inside the barn (and
will presumably shatter when the doors are closed)."
Your brothers Einsteinians also teach that, if Einstein's 1905
constant-speed-of-light postulate is true, a bug can be both dead
(according to one observer) and alive (according to the other):
http://hyperphysics.phy-astr.gsu.edu/Hbase/Relativ/bugrivet.html
"The bug-rivet paradox is a variation on the twin paradox and is
similar to the pole-barn paradox.....The end of the rivet hits the
bottom of the hole before the head of the rivet hits the wall. So it
looks like the bug is squashed.....All this is nonsense from the bug's
point of view. The rivet head hits the wall when the rivet end is just
0.35 cm down in the hole! The rivet doesn't get close to the
bug....The paradox is not resolved."
As far as I remember, you hate this example but, again, don't blame me
- just send a protesting letter to Georgia State University.
Pentcho Valev
pva...@yahoo.com
Tom Roberts
> xxein: Tom, Tom, Tom. You should know by now that the 'physic', the
> measure of it and the illusion of it are not the same thing. The
> 'physic' is not the 'physics'. I remember you preaching that very
> point.
I have no idea what you are trying to say, and doubt very much that you actually
do, either (you may think you do, but that is something else...).
While using the apparent singular of "physics" is cute, it is also devoid of
meaning. I have never "preached" anything related to that, though I do often
point out that the map is not the territory.
> [... much nonsense displaying total ignorance of SR, ignored]
> Show me that gamma^2 is not time dilation x physical
> length contraction.
There is no "physical length contraction" in SR, there is only "length
contraction" which is a geometrical projection -- nothing "physical" happens to
the object itself. Attempting to multiply "time dilation" and "length
contraction" is meaningless.
> [... further nonsense and unsubstantiated claims]
Tom Roberts
Aetherist
>On 8/28/2011 10:39 AM, Aetherist wrote:
>> On Fri, 26 Aug 2011 22:39:42 -0500, Tom Roberts<tjrobe...@sbcglobal.net> wrote:
>>
>> {snip...}
>>
>>> BARN FRAME US door closes:
>>>
>>> --------
>>> |.... |
>>> --------
>>>
>>> BARN FRAME pole center and barn center coincide:
>>>
>>> --------
>>> | .... |
>>> --------
>>
>> I have some questions,
>>
>> 1. Is the pole solid& substantive?
>
>Yes.
Good,...
>> 2. Are the doors solid& substantive?
>
>Yes.
Good...
>> 3. If we had a high speed camara set up and it took a pricture would it
>> show this? (The pole inside the barn with both doors closed?
>
>Yes, if it is positioned properly and is at rest with respect to the
>barn. Note however you don't need to have a camera. All that you need is
>the lack of impact of the pole on the doors.
Good that means that for an 'instant' both doors are closed WITH the
pole in the barn, right? THe pole is physically substantive, the
doors are also, so, if at that instant both are closed AND the pole
IS there, the pole fits into the barn.
>> 4. If all of the above is this instant 'an event'
>
>NO. That's not what an event is. It's important to learn what this word
>means to a physicist. An event is something that happens at a specific
>*location* and *time*. By asking about things at different locations at
>the same time (in this frame), you are asking about an assemblage of events.
That IS a specific location and time, how could it not be? If not,
why not?
>> 5. Finally, if all of the above are true how can the below also be 'true'
>> since even with relative simultaniety it is the apparent order of 'events'
>> not the events that are affected. If indeed at some instant both doors
>> as physically closed with the pole physically in the barn as evidenced
>> but 'a measurement' (the photo of the event) what is the physical
>> reality?
>
>The physical reality is that there are four events you can look at:
>1. Where and when the front barn door is closed.
>2. Where and when the rear barn door is closed.
>3. Where and when the front of the pole is between the two barn doors.
>4. Where and when the rear of the pole is between the two barn doors.
>and there is also the confirmable observation that
>5. There are no impact marks on either barn door after the whole shebang.
>6. There are no impact marks on the pole after the whole shebang.
>The physical reality is that in the reference frame in which the barn is
>at rest, you can choose a time where the "whens" for all four events
How do 'you choose'? the trjectory either will or will not pass thru
the doors, the doors don't even need to be cycled... We just need the
super-duper wammie-dyne camara to take a photo showing the pole 'in the
barn;, that IS assuming the camara is properly situated to be tangential
AND mid-point between the barn doors. If even one photo shows an image
of the pole between the doors the pole fit in the barn. That seems to me
to meet the criteria of location and time for an 'event'.
>above are the same. The physical reality is that the "whens" for those
>four events in the reference frame in which the pole is at rest will all
>be different.
No, the question seems to be is there a single time where, in the barn's
FOR the front & end of the pole coordinates are BOTH beteen the barn doors.
This seems simple enough.
PD
> On Mon, 29 Aug 2011 09:02:03 -0500, PD <thedraperfam...@gmail.com> wrote:
> >On 8/28/2011 10:39 AM, Aetherist wrote:
In the frame in which the barn is at rest. I told you that below.
>
> >> 4. If all of the above is this instant 'an event'
>
> >NO. That's not what an event is. It's important to learn what this word
> >means to a physicist. An event is something that happens at a specific
> >*location* and *time*. By asking about things at different locations at
> >the same time (in this frame), you are asking about an assemblage of events.
>
> That IS a specific location and time, how could it not be? If not,
> why not?
I told you already. You are looking at different locations: both ends
of the pole, both ends of the barn. Those are therefore *different*
events. An event is something that takes place at a specific location
(not locations or a range of location) and at a specific time (not
times or a range of time).
>
>
>
>
>
>
>
>
>
> >> 5. Finally, if all of the above are true how can the below also be 'true'
> >> since even with relative simultaniety it is the apparent order of 'events'
> >> not the events that are affected. If indeed at some instant both doors
> >> as physically closed with the pole physically in the barn as evidenced
> >> but 'a measurement' (the photo of the event) what is the physical
> >> reality?
>
> >The physical reality is that there are four events you can look at:
> >1. Where and when the front barn door is closed.
> >2. Where and when the rear barn door is closed.
> >3. Where and when the front of the pole is between the two barn doors.
> >4. Where and when the rear of the pole is between the two barn doors.
> >and there is also the confirmable observation that
> >5. There are no impact marks on either barn door after the whole shebang.
> >6. There are no impact marks on the pole after the whole shebang.
> >The physical reality is that in the reference frame in which the barn is
> >at rest, you can choose a time where the "whens" for all four events
>
> How do 'you choose'?
There's a narrow range of such times where conditions (1)-(4) apply,
in this frame.
In the frame in which the pole is at rest, there IS no such range of
times where all four conditions apply.
> the trjectory either will or will not pass thru
> the doors, the doors don't even need to be cycled... We just need the
> super-duper wammie-dyne camara to take a photo showing the pole 'in the
> barn;, that IS assuming the camara is properly situated to be tangential
> AND mid-point between the barn doors. If even one photo shows an image
> of the pole between the doors the pole fit in the barn. That seems to me
> to meet the criteria of location and time for an 'event'.
No, it does NOT. A camera does not take a picture of an event. It
takes a picture of a whole slew of events, where those events have
different locations and common times. It helps to know what the lingo
means.
>
> >above are the same. The physical reality is that the "whens" for those
> >four events in the reference frame in which the pole is at rest will all
> >be different.
>
> No, the question seems to be is there a single time where, in the barn's
> FOR the front & end of the pole coordinates are BOTH beteen the barn doors.
> This seems simple enough.
Yes it is, and there is, in the barn's reference frame. Not so in the
rest frame of the pole.
bert
Think wormhole it goes well with SR + GR Get the picture TreBert
Tom Roberts
> [I happened to see this skimming by, and ignore the rest]
> If we say that there is no physical shortened pole,
> and only the angled pole is passing through the barn,
> then, in this case, any location along the pole could
> possibly strike the door, rather than only the front of
> it (just like any part of a long ladder carried through a
> door could strike the doorpost). In fact, only the front
> of the pole can ever strike the door.
You are VERY confused. An analogy is merely that, and not an explicitly accurate
description.
The "angle" of the moving pole moving along the x axis is in the x-t plane. In
the loose analogy to ladder and doorway, it would be different TIMES of the pole
that could potentially strike the doorway. But the gedanken was explicitly
constructed so that does not happen.
Tom Roberts
Alen
I could never accept such a rule as valid.
To me, it is the abdication of the understanding
from any attempt or hope of understanding anything.
The quantitative results might be correct, but the
model cannot be. The correct model MUST be
something understandable - that is my conviction,
and my rule for myself. So I shall have to remain at
loggerheads with this kind of modelling of reality.
Alen
Alen
I know it is merely an analogy. The problem for
me is that we have nothing clearer than an analogy.
We have no explicit description that really works.
This, to me, is a sign the model is not the correct
one to explain the reality that underlies SR, and
that is why I abandoned Minkowski spacetime and
looked (successfully) for an alternative model that
can give an understandable picture that describes
the working of the underlying reality. This is the
only kind of modelling I can ever be satisfied with!
Alen
set...@att.net
I agree with you....different observer have different perspective so
does that mean that the pole will have an infinite number of angles
relative to the barn doors to satisfy the math of SR? I don't think
so.
Perspective length contraction in SR is to satisfy the SR postulate of
constancy of the speed of light. I have a new theory of relativity
called IRT. IRT says that the physical length of a meter stick remains
the same in all frames. The light-path length of an observed meter
stick is predicted to be 1/gamma or gamma meters long....the light-
path length of the observer's meter stick is assumed to be its
physical length for these predictions. IRT will resolve all the
paradoxes of SR and at the same time it is compatible with the SR or
LET math. A paper on IRT is available in the following link:
http://www.modelmechanics.org/2011irt.dtg.pdf
Ken Seto
>
> Alen- Hide quoted text -
>
> - Show quoted text -
set...@att.net
Then why do you SRians tried to fit the a long pole into a shorter
barn with both doors close simultaneously?????
PD
As you wish. This is where you separate yourself from science.
As a word of encouragement, with practice you learn how to *adjust* your
conceptual understanding by learning how to read physical meaning in
mathematics. For physics, mathematics really is a language which
augments English prose, having its own semantics, connotations, and
idioms. There are some things in mathematically phrased physical
descriptions that simply do not translate well into English words.
PD
>
> I agree with you....different observer have different perspective so
> does that mean that the pole will have an infinite number of angles
> relative to the barn doors to satisfy the math of SR? I don't think
> so.
And again, I point out that there are no ANGLES in boosts. There is
something that is LIKE an angle but is not an angle. I know this
completely frustrates you.
Alen
What do you mean by 'light-path-length'
compared to 'physical length'?
Alen
PD
>
> What do you mean by 'light-path-length'
> compared to 'physical length'?
>
He has no idea. Furthermore, since he doesn't know the definitions of
the words that he might use to try to convey it to you (and it's
possible you don't either), then any attempt to communicate it to you
would be an exchange of lightly-tossed word salad.
Remember that word salad is a string of words in correct English syntax,
where there is not a common understanding of what those words mean. This
gives the dissonant experience of looking *like* it should make sense,
but it makes no sense whatsoever.
It would be like me explaining Newton's second law to you by saying that
the motivating impulse is in consonant rise with the combination of
inertial momentum and compounded displacement-over-displacement.
set...@att.net
Light-path length is the length that light need to travel to cover the
physical length of a meter stick. An IRT observer assumes that the
light-path length of his meter stick is its physical length.....with
that assumption the IRT observer predicts that the light path length
of a meter stick moving wrt him to be 1/gamma or gamma meters.
set...@att.net
> On 8/30/2011 10:16 AM, Alen wrote:
>
>
>
> > What do you mean by 'light-path-length'
> > compared to 'physical length'?
>
> He has no idea. Furthermore, since he doesn't know the definitions of
> the words that he might use to try to convey it to you (and it's
> possible you don't either), then any attempt to communicate it to you
> would be an exchange of lightly-tossed word salad.
You are an indoctrinated idiot....light-path length in IRT is decribed
as follows:
Light-path length is the length that light need to travel to cover the
physical length of a meter stick. An IRT observer assumes that the
light-path length of his meter stick is its physical length.....with
that assumption the IRT observer predicts that the light path length
of a meter stick moving wrt him to be 1/gamma or gamma meters. Gee you
are so stupid....I feel sorry for your students.
Ken Seto
set...@att.net
> On 8/30/2011 7:46 AM, seto...@att.net wrote:
>
>
>
> > I agree with you....different observer have different perspective so
> > does that mean that the pole will have an infinite number of angles
> > relative to the barn doors to satisfy the math of SR? I don't think
> > so.
>
> And again, I point out that there are no ANGLES in boosts. There is
> something that is LIKE an angle but is not an angle. I know this
> completely frustrates you.
It doesn't frustrate me with stuff that you made up.
>
>
>
> > Perspective length contraction in SR is to satisfy the SR postulate of
> > constancy of the speed of light. I have a new theory of relativity
> > called IRT. IRT says that the physical length of a meter stick remains
> > the same in all frames. The light-path length of an observed meter
> > stick is predicted to be 1/gamma or gamma meters long....the light-
> > path length of the observer's meter stick is assumed to be its
> > physical length for these predictions. IRT will resolve all the
> > paradoxes of SR and at the same time it is compatible with the SR or
> > LET math. A paper on IRT is available in the following link:
> >http://www.modelmechanics.org/2011irt.dtg.pdf
>
> > Ken Seto- Hide quoted text -
PD
> On Aug 30, 12:22 pm, PD<thedraperfam...@gmail.com> wrote:
>> On 8/30/2011 10:16 AM, Alen wrote:
>>
>>
>>
>>> What do you mean by 'light-path-length'
>>> compared to 'physical length'?
>>
>> He has no idea. Furthermore, since he doesn't know the definitions of
>> the words that he might use to try to convey it to you (and it's
>> possible you don't either), then any attempt to communicate it to you
>> would be an exchange of lightly-tossed word salad.
>
> You are an indoctrinated idiot....light-path length in IRT is decribed
> as follows:
> Light-path length is the length that light need to travel to cover the
> physical length of a meter stick. An IRT observer assumes that the
> light-path length of his meter stick is its physical length.....with
> that assumption the IRT observer predicts that the light path length
> of a meter stick moving wrt him to be 1/gamma or gamma meters. Gee you
> are so stupid....I feel sorry for your students.
>
> Ken Seto
>
>
Thank you for making my point.
PD
> On Aug 30, 10:30 am, PD<thedraperfam...@gmail.com> wrote:
>> On 8/30/2011 7:46 AM, seto...@att.net wrote:
>>
>>
>>
>>> I agree with you....different observer have different perspective so
>>> does that mean that the pole will have an infinite number of angles
>>> relative to the barn doors to satisfy the math of SR? I don't think
>>> so.
>>
>> And again, I point out that there are no ANGLES in boosts. There is
>> something that is LIKE an angle but is not an angle. I know this
>> completely frustrates you.
>
> It doesn't frustrate me with stuff that you made up.
I made nothing up, Ken. This stuff is as old as the hills. Older than
you in fact. You're 74, right?
Just because you never learned it doesn't mean that any of it is made up.
set...@att.net
"The bug dies twice: before and after the head of the rivet hits the
wall of the hole."
The pole inside the barn with both doors close simultaneously and the
pole was never inside the barn with both doors close simultaneously.
These are stuff you SRians made up to explain length contraction.
PD
> On Aug 30, 1:32 pm, PD<thedraperfam...@gmail.com> wrote:
>> On 8/30/2011 12:27 PM, seto...@att.net wrote:
>>
>>
>>> It doesn't frustrate me with stuff that you made up.
>>
>> I made nothing up, Ken. This stuff is as old as the hills. Older than
>> you in fact. You're 74, right?
>>
>> Just because you never learned it doesn't mean that any of it is made up.
>
> "There is something that is LIKE an angle but is not an angle."
As I said, just because you never learned it doesn't mean that it's just
made up.
> "The bug dies twice: before and after the head of the rivet hits the
> wall of the hole."
Nobody said that but you. YOU made that up.
> The pole inside the barn with both doors close simultaneously and the
> pole was never inside the barn with both doors close simultaneously.
Again, just because you never learned what a frame-dependent description
is, doesn't mean it's made up.
micro...@hotmail.com
> On Aug 26, 3:39 pm, Tom Roberts <tjroberts...@sbcglobal.net> wrote in
> sci.physics.relativity:
>
> http://groups.google.com/group/sci.physics.relativity/msg/737d548d1bf...
>
>
>
> > If you are thinking of "length contraction" in SR, then you are
> > confused. That does not affect any object, it is merely a
> > geometrical projection between relatively moving frames.
>
> > Tom Roberts
>
> Then explain this, Honest Roberts (the quotations below act like the
> face of Medusa the Gorgon - on seeing them, Roberts gets petrified and
> never replies):
>
> http://math.ucr.edu/home/baez/physics/Relativity/SR/barn_pole.html
> "These are the props. You own a barn, 40m long, with automatic doors
> at either end, that can be opened and closed simultaneously by a
> switch. You also have a pole, 80m long, which of course won't fit in
> the barn. Now someone takes the pole and tries to run (at nearly the
> speed of light) through the barn with the pole horizontal. Special
> Relativity (SR) says that a moving object is contracted in the
> direction of motion: this is called the Lorentz Contraction. So, if
> the pole is set in motion lengthwise, then it will contract in the
> reference frame of a stationary observer.....So, as the pole passes
> through the barn, there is an instant when it is completely within the
> barn. At that instant, you close both doors simultaneously, with your
> switch. Of course, you open them again pretty quickly, but at least
> momentarily you had the contracted pole shut up in your barn. The
> runner emerges from the far door unscathed.....If the doors are kept
> shut the rod will obviously smash into the barn door at one end. If
> the door withstands this the leading end of the rod will come to rest
> in the frame of reference of the stationary observer. There can be no
> such thing as a rigid rod in relativity so the trailing end will not
> stop immediately and the rod will be compressed beyond the amount it
> was Lorentz contracted. If it does not explode under the strain and it
> is sufficiently elastic it will come to rest and start to spring back
> end is now going to crash into the back door and the rod will be
> trapped IN A COMPRESSED STATE inside the barn."
>
> Stéphane Durand: "Pour mieux comprendre le phénomène de ralentissement
> du temps, il est préférable d'aborder un autre phénomène tout aussi
> paradoxal: la contraction des longueurs. Car la vitesse affecte non
> seulement l'écoulement du temps, mais aussi la longueur des objets.
> Ainsi, une fusée en mouvement apparaît plus courte que lorsqu'elle est
> au repos. Là aussi, plus la vitesse est grande, plus la contraction
> est importante. Et, comme pour le temps, les effets ne deviennent
> considérables qu'à des vitesses proches de celle de la lumière. Dans
> la vie de tous les jours, cette contraction est imperceptible.
> Cependant, si une fusée de 100 m passait devant nous à une vitesse
> proche de celle de la lumière, elle pourrait sembler ne mesurer que 50
> m, ou même moins. Bien sûr, la question qui vient tout de suite à
> l'esprit est: «Cette contraction n'est-elle qu'une illusion?» Il
> semble tout à fait incroyable que le simple mouvement puisse comprimer
> un objet aussi rigide qu'une fusée. Et pourtant, la contraction est
> réelle... mais SANS COMPRESSION physique de l'objet! Ainsi, une fusée
> de 100 m passant à toute vitesse dans un tunnel de 60 m pourrait être
> entièrement contenue dans ce tunnel pendant une fraction de seconde,
> durant laquelle il serait possible de fermer des portes aux deux
> bouts! La fusée est donc réellement plus courte. Pourtant, il n'y a
> PAS DE COMPRESSION matérielle ou physique de l'engin."
>
> http://www.parabola.unsw.edu.au/vol35_no1/vol35_no1_2.pdf
> Parabola Volume 35, Issue 1 (1999)
> LENGTH AND RELATIVITY by John Steele
> we can invent some amusing uses of it. Suppose you want to fit a 20m
> pole into a 10m barn. If the pole were moving fast enough, then length
> contraction means it would be short enough. (...) Now comes the
> paradox. According to your friend who is going to slam the barn doors
> shut just as the end of the pole goes in, the pole is 10m long, and
> therefore it fits. However as far as you are concerned, the pole is
> still 20m long but the barn is now only 5m long: length contraction
> must work both ways by the first postulate. How can you fit this 20m
> pole into a 5m barn? This paradox is apparently due to Wolfgang
> Rindler of the University of Texas at Dallas. Of course the key to
> this is relativity of simultaneity. Your friend sees the front end of
> the pole hit the back wall of the barn at the same time as the doors
> are closed, but you (and the pole) do not see things this way. You are
> standing still and see a 5m long barn coming towards you at some
> shockingly high speed. When the back of the barn hits the front of the
> pole (and takes the front of the pole with it), the back end of the
> pole must still be at rest. It cannot 'know' about the crash at the
> front, because the shock wave travelling along the pole telling it
> about the crash travels at some finite speed. The front of the barn
> has only 15m to go to get to the back of the pole, but the shock wave
> has to travel the whole length of the pole, namely 20m. The speed of
> the barn is such that even if this shock wave travelled at the speed
> of light, it would not get to the back of the pole before the front of
> the barn did. Hence in both frames of reference, the pole fits inside
> the barn (and will presumably shatter when the doors are closed)."
>
> pva...@yahoo.com
From what side does the train begin to shrink?
Tom Roberts
> On Aug 30, 1:47 pm, Tom Roberts <tjroberts...@sbcglobal.net> wrote:
>> The "angle" of the moving pole moving along the x axis is in the x-t plane. In
>> the loose analogy to ladder and doorway, it would be different TIMES of the pole
>> that could potentially strike the doorway. But the gedanken was explicitly
>> constructed so that does not happen.
>
> me is that we have nothing clearer than an analogy.
> We have no explicit description that really works.
_WE_ have such descriptions, it is merely YOU who does not. But you do need to
STUDY in order to understand them; posting nonsense to the net will not do it.
(By "we" I mean the physics community.)
> This, to me, is a sign the model is not the correct
> one to explain the reality that underlies SR,
You are hopelessly naive to think that the "underlying reality" at scales VASTLY
different from your personal experience can be described in terms of that
experience, or in analogies to that experience. After all, you cannot crawl on
the ceiling but flies can, and that is a mere factor of ~400 in scale; the
regime where SR is different from Newtonian mechanics is MUCH further from your
everyday experience.
> This is the
> only kind of modelling I can ever be satisfied with!
Then physics is forever beyond you. Attempting to understand quantum phenomena
will be hopeless, as will cosmology. YOUR problem,not mine, and not physics'.
Tom Roberts
The Ghost In The Machine
BOOWAHAHAHAHA! SIGH~PHYSICS )+;
set...@att.net
> On 8/30/2011 2:32 PM, seto...@att.net wrote:
>
> > On Aug 30, 1:32 pm, PD<thedraperfam...@gmail.com> wrote:
> >> On 8/30/2011 12:27 PM, seto...@att.net wrote:
>
> >>> It doesn't frustrate me with stuff that you made up.
>
> >> I made nothing up, Ken. This stuff is as old as the hills. Older than
> >> you in fact. You're 74, right?
>
> >> Just because you never learned it doesn't mean that any of it is made up.
>
> > "There is something that is LIKE an angle but is not an angle."
>
> As I said, just because you never learned it doesn't mean that it's just
> made up.
It is something you guys made up because such assertion is not
observable or testable experimentally.
>
> > "The bug dies twice: before and after the head of the rivet hits the
> > wall of the hole."
>
> Nobody said that but you. YOU made that up.
Fron the hole point of view the bug dies after the head of the rivet
hits the wall of the hole. From the rivet point of view the bug dies
before the head of the rivet hits the wall of the hole. This clearly
means that the bug dies twice.
>
> > The pole inside the barn with both doors close simultaneously and the
> > pole was never inside the barn with both doors close simultaneously.
>
> Again, just because you never learned what a frame-dependent description
> is, doesn't mean it's made up.
In this universe....the posibilities for this gedanken are as follows:
1. The pole can be completely inside the barn with both door close
simultaneously,,,,that means that there is real physical (matrial)
contraction.
2. The pole cannot fit into the barn with both doors close
simultaneously....that means that there is no physical (material)
length contraction.
You can choose one or two but not both as you wanted.
Ken Seto
>
>
>
> > These are stuff you SRians made up to explain length contraction.- Hide quoted text -
set...@att.net
So you agree with the point that "you are so stupid"??????
PD
> On Aug 30, 4:01 pm, PD<thedraperfam...@gmail.com> wrote:
>> On 8/30/2011 2:32 PM, seto...@att.net wrote:
>>
>>> On Aug 30, 1:32 pm, PD<thedraperfam...@gmail.com> wrote:
>>>> On 8/30/2011 12:27 PM, seto...@att.net wrote:
>>
>>>>> It doesn't frustrate me with stuff that you made up.
>>
>>>> I made nothing up, Ken. This stuff is as old as the hills. Older than
>>>> you in fact. You're 74, right?
>>
>>>> Just because you never learned it doesn't mean that any of it is made up.
>>
>>> "There is something that is LIKE an angle but is not an angle."
>>
>> As I said, just because you never learned it doesn't mean that it's just
>> made up.
>
> It is something you guys made up because such assertion is not
> observable or testable experimentally.
It most certainly is. Stop making things up, Ken. You are such a
shameless LIAR. You're as bad as Henry, who just lies and lies and lies
and feels no shame about it at all. How low have you stooped, Ken?
>
>>
>>> "The bug dies twice: before and after the head of the rivet hits the
>>> wall of the hole."
>>
>> Nobody said that but you. YOU made that up.
>
> Fron the hole point of view the bug dies after the head of the rivet
> hits the wall of the hole. From the rivet point of view the bug dies
> before the head of the rivet hits the wall of the hole. This clearly
> means that the bug dies twice.
No it does not mean that, Ken. Remember the blue box and the red box.
The blue box being to the left of the red box in one reference frame,
and to the right of the red box in another reference frame, with right
and left meaning the SAME THING in both frames -- that doesn't mean the
blue box is sitting in two different places.
You're an idiot, Ken. Not worth the time to try to explain simple things
to you, especially since you seem to think that 18.3 s and 22.7 s are
the same amount.
set...@att.net
> On 8/31/2011 8:54 AM, seto...@att.net wrote:
>
>
>
>
>
> > On Aug 30, 4:01 pm, PD<thedraperfam...@gmail.com> wrote:
> >> On 8/30/2011 2:32 PM, seto...@att.net wrote:
>
> >>> On Aug 30, 1:32 pm, PD<thedraperfam...@gmail.com> wrote:
> >>>> On 8/30/2011 12:27 PM, seto...@att.net wrote:
>
> >>>>> It doesn't frustrate me with stuff that you made up.
>
> >>>> I made nothing up, Ken. This stuff is as old as the hills. Older than
> >>>> you in fact. You're 74, right?
>
> >>>> Just because you never learned it doesn't mean that any of it is made up.
>
> >>> "There is something that is LIKE an angle but is not an angle."
>
> >> As I said, just because you never learned it doesn't mean that it's just
> >> made up.
>
> > It is something you guys made up because such assertion is not
> > observable or testable experimentally.
>
> It most certainly is. Stop making things up, Ken. You are such a
> shameless LIAR. You're as bad as Henry, who just lies and lies and lies
> and feels no shame about it at all. How low have you stooped, Ken?
ROTFLOL..so you think that a moving meter stick will orient at
different angles to give you the correct projection of its projected
length onto your x-axis.... How do you test this experimentally.
Remember that length contraction never been measured directly.
>
>
>
> >>> "The bug dies twice: before and after the head of the rivet hits the
> >>> wall of the hole."
>
> >> Nobody said that but you. YOU made that up.
>
> > Fron the hole point of view the bug dies after the head of the rivet
> > hits the wall of the hole. From the rivet point of view the bug dies
> > before the head of the rivet hits the wall of the hole. This clearly
> > means that the bug dies twice.
>
> No it does not mean that, Ken.
Yes it means that....from the rivet point of view the bug dies before
the head of the rivet hits the hole of the wall an dfrom the hole
point of view the bug dies after the head of the rivet hits the wall
of the hole. These are two instants of time.
>Remember the blue box and the red box.
> The blue box being to the left of the red box in one reference frame,
> and to the right of the red box in another reference frame, with right
> and left meaning the SAME THING in both frames -- that doesn't mean the
> blue box is sitting in two different places.
>
> You're an idiot, Ken. Not worth the time to try to explain simple things
> to you, especially since you seem to think that 18.3 s and 22.7 s are
> the same amount.
No you are the idiot.....I feel sorry for your students.
>
>
>
>
>
> >>> The pole inside the barn with both doors close simultaneously and the
> >>> pole was never inside the barn with both doors close simultaneously.
>
> >> Again, just because you never learned what a frame-dependent description
> >> is, doesn't mean it's made up.
>
> > In this universe....the posibilities for this gedanken are as follows:
> > 1. The pole can be completely inside the barn with both door close
> > simultaneously,,,,that means that there is real physical (matrial)
> > contraction.
> > 2. The pole cannot fit into the barn with both doors close
> > simultaneously....that means that there is no physical (material)
> > length contraction.
>
> > You can choose one or two but not both as you wanted.
>
> > Ken Seto
>
> >>> These are stuff you SRians made up to explain length contraction.- Hide quoted text -
>
> >> - Show quoted text -- Hide quoted text -
>
> - Show quoted text -- Hide quoted text -
micro...@hotmail.com
PD
> On Aug 31, 12:22 pm, PD <thedraperfam...@gmail.com> wrote:
>
>
>
>
>
>
>
>
>
> > On 8/31/2011 8:54 AM, seto...@att.net wrote:
>
> > > On Aug 30, 4:01 pm, PD<thedraperfam...@gmail.com> wrote:
> > >> On 8/30/2011 2:32 PM, seto...@att.net wrote:
>
> > >>> On Aug 30, 1:32 pm, PD<thedraperfam...@gmail.com> wrote:
> > >>>> On 8/30/2011 12:27 PM, seto...@att.net wrote:
>
> > >>>>> It doesn't frustrate me with stuff that you made up.
>
> > >>>> I made nothing up, Ken. This stuff is as old as the hills. Older than
> > >>>> you in fact. You're 74, right?
>
> > >>>> Just because you never learned it doesn't mean that any of it is made up.
>
> > >>> "There is something that is LIKE an angle but is not an angle."
>
> > >> As I said, just because you never learned it doesn't mean that it's just
> > >> made up.
>
> > > It is something you guys made up because such assertion is not
> > > observable or testable experimentally.
>
> > It most certainly is. Stop making things up, Ken. You are such a
> > shameless LIAR. You're as bad as Henry, who just lies and lies and lies
> > and feels no shame about it at all. How low have you stooped, Ken?
>
> ROTFLOL..so you think that a moving meter stick will orient at
> different angles to give you the correct projection of its projected
> length onto your x-axis.
No, Ken, I don't think that, and I explicitly told you it is NOT a
reorientation of spatial angle that is in play here.
I tell you one thing explicitly and you read it as the complete
opposite. It's no wonder you're confused. You can't read.
>... How do you test this experimentally.
> Remember that length contraction never been measured directly.
>
>
>
> > >>> "The bug dies twice: before and after the head of the rivet hits the
> > >>> wall of the hole."
>
> > >> Nobody said that but you. YOU made that up.
>
> > > Fron the hole point of view the bug dies after the head of the rivet
> > > hits the wall of the hole. From the rivet point of view the bug dies
> > > before the head of the rivet hits the wall of the hole. This clearly
> > > means that the bug dies twice.
>
> > No it does not mean that, Ken.
>
> Yes it means that....from the rivet point of view the bug dies before
> the head of the rivet hits the hole of the wall an dfrom the hole
> point of view the bug dies after the head of the rivet hits the wall
> of the hole. These are two instants of time.
No they are not, Ken, any more than the blue box is in two different
places. It's OBVIOUS, Ken. It's a real pity you can't see something so
simple. I've not had much trouble getting students to see this, but
you've been hopeless.
micro...@hotmail.com
If measurements are supposed to change where is the documented
evidence?
You will probably make something up you gutless wonders!
set...@att.net
Yes they are....the hole observer says that the bug dies after the
head of the rivet hits the wall of the hole and from the rivet point
of view the bug dies before the head of the rivet hits the wall of the
hole....these are two different instants of time.
With you exampleyou are merely change your definition for left and
right. for the blue box. It is not the same as the rivet and the bug
paradox.
PD
Nope. There is no redefinition at all. Right is right and left and
left, and the blue box is not in two places at once.
This is so bonehead simple, and you're the only one that can't make
sense of it. What does that tell you?
set...@att.net
Sure there is redefinition....you took the mirror image of your right
to be you left. Gee you are so stupid.
Ken Seto
PD
> On Sep 5, 12:14 pm, PD<thedraperfam...@gmail.com> wrote:
>>
>>>> No they are not, Ken, any more than the blue box is in two different
>>>> places. It's OBVIOUS, Ken. It's a real pity you can't see something so
>>>> simple. I've not had much trouble getting students to see this, but
>>>> you've been hopeless.
>>
>>> Yes they are....the hole observer says that the bug dies after the
>>> head of the rivet hits the wall of the hole and from the rivet point
>>> of view the bug dies before the head of the rivet hits the wall of the
>>> hole....these are two different instants of time.
>>> With you exampleyou are merely change your definition for left and
>>> right. for the blue box.
>>
>> Nope. There is no redefinition at all. Right is right and left and
>> left, and the blue box is not in two places at once.
>
> Sure there is redefinition....you took the mirror image of your right
> to be you left. Gee you are so stupid.
>
> Ken Seto
I'm not looking at any mirror image. There are TWO observers here, TWO
reference frames, not one.
There is a pair of boxes on the floor:
|R|
|B|
Is the red box to the right of the blue box or to the left of the blue
box, Ken?
|R|
O1-> <-O2
|B|
O1 is facing in the direction of the arrow ->. He knows where his right
and left hands are. He wears his wedding ring on his left hand.
O2 is facing in the direction of the arrow <-. He knows where his right
and left hands are. He wears his wedding ring on his left hand.
Is the red box to the right of the blue box or to the left of the blue
box, Ken?
Surely you can answer a simple question like this....
You can't answer a question about the amount of absolute time between
two events. But SURELY you can answer whether the red box is to the left
or right of the blue box. It's a multiple choice question.
eric gisse
news:edef05ec-139b-484f...@dl2g2000vbb.googlegroups.com:
[...]
I see that Paul (Stowe) is once again putting to rest his theory that he
understands relativity.
micro...@hotmail.com
>
> [...]
>
> I see that Paul (Stowe) is once again putting to rest his theory that he
> understands relativity.
to really move and sense this weight of which is also opposite to
dierction of acceleration.
set...@att.net
>
>
>
>
>
> > On Sep 5, 12:14 pm, PD<thedraperfam...@gmail.com> wrote:
>
> >>>> No they are not, Ken, any more than the blue box is in two different
> >>>> places. It's OBVIOUS, Ken. It's a real pity you can't see something so
> >>>> simple. I've not had much trouble getting students to see this, but
> >>>> you've been hopeless.
>
> >>> Yes they are....the hole observer says that the bug dies after the
> >>> head of the rivet hits the wall of the hole and from the rivet point
> >>> of view the bug dies before the head of the rivet hits the wall of the
> >>> hole....these are two different instants of time.
> >>> With you exampleyou are merely change your definition for left and
> >>> right. for the blue box.
>
> >> Nope. There is no redefinition at all. Right is right and left and
> >> left, and the blue box is not in two places at once.
>
> > Sure there is redefinition....you took the mirror image of your right
> > to be you left. Gee you are so stupid.
>
> > Ken Seto
>
> I'm not looking at any mirror image. There are TWO observers here, TWO
> reference frames, not one.
right. This example is not the same as the pole and the barn paradox
where SR claims that
the longer pole can fit into a shorter barn with both doors close
simultaneously and at the same time claims that the longer pole cannot
fit into the shorter barn with both doors close simutaneously. These
are two absolute events and they are not observer dependent.
> There is a pair of boxes on the floor:
>
> |R|
>
> |B|
>
> Is the red box to the right of the blue box or to the left of the blue
> box, Ken?
>
> |R|
> O1-> <-O2
> |B|
>
> O1 is facing in the direction of the arrow ->. He knows where his right
> and left hands are. He wears his wedding ring on his left hand.
> O2 is facing in the direction of the arrow <-. He knows where his right
> and left hands are. He wears his wedding ring on his left hand.
>
> Is the red box to the right of the blue box or to the left of the blue
> box, Ken?
>
> Surely you can answer a simple question like this....
> You can't answer a question about the amount of absolute time between
> two events. But SURELY you can answer whether the red box is to the left
PD
> On Sep 6, 12:38 pm, PD<thedraperfam...@gmail.com> wrote:
>>
>> I'm not looking at any mirror image. There are TWO observers here, TWO
>> reference frames, not one.
>
> Hey idiot the two observer have different definition for left and
> right.
ring is, and that's on the hand that is closest to the heart. THere is
no difference in the definitions of left and right. Really, can you not
see this? Look at the diagram below.
set...@att.net
>
> > On Sep 6, 12:38 pm, PD<thedraperfam...@gmail.com> wrote:
>
> >> I'm not looking at any mirror image. There are TWO observers here, TWO
> >> reference frames, not one.
>
> > Hey idiot the two observer have different definition for left and
> > right.
>
> No they don't, Ken. For each of them, the left is where their wedding
> ring is, and that's on the hand that is closest to the heart. THere is
> no difference in the definitions of left and right. Really, can you not
> see this? Look at the diagram below.
You are wasting my time with these nonsense.
Ken Seto
>
> >This example is not the same as the pole and the barn paradox
> > where SR claims that
> > the longer pole can fit into a shorter barn with both doors close
> > simultaneously and at the same time claims that the longer pole cannot
> > fit into the shorter barn with both doors close simutaneously. These
> > are two absolute events and they are not observer dependent.
>
> >> There is a pair of boxes on the floor:
>
> >> |R|
>
> >> |B|
>
> >> Is the red box to the right of the blue box or to the left of the blue
> >> box, Ken?
>
> >> |R|
> >> O1-> <-O2
> >> |B|
>
> >> O1 is facing in the direction of the arrow ->. He knows where his right
> >> and left hands are. He wears his wedding ring on his left hand.
> >> O2 is facing in the direction of the arrow<-. He knows where his right
> >> and left hands are. He wears his wedding ring on his left hand.
>
> >> Is the red box to the right of the blue box or to the left of the blue
> >> box, Ken?
>
> >> Surely you can answer a simple question like this....
> >> You can't answer a question about the amount of absolute time between
> >> two events. But SURELY you can answer whether the red box is to the left
> >> or right of the blue box. It's a multiple choice question.- Hide quoted text -
>
donkey
> 1. The pole can be completely inside the barn with both door close
> simultaneously,,,,that means that there is real physical (matrial)
> contraction.
> 2. The pole cannot fit into the barn with both doors close
> simultaneously....that means that there is no physical (material)
> length contraction.
>
> You can choose one or two but not both as you wanted.
>
> Ken Seto
>
longer pole can fit in the barn with both doors closed because the
pole is rotated (but hyperbolic) in another dimension (time). as an
analogy, remove roof of the barn and elevate front end of the pole, so
that pole can fit. up direction represents time so we can't see the
rotation directly, instead we see the shadow of the pole which is
contracted. hope this helps.
donkey
rotation:
http://www.phys.vt.edu/~takeuchi/relativity/notes/Lorentz-STD.gif
also I recently watched this video and it helped me understand it
better:
Lecture 1 | Modern Physics: Special Relativity (Stanford)
http://www.youtube.com/watch?v=BAurgxtOdxY
micro...@hotmail.com
I say we have none. It requires to high of speeds.
I challenge anyone to show frame shrinking measurement
with increasing speed. Where are those measurements?
We cannot watch what a particle sees as it is accelerated
so that would be moot to even bring up.