| Topic: |
Science > Physics |
| User: |
"kenseto" |
| Date: |
10 Apr 2007 09:55:25 AM |
| Object: |
Questions on the meaning of a clock second in SR. |
1. In Alan Lightman's book "Great Ideas in Physics" (Page 126?) he
said (and SR says) that the passage of a clock second in observer A's
frame corresponds to the passage of less than a clock second in the
observed B frame. This means that a clock second is not an interval of
universal time (absolute time).
2. In SR the second postulates says that the speed of light is a
universal constant in all frames (A and B frames). This means that:
Speed of light in A's frame is 299,792,458 m/1 of A's clock second
Speed of light in B's frame is 299,792,458m/1 of B's clock second
This means that 1 of A's second = 1 of B's second.
This means that a clock second is an interval of universal time
(absolute time).
3. In the twin paradox case the traveling clock B's clock seconds is
compared directly with the stay at home clock A's clock seconds to
reach the conclusion that B is younger than A. This direct comparison
means that:
The passage of A's clock second = the passage of B's clock second.
Question:
#1 says that a clock second is not an interval of universal time and #
2 and 3 say that a clock second is an interval of universal time. Is
this why SR is so sucessful because it includes all the possibilities
even though they are contradictory? :-)
Ken Seto
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| User: "Sam Wormley" |
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| Title: Re: Questions on the meaning of a clock second in SR. |
18 Apr 2007 04:33:08 PM |
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kenseto wrote:
On Apr 17, 5:23 pm, Sam Wormley <sworml...@mchsi.com> wrote:
kenseto wrote:
Hey idiot.....there is no frame jumping. we have two inertial frames A
and B. The observer A cannot assertion that his clock is the faster
running clock. On=bserver A must include the possibility that his
clock can run slower than B's clock.
Be either A or B... if you choose A and there is relative velocity
between A and B, A will *measure* B's clock to run slow.
Hey idiot how many times do I have to tell you that is assuming that A
is at rest and B is doing the moving? Besides there is no measurement
of the rate of B's clock by A. SR assumes (predicts) that B's clock is
running slow. This SR assumption is only valid for clocks that were
originated from A's frame. For clocks that were not originated from
A's frame A must include the possibility that B's clock can run at a
faster rate than A's clock.
However if you choose b and there is relative velocity between A
and B, B will *measure* A's clock to run slow.
No idiot. This assumes that B is at rest and A is doing the moving. In
real life all objects in the universe are in a state of motion and the
rate of passage of clock seconds of a clock is dependent on this state
of individual motion.
No, no, Ken, I'm not assuming either A or B are at rest--just that they
have relative motion such that dv/dt = 0 and c > |dr/dt| > 0 .
Let's consider the observer A. A will *measure* B's clock to run slow.
Similarly, B will *measure* A's clock to run slow. And, of course, this
is expected due to the symmetric relationship between A and B. The degree
of time dilation is exactly as is predicted by SR.
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| User: "Sam Wormley" |
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| Title: Re: Questions on the meaning of a clock second in SR. |
16 Apr 2007 08:36:44 AM |
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kenseto wrote:
The asymmetry is illustrated by the GPS clock compared to the ground
clock.
The asymmetry in satellite and ground based clocks is due to the
difference in gravitational potential, Seto.
Relativistic Effects on Satellite Clocks
http://relativity.livingreviews.org/open?pubNo=lrr-2003-1&page=node5.html
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| User: "Sam Wormley" |
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| Title: Re: Questions on the meaning of a clock second in SR. |
13 Apr 2007 10:17:47 AM |
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kenseto wrote:
Since all relative clocks are running at different rates there is no
valid procedure to synchronize two relative clocks. Why? because they
will be out of synch soon after you synchronize them
Owe! Major misunderstanding Seto. I synchronize my GPS receiver clock
with satellite clocks all the time!
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| User: "Sam Wormley" |
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| Title: Re: Questions on the meaning of a clock second in SR. |
10 Apr 2007 10:40:30 AM |
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kenseto wrote:
1. In Alan Lightman's book "Great Ideas in Physics" (Page 126?) he
said (and SR says) that the passage of a clock second in observer A's
frame corresponds to the passage of less than a clock second in the
observed B frame. This means that a clock second is not an interval of
universal time (absolute time).
No!
Seto, listen carefully--Each observer's own clock reads *proper time*
and measuring the clocks in other inertial frames having relative motion
is accurately predicted by special relativity. This is true for any and
all inertial observers.
Nobody is privileged or special!
Proper Time
http://en.wikipedia.org/wiki/Proper_time
http://www.iep.utm.edu/ancillaries/Proper-Time.htm#Proper%20Time
http://scienceworld.wolfram.com/physics/ProperTime.html
http://www.answers.com/topic/proper-time
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| User: "Sam Wormley" |
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| Title: Re: Questions on the meaning of a clock second in SR. |
10 Apr 2007 10:18:24 AM |
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kenseto wrote:
2. In SR the second postulates says that the speed of light is a
universal constant in all frames (A and B frames).
No, the second postulate states, "light is always propagated in
empty space with a definite velocity c which is independent of
the state of motion of the emitting body".
Ref: ON THE ELECTRODYNAMICS OF MOVING BODIES
By A. Einstein
June 30, 1905
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| User: "The Ghost In The Machine" |
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| Title: Re: Questions on the meaning of a clock second in SR. |
10 Apr 2007 11:18:39 AM |
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In sci.physics.relativity, Sam Wormley
<swormley1@mchsi.com>
wrote
on Tue, 10 Apr 2007 15:18:24 GMT
<3VNSh.45348$oV.32276@attbi_s21>:
kenseto wrote:
2. In SR the second postulates says that the speed of light is a
universal constant in all frames (A and B frames).
No, the second postulate states, "light is always propagated in
empty space with a definite velocity c which is independent of
the state of motion of the emitting body".
I'm assuming that's along the lines of "independent of the
state of motion of the emitting body, relative to either
the nonexistent aether or the receiving body".
Galilean relativity can assume lightspeed c relative to
the source, for example.
Ref: ON THE ELECTRODYNAMICS OF MOVING BODIES
By A. Einstein
June 30, 1905
--
#191,
Error 16: Not enough space on file system to delete file(s)
--
Posted via a free Usenet account from http://www.teranews.com
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| User: "Sam Wormley" |
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| Title: Re: Questions on the meaning of a clock second in SR. |
10 Apr 2007 11:47:19 AM |
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The Ghost In The Machine wrote:
I'm assuming that's along the lines of "independent of the
state of motion of the emitting body, relative to either
the nonexistent aether or the receiving body".
From A. Einstein (1905)
http://www.fourmilab.ch/etexts/einstein/specrel/www/
"It is known that Maxwell's electrodynamics--as usually understood at
the present time--when applied to moving bodies, leads to asymmetries
which do not appear to be inherent in the phenomena. Take, for
example, the reciprocal electrodynamic action of a magnet and a
conductor. The observable phenomenon here depends only on the
relative motion of the conductor and the magnet, whereas the
customary view draws a sharp distinction between the two cases in
which either the one or the other of these bodies is in motion. For
if the magnet is in motion and the conductor at rest, there arises in
the neighbourhood of the magnet an electric field with a certain
definite energy, producing a current at the places where parts of the
conductor are situated. But if the magnet is stationary and the
conductor in motion, no electric field arises in the neighbourhood of
the magnet. In the conductor, however, we find an electromotive
force, to which in itself there is no corresponding energy, but which
gives rise--assuming equality of relative motion in the two cases
discussed--to electric currents of the same path and intensity as
those produced by the electric forces in the former case".
"Examples of this sort, together with the unsuccessful attempts to
discover any motion of the earth relatively to the 'light medium,'
suggest that the phenomena of electrodynamics as well as of mechanics
possess no properties corresponding to the idea of absolute rest.
They suggest rather that, as has already been shown to the first
order of small quantities, the same laws of electrodynamics and
optics will be valid for all frames of reference for which the
equations of mechanics hold good. We will raise this conjecture (the
purport of which will hereafter be called the 'Principle of
Relativity') to the status of a postulate, and also introduce another
postulate, which is only apparently irreconcilable with the former,
namely, that light is always propagated in empty space with a
definite velocity c which is independent of the state of motion of
the emitting body. These two postulates suffice for the attainment of
a simple and consistent theory of the electrodynamics of moving
bodies based on Maxwell's theory for stationary bodies. The
introduction of a 'luminiferous ether' will prove to be superfluous
inasmuch as the view here to be developed will not require an
'absolutely stationary space' provided with special properties, nor
assign a velocity-vector to a point of the empty space in which
electromagnetic processes take place".
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| User: "kenseto" |
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| Title: Re: Questions on the meaning of a clock second in SR. |
10 Apr 2007 12:37:05 PM |
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On Apr 10, 11:18 am, Sam Wormley <sworml...@mchsi.com> wrote:
kenseto wrote:
2. In SR the second postulates says that the speed of light is a
universal constant in all frames (A and B frames).
No, the second postulate states, "light is always propagated in
empty space with a definite velocity c which is independent of
the state of motion of the emitting body".
Hey idiot runt are you saying that SR doesn't say that A measure the
speed of light to be:
299,792,458m/1 A clock second?
And
B measures the speed of light to be:
299,792,458m/1 B clock seocnd?
Ken Seto
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| User: "Dirk Van de moortel" |
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| Title: Re: Questions on the meaning of a clock second in SR. |
10 Apr 2007 12:56:18 PM |
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"kenseto" <kenseto@erinet.com> wrote in message news:1176226625.742648.304800@y80g2000hsf.googlegroups.com...
On Apr 10, 11:18 am, Sam Wormley <sworml...@mchsi.com> wrote:
kenseto wrote:
2. In SR the second postulates says that the speed of light is a
universal constant in all frames (A and B frames).
No, the second postulate states, "light is always propagated in
empty space with a definite velocity c which is independent of
the state of motion of the emitting body".
Hey idiot runt are you saying that SR doesn't say that A measure the
speed of light to be:
299,792,458m/1 A clock second?
And
B measures the speed of light to be:
299,792,458m/1 B clock seocnd?
STAMP COLLECTING, I said.
Dirk Vdm
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| User: "Sam Wormley" |
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| Title: Re: Questions on the meaning of a clock second in SR. |
10 Apr 2007 04:55:32 PM |
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kenseto wrote:
Hey idiot runt are you saying that SR doesn't say that A measure the
speed of light to be:
299,792,458m/1 A clock second?
Seto the second postulate states, "light is always propagated in
empty space with a definite velocity c which is independent of
the state of motion of the emitting body". It doesn't say anything
about units.
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