In solutions to various problems (as in the twin's paradox) clocks
appear to get reset when frames are changed. And the change in time
is a function of the distance of events, although in any given
reference frame distances between clocks have nothing to do with clock
rates and resynchronization. I don't understand what physically
causes this to happen, so I setup a simple SR clock problem. I don't
see how to explain the result of this simple problem using Einstein's
notions of time and space.

There are two reference frames that have a relative velocity V=0.866c
along the x-axis. I use that value so that its simple to talk about
the clock rates. Einstein really didn't detail how to synchronize
clocks so I am using a simple method. At time t0 = 0, a light pulse is
emitted from a point on the x-axis. In their respective inertial
frames, the distance from each clock to this point is measured. When
the light pulse arrives at a clock, the clock is set to the time equal
to this distance divided by c. Now all clocks in their respective
frames run at the same rate and are set to the same time.

Here's the problem. Let one frame be called the rest frame and the
other frame be called the moving frame. With the relative velocity
between the two frames at 0.866c, each frame measures that clocks in
the other frame run at half the rate of clocks in their own frame. So
let's say observers in the moving frame want to place a clock in the
rest frame that runs at the same rate as all of their clocks in the
moving frame. Since "time" in the rest frame runs half as fast as in
their own frame, they modify the oscillator frequency of the clock by
doubling it. I'll call this clock Cd (d for double the rate of ideal
clocks). So now the moving observers have a clock in the rest frame
that runs at the same rate as all of their clocks. They place it in
the rest frame at time t=0 at the point where the pulse of light used
to synchronize all clocks originated.

The rest frame observers say that this clock is not setup correctly.
They say clocks in the moving frame run at half the rate of the rest
frame clocks, so they say that instead of doubling the oscillator
frequency, the clock in the rest frame that runs at the same rate as
all the moving frame clocks should have its oscillator refrequency cut
in half instaed of doubled. So the rest frame observers modify a
clock so that it runs at half the rate of an ideal clock. I'll call
this clock Ch (h for half the rate of ideal clocks). This clock is
also placed in the rest frame at time t=0 at the point where the pulse
of light used to synchronize all clocks originated.

Now let two clocks in the moving frame be separated by 866
light-seconds. I'll call these clock A and Clock B. And let clock A
be at the point of origin of the light pulse used to synchronize all
clocks. Let the moving frame be moving in the negative x-direction
relative to the rest frame. Clocks Cd and Ch will take 1000 seconds
(as measured in the moving frame) to reach clock B. Now we can apply
Einstein's equations, and find that the rest frame observers say that
the separation between these two moving frame clocks is 433
light-seconds and the second moving frame clock will be at the same
point in space as clocks Cd and Ch in only 500 seconds. So we find
that when the clocks meet, clock B reads 1000 seconds, clock Cd reads
1000 seconds (it is running at twice the rate as other rest frame
clocks), but clock Ch only reads 250 seconds (it is running at half
the rate as other rest frame clocks). So clock Ch is not synchronized
with all of the moving frame clocks as thought by the rest frame
observers.

I don't see how to resolve this problem. According to the rest frame
observers, clock Ch is running at the same rate as every moving frame
clock. Clock Ch got set to zero at the same time as Clock A in the
moving frame and Clock Cd were set to zero. According to the rest
frame observers, Clock Ch is running at the same rate as Clock A and
Clock B, so therefore this must have been some problem with the
initialization of Clock B. But I could not determine how the rest
frame observers say the initialization of Clock B should have been
done.

Can anyone explain how the rest frame observers resolve the
discrepancy between clock Ch reading 250 and clock B reading 1000 when
they meet?
Thanks,
Dave Seppala

On Apr 5, 5:34 am, David wrote:
In solutions to various problems (as in the twin's paradox) clocks
appear to get reset when frames are changed. And the change in time
is a function of the distance of events, although in any given
reference frame distances between clocks have nothing to do with clock
rates and resynchronization. I don't understand what physically
causes this to happen,

What *physically* causes an object to appear smaller when you view it
from farther away? What *phyically* caused it to look smaller, and
how can it be that everybody doesn't agree that it always looks the
same size?

[snip]


Can anyone explain how

People tend not to try to explain things to induhviduals who
repeatedly demonstrate zero learning ability.

Paul Cardinale

On Apr 5, 2:34 pm, David wrote:
In solutions to various problems (as in the twin's paradox) clocks
appear to get reset when frames are changed. And the change in time
is a function of the distance of events, although in any given
reference frame distances between clocks have nothing to do with clock
rates and resynchronization. I don't understand what physically
causes this to happen, so I setup a simple SR clock problem. I don't
see how to explain the result of this simple problem using Einstein's
notions of time and space.

There are two reference frames that have a relative velocity V=0.866c
along the x-axis. I use that value so that its simple to talk about
the clock rates. Einstein really didn't detail how to synchronize
clocks so I am using a simple method. At time t0 = 0, a light pulse is
emitted from a point on the x-axis. In their respective inertial
frames, the distance from each clock to this point is measured. When
the light pulse arrives at a clock, the clock is set to the time equal
to this distance divided by c. Now all clocks in their respective
frames run at the same rate and are set to the same time.

Here's the problem. Let one frame be called the rest frame and the
other frame be called the moving frame. With the relative velocity
between the two frames at 0.866c, each frame measures that clocks in
the other frame run at half the rate of clocks in their own frame. So
let's say observers in the moving frame want to place a clock in the
rest frame that runs at the same rate as all of their clocks in the
moving frame. Since "time" in the rest frame runs half as fast as in
their own frame, they modify the oscillator frequency of the clock by
doubling it. I'll call this clock Cd (d for double the rate of ideal
clocks). So now the moving observers have a clock in the rest frame
that runs at the same rate as all of their clocks. They place it in
the rest frame at time t=0 at the point where the pulse of light used
to synchronize all clocks originated.

The rest frame observers say that this clock is not setup correctly.
They say clocks in the moving frame run at half the rate of the rest
frame clocks, so they say that instead of doubling the oscillator
frequency, the clock in the rest frame that runs at the same rate as
all the moving frame clocks should have its oscillator refrequency cut
in half instaed of doubled. So the rest frame observers modify a
clock so that it runs at half the rate of an ideal clock. I'll call
this clock Ch (h for half the rate of ideal clocks). This clock is
also placed in the rest frame at time t=0 at the point where the pulse
of light used to synchronize all clocks originated.

Now let two clocks in the moving frame be separated by 866
light-seconds. I'll call these clock A and Clock B. And let clock A
be at the point of origin of the light pulse used to synchronize all
clocks. Let the moving frame be moving in the negative x-direction
relative to the rest frame. Clocks Cd and Ch will take 1000 seconds
(as measured in the moving frame) to reach clock B. Now we can apply
Einstein's equations, and find that the rest frame observers say that
the separation between these two moving frame clocks is 433
light-seconds and the second moving frame clock will be at the same
point in space as clocks Cd and Ch in only 500 seconds. So we find
that when the clocks meet, clock B reads 1000 seconds, clock Cd reads
1000 seconds (it is running at twice the rate as other rest frame
clocks), but clock Ch only reads 250 seconds (it is running at half
the rate as other rest frame clocks). So clock Ch is not synchronized
with all of the moving frame clocks as thought by the rest frame
observers.

I don't see how to resolve this problem. According to the rest frame
observers, clock Ch is running at the same rate as every moving frame
clock. Clock Ch got set to zero at the same time as Clock A in the
moving frame and Clock Cd were set to zero. According to the rest
frame observers, Clock Ch is running at the same rate as Clock A and
Clock B, so therefore this must have been some problem with the
initialization of Clock B. But I could not determine how the rest
frame observers say the initialization of Clock B should have been
done.

Can anyone explain how the rest frame observers resolve the
discrepancy between clock Ch reading 250 and clock B reading 1000 when
they meet?
Thanks,
Dave Seppala

This one is very simple, it's a classical beginner's mistake!
Apparently you were so focussed on the 2nd order effect (time
dilation) that you forgot to account for the first order effect:
relativity of simultaneity. As measured in the rest frame, the clocks
in the moving frame are all out of sync.

Cheers,
Harald

On 5 Apr 2007 13:08:32 -0700, "harry"
wrote:

On Apr 5, 2:34 pm, David wrote:
In solutions to various problems (as in the twin's paradox) clocks
appear to get reset when frames are changed. And the change in time
is a function of the distance of events, although in any given
reference frame distances between clocks have nothing to do with clock
rates and resynchronization. I don't understand what physically
causes this to happen, so I setup a simple SR clock problem. I don't
see how to explain the result of this simple problem using Einstein's
notions of time and space.

There are two reference frames that have a relative velocity V=0.866c
along the x-axis. I use that value so that its simple to talk about
the clock rates. Einstein really didn't detail how to synchronize
clocks so I am using a simple method. At time t0 = 0, a light pulse is
emitted from a point on the x-axis. In their respective inertial
frames, the distance from each clock to this point is measured. When
the light pulse arrives at a clock, the clock is set to the time equal
to this distance divided by c. Now all clocks in their respective
frames run at the same rate and are set to the same time.

Here's the problem. Let one frame be called the rest frame and the
other frame be called the moving frame. With the relative velocity
between the two frames at 0.866c, each frame measures that clocks in
the other frame run at half the rate of clocks in their own frame. So
let's say observers in the moving frame want to place a clock in the
rest frame that runs at the same rate as all of their clocks in the
moving frame. Since "time" in the rest frame runs half as fast as in
their own frame, they modify the oscillator frequency of the clock by
doubling it. I'll call this clock Cd (d for double the rate of ideal
clocks). So now the moving observers have a clock in the rest frame
that runs at the same rate as all of their clocks. They place it in
the rest frame at time t=0 at the point where the pulse of light used
to synchronize all clocks originated.

The rest frame observers say that this clock is not setup correctly.
They say clocks in the moving frame run at half the rate of the rest
frame clocks, so they say that instead of doubling the oscillator
frequency, the clock in the rest frame that runs at the same rate as
all the moving frame clocks should have its oscillator refrequency cut
in half instaed of doubled. So the rest frame observers modify a
clock so that it runs at half the rate of an ideal clock. I'll call
this clock Ch (h for half the rate of ideal clocks). This clock is
also placed in the rest frame at time t=0 at the point where the pulse
of light used to synchronize all clocks originated.

Now let two clocks in the moving frame be separated by 866
light-seconds. I'll call these clock A and Clock B. And let clock A
be at the point of origin of the light pulse used to synchronize all
clocks. Let the moving frame be moving in the negative x-direction
relative to the rest frame. Clocks Cd and Ch will take 1000 seconds
(as measured in the moving frame) to reach clock B. Now we can apply
Einstein's equations, and find that the rest frame observers say that
the separation between these two moving frame clocks is 433
light-seconds and the second moving frame clock will be at the same
point in space as clocks Cd and Ch in only 500 seconds. So we find
that when the clocks meet, clock B reads 1000 seconds, clock Cd reads
1000 seconds (it is running at twice the rate as other rest frame
clocks), but clock Ch only reads 250 seconds (it is running at half
the rate as other rest frame clocks). So clock Ch is not synchronized
with all of the moving frame clocks as thought by the rest frame
observers.

I don't see how to resolve this problem. According to the rest frame
observers, clock Ch is running at the same rate as every moving frame
clock. Clock Ch got set to zero at the same time as Clock A in the
moving frame and Clock Cd were set to zero. According to the rest
frame observers, Clock Ch is running at the same rate as Clock A and
Clock B, so therefore this must have been some problem with the
initialization of Clock B. But I could not determine how the rest
frame observers say the initialization of Clock B should have been
done.

Can anyone explain how the rest frame observers resolve the
discrepancy between clock Ch reading 250 and clock B reading 1000 when
they meet?
Thanks,
Dave Seppala

This one is very simple, it's a classical beginner's mistake!
Apparently you were so focussed on the 2nd order effect (time
dilation) that you forgot to account for the first order effect:
relativity of simultaneity. As measured in the rest frame, the clocks
in the moving frame are all out of sync.
I have 2 clocks in the rest frame, one at twice the standard frequency
and one a half the standard frequency. The rest frame clock that is
running at twice the standard frequency is in sync with every moving
frame clock in the problem. That clock matches every moving frame
clock that passes it. But the rest frame obsevers say the correct
clock to use runs at half the rate of the standard clock instead of
the one running at twice the rate that is in sync with every clock
that it passes. The clock running at half the rate however doesn't
match any moving frame clock that passes it.
David


Cheers,
Harald

On Apr 5, 6:05 pm, David wrote:
On 5 Apr 2007 13:08:32 -0700, "harry"
wrote:



On Apr 5, 2:34 pm, David wrote:
In solutions to various problems (as in the twin's paradox) clocks
appear to get reset when frames are changed. And the change in time
is a function of the distance of events, although in any given
reference frame distances between clocks have nothing to do with clock
rates and resynchronization. I don't understand what physically
causes this to happen, so I setup a simple SR clock problem. I don't
see how to explain the result of this simple problem using Einstein's
notions of time and space.

There are two reference frames that have a relative velocity V=0.866c
along the x-axis. I use that value so that its simple to talk about
the clock rates. Einstein really didn't detail how to synchronize
clocks so I am using a simple method. At time t0 = 0, a light pulse is
emitted from a point on the x-axis. In their respective inertial
frames, the distance from each clock to this point is measured. When
the light pulse arrives at a clock, the clock is set to the time equal
to this distance divided by c. Now all clocks in their respective
frames run at the same rate and are set to the same time.

Here's the problem. Let one frame be called the rest frame and the
other frame be called the moving frame. With the relative velocity
between the two frames at 0.866c, each frame measures that clocks in
the other frame run at half the rate of clocks in their own frame. So
let's say observers in the moving frame want to place a clock in the
rest frame that runs at the same rate as all of their clocks in the
moving frame. Since "time" in the rest frame runs half as fast as in
their own frame, they modify the oscillator frequency of the clock by
doubling it. I'll call this clock Cd (d for double the rate of ideal
clocks). So now the moving observers have a clock in the rest frame
that runs at the same rate as all of their clocks. They place it in
the rest frame at time t=0 at the point where the pulse of light used
to synchronize all clocks originated.

The rest frame observers say that this clock is not setup correctly.
They say clocks in the moving frame run at half the rate of the rest
frame clocks, so they say that instead of doubling the oscillator
frequency, the clock in the rest frame that runs at the same rate as
all the moving frame clocks should have its oscillator refrequency cut
in half instaed of doubled. So the rest frame observers modify a
clock so that it runs at half the rate of an ideal clock. I'll call
this clock Ch (h for half the rate of ideal clocks). This clock is
also placed in the rest frame at time t=0 at the point where the pulse
of light used to synchronize all clocks originated.

Now let two clocks in the moving frame be separated by 866
light-seconds. I'll call these clock A and Clock B. And let clock A
be at the point of origin of the light pulse used to synchronize all
clocks. Let the moving frame be moving in the negative x-direction
relative to the rest frame. Clocks Cd and Ch will take 1000 seconds
(as measured in the moving frame) to reach clock B. Now we can apply
Einstein's equations, and find that the rest frame observers say that
the separation between these two moving frame clocks is 433
light-seconds and the second moving frame clock will be at the same
point in space as clocks Cd and Ch in only 500 seconds. So we find
that when the clocks meet, clock B reads 1000 seconds, clock Cd reads
1000 seconds (it is running at twice the rate as other rest frame
clocks), but clock Ch only reads 250 seconds (it is running at half
the rate as other rest frame clocks). So clock Ch is not synchronized
with all of the moving frame clocks as thought by the rest frame
observers.

I don't see how to resolve this problem. According to the rest frame
observers, clock Ch is running at the same rate as every moving frame
clock. Clock Ch got set to zero at the same time as Clock A in the
moving frame and Clock Cd were set to zero. According to the rest
frame observers, Clock Ch is running at the same rate as Clock A and
Clock B, so therefore this must have been some problem with the
initialization of Clock B. But I could not determine how the rest
frame observers say the initialization of Clock B should have been
done.

Can anyone explain how the rest frame observers resolve the
discrepancy between clock Ch reading 250 and clock B reading 1000 when
they meet?
Thanks,
Dave Seppala

This one is very simple, it's a classical beginner's mistake!
Apparently you were so focussed on the 2nd order effect (time
dilation) that you forgot to account for the first order effect:
relativity of simultaneity. As measured in the rest frame, the clocks
in the moving frame are all out of sync.

I have 2 clocks in the rest frame, one at twice the standard frequency
and one a half the standard frequency.

Irrelevant.

The rest frame clock that is
running at twice the standard frequency is in sync with every MOVING
frame clock in the problem.

No, imbecile. You can't have that, harry just explained to you cannot
have absolute synchronization, i.e. you cannot have synchronization
between moving clocks.



That clock matches every moving frame
clock that passes it.


No, persistent cretin. You can't have that.



rest of your imbecilities snipped, you have exceeded the quota of
cretinisms

Stick to selling real estate, physics is not for you.

On Apr 5, 4:34 am, David wrote:

[...]

Oh look David thinks of yet another SR problem that he is, as usual,
unable to solve.

Why ask the questions when you are unable to learn from the answers,
David?

The usual appealS from Rube Seppala. Here's an idea, Rube. Why don't
you tell us what, if anything, you learned from the last session before
you start a new one.

David wrote:
In solutions to various problems (as in the twin's paradox) clocks
appear to get reset when frames are changed. And the change in time
is a function of the distance of events, although in any given
reference frame distances between clocks have nothing to do with clock
rates and resynchronization. I don't understand what physically
causes this to happen, so I setup a simple SR clock problem. I don't
see how to explain the result of this simple problem using Einstein's
notions of time and space.

There are two reference frames that have a relative velocity V=0.866c
along the x-axis. I use that value so that its simple to talk about
the clock rates. Einstein really didn't detail how to synchronize
clocks so I am using a simple method. At time t0 = 0, a light pulse is
emitted from a point on the x-axis. In their respective inertial
frames, the distance from each clock to this point is measured. When
the light pulse arrives at a clock, the clock is set to the time equal
to this distance divided by c. Now all clocks in their respective
frames run at the same rate and are set to the same time.

Here's the problem. Let one frame be called the rest frame and the
other frame be called the moving frame. With the relative velocity
between the two frames at 0.866c, each frame measures that clocks in
the other frame run at half the rate of clocks in their own frame. So
let's say observers in the moving frame want to place a clock in the
rest frame that runs at the same rate as all of their clocks in the
moving frame. Since "time" in the rest frame runs half as fast as in
their own frame, they modify the oscillator frequency of the clock by
doubling it. I'll call this clock Cd (d for double the rate of ideal
clocks). So now the moving observers have a clock in the rest frame
that runs at the same rate as all of their clocks. They place it in
the rest frame at time t=0 at the point where the pulse of light used
to synchronize all clocks originated.

The rest frame observers say that this clock is not setup correctly.
They say clocks in the moving frame run at half the rate of the rest
frame clocks, so they say that instead of doubling the oscillator
frequency, the clock in the rest frame that runs at the same rate as
all the moving frame clocks should have its oscillator refrequency cut
in half instaed of doubled. So the rest frame observers modify a
clock so that it runs at half the rate of an ideal clock. I'll call
this clock Ch (h for half the rate of ideal clocks). This clock is
also placed in the rest frame at time t=0 at the point where the pulse
of light used to synchronize all clocks originated.

Now let two clocks in the moving frame be separated by 866
light-seconds. I'll call these clock A and Clock B. And let clock A
be at the point of origin of the light pulse used to synchronize all
clocks. Let the moving frame be moving in the negative x-direction
relative to the rest frame. Clocks Cd and Ch will take 1000 seconds
(as measured in the moving frame) to reach clock B. Now we can apply
Einstein's equations, and find that the rest frame observers say that
the separation between these two moving frame clocks is 433
light-seconds and the second moving frame clock will be at the same
point in space as clocks Cd and Ch in only 500 seconds. So we find
that when the clocks meet, clock B reads 1000 seconds, clock Cd reads
1000 seconds (it is running at twice the rate as other rest frame
clocks), but clock Ch only reads 250 seconds (it is running at half
the rate as other rest frame clocks). So clock Ch is not synchronized
with all of the moving frame clocks as thought by the rest frame
observers.

I don't see how to resolve this problem. According to the rest frame
observers, clock Ch is running at the same rate as every moving frame
clock. Clock Ch got set to zero at the same time as Clock A in the
moving frame and Clock Cd were set to zero. According to the rest
frame observers, Clock Ch is running at the same rate as Clock A and
Clock B, so therefore this must have been some problem with the
initialization of Clock B. But I could not determine how the rest
frame observers say the initialization of Clock B should have been
done.

Can anyone explain how the rest frame observers resolve the
discrepancy between clock Ch reading 250 and clock B reading 1000 when
they meet?
Thanks,
Dave Seppala

On 5 Apr 2007 18:11:04 -0700, wrote:

On Apr 5, 6:05 pm, David wrote:
On 5 Apr 2007 13:08:32 -0700, "harry"
wrote:



On Apr 5, 2:34 pm, David wrote:
In solutions to various problems (as in the twin's paradox) clocks
appear to get reset when frames are changed. And the change in time
is a function of the distance of events, although in any given
reference frame distances between clocks have nothing to do with clock
rates and resynchronization. I don't understand what physically
causes this to happen, so I setup a simple SR clock problem. I don't
see how to explain the result of this simple problem using Einstein's
notions of time and space.

There are two reference frames that have a relative velocity V=0.866c
along the x-axis. I use that value so that its simple to talk about
the clock rates. Einstein really didn't detail how to synchronize
clocks so I am using a simple method. At time t0 = 0, a light pulse is
emitted from a point on the x-axis. In their respective inertial
frames, the distance from each clock to this point is measured. When
the light pulse arrives at a clock, the clock is set to the time equal
to this distance divided by c. Now all clocks in their respective
frames run at the same rate and are set to the same time.

Here's the problem. Let one frame be called the rest frame and the
other frame be called the moving frame. With the relative velocity
between the two frames at 0.866c, each frame measures that clocks in
the other frame run at half the rate of clocks in their own frame. So
let's say observers in the moving frame want to place a clock in the
rest frame that runs at the same rate as all of their clocks in the
moving frame. Since "time" in the rest frame runs half as fast as in
their own frame, they modify the oscillator frequency of the clock by
doubling it. I'll call this clock Cd (d for double the rate of ideal
clocks). So now the moving observers have a clock in the rest frame
that runs at the same rate as all of their clocks. They place it in
the rest frame at time t=0 at the point where the pulse of light used
to synchronize all clocks originated.

The rest frame observers say that this clock is not setup correctly.
They say clocks in the moving frame run at half the rate of the rest
frame clocks, so they say that instead of doubling the oscillator
frequency, the clock in the rest frame that runs at the same rate as
all the moving frame clocks should have its oscillator refrequency cut
in half instaed of doubled. So the rest frame observers modify a
clock so that it runs at half the rate of an ideal clock. I'll call
this clock Ch (h for half the rate of ideal clocks). This clock is
also placed in the rest frame at time t=0 at the point where the pulse
of light used to synchronize all clocks originated.

Now let two clocks in the moving frame be separated by 866
light-seconds. I'll call these clock A and Clock B. And let clock A
be at the point of origin of the light pulse used to synchronize all
clocks. Let the moving frame be moving in the negative x-direction
relative to the rest frame. Clocks Cd and Ch will take 1000 seconds
(as measured in the moving frame) to reach clock B. Now we can apply
Einstein's equations, and find that the rest frame observers say that
the separation between these two moving frame clocks is 433
light-seconds and the second moving frame clock will be at the same
point in space as clocks Cd and Ch in only 500 seconds. So we find
that when the clocks meet, clock B reads 1000 seconds, clock Cd reads
1000 seconds (it is running at twice the rate as other rest frame
clocks), but clock Ch only reads 250 seconds (it is running at half
the rate as other rest frame clocks). So clock Ch is not synchronized
with all of the moving frame clocks as thought by the rest frame
observers.

I don't see how to resolve this problem. According to the rest frame
observers, clock Ch is running at the same rate as every moving frame
clock. Clock Ch got set to zero at the same time as Clock A in the
moving frame and Clock Cd were set to zero. According to the rest
frame observers, Clock Ch is running at the same rate as Clock A and
Clock B, so therefore this must have been some problem with the
initialization of Clock B. But I could not determine how the rest
frame observers say the initialization of Clock B should have been
done.

Can anyone explain how the rest frame observers resolve the
discrepancy between clock Ch reading 250 and clock B reading 1000 when
they meet?
Thanks,
Dave Seppala

This one is very simple, it's a classical beginner's mistake!
Apparently you were so focussed on the 2nd order effect (time
dilation) that you forgot to account for the first order effect:
relativity of simultaneity. As measured in the rest frame, the clocks
in the moving frame are all out of sync.

I have 2 clocks in the rest frame, one at twice the standard frequency
and one a half the standard frequency.

Irrelevant.

The rest frame clock that is
running at twice the standard frequency is in sync with every MOVING
frame clock in the problem.

No, imbecile. You can't have that, harry just explained to you cannot
have absolute synchronization, i.e. you cannot have synchronization
between moving clocks.



That clock matches every moving frame
clock that passes it.


No, persistent cretin. You can't have that.
When the clock that is running at twice the standard rate in the rest
frame passes any other clock in the moving frame where the relative
velocity of the two frames is 0.866c, that clock matches the time
shown on every clock in the moving frame that it passes. This is just
the application of the Lorentz transform.
David



rest of your imbecilities snipped, you have exceeded the quota of
cretinisms

Stick to selling real estate, physics is not for you.

On 5 Apr 2007 11:28:00 -0700, "Paul Cardinale"
wrote:

On Apr 5, 5:34 am, David wrote:
In solutions to various problems (as in the twin's paradox) clocks
appear to get reset when frames are changed. And the change in time
is a function of the distance of events, although in any given
reference frame distances between clocks have nothing to do with clock
rates and resynchronization. I don't understand what physically
causes this to happen,

What *physically* causes an object to appear smaller when you view it
from farther away? What *phyically* caused it to look smaller, and
how can it be that everybody doesn't agree that it always looks the
same size?
What *physically* causes an object to appear smaller when you view it
from farther away is caused because the angle of light rays hitting a
lens determines the size of the image. In addtion, the brain tends to
perceive things in relationship to previously stored info, so images
that are actually the same size may appear to be different sizes in
some contexts when interpreted by the brain.
Now why does a clock in the rest frame running at twice the rate
of standard clocks match the time shown on every moving frame clock it
passes, when this rate is four times the rate rest frame observers say
the moving frame clocks are running (v = 0.866c)?
David

[snip]


Can anyone explain how

People tend not to try to explain things to induhviduals who
repeatedly demonstrate zero learning ability.

Paul Cardinale

On Apr 6, 7:12 am, David wrote:
On 5 Apr 2007 18:11:04 -0700, wrote:





On Apr 5, 6:05 pm, David wrote:
On 5 Apr 2007 13:08:32 -0700, "harry"
wrote:

On Apr 5, 2:34 pm, David wrote:
In solutions to various problems (as in the twin's paradox) clocks
appear to get reset when frames are changed. And the change in time
is a function of the distance of events, although in any given
reference frame distances between clocks have nothing to do with clock
rates and resynchronization. I don't understand what physically
causes this to happen, so I setup a simple SR clock problem. I don't
see how to explain the result of this simple problem using Einstein's
notions of time and space.

There are two reference frames that have a relative velocity V=0.866c
along the x-axis. I use that value so that its simple to talk about
the clock rates. Einstein really didn't detail how to synchronize
clocks so I am using a simple method. At time t0 = 0, a light pulse is
emitted from a point on the x-axis. In their respective inertial
frames, the distance from each clock to this point is measured. When
the light pulse arrives at a clock, the clock is set to the time equal
to this distance divided by c. Now all clocks in their respective
frames run at the same rate and are set to the same time.

Here's the problem. Let one frame be called the rest frame and the
other frame be called the moving frame. With the relative velocity
between the two frames at 0.866c, each frame measures that clocks in
the other frame run at half the rate of clocks in their own frame. So
let's say observers in the moving frame want to place a clock in the
rest frame that runs at the same rate as all of their clocks in the
moving frame. Since "time" in the rest frame runs half as fast as in
their own frame, they modify the oscillator frequency of the clock by
doubling it. I'll call this clock Cd (d for double the rate of ideal
clocks). So now the moving observers have a clock in the rest frame
that runs at the same rate as all of their clocks. They place it in
the rest frame at time t=0 at the point where the pulse of light used
to synchronize all clocks originated.

The rest frame observers say that this clock is not setup correctly.
They say clocks in the moving frame run at half the rate of the rest
frame clocks, so they say that instead of doubling the oscillator
frequency, the clock in the rest frame that runs at the same rate as
all the moving frame clocks should have its oscillator refrequency cut
in half instaed of doubled. So the rest frame observers modify a
clock so that it runs at half the rate of an ideal clock. I'll call
this clock Ch (h for half the rate of ideal clocks). This clock is
also placed in the rest frame at time t=0 at the point where the pulse
of light used to synchronize all clocks originated.

Now let two clocks in the moving frame be separated by 866
light-seconds. I'll call these clock A and Clock B. And let clock A
be at the point of origin of the light pulse used to synchronize all
clocks. Let the moving frame be moving in the negative x-direction
relative to the rest frame. Clocks Cd and Ch will take 1000 seconds
(as measured in the moving frame) to reach clock B. Now we can apply
Einstein's equations, and find that the rest frame observers say that
the separation between these two moving frame clocks is 433
light-seconds and the second moving frame clock will be at the same
point in space as clocks Cd and Ch in only 500 seconds. So we find
that when the clocks meet, clock B reads 1000 seconds, clock Cd reads
1000 seconds (it is running at twice the rate as other rest frame
clocks), but clock Ch only reads 250 seconds (it is running at half
the rate as other rest frame clocks). So clock Ch is not synchronized
with all of the moving frame clocks as thought by the rest frame
observers.

I don't see how to resolve this problem. According to the rest frame
observers, clock Ch is running at the same rate as every moving frame
clock. Clock Ch got set to zero at the same time as Clock A in the
moving frame and Clock Cd were set to zero. According to the rest
frame observers, Clock Ch is running at the same rate as Clock A and
Clock B, so therefore this must have been some problem with the
initialization of Clock B. But I could not determine how the rest
frame observers say the initialization of Clock B should have been
done.

Can anyone explain how the rest frame observers resolve the
discrepancy between clock Ch reading 250 and clock B reading 1000 when
they meet?
Thanks,
Dave Seppala

This one is very simple, it's a classical beginner's mistake!
Apparently you were so focussed on the 2nd order effect (time
dilation) that you forgot to account for the first order effect:
relativity of simultaneity. As measured in the rest frame, the clocks
in the moving frame are all out of sync.

I have 2 clocks in the rest frame, one at twice the standard frequency
and one a half the standard frequency.

Irrelevant.

The rest frame clock that is
running at twice the standard frequency is in sync with every MOVING
frame clock in the problem.

No, imbecile. You can't have that, harry just explained to you cannot
have absolute synchronization, i.e. you cannot have synchronization
between moving clocks.

That clock matches every moving frame
clock that passes it.

No, persistent cretin. You can't have that.

When the clock that is running at twice the standard rate in the rest
frame passes any other clock in the moving frame where the relative
velocity of the two frames is 0.866c, that clock matches the time
shown on every clock in the moving frame that it passes. This is just
the application of the Lorentz transform.
David





rest of your imbecilities snipped, you have exceeded the quota of
cretinisms

Stick to selling real estate, physics is not for you.- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

This means that the observer in the frame sees the clocks running at
the same rate. This does not mean that the clocks show the same time
since there is no way to synchronize them That was the point. Stick to
selling real estate, imbecile.