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 Posted: Wed Jul 16, 2008 9:51 am Post subject: Re: Are *observed* SR effects real? |
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On Jul 15, 4:44 pm, PD <TheDraperFam...@gmail.com> wrote:
| Quote: |
On Jul 15, 7:22 am, mluttg...@wanadoo.fr wrote:
If you have no comments or questions regarding this post,
No comment, I am eager to read the next episode :-)
Marcel Luttgens
Alright, it's fine that you have no comments or questions so far,
though I'm surprised. Some of what I've told you already flies in the
face of common sense -- which is not necessarily a bad thing, but a
hurdle to overcome anyway.
So, as promised, what I will take is a scenario similar to what
Einstein used as an explanatory instrument, and for the same purpose.
I will first tell you what two different observers see (and this is in
fact confirmed in equivalent experiments), and then we'll show that
this is completely consistent with the laws of physics, even though
their observations might be surprising at first.
There is a federal train whipping through a campus town. It's an
electric train and it receives its power from a suspended wire
alongside the track, via electrical brushes mounted near the ends of
the train. As the train passes by a pole supporting the wire,
occasionally a bright spark is thrown at the wire support at the pole
and the electric brush as the brush whisks by it, sometimes a reddish
spark, sometimes greenish, sometimes yellowish.
There's a physicist working in a lab next to the tracks, and there's a
physicist working in a lab on the train. As it turns out, they are
both doing independent and competing light-speed isotropy experiments,
and they know each other. Both of them just about a half-hour ago
completed measurements that showed that light speed is isotropic, and
this is true even though one lab is moving relative to the other.
(This repeats an earlier published test of Einstein's light speed
postulate, but now with higher precision.)
As the train passes by, Stan, the researcher in the lab in town, looks
out and sees the following:
1. Two flashes simultaneously, one yellow from the back of the train
and one green from the front of the train.
2. A short time later still, a bright red flash at the front of the
train.
Tom, the researcher on the train, sees the very same flashes (the only
ones that actually happen that day), but sees them in the following
order:
3. A green flash from the front of the train.
4. A short time later, two flashes simultaneously, one yellow from the
back of the train and one red from the front of the train.
They radio each other to see if this disrupted the other's isotropy
experiment (it didn't) and to relate what they saw.
Stan goes out after the conversation and measures the distance from
the three poles where he saw the flashes to his lab. As it turns out,
the poles where the yellow and green flashes came from are equidistant
from his lab, though the pole where the red flash came from is further
away. He uses his three observations: isotropy, equal distance from
source, and (1) above to CORRECTLY conclude that the yellow and green
flashes are simultaneous. He is using the *definition* of simultaneity
that we cited last time.
He's not sure about whether the red flash was later just because the
flash was coming from further away, but since he's measured the
distance, he can figure out the propagation delay knowing the speed of
light. There is indeed a delay but not as long as what he observed
between the red and yellow flashes. So he CORRECTLY concludes that the
red and yellow flashes are not simultaneous.
Stan also notes that the two poles where the simultaneous (yellow and
green) flashes came from are 600 m apart, and since they came from the
brushes at the front and back of the train, he knows the train is 600
m long. Remember that he also knows the distance to the pole where the
red flash happened -- we may use that later.
Tom, on the other hand, notes that he was standing exactly midway
between the two brushes at the end of the train when any of the
flashes happened. The distance from either end of the train to his lab
is 400 m, so he knows the whole train is 800 m long. So he uses his
isotropy results, and the fact that he was equidistant from the
brushes and observation (4) to CORRECTLY conclude that the red and
yellow flashes are simultaneous and that the green and yellow flashes
are not simultaneous.
So, they radio this information to each other:
Stan: Using the *definition* of simultaneity, the green and yellow
flashes are simultaneous, and the red and yellow flashes are not
simultaneous.
Tom: Using the *same definition* of simultaneity, the red and yellow
flashes are simultaneous and the green and yellow flashes are not
simultaneous.
Note they have both *taken into account* propagation delay, and that
they each use only the *measurements* they individually make.
So, there is obviously a disagreement here about the simultaneity, and
this causes some head-scratching about how it is the other could have
seen what they saw. We'll come back to that next time, using the laws
of physics.
Incidentally, they also disagree about the length of the train, as you
can see. But they both immediately see that this is simply rooted in
the problem of the simultaneity. For instance:
Stan says the train is 600 m long, "...because I used the
*simultaneous* marking of the locations of the ends of the train using
the green and yellow flashes, which is the *definition* of physical
length." But Tom replies, "But those flashes were NOT simultaneous.
The green flash at the front came before the yellow flash at the back.
If you mark the front of the train first and then mark the back of the
train second, OF COURSE you will come up with a number that is too
small." "But that's not what happened with the green and yellow
flashes," says Stan. "Yes, it is!" shouts Tom, "You should have used
the yellow and RED flashes."
Then, after a pause, Stan says, "Look, if you measure the back of the
train first and then the front of the train second, you'll get a
number that's too long for the train. That's why I didn't use the
yellow and red flashes." "But that's not what happened with the yellow
and red flashes," says Tom. "Yes it is!" shouts Stan.
And it appears there is no way to settle this, because they both use
the same definition of physical length and they both use the same
definition of simultaneity and all propagation delays have been
accounted for, and there is still disagreement about both the
simultaneity and, as a result, the length of the train. Finally, note
that there is NO implication whatsoever of something physically
happening to the train to squeeze it or stretch it out. But nor is it
an optical illusion. It all rests on the *definition* of simultaneity,
which we defined last time and which makes perfect sense.
Comments? Questions?
PD
|
Question:
Which were their measurements that showed that
light speed is isotropic?
Comments:
Stan says the train is 600 m long, Tom disagrees and
claims that the train is 800 m long.
Then Stan said, use your ruler to measure the length,
you will find that it is 600 m. Tom did it, and found
600 m, and claimed that there must be something wrong
with the simultaneity rule.
Stan replied: "Perhaps not if the train is moving at
100 m/s".
We have experimentally found that the speed of
light is 300 m/s (!). As I determined the length of
the train from the time taken by light to reach me
at 300 m/s, i.e. 1 second, I inferred that that the half
length of the train is 300 m.
After 1 second, the middle of the train, where you
were sitting, travelled 100 m, so you were at 300 m
+ 100 m = 400 m from the yellow flash, and the
red light reached you after 1 second if we add
to its velocity the velocity of the train.
Marcel Luttgens |
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| Posted: Wed Jul 16, 2008 10:12 am Post subject: Re: Are *observed* SR effects real? |
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On Jul 15, 9:00 pm, carlip-nos...@physics.ucdavis.edu wrote:
| Quote: |
mluttg...@wanadoo.fr wrote:
On Jul 13, 7:26 pm, Dono <sa...@comcast.net> wrote:
[...]
Here some more recent info, from GPS and ISS (and some other clock-
carrying satellites), look at table 1:
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
Stupid,
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
is certainly not a confirmation of H&K's
experimental results.
Of course it is!
The authors are more careful than you and some of
your SR buddies. They nowhere claim that the relativistic
effects are real:
"Thus on account of its velocity, a GPS satellite clock
*appears* to run slow by 7 µs per day.
At an altitude of 20,184 km, the clock *appears*
to run fast by 45 µs per day.
[...]
This is standard experimentalist jargon. "Appears" means "The
evidence of our experiment shows." If you read more scientific
papers you'd recognize the usage.
And they didn't bring back the airborne clocks to
the ground in order to compare their reading with
the ground clocks:
Of course they did!
"As shown, when the flight was completed the flight clock
was theoretically ahead of the clock on the ground by 7.67 ns.
The actual flight clock data, when compared to the ground
clock before and after the flight, was ahead by 7.3 ± 1.7 ns.
The uncertainty represents the one-sigma variation in the
pre-flight clock comparison data over a span of 6 hours, which
is equivalent to the time the clocks were separated. The two
additional flight tests during this series produced similar results.
It is significant that the error in the clock closure would have
been nearly five times the uncertainty in the measured clock
data had relativity not been taken into account."
|
No, they didn't!
They only compared the *actual flight clock data* to the
ground clock before and after the flight.
"Flight data" means data obtained from the clocks in flight,
not readings measured on the ground.
Marcel Luttgens
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Eric Gisse
Guest
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| Posted: Wed Jul 16, 2008 11:12 am Post subject: Re: Are *observed* SR effects real? |
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On Jul 14, 4:44 am, mluttg...@wanadoo.fr wrote:
| Quote: |
On Jul 14, 11:09 am, Eric Gisse <jowr...@gmail.com> wrote:
On Jul 14, 1:01 am, mluttg...@wanadoo.fr wrote:
[snip]
At least you have progressed from denying the effect. Too bad you now
argue the effect isn't real.
Stupid, I never denied that the effects were
*observed*, try to find in my posts where I claimed
they are real. Only SRists believe in their physical
reality, they even used H&K's experimental pseudo-results
as a proof.
Marcel Luttgens
|
Yea, Marcel. Its' just a COINCIDENCE that SR is validated by every
experiment performed. |
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PD
Guest
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| Posted: Wed Jul 16, 2008 12:30 pm Post subject: Re: Are *observed* SR effects real? |
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|
On Jul 15, 3:09 pm, Pentcho Valev <pva...@yahoo.com> wrote:
| Quote: |
On Jul 15, 9:00 pm, carlip-nos...@physics.ucdavis.edu wrote:
mluttg...@wanadoo.fr wrote:
On Jul 13, 7:26 pm, Dono <sa...@comcast.net> wrote:
[...]
Here some more recent info, from GPS and ISS (and some other clock-
carrying satellites), look at table 1:
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
Stupid,
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
is certainly not a confirmation of H&K's
experimental results.
Of course it is!
The authors are more careful than you and some of
your SR buddies. They nowhere claim that the relativistic
effects are real:
"Thus on account of its velocity, a GPS satellite clock
*appears* to run slow by 7 µs per day.
At an altitude of 20,184 km, the clock *appears*
to run fast by 45 µs per day.
[...]
This is standard experimentalist jargon. "Appears" means "The
evidence of our experiment shows." If you read more scientific
papers you'd recognize the usage.
And they didn't bring back the airborne clocks to
the ground in order to compare their reading with
the ground clocks:
Of course they did!
"As shown, when the flight was completed the flight clock
was theoretically ahead of the clock on the ground by 7.67 ns.
The actual flight clock data, when compared to the ground
clock before and after the flight, was ahead by 7.3 ± 1.7 ns.
The uncertainty represents the one-sigma variation in the
pre-flight clock comparison data over a span of 6 hours, which
is equivalent to the time the clocks were separated. The two
additional flight tests during this series produced similar results.
It is significant that the error in the clock closure would have
been nearly five times the uncertainty in the measured clock
data had relativity not been taken into account."
You will find similar results inhttp://tycho.usno.navy.mil/ptti/1981/Vol13_37.pdf
Look in particular at figure 44, which shows time before, during,
and after a flight of an atomic clock compared to a ground-based
reference clock.
Steve Carlip
Bravo Honest Carlip! You have not left the sinking ship yet! Now you
will have to give some explanations:
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
"First, there is the effect of time dilation. The velocity of a moving
clock causes it to appear to run slow relative to a clock on the
Earth. GPS satellites revolve around the Earth with an orbital period
of 11.967 hours and a velocity of 3.874 km/s. Thus on account of its
velocity, a GPS satellite clock appears to run slow by 7 µs per day."
This must be special relativity isn't it Honest Carlip. Then why is
time dilation not reciprocal? Why should the clock on the earth run
FASTER, Honest Carlip?
|
Because we're not dealing with two *inertial* reference frames. The
satellite is undergoing a *closed* orbit. This does not mean that
special relativity and time dilation cannot be used -- special
relativity can certainly be used in non-inertial reference frames.
However, special relativity says that the *mutual* time dilation that
you are looking for ONLY applies when BOTH reference frames are
inertial.
Your very shallow grasp on special relativity seems to trip you up
wherever you go.
Fortunately, it is not complicated, and it is not reserved for
geniuses and magicians. All you need to do is to find a decent book
and a decent teacher to interact with. The way you are going about it
is perhaps less than constructive.
| Quote: |
Perhaps the gravitational potential difference
between the two clocks should be taken into account but then this is
not special relativity is it Honest Carlip. Why don't you explain -
you are such a great theoretician (only Tom Roberts is greater than
you).
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
"Second, there is the effect of the gravitational redshift, a
frequency shift caused by the difference in gravitational potential.
(The term “redshift” is generic regardless of sign, but for a
satellite clock the frequency shift is actually a blueshift.) The
difference in gravitational potential between the altitude of the
orbit and the surface of the Earth causes the satellite clock to
appear to run fast. At an altitude of 20,184 km, the clock appears to
run fast by 45 µs per day."
Another enigma, Honest Carlip. The frequency varies with the
gravitational potential V in accordance with the equation:
f' = f(1+V/c^2)
and this equation seems to be consistent with Einstein's 1911 equation
showing how the speed of light varies with the gravitational
potential:
c' = c(1+V/c^2)
But, Honest Carlip, if the frequency variation is due to speed of
light variation, then there is NO GRAVITATIONAL TIME DILATION, and
this can be seen even by Einsteinians sillier than you. And if there
is no gravitational time dilation, Honest Carlip, then what do your
brothers Einsteinians measure? Are they lying? Explain, Honest Carlip!
Is the frequency variation in a gravitational field due to speed of
light variation?
Pentcho Valev
pva...@yahoo.com |
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PD
Guest
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| Posted: Wed Jul 16, 2008 12:36 pm Post subject: Re: Are *observed* SR effects real? |
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|
On Jul 16, 4:51 am, mluttg...@wanadoo.fr wrote:
| Quote: |
On Jul 15, 4:44 pm, PD <TheDraperFam...@gmail.com> wrote:
On Jul 15, 7:22 am, mluttg...@wanadoo.fr wrote:
If you have no comments or questions regarding this post,
No comment, I am eager to read the next episode :-)
Marcel Luttgens
Alright, it's fine that you have no comments or questions so far,
though I'm surprised. Some of what I've told you already flies in the
face of common sense -- which is not necessarily a bad thing, but a
hurdle to overcome anyway.
So, as promised, what I will take is a scenario similar to what
Einstein used as an explanatory instrument, and for the same purpose.
I will first tell you what two different observers see (and this is in
fact confirmed in equivalent experiments), and then we'll show that
this is completely consistent with the laws of physics, even though
their observations might be surprising at first.
There is a federal train whipping through a campus town. It's an
electric train and it receives its power from a suspended wire
alongside the track, via electrical brushes mounted near the ends of
the train. As the train passes by a pole supporting the wire,
occasionally a bright spark is thrown at the wire support at the pole
and the electric brush as the brush whisks by it, sometimes a reddish
spark, sometimes greenish, sometimes yellowish.
There's a physicist working in a lab next to the tracks, and there's a
physicist working in a lab on the train. As it turns out, they are
both doing independent and competing light-speed isotropy experiments,
and they know each other. Both of them just about a half-hour ago
completed measurements that showed that light speed is isotropic, and
this is true even though one lab is moving relative to the other.
(This repeats an earlier published test of Einstein's light speed
postulate, but now with higher precision.)
As the train passes by, Stan, the researcher in the lab in town, looks
out and sees the following:
1. Two flashes simultaneously, one yellow from the back of the train
and one green from the front of the train.
2. A short time later still, a bright red flash at the front of the
train.
Tom, the researcher on the train, sees the very same flashes (the only
ones that actually happen that day), but sees them in the following
order:
3. A green flash from the front of the train.
4. A short time later, two flashes simultaneously, one yellow from the
back of the train and one red from the front of the train.
They radio each other to see if this disrupted the other's isotropy
experiment (it didn't) and to relate what they saw.
Stan goes out after the conversation and measures the distance from
the three poles where he saw the flashes to his lab. As it turns out,
the poles where the yellow and green flashes came from are equidistant
from his lab, though the pole where the red flash came from is further
away. He uses his three observations: isotropy, equal distance from
source, and (1) above to CORRECTLY conclude that the yellow and green
flashes are simultaneous. He is using the *definition* of simultaneity
that we cited last time.
He's not sure about whether the red flash was later just because the
flash was coming from further away, but since he's measured the
distance, he can figure out the propagation delay knowing the speed of
light. There is indeed a delay but not as long as what he observed
between the red and yellow flashes. So he CORRECTLY concludes that the
red and yellow flashes are not simultaneous.
Stan also notes that the two poles where the simultaneous (yellow and
green) flashes came from are 600 m apart, and since they came from the
brushes at the front and back of the train, he knows the train is 600
m long. Remember that he also knows the distance to the pole where the
red flash happened -- we may use that later.
Tom, on the other hand, notes that he was standing exactly midway
between the two brushes at the end of the train when any of the
flashes happened. The distance from either end of the train to his lab
is 400 m, so he knows the whole train is 800 m long. So he uses his
isotropy results, and the fact that he was equidistant from the
brushes and observation (4) to CORRECTLY conclude that the red and
yellow flashes are simultaneous and that the green and yellow flashes
are not simultaneous.
So, they radio this information to each other:
Stan: Using the *definition* of simultaneity, the green and yellow
flashes are simultaneous, and the red and yellow flashes are not
simultaneous.
Tom: Using the *same definition* of simultaneity, the red and yellow
flashes are simultaneous and the green and yellow flashes are not
simultaneous.
Note they have both *taken into account* propagation delay, and that
they each use only the *measurements* they individually make.
So, there is obviously a disagreement here about the simultaneity, and
this causes some head-scratching about how it is the other could have
seen what they saw. We'll come back to that next time, using the laws
of physics.
Incidentally, they also disagree about the length of the train, as you
can see. But they both immediately see that this is simply rooted in
the problem of the simultaneity. For instance:
Stan says the train is 600 m long, "...because I used the
*simultaneous* marking of the locations of the ends of the train using
the green and yellow flashes, which is the *definition* of physical
length." But Tom replies, "But those flashes were NOT simultaneous.
The green flash at the front came before the yellow flash at the back.
If you mark the front of the train first and then mark the back of the
train second, OF COURSE you will come up with a number that is too
small." "But that's not what happened with the green and yellow
flashes," says Stan. "Yes, it is!" shouts Tom, "You should have used
the yellow and RED flashes."
Then, after a pause, Stan says, "Look, if you measure the back of the
train first and then the front of the train second, you'll get a
number that's too long for the train. That's why I didn't use the
yellow and red flashes." "But that's not what happened with the yellow
and red flashes," says Tom. "Yes it is!" shouts Stan.
And it appears there is no way to settle this, because they both use
the same definition of physical length and they both use the same
definition of simultaneity and all propagation delays have been
accounted for, and there is still disagreement about both the
simultaneity and, as a result, the length of the train. Finally, note
that there is NO implication whatsoever of something physically
happening to the train to squeeze it or stretch it out. But nor is it
an optical illusion. It all rests on the *definition* of simultaneity,
which we defined last time and which makes perfect sense.
Comments? Questions?
PD
Question:
Which were their measurements that showed that
light speed is isotropic?
|
They were doing experiments in their labs that were independent of the
green, yellow, and red flashes. As mentioned in the first long post I
gave you, they were performing experiments similar to those found
here:
http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html#round-trip_tests
So they already *know* from these other measurements that light speed
is isotropic.
| Quote: |
Comments:
Stan says the train is 600 m long, Tom disagrees and
claims that the train is 800 m long.
|
Yes.
| Quote: |
Then Stan said, use your ruler to measure the length,
you will find that it is 600 m.
|
OK.
| Quote: |
Tom did it, and found
600 m,
|
No, please read what I wrote again. Tom measured the distances from
each of the brushes to where he was standing -- those were each 400 m.
He did this with a ruler. 400 m + 400 m = 800 m, and he was in the
middle between the two brushes.
| Quote: |
and claimed that there must be something wrong
with the simultaneity rule.
Stan replied: "Perhaps not if the train is moving at
100 m/s".
We have experimentally found that the speed of
light is 300 m/s (!). As I determined the length of
the train from the time taken by light to reach me
at 300 m/s, i.e. 1 second, I inferred that that the half
length of the train is 300 m.
After 1 second, the middle of the train, where you
were sitting, travelled 100 m, so you were at 300 m
+ 100 m = 400 m from the yellow flash, and the
red light reached you after 1 second if we add
to its velocity the velocity of the train.
Marcel Luttgens |
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Danny Milano
Guest
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| Posted: Wed Jul 16, 2008 12:54 pm Post subject: Re: Are *observed* SR effects real? |
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|
On Jul 16, 8:30 pm, PD <TheDraperFam...@gmail.com> wrote:
| Quote: |
On Jul 15, 3:09 pm, Pentcho Valev <pva...@yahoo.com> wrote:
On Jul 15, 9:00 pm, carlip-nos...@physics.ucdavis.edu wrote:
mluttg...@wanadoo.fr wrote:
On Jul 13, 7:26 pm, Dono <sa...@comcast.net> wrote:
[...]
Here some more recent info, from GPS and ISS (and some other clock-
carrying satellites), look at table 1:
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
Stupid,
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
is certainly not a confirmation of H&K's
experimental results.
Of course it is!
The authors are more careful than you and some of
your SR buddies. They nowhere claim that the relativistic
effects are real:
"Thus on account of its velocity, a GPS satellite clock
*appears* to run slow by 7 µs per day.
At an altitude of 20,184 km, the clock *appears*
to run fast by 45 µs per day.
[...]
This is standard experimentalist jargon. "Appears" means "The
evidence of our experiment shows." If you read more scientific
papers you'd recognize the usage.
And they didn't bring back the airborne clocks to
the ground in order to compare their reading with
the ground clocks:
Of course they did!
"As shown, when the flight was completed the flight clock
was theoretically ahead of the clock on the ground by 7.67 ns..
The actual flight clock data, when compared to the ground
clock before and after the flight, was ahead by 7.3 ± 1.7 ns.
The uncertainty represents the one-sigma variation in the
pre-flight clock comparison data over a span of 6 hours, which
is equivalent to the time the clocks were separated. The two
additional flight tests during this series produced similar results.
It is significant that the error in the clock closure would have
been nearly five times the uncertainty in the measured clock
data had relativity not been taken into account."
You will find similar results inhttp://tycho.usno.navy.mil/ptti/1981/Vol13_37.pdf
Look in particular at figure 44, which shows time before, during,
and after a flight of an atomic clock compared to a ground-based
reference clock.
Steve Carlip
Bravo Honest Carlip! You have not left the sinking ship yet! Now you
will have to give some explanations:
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
"First, there is the effect of time dilation. The velocity of a moving
clock causes it to appear to run slow relative to a clock on the
Earth. GPS satellites revolve around the Earth with an orbital period
of 11.967 hours and a velocity of 3.874 km/s. Thus on account of its
velocity, a GPS satellite clock appears to run slow by 7 µs per day."
This must be special relativity isn't it Honest Carlip. Then why is
time dilation not reciprocal? Why should the clock on the earth run
FASTER, Honest Carlip?
Because we're not dealing with two *inertial* reference frames. The
satellite is undergoing a *closed* orbit. This does not mean that
special relativity and time dilation cannot be used -- special
relativity can certainly be used in non-inertial reference frames.
However, special relativity says that the *mutual* time dilation that
you are looking for ONLY applies when BOTH reference frames are
inertial.
Your very shallow grasp on special relativity seems to trip you up
wherever you go.
Fortunately, it is not complicated, and it is not reserved for
geniuses and magicians. All you need to do is to find a decent book
and a decent teacher to interact with. The way you are going about it
is perhaps less than constructive.
|
Hi,
Without relativistic corrections. Do you know how many error would
the GPS introduce? How many inches, meters or miles? I remember
Baird saying that GPS folks use the relativity equations just to make
them feel "in" and pure newtonian equation is as accurate as it gets.
If the differences is only a few inches. Then GPS is not proof of SR
at all.
D.
| Quote: |
Perhaps the gravitational potential difference
between the two clocks should be taken into account but then this is
not special relativity is it Honest Carlip. Why don't you explain -
you are such a great theoretician (only Tom Roberts is greater than
you).
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
"Second, there is the effect of the gravitational redshift, a
frequency shift caused by the difference in gravitational potential.
(The term “redshift” is generic regardless of sign, but for a
satellite clock the frequency shift is actually a blueshift.) The
difference in gravitational potential between the altitude of the
orbit and the surface of the Earth causes the satellite clock to
appear to run fast. At an altitude of 20,184 km, the clock appears to
run fast by 45 µs per day."
Another enigma, Honest Carlip. The frequency varies with the
gravitational potential V in accordance with the equation:
f' = f(1+V/c^2)
and this equation seems to be consistent with Einstein's 1911 equation
showing how the speed of light varies with the gravitational
potential:
c' = c(1+V/c^2)
But, Honest Carlip, if the frequency variation is due to speed of
light variation, then there is NO GRAVITATIONAL TIME DILATION, and
this can be seen even by Einsteinians sillier than you. And if there
is no gravitational time dilation, Honest Carlip, then what do your
brothers Einsteinians measure? Are they lying? Explain, Honest Carlip!
Is the frequency variation in a gravitational field due to speed of
light variation?
Pentcho Valev
pva...@yahoo.com- Hide quoted text -
- Show quoted text -- Hide quoted text -
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Guest
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| Posted: Wed Jul 16, 2008 1:21 pm Post subject: Re: Are *observed* SR effects real? |
|
|
On Jul 16, 2:36 pm, PD <TheDraperFam...@gmail.com> wrote:
| Quote: |
On Jul 16, 4:51 am, mluttg...@wanadoo.fr wrote:
On Jul 15, 4:44 pm, PD <TheDraperFam...@gmail.com> wrote:
On Jul 15, 7:22 am, mluttg...@wanadoo.fr wrote:
If you have no comments or questions regarding this post,
No comment, I am eager to read the next episode :-)
Marcel Luttgens
Alright, it's fine that you have no comments or questions so far,
though I'm surprised. Some of what I've told you already flies in the
face of common sense -- which is not necessarily a bad thing, but a
hurdle to overcome anyway.
So, as promised, what I will take is a scenario similar to what
Einstein used as an explanatory instrument, and for the same purpose.
I will first tell you what two different observers see (and this is in
fact confirmed in equivalent experiments), and then we'll show that
this is completely consistent with the laws of physics, even though
their observations might be surprising at first.
There is a federal train whipping through a campus town. It's an
electric train and it receives its power from a suspended wire
alongside the track, via electrical brushes mounted near the ends of
the train. As the train passes by a pole supporting the wire,
occasionally a bright spark is thrown at the wire support at the pole
and the electric brush as the brush whisks by it, sometimes a reddish
spark, sometimes greenish, sometimes yellowish.
There's a physicist working in a lab next to the tracks, and there's a
physicist working in a lab on the train. As it turns out, they are
both doing independent and competing light-speed isotropy experiments,
and they know each other. Both of them just about a half-hour ago
completed measurements that showed that light speed is isotropic, and
this is true even though one lab is moving relative to the other.
(This repeats an earlier published test of Einstein's light speed
postulate, but now with higher precision.)
As the train passes by, Stan, the researcher in the lab in town, looks
out and sees the following:
1. Two flashes simultaneously, one yellow from the back of the train
and one green from the front of the train.
2. A short time later still, a bright red flash at the front of the
train.
Tom, the researcher on the train, sees the very same flashes (the only
ones that actually happen that day), but sees them in the following
order:
3. A green flash from the front of the train.
4. A short time later, two flashes simultaneously, one yellow from the
back of the train and one red from the front of the train.
They radio each other to see if this disrupted the other's isotropy
experiment (it didn't) and to relate what they saw.
Stan goes out after the conversation and measures the distance from
the three poles where he saw the flashes to his lab. As it turns out,
the poles where the yellow and green flashes came from are equidistant
from his lab, though the pole where the red flash came from is further
away. He uses his three observations: isotropy, equal distance from
source, and (1) above to CORRECTLY conclude that the yellow and green
flashes are simultaneous. He is using the *definition* of simultaneity
that we cited last time.
He's not sure about whether the red flash was later just because the
flash was coming from further away, but since he's measured the
distance, he can figure out the propagation delay knowing the speed of
light. There is indeed a delay but not as long as what he observed
between the red and yellow flashes. So he CORRECTLY concludes that the
red and yellow flashes are not simultaneous.
Stan also notes that the two poles where the simultaneous (yellow and
green) flashes came from are 600 m apart, and since they came from the
brushes at the front and back of the train, he knows the train is 600
m long. Remember that he also knows the distance to the pole where the
red flash happened -- we may use that later.
Tom, on the other hand, notes that he was standing exactly midway
between the two brushes at the end of the train when any of the
flashes happened. The distance from either end of the train to his lab
is 400 m, so he knows the whole train is 800 m long. So he uses his
isotropy results, and the fact that he was equidistant from the
brushes and observation (4) to CORRECTLY conclude that the red and
yellow flashes are simultaneous and that the green and yellow flashes
are not simultaneous.
So, they radio this information to each other:
Stan: Using the *definition* of simultaneity, the green and yellow
flashes are simultaneous, and the red and yellow flashes are not
simultaneous.
Tom: Using the *same definition* of simultaneity, the red and yellow
flashes are simultaneous and the green and yellow flashes are not
simultaneous.
Note they have both *taken into account* propagation delay, and that
they each use only the *measurements* they individually make.
So, there is obviously a disagreement here about the simultaneity, and
this causes some head-scratching about how it is the other could have
seen what they saw. We'll come back to that next time, using the laws
of physics.
Incidentally, they also disagree about the length of the train, as you
can see. But they both immediately see that this is simply rooted in
the problem of the simultaneity. For instance:
Stan says the train is 600 m long, "...because I used the
*simultaneous* marking of the locations of the ends of the train using
the green and yellow flashes, which is the *definition* of physical
length." But Tom replies, "But those flashes were NOT simultaneous.
The green flash at the front came before the yellow flash at the back..
If you mark the front of the train first and then mark the back of the
train second, OF COURSE you will come up with a number that is too
small." "But that's not what happened with the green and yellow
flashes," says Stan. "Yes, it is!" shouts Tom, "You should have used
the yellow and RED flashes."
Then, after a pause, Stan says, "Look, if you measure the back of the
train first and then the front of the train second, you'll get a
number that's too long for the train. That's why I didn't use the
yellow and red flashes." "But that's not what happened with the yellow
and red flashes," says Tom. "Yes it is!" shouts Stan.
And it appears there is no way to settle this, because they both use
the same definition of physical length and they both use the same
definition of simultaneity and all propagation delays have been
accounted for, and there is still disagreement about both the
simultaneity and, as a result, the length of the train. Finally, note
that there is NO implication whatsoever of something physically
happening to the train to squeeze it or stretch it out. But nor is it
an optical illusion. It all rests on the *definition* of simultaneity,
which we defined last time and which makes perfect sense.
Comments? Questions?
PD
Question:
Which were their measurements that showed that
light speed is isotropic?
They were doing experiments in their labs that were independent of the
green, yellow, and red flashes. As mentioned in the first long post I
gave you, they were performing experiments similar to those found
here:http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html#...
So they already *know* from these other measurements that light speed
is isotropic.
|
Ok, I just wanted such precision.
| Quote: |
Comments:
Stan says the train is 600 m long, Tom disagrees and
claims that the train is 800 m long.
Yes.
Then Stan said, use your ruler to measure the length,
you will find that it is 600 m.
OK.
Tom did it, and found
600 m,
No, please read what I wrote again. Tom measured the distances from
each of the brushes to where he was standing -- those were each 400 m.
He did this with a ruler. 400 m + 400 m = 800 m, and he was in the
middle between the two brushes.
|
Yes, you wrote that, but I added to the scenario that
Stan asked Tom to also measure the length of the train by
using the ruler on the train itself. Then, Tom found
600 m.
Marcel Luttgens
| Quote: |
and claimed that there must be something wrong
with the simultaneity rule.
Stan replied: "Perhaps not if the train is moving at
100 m/s".
We have experimentally found that the speed of
light is 300 m/s (!). As I determined the length of
the train from the time taken by light to reach me
at 300 m/s, i.e. 1 second, I inferred that that the half
length of the train is 300 m.
After 1 second, the middle of the train, where you
were sitting, travelled 100 m, so you were at 300 m
+ 100 m = 400 m from the yellow flash, and the
red light reached you after 1 second if we add
to its velocity the velocity of the train.
Marcel Luttgens |
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Puppet_Sock
Guest
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| Posted: Wed Jul 16, 2008 1:40 pm Post subject: Re: Are *observed* SR effects real? |
|
|
Off topic news groups snipped. Folks, it is decidedly rude to post
relativity whinges in groups where they are off topic.
On Jul 16, 8:54 am, Danny Milano <milanoda...@yahoo.com> wrote:
[snip]
| Quote: |
Without relativistic corrections. Do you know how many error would
the GPS introduce? How many inches, meters or miles?
|
http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html
Round about 10 km a day.
| Quote: |
I remember
Baird saying that GPS folks use the relativity equations just to make
them feel "in" and pure newtonian equation is as accurate as it gets.
|
You remember that, do you? When I dream, I have a pony.
| Quote: |
If the differences is only a few inches. Then GPS is not proof of SR
at all.
|
Science does not deal in proof of theory, but validation and disproof.
To date, there are no disproofs of relativity. There are some
tantalizing hints at the limits of experimental accuracy, mostly in
situations that are hard to observe and hard to reproduce. (The last
100 years of the history of particular eclipsing binaries is pretty
hard
to reproduce.) To date, relativity is still valid.
But there is a huge amount of data that shows Newton is wrong.
In some cases, easy to reproduce cases, by 100's of sigmas.
(Ask your teacher what "sigma" means in this context.)
Socks |
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PD
Guest
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| Posted: Wed Jul 16, 2008 2:11 pm Post subject: Re: Are *observed* SR effects real? |
|
|
On Jul 16, 7:54 am, Danny Milano <milanoda...@yahoo.com> wrote:
| Quote: |
On Jul 16, 8:30 pm, PD <TheDraperFam...@gmail.com> wrote:
On Jul 15, 3:09 pm, Pentcho Valev <pva...@yahoo.com> wrote:
On Jul 15, 9:00 pm, carlip-nos...@physics.ucdavis.edu wrote:
mluttg...@wanadoo.fr wrote:
On Jul 13, 7:26 pm, Dono <sa...@comcast.net> wrote:
[...]
Here some more recent info, from GPS and ISS (and some other clock-
carrying satellites), look at table 1:
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
Stupid,
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
is certainly not a confirmation of H&K's
experimental results.
Of course it is!
The authors are more careful than you and some of
your SR buddies. They nowhere claim that the relativistic
effects are real:
"Thus on account of its velocity, a GPS satellite clock
*appears* to run slow by 7 µs per day.
At an altitude of 20,184 km, the clock *appears*
to run fast by 45 µs per day.
[...]
This is standard experimentalist jargon. "Appears" means "The
evidence of our experiment shows." If you read more scientific
papers you'd recognize the usage.
And they didn't bring back the airborne clocks to
the ground in order to compare their reading with
the ground clocks:
Of course they did!
"As shown, when the flight was completed the flight clock
was theoretically ahead of the clock on the ground by 7.67 ns.
The actual flight clock data, when compared to the ground
clock before and after the flight, was ahead by 7.3 ± 1.7 ns.
The uncertainty represents the one-sigma variation in the
pre-flight clock comparison data over a span of 6 hours, which
is equivalent to the time the clocks were separated. The two
additional flight tests during this series produced similar results.
It is significant that the error in the clock closure would have
been nearly five times the uncertainty in the measured clock
data had relativity not been taken into account."
You will find similar results inhttp://tycho.usno.navy.mil/ptti/1981/Vol13_37.pdf
Look in particular at figure 44, which shows time before, during,
and after a flight of an atomic clock compared to a ground-based
reference clock.
Steve Carlip
Bravo Honest Carlip! You have not left the sinking ship yet! Now you
will have to give some explanations:
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
"First, there is the effect of time dilation. The velocity of a moving
clock causes it to appear to run slow relative to a clock on the
Earth. GPS satellites revolve around the Earth with an orbital period
of 11.967 hours and a velocity of 3.874 km/s. Thus on account of its
velocity, a GPS satellite clock appears to run slow by 7 µs per day.."
This must be special relativity isn't it Honest Carlip. Then why is
time dilation not reciprocal? Why should the clock on the earth run
FASTER, Honest Carlip?
Because we're not dealing with two *inertial* reference frames. The
satellite is undergoing a *closed* orbit. This does not mean that
special relativity and time dilation cannot be used -- special
relativity can certainly be used in non-inertial reference frames.
However, special relativity says that the *mutual* time dilation that
you are looking for ONLY applies when BOTH reference frames are
inertial.
Your very shallow grasp on special relativity seems to trip you up
wherever you go.
Fortunately, it is not complicated, and it is not reserved for
geniuses and magicians. All you need to do is to find a decent book
and a decent teacher to interact with. The way you are going about it
is perhaps less than constructive.
Hi,
Without relativistic corrections. Do you know how many error would
the GPS introduce? How many inches, meters or miles? I remember
Baird saying that GPS folks use the relativity equations just to make
them feel "in" and pure newtonian equation is as accurate as it gets.
If the differences is only a few inches. Then GPS is not proof of SR
at all.
|
This is further demonstration that Baird doesn't know what he's
talking about. The degree to which GPS would be badly designed if GPS
were not included is a frequently reminded topic on this newsgroup. A
search will pull up loads of details.
| Quote: |
D.
Perhaps the gravitational potential difference
between the two clocks should be taken into account but then this is
not special relativity is it Honest Carlip. Why don't you explain -
you are such a great theoretician (only Tom Roberts is greater than
you).
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
"Second, there is the effect of the gravitational redshift, a
frequency shift caused by the difference in gravitational potential.
(The term “redshift” is generic regardless of sign, but for a
satellite clock the frequency shift is actually a blueshift.) The
difference in gravitational potential between the altitude of the
orbit and the surface of the Earth causes the satellite clock to
appear to run fast. At an altitude of 20,184 km, the clock appears to
run fast by 45 µs per day."
Another enigma, Honest Carlip. The frequency varies with the
gravitational potential V in accordance with the equation:
f' = f(1+V/c^2)
and this equation seems to be consistent with Einstein's 1911 equation
showing how the speed of light varies with the gravitational
potential:
c' = c(1+V/c^2)
But, Honest Carlip, if the frequency variation is due to speed of
light variation, then there is NO GRAVITATIONAL TIME DILATION, and
this can be seen even by Einsteinians sillier than you. And if there
is no gravitational time dilation, Honest Carlip, then what do your
brothers Einsteinians measure? Are they lying? Explain, Honest Carlip!
Is the frequency variation in a gravitational field due to speed of
light variation?
Pentcho Valev
pva...@yahoo.com- Hide quoted text -
- Show quoted text -- Hide quoted text -
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PD
Guest
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| Posted: Wed Jul 16, 2008 2:16 pm Post subject: Re: Are *observed* SR effects real? |
|
|
On Jul 16, 8:21 am, mluttg...@wanadoo.fr wrote:
| Quote: |
On Jul 16, 2:36 pm, PD <TheDraperFam...@gmail.com> wrote:
On Jul 16, 4:51 am, mluttg...@wanadoo.fr wrote:
On Jul 15, 4:44 pm, PD <TheDraperFam...@gmail.com> wrote:
On Jul 15, 7:22 am, mluttg...@wanadoo.fr wrote:
If you have no comments or questions regarding this post,
No comment, I am eager to read the next episode :-)
Marcel Luttgens
Alright, it's fine that you have no comments or questions so far,
though I'm surprised. Some of what I've told you already flies in the
face of common sense -- which is not necessarily a bad thing, but a
hurdle to overcome anyway.
So, as promised, what I will take is a scenario similar to what
Einstein used as an explanatory instrument, and for the same purpose.
I will first tell you what two different observers see (and this is in
fact confirmed in equivalent experiments), and then we'll show that
this is completely consistent with the laws of physics, even though
their observations might be surprising at first.
There is a federal train whipping through a campus town. It's an
electric train and it receives its power from a suspended wire
alongside the track, via electrical brushes mounted near the ends of
the train. As the train passes by a pole supporting the wire,
occasionally a bright spark is thrown at the wire support at the pole
and the electric brush as the brush whisks by it, sometimes a reddish
spark, sometimes greenish, sometimes yellowish.
There's a physicist working in a lab next to the tracks, and there's a
physicist working in a lab on the train. As it turns out, they are
both doing independent and competing light-speed isotropy experiments,
and they know each other. Both of them just about a half-hour ago
completed measurements that showed that light speed is isotropic, and
this is true even though one lab is moving relative to the other.
(This repeats an earlier published test of Einstein's light speed
postulate, but now with higher precision.)
As the train passes by, Stan, the researcher in the lab in town, looks
out and sees the following:
1. Two flashes simultaneously, one yellow from the back of the train
and one green from the front of the train.
2. A short time later still, a bright red flash at the front of the
train.
Tom, the researcher on the train, sees the very same flashes (the only
ones that actually happen that day), but sees them in the following
order:
3. A green flash from the front of the train.
4. A short time later, two flashes simultaneously, one yellow from the
back of the train and one red from the front of the train.
They radio each other to see if this disrupted the other's isotropy
experiment (it didn't) and to relate what they saw.
Stan goes out after the conversation and measures the distance from
the three poles where he saw the flashes to his lab. As it turns out,
the poles where the yellow and green flashes came from are equidistant
from his lab, though the pole where the red flash came from is further
away. He uses his three observations: isotropy, equal distance from
source, and (1) above to CORRECTLY conclude that the yellow and green
flashes are simultaneous. He is using the *definition* of simultaneity
that we cited last time.
He's not sure about whether the red flash was later just because the
flash was coming from further away, but since he's measured the
distance, he can figure out the propagation delay knowing the speed of
light. There is indeed a delay but not as long as what he observed
between the red and yellow flashes. So he CORRECTLY concludes that the
red and yellow flashes are not simultaneous.
Stan also notes that the two poles where the simultaneous (yellow and
green) flashes came from are 600 m apart, and since they came from the
brushes at the front and back of the train, he knows the train is 600
m long. Remember that he also knows the distance to the pole where the
red flash happened -- we may use that later.
Tom, on the other hand, notes that he was standing exactly midway
between the two brushes at the end of the train when any of the
flashes happened. The distance from either end of the train to his lab
is 400 m, so he knows the whole train is 800 m long. So he uses his
isotropy results, and the fact that he was equidistant from the
brushes and observation (4) to CORRECTLY conclude that the red and
yellow flashes are simultaneous and that the green and yellow flashes
are not simultaneous.
So, they radio this information to each other:
Stan: Using the *definition* of simultaneity, the green and yellow
flashes are simultaneous, and the red and yellow flashes are not
simultaneous.
Tom: Using the *same definition* of simultaneity, the red and yellow
flashes are simultaneous and the green and yellow flashes are not
simultaneous.
Note they have both *taken into account* propagation delay, and that
they each use only the *measurements* they individually make.
So, there is obviously a disagreement here about the simultaneity, and
this causes some head-scratching about how it is the other could have
seen what they saw. We'll come back to that next time, using the laws
of physics.
Incidentally, they also disagree about the length of the train, as you
can see. But they both immediately see that this is simply rooted in
the problem of the simultaneity. For instance:
Stan says the train is 600 m long, "...because I used the
*simultaneous* marking of the locations of the ends of the train using
the green and yellow flashes, which is the *definition* of physical
length." But Tom replies, "But those flashes were NOT simultaneous.
The green flash at the front came before the yellow flash at the back.
If you mark the front of the train first and then mark the back of the
train second, OF COURSE you will come up with a number that is too
small." "But that's not what happened with the green and yellow
flashes," says Stan. "Yes, it is!" shouts Tom, "You should have used
the yellow and RED flashes."
Then, after a pause, Stan says, "Look, if you measure the back of the
train first and then the front of the train second, you'll get a
number that's too long for the train. That's why I didn't use the
yellow and red flashes." "But that's not what happened with the yellow
and red flashes," says Tom. "Yes it is!" shouts Stan.
And it appears there is no way to settle this, because they both use
the same definition of physical length and they both use the same
definition of simultaneity and all propagation delays have been
accounted for, and there is still disagreement about both the
simultaneity and, as a result, the length of the train. Finally, note
that there is NO implication whatsoever of something physically
happening to the train to squeeze it or stretch it out. But nor is it
an optical illusion. It all rests on the *definition* of simultaneity,
which we defined last time and which makes perfect sense.
Comments? Questions?
PD
Question:
Which were their measurements that showed that
light speed is isotropic?
They were doing experiments in their labs that were independent of the
green, yellow, and red flashes. As mentioned in the first long post I
gave you, they were performing experiments similar to those found
here:http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html#...
So they already *know* from these other measurements that light speed
is isotropic.
Ok, I just wanted such precision.
Comments:
Stan says the train is 600 m long, Tom disagrees and
claims that the train is 800 m long.
Yes.
Then Stan said, use your ruler to measure the length,
you will find that it is 600 m.
OK.
Tom did it, and found
600 m,
No, please read what I wrote again. Tom measured the distances from
each of the brushes to where he was standing -- those were each 400 m.
He did this with a ruler. 400 m + 400 m = 800 m, and he was in the
middle between the two brushes.
Yes, you wrote that, but I added to the scenario that
Stan asked Tom to also measure the length of the train by
using the ruler on the train itself. Then, Tom found
600 m.
|
The ruler that Tom used was a ruler on the train itself. It yielded
400 m from where he was standing to the brush on the train, and 400 m
from where he was standing to the other brush on the train. I am
reporting to you what he *observed*.
You are not *adding* to the scenario. You are *changing* the scenario.
The observations that are in my scenario are consistent with setups
and results in equivalent experiments recorded in the literature. The
*altered* scenario you just proposed is inconsistent with experimental
results in the literature.
But just to bring us back on track, the key thing is that, according
to the observations made, the yellow and green flashes are
simultaneous for Stan but not for Tom, and the yellow and red flashes
are simultaneous for Tom but not for Stan.
| Quote: |
Marcel Luttgens
and claimed that there must be something wrong
with the simultaneity rule.
Stan replied: "Perhaps not if the train is moving at
100 m/s".
We have experimentally found that the speed of
light is 300 m/s (!). As I determined the length of
the train from the time taken by light to reach me
at 300 m/s, i.e. 1 second, I inferred that that the half
length of the train is 300 m.
After 1 second, the middle of the train, where you
were sitting, travelled 100 m, so you were at 300 m
+ 100 m = 400 m from the yellow flash, and the
red light reached you after 1 second if we add
to its velocity the velocity of the train.
Marcel Luttgens |
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Eric Gisse
Guest
|
| Posted: Wed Jul 16, 2008 2:37 pm Post subject: Re: Are *observed* SR effects real? |
|
|
On Jul 16, 4:54 am, Danny Milano <milanoda...@yahoo.com> wrote:
| Quote: |
On Jul 16, 8:30 pm, PD <TheDraperFam...@gmail.com> wrote:
On Jul 15, 3:09 pm, Pentcho Valev <pva...@yahoo.com> wrote:
On Jul 15, 9:00 pm, carlip-nos...@physics.ucdavis.edu wrote:
mluttg...@wanadoo.fr wrote:
On Jul 13, 7:26 pm, Dono <sa...@comcast.net> wrote:
[...]
Here some more recent info, from GPS and ISS (and some other clock-
carrying satellites), look at table 1:
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
Stupid,
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
is certainly not a confirmation of H&K's
experimental results.
Of course it is!
The authors are more careful than you and some of
your SR buddies. They nowhere claim that the relativistic
effects are real:
"Thus on account of its velocity, a GPS satellite clock
*appears* to run slow by 7 µs per day.
At an altitude of 20,184 km, the clock *appears*
to run fast by 45 µs per day.
[...]
This is standard experimentalist jargon. "Appears" means "The
evidence of our experiment shows." If you read more scientific
papers you'd recognize the usage.
And they didn't bring back the airborne clocks to
the ground in order to compare their reading with
the ground clocks:
Of course they did!
"As shown, when the flight was completed the flight clock
was theoretically ahead of the clock on the ground by 7.67 ns.
The actual flight clock data, when compared to the ground
clock before and after the flight, was ahead by 7.3 ± 1.7 ns.
The uncertainty represents the one-sigma variation in the
pre-flight clock comparison data over a span of 6 hours, which
is equivalent to the time the clocks were separated. The two
additional flight tests during this series produced similar results.
It is significant that the error in the clock closure would have
been nearly five times the uncertainty in the measured clock
data had relativity not been taken into account."
You will find similar results inhttp://tycho.usno.navy.mil/ptti/1981/Vol13_37.pdf
Look in particular at figure 44, which shows time before, during,
and after a flight of an atomic clock compared to a ground-based
reference clock.
Steve Carlip
Bravo Honest Carlip! You have not left the sinking ship yet! Now you
will have to give some explanations:
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
"First, there is the effect of time dilation. The velocity of a moving
clock causes it to appear to run slow relative to a clock on the
Earth. GPS satellites revolve around the Earth with an orbital period
of 11.967 hours and a velocity of 3.874 km/s. Thus on account of its
velocity, a GPS satellite clock appears to run slow by 7 µs per day.."
This must be special relativity isn't it Honest Carlip. Then why is
time dilation not reciprocal? Why should the clock on the earth run
FASTER, Honest Carlip?
Because we're not dealing with two *inertial* reference frames. The
satellite is undergoing a *closed* orbit. This does not mean that
special relativity and time dilation cannot be used -- special
relativity can certainly be used in non-inertial reference frames.
However, special relativity says that the *mutual* time dilation that
you are looking for ONLY applies when BOTH reference frames are
inertial.
Your very shallow grasp on special relativity seems to trip you up
wherever you go.
Fortunately, it is not complicated, and it is not reserved for
geniuses and magicians. All you need to do is to find a decent book
and a decent teacher to interact with. The way you are going about it
is perhaps less than constructive.
Hi,
Without relativistic corrections. Do you know how many error would
the GPS introduce? How many inches, meters or miles? I remember
Baird saying that GPS folks use the relativity equations just to make
them feel "in" and pure newtonian equation is as accurate as it gets.
If the differences is only a few inches. Then GPS is not proof of SR
at all.
|
Yea, because something like differential GPS that obtains your
position within a cm doesn't exist. Oh, and because a ~50,000 nanosec/
day clock drift relative to the satellite's orbit and Earth's surface
manifests a...let's see.
What's light speed? Roughly a foot/ns. That's an approximately 10
miles/day of drift without the general relativistic corrections.
Eric, why do you post under a pseudonym? The sock puppet is blindingly
obvious, as is your lack of education in physics.
[...] |
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Pentcho Valev
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| Posted: Wed Jul 16, 2008 2:40 pm Post subject: Re: Are *observed* SR effects real? |
|
|
On Jul 16, 2:30 pm, PD <TheDraperFam...@gmail.com> wrote:
| Quote: |
On Jul 15, 3:09 pm, Pentcho Valev <pva...@yahoo.com> wrote:
On Jul 15, 9:00 pm, carlip-nos...@physics.ucdavis.edu wrote:
mluttg...@wanadoo.fr wrote:
On Jul 13, 7:26 pm, Dono <sa...@comcast.net> wrote:
[...]
Here some more recent info, from GPS and ISS (and some other clock-
carrying satellites), look at table 1:
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
Stupid,
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
is certainly not a confirmation of H&K's
experimental results.
Of course it is!
The authors are more careful than you and some of
your SR buddies. They nowhere claim that the relativistic
effects are real:
"Thus on account of its velocity, a GPS satellite clock
*appears* to run slow by 7 µs per day.
At an altitude of 20,184 km, the clock *appears*
to run fast by 45 µs per day.
[...]
This is standard experimentalist jargon. "Appears" means "The
evidence of our experiment shows." If you read more scientific
papers you'd recognize the usage.
And they didn't bring back the airborne clocks to
the ground in order to compare their reading with
the ground clocks:
Of course they did!
"As shown, when the flight was completed the flight clock
was theoretically ahead of the clock on the ground by 7.67 ns..
The actual flight clock data, when compared to the ground
clock before and after the flight, was ahead by 7.3 ± 1.7 ns.
The uncertainty represents the one-sigma variation in the
pre-flight clock comparison data over a span of 6 hours, which
is equivalent to the time the clocks were separated. The two
additional flight tests during this series produced similar results.
It is significant that the error in the clock closure would have
been nearly five times the uncertainty in the measured clock
data had relativity not been taken into account."
You will find similar results in http://tycho.usno.navy.mil/ptti/1981/Vol13_37.pdf
Look in particular at figure 44, which shows time before, during,
and after a flight of an atomic clock compared to a ground-based
reference clock.
Steve Carlip
Bravo Honest Carlip! You have not left the sinking ship yet! Now you
will have to give some explanations:
http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
"First, there is the effect of time dilation. The velocity of a moving
clock causes it to appear to run slow relative to a clock on the
Earth. GPS satellites revolve around the Earth with an orbital period
of 11.967 hours and a velocity of 3.874 km/s. Thus on account of its
velocity, a GPS satellite clock appears to run slow by 7 µs per day."
This must be special relativity isn't it Honest Carlip. Then why is
time dilation not reciprocal? Why should the clock on the earth run
FASTER, Honest Carlip?
Because we're not dealing with two *inertial* reference frames. The
satellite is undergoing a *closed* orbit. This does not mean that
special relativity and time dilation cannot be used -- special
relativity can certainly be us | | | |
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