Science > Physics > Has the speed of light emitted by a fast moving particle been measured ?
| Topic: |
Science > Physics |
| User: |
"blackboab" |
| Date: |
30 Sep 2005 04:11:57 AM |
| Object: |
Has the speed of light emitted by a fast moving particle been measured ? |
if a particle going close to the speed of light - eg in a particle
accelerator - emits a photon can its speed be measured ?
if so how ?
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| User: "Androcles Androcles@ MyPlace.org" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
30 Sep 2005 04:53:07 AM |
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"blackboab" <blackboab@gmail.com> wrote in message
news:1128071517.033069.186720@g14g2000cwa.googlegroups.com...
| if a particle going close to the speed of light - eg in a particle
| accelerator - emits a photon can its speed be measured ?
|
| if so how ?
|
T. Alväger, F.J.M. Farley, J. Kjellman and I Wallin, "Test of the Second
Postulate of Relativity in the GeV Region'' Phys. Lett. 12 260-262
(1964);
The hard part is measuring the speed of the emitting pion inside the
beryllium block that the idiots Alväger, Farley, Kjellman and Wallin
call a vacuum.
Androcles.
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| User: "" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
30 Sep 2005 05:29:22 PM |
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Funny how everybody's an idiot except your cocksucking *****,
Amdro-cheese. Go take a thorn out of of lion's paw, get your
cocksucking foul mouth eaten, and we'll be rid of your fucking,
cocksucking *****, Mother Fucker. Oh - and have a nice day, *****.
.
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| User: "blackboab" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
30 Sep 2005 05:12:43 AM |
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and this is the sole experimental proof for the second postulate of
special relativity ?
what is wrong with it in your opinion ?
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| User: "Androcles Androcles@ MyPlace.org" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
30 Sep 2005 05:23:06 AM |
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"blackboab" <blackboab@gmail.com> wrote in message
news:1128075163.643745.43300@o13g2000cwo.googlegroups.com...
| and this is the sole experimental proof for the second postulate of
| special relativity ?
|
| what is wrong with it in your opinion ?
Hit a beryllium block with a proton beam, it glows gamma rays.
Then claim the speed of the gamma ray has been added to the
speed of a particle inside the block, which "proves" that the speed
of gamma rays in the vacuum of the tube is independent of it's source.
Beryllium blocks are vacuum...yeah, right. Never mind, it's only your
taxes that pay for this kind of garbage.
Androcles.
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| User: "Rene Tschaggelar" |
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| Title: Re: Has the speed of light emitted by a fast moving particle beenmeasured ? |
30 Sep 2005 05:43:18 AM |
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Androcles wrote:
"blackboab" <blackboab@gmail.com> wrote in message
news:1128075163.643745.43300@o13g2000cwo.googlegroups.com...
| and this is the sole experimental proof for the second postulate of
| special relativity ?
|
| what is wrong with it in your opinion ?
Hit a beryllium block with a proton beam, it glows gamma rays.
Then claim the speed of the gamma ray has been added to the
speed of a particle inside the block, which "proves" that the speed
of gamma rays in the vacuum of the tube is independent of it's source.
Beryllium blocks are vacuum...yeah, right. Never mind, it's only your
taxes that pay for this kind of garbage.
Vacuum ? Isn't the epsilon of a metal considered
infinite ? Ah, yes, for gammas it falls to 1.
Rene
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| User: "Androcles Androcles@ MyPlace.org" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
30 Sep 2005 06:19:28 AM |
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"Rene Tschaggelar" <none@none.net> wrote in message
news:433d170d$0$1145$5402220f@news.sunrise.ch...
| Androcles wrote:
|
| > "blackboab" <blackboab@gmail.com> wrote in message
| > news:1128075163.643745.43300@o13g2000cwo.googlegroups.com...
| > | and this is the sole experimental proof for the second postulate
of
| > | special relativity ?
| > |
| > | what is wrong with it in your opinion ?
| >
| > Hit a beryllium block with a proton beam, it glows gamma rays.
| > Then claim the speed of the gamma ray has been added to the
| > speed of a particle inside the block, which "proves" that the speed
| > of gamma rays in the vacuum of the tube is independent of it's
source.
| > Beryllium blocks are vacuum...yeah, right. Never mind, it's only
your
| > taxes that pay for this kind of garbage.
|
| Vacuum ? Isn't the epsilon of a metal considered
| infinite ? Ah, yes, for gammas it falls to 1.
| Rene
The relativist's lookup table:
gamma Desired velocity
1 0.000000000000000
10 0.994987437106620
100 0.999949998749938
1000 0.999999499999875
10000 0.999999995000000
100000 0.999999999950000
1000000 0.999999999999500
10000000 0.999999999999995
Measure the energy, calculate a gamma, look
up the speed of the particle. It will always be
within the limits of experimental error.
Androcles.
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| User: "blackboab" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
30 Sep 2005 05:30:38 AM |
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it does sound a bit ropey. is that the only direct proof of the second
postulate ?
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| User: "Androcles Androcles@ MyPlace.org" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
30 Sep 2005 06:13:13 AM |
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"blackboab" <blackboab@gmail.com> wrote in message
news:1128076238.035552.46610@g49g2000cwa.googlegroups.com...
| it does sound a bit ropey. is that the only direct proof of the second
| postulate ?
Since the second postulate is false, there can be no proof.
By 1920, 15 years later, Einstein was still trying to persuade people of
how right
his hoax was. He succeeded.
http://www.bartleby.com/173/7.html
Comments in square brackets are mine.
"Albert Einstein (1879-1955). Relativity: The Special and
General Theory. 1920.
The Apparent Incompatibility of the Law of Propagation of
Light with the Principle of Relativity.
THERE is hardly a simpler law in physics than that according
to which light is propagated in empty space
[except the Principle of Relativity, a really simple law].
Every child at school knows, or believes he knows, that this
[Harry Potter]
propagation takes place in straight lines with a velocity
c = 300,000 km./sec
[relative to the source, but cosmic muons can win that race by a mile,
literally. Einstein seems to have forgotten he said "we shall, however,
find in what follows, that the velocity of light in our theory plays the
part, physically, of an infinitely great velocity"].
At all events we know with great exactness that this velocity
is the same for all colours, because if this were not the case
[prisms would split white light into different colours and we
never see that, and ]
the minimum of emission would not be observed simultaneously
for different colours during the eclipse of a fixed star by its dark
neighbour
[except that Algol has no dark neighbour, John Goodricke, 18 years
old with a toy telescope in 1782 forgot to include the velocity of
light into his calculations and an eclipse means no light at all,
not a reduction in magnitude, besides which calculations reveal
that such a system is unstable, the "dark neighbour" is at the Roche
limit and will break up]
By means of similar considerations based on observations of
double stars
[Sirius, 8 light years away with a period of 50 years,
http://www.star.ucl.ac.uk/~apod/apod/ap001006.html
no other double has ever been seen]
the Dutch astronomer De Sitter was also able to show that the
velocity of propagation of light cannot depend on the velocity
of motion of the body emitting the light
[oh really? how? I see no significant velocity v from Sirius to add to
c].
The assumption that this velocity of propagation is dependent
on the direction "in space" is in itself improbable
[but factually true. Compare http://www.ebicom.net/~rsf1/sekerin.htm
(fig 3 with http://www.britastro.org/vss/gifc/00918-ck.gif
Real scientists don't deal in assumptions and probables or persuasion].
In short, let us assume
[No, I will not assume]
that the simple law
[because Einstein says it is a law]
of the constancy of the velocity of light c (in vacuum) is justifiably
believed by the child at school
[who also believes in Santa Claus, but not believed by thinking
rational adults].
Who would imagine that this simple law has plunged the conscientiously
thoughtful physicist into the greatest intellectual difficulties?
[and solved them, not being a peanut brain like Einstein, it wasn't that
difficult]
Let us consider how these difficulties arise
[because Einstein can make up stories] ."
[Skip silly train story]
At this juncture the theory of relativity entered the arena.
(Einstein wants to be famous]
As a result of an analysis of the physical conceptions of time
and space,
[insert here this 'analysis' in Einstein's own words]
"we establish by definition that the "time" required by light to travel
from A to B equals the "time" it requires to travel from B to A."
[end insert. Some great analysis, that was.]
it became evident that
[Einstein is lying through my teeth]
in reality there is not the least incompatibility between the
principle of relativity
[which he hasn't discussed at all]
and the law of propagation of light
[Because Einstein says so, it's a LAW, stomp foot]
and that by systematically holding fast to both these laws a
logically [huh?] rigid theory could be arrived at
[such as the speed of light being infinitely great in his theory].
This theory has been called the special theory of relativity
[or the special theory of the excrement of the male bovine]
to distinguish it from the extended theory, with which
we shall deal later.
In the following pages we shall present the fundamental ideas
of the special theory of relativity
[but the conscientiously thoughtful physicist isn't taken in by it]."
Androcles.
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| User: "Pyriform" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
30 Sep 2005 05:22:44 PM |
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blackboab wrote:
it does sound a bit ropey. is that the only direct proof of the second
postulate ?
A word of caution; "androcles" is an established crackpot and moron. You
should treat his assertions accordingly.
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| User: "Sam Wormley" |
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| Title: Re: Has the speed of light emitted by a fast moving particle beenmeasured ? |
30 Sep 2005 09:00:44 AM |
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blackboab wrote:
and this is the sole experimental proof for the second postulate of
special relativity ?
"Proofs" are found in mathematics.
In physics, one used observational (and experimental) data to
support or refute a hypothesis.
Special relativity makes predictions. Observational data confirms
those predictions. There has never been a prediction of special
relativity that was contradicted by an observation.
.
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| User: "" |
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| Title: Re: Has the speed of light emitted by a fast moving particle beenmeasured ? |
02 Oct 2005 04:56:35 AM |
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In article <gyb%e.376949$x96.314509@attbi_s72>,
Sam Wormley <swormley1@mchsi.com> wrote:
blackboab wrote:
and this is the sole experimental proof for the second postulate of
special relativity ?
"Proofs" are found in mathematics.
In physics, one used observational (and experimental) data to
support or refute a hypothesis.
This lack of knowledge seems to be getting common. Was it
unusual for me to figure this difference out by taking
a plane geometry course and a science course in the same
year in high school?
One of the cool things about math is you start with nothing
and you can build anything you want. With science, you
gather a mess and then sort it out using the Scientific Method.
I exaggerate slightly here.
/BAH
Special relativity makes predictions. Observational data confirms
those predictions. There has never been a prediction of special
relativity that was contradicted by an observation.
.
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| User: "" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
02 Oct 2005 02:11:28 PM |
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In article <dhoasj$8qk_003@s873.apx1.sbo.ma.dialup.rcn.com>, writes:
In article <gyb%e.376949$x96.314509@attbi_s72>,
Sam Wormley <swormley1@mchsi.com> wrote:
blackboab wrote:
and this is the sole experimental proof for the second postulate of
special relativity ?
"Proofs" are found in mathematics.
In physics, one used observational (and experimental) data to
support or refute a hypothesis.
This lack of knowledge seems to be getting common. Was it
unusual for me to figure this difference out by taking
a plane geometry course and a science course in the same
year in high school?
One of the cool things about math is you start with nothing
and you can build anything you want. With science, you
gather a mess and then sort it out using the Scientific Method.
I exaggerate slightly here.
No, you don't exagerate, that's pretty much how it works. With the
slight correcton that in math you start with very little (instead of
"nothing"). But beyond this, it is just what you described.
Mati Meron | "When you argue with a fool,
meron@cars.uchicago.edu | chances are he is doing just the same"
.
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| User: "" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
03 Oct 2005 04:41:21 AM |
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In article <AhW%e.1$45.657@news.uchicago.edu>,
wrote:
In article <dhoasj$8qk_003@s873.apx1.sbo.ma.dialup.rcn.com>,
jmfbahciv@aol.com writes:
In article <gyb%e.376949$x96.314509@attbi_s72>,
Sam Wormley <swormley1@mchsi.com> wrote:
blackboab wrote:
and this is the sole experimental proof for the second postulate of
special relativity ?
"Proofs" are found in mathematics.
In physics, one used observational (and experimental) data to
support or refute a hypothesis.
This lack of knowledge seems to be getting common. Was it
unusual for me to figure this difference out by taking
a plane geometry course and a science course in the same
year in high school?
One of the cool things about math is you start with nothing
and you can build anything you want. With science, you
gather a mess and then sort it out using the Scientific Method.
I exaggerate slightly here.
No, you don't exagerate, that's pretty much how it works. With the
slight correcton that in math you start with very little (instead of
"nothing"). But beyond this, it is just what you described.
The first step with math is to carefully pick a set of axioms and
then build from these few items. That was what I meant by "nothing".
I didn't mention that those couple of things chosen need to be
carefully chosen. ;-) One of the things I always wanted to do
was to take a set of established axioms and then tweak one
slightly, go throught the build process, and then see what differences
beween the two. And do this a thousand different ways.
/BAH
.
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| User: "" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
03 Oct 2005 10:11:58 AM |
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In article <dhquc1$8ss_002@s1263.apx1.sbo.ma.dialup.rcn.com>, writes:
In article <AhW%e.1$45.657@news.uchicago.edu>,
mmeron@cars3.uchicago.edu wrote:
In article <dhoasj$8qk_003@s873.apx1.sbo.ma.dialup.rcn.com>,
writes:
In article <gyb%e.376949$x96.314509@attbi_s72>,
Sam Wormley <swormley1@mchsi.com> wrote:
blackboab wrote:
and this is the sole experimental proof for the second postulate of
special relativity ?
"Proofs" are found in mathematics.
In physics, one used observational (and experimental) data to
support or refute a hypothesis.
This lack of knowledge seems to be getting common. Was it
unusual for me to figure this difference out by taking
a plane geometry course and a science course in the same
year in high school?
One of the cool things about math is you start with nothing
and you can build anything you want. With science, you
gather a mess and then sort it out using the Scientific Method.
I exaggerate slightly here.
No, you don't exagerate, that's pretty much how it works. With the
slight correcton that in math you start with very little (instead of
"nothing"). But beyond this, it is just what you described.
The first step with math is to carefully pick a set of axioms and
then build from these few items. That was what I meant by "nothing".
And that is what I meant "not nothing". These few items aren't
nothing. In fact, in a way they're everything.
I didn't mention that those couple of things chosen need to be
carefully chosen. ;-) One of the things I always wanted to do
was to take a set of established axioms and then tweak one
slightly, go throught the build process, and then see what differences
beween the two. And do this a thousand different ways.
Well, that's one of the major games math plays. That's how
non-Euclidean geometry came into being.
Mati Meron | "When you argue with a fool,
meron@cars.uchicago.edu | chances are he is doing just the same"
.
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| User: "" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
04 Oct 2005 05:58:48 AM |
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|
In article <2Tb0f.7$45.1302@news.uchicago.edu>,
wrote:
In article <dhquc1$8ss_002@s1263.apx1.sbo.ma.dialup.rcn.com>,
jmfbahciv@aol.com writes:
In article <AhW%e.1$45.657@news.uchicago.edu>,
wrote:
In article <dhoasj$8qk_003@s873.apx1.sbo.ma.dialup.rcn.com>,
jmfbahciv@aol.com writes:
In article <gyb%e.376949$x96.314509@attbi_s72>,
Sam Wormley <swormley1@mchsi.com> wrote:
blackboab wrote:
and this is the sole experimental proof for the second postulate of
special relativity ?
"Proofs" are found in mathematics.
In physics, one used observational (and experimental) data to
support or refute a hypothesis.
This lack of knowledge seems to be getting common. Was it
unusual for me to figure this difference out by taking
a plane geometry course and a science course in the same
year in high school?
One of the cool things about math is you start with nothing
and you can build anything you want. With science, you
gather a mess and then sort it out using the Scientific Method.
I exaggerate slightly here.
No, you don't exagerate, that's pretty much how it works. With the
slight correcton that in math you start with very little (instead of
"nothing"). But beyond this, it is just what you described.
The first step with math is to carefully pick a set of axioms and
then build from these few items. That was what I meant by "nothing".
And that is what I meant "not nothing". These few items aren't
nothing. In fact, in a way they're everything.
Of course. I think I was describing how I approached the
learning. It is very similar to learning a new programming
language or operating system. I memorize the "axioms", then
scan the tech specification to fill in the details...at least
that was how things were done when quality was distributed.
In this way, I could learn a new language and/or OS within
a day. Then the real work started by using the stuff and
learning its foilble. Developing a brand new piece is the
same way. You establish the basic rules and go from there.
I didn't mention that those couple of things chosen need to be
carefully chosen. ;-) One of the things I always wanted to do
was to take a set of established axioms and then tweak one
slightly, go throught the build process, and then see what differences
beween the two. And do this a thousand different ways.
Well, that's one of the major games math plays. That's how
non-Euclidean geometry came into being.
Since I was <ahem>geometry-challenged, I tended toward algebras.
/BAH
.
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| User: "Timo Nieminen" |
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| Title: Re: Has the speed of light emitted by a fast moving particle beenmeasured ? |
03 Oct 2005 06:34:11 AM |
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On Mon, 3 Oct 2005 wrote:
mmeron@cars3.uchicago.edu wrote:
writes:
One of the cool things about math is you start with nothing
and you can build anything you want. With science, you
gather a mess and then sort it out using the Scientific Method.
I exaggerate slightly here.
No, you don't exagerate, that's pretty much how it works. With the
slight correcton that in math you start with very little (instead of
"nothing"). But beyond this, it is just what you described.
The first step with math is to carefully pick a set of axioms and
then build from these few items. That was what I meant by "nothing".
I didn't mention that those couple of things chosen need to be
carefully chosen. ;-) One of the things I always wanted to do
was to take a set of established axioms and then tweak one
slightly, go throught the build process, and then see what differences
beween the two. And do this a thousand different ways.
The first step with science is to find something odd. Something funny in
some experimental/observational data; usually this is something that most
would dismiss without a closer look as merely an experimental error in
measurement. So you do a better experiment, to look at it more closely. A
problem in theory, so you think about it for 7 days or 7 years, however
long it takes, and step sideways around the difficulty. Hard work either
way.
It's all about having just the right amount of obsession! Too little, and
you ignore the interesting stuff because it's unexpected. Too much, and
you get hung up on trivia, or become convinced that some experimental
error is a real effect, or an imagined theoretical error is a real error.
Very Buddhist middle road.
--
Timo Nieminen - Home page: http://www.physics.uq.edu.au/people/nieminen/
E-prints: http://eprint.uq.edu.au/view/person/Nieminen,_Timo_A..html
Shrine to Spirits: http://www.users.bigpond.com/timo_nieminen/spirits.html
.
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| User: "Androcles Androcles@ MyPlace.org" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
03 Oct 2005 07:52:10 AM |
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"Timo Nieminen" <uqtniemi@mailbox.uq.edu.au> wrote in message
news:20051003211125.H47989@emu.uq.edu.au...
| The first step with science is to find something odd.
The system K is the road.
The system k is the bus.
x is a place on the road.
x' is a seat on the bus, being a point at rest in the system k which
must have a system of values x', y, z, independent of time, defined as
x' = x-vt.
The driver of the bus sits in the seat xi.
the seat xi is not the seat x',
xi = x'/sqrt(1-v^2/c^2)
= (x-vt)/sqrt(1-v^2/c^2)
The faster the bus goes, the further away the passenger in seat x' is
from
the driver in seat xi.
When v = c, the distance between the passenger and the driver is
infinite.
This is to prevent the passenger shining a light in the driver's
rear-view mirror
and dazzling the driver.
How odd.
Androcles.
.
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| User: "" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
03 Oct 2005 06:57:19 AM |
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In article <_P90f.66607$RW.688@fe2.news.blueyonder.co.uk>,
"Androcles" <Androcles@ MyPlace.org> wrote:
"Timo Nieminen" <uqtniemi@mailbox.uq.edu.au> wrote in message
news:20051003211125.H47989@emu.uq.edu.au...
| The first step with science is to find something odd.
<snip silly stuff>
Androcles.
'ey, Timo! Here is an example of something odd but not
unusual.
/BAH
.
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| User: "Androcles Androcles@ MyPlace.org" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
03 Oct 2005 08:35:21 AM |
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<jmfbahciv@aol.com> wrote in message
news:dhr6av$8qk_002@s1263.apx1.sbo.ma.dialup.rcn.com...
| In article <_P90f.66607$RW.688@fe2.news.blueyonder.co.uk>,
| "Androcles" <Androcles@ MyPlace.org> wrote:
| >
| >"Timo Nieminen" <uqtniemi@mailbox.uq.edu.au> wrote in message
| >news:20051003211125.H47989@emu.uq.edu.au...
| >| The first step with science is to find something odd.
| <snip silly stuff>
|
| >Androcles.
|
| 'ey, Timo! Here is an example of something odd but not
| unusual.
|
| /BAH
Ya think Einstein's 1905 paper is silly stuff, eh?
I agree.
Androcles.
.
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| User: "" |
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| Title: Re: Has the speed of light emitted by a fast moving particle beenmeasured ? |
03 Oct 2005 06:55:13 AM |
|
|
In article <20051003211125.H47989@emu.uq.edu.au>,
Timo Nieminen <uqtniemi@mailbox.uq.edu.au> wrote:
On Mon, 3 Oct 2005 wrote:
mmeron@cars3.uchicago.edu wrote:
writes:
One of the cool things about math is you start with nothing
and you can build anything you want. With science, you
gather a mess and then sort it out using the Scientific Method.
I exaggerate slightly here.
No, you don't exagerate, that's pretty much how it works. With the
slight correcton that in math you start with very little (instead of
"nothing"). But beyond this, it is just what you described.
The first step with math is to carefully pick a set of axioms and
then build from these few items. That was what I meant by "nothing".
I didn't mention that those couple of things chosen need to be
carefully chosen. ;-) One of the things I always wanted to do
was to take a set of established axioms and then tweak one
slightly, go throught the build process, and then see what differences
beween the two. And do this a thousand different ways.
The first step with science is to find something odd. Something funny in
some experimental/observational data; usually this is something that most
would dismiss without a closer look as merely an experimental error in
measurement. So you do a better experiment, to look at it more closely.
This isn't really the First Step. Nature is a big mess. To
learn anything about it you have to first pick a teensy little
area to start on and clean that up. Then mankind picks another
teensy little area; cleans that up. Of course, as in housework,
cleaning up the second mess can restore the first mess or
create five hundred more messes that need attention.
... A
problem in theory, so you think about it for 7 days or 7 years, however
long it takes, and step sideways around the difficulty.
I suppose, if it takes 7 centuries one gets the reputation of
an Einstein.
.. Hard work either way.
Yea, and loads of sanity checks. That is one procedure your science
biz has established that my computer biz needs desparately. We
don't have much in place to institutionalize the sanity checks nor
teaching the ones that exist (and are soon to be forgotten).
It's all about having just the right amount of obsession! Too little, and
you ignore the interesting stuff because it's unexpected. Too much, and
you get hung up on trivia, or become convinced that some experimental
error is a real effect, or an imagined theoretical error is a real error.
Very Buddhist middle road.
That's what you advisors are here for. right? Keep us young
and foolish things pointed in the correct direction?
This middle road is also formed by your publishing processes, too.
(which implies the info become public). Is it a trend that
this publicity vehicle is turning into the ad business?
/BAH
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| User: "Timo Nieminen" |
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| Title: Re: Has the speed of light emitted by a fast moving particle beenmeasured ? |
03 Oct 2005 01:50:26 PM |
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On Mon, 3 Oct 2005 wrote:
Timo Nieminen <uqtniemi@mailbox.uq.edu.au> wrote:
The first step with science is to find something odd. Something funny in
some experimental/observational data; usually this is something that most
would dismiss without a closer look as merely an experimental error in
measurement. So you do a better experiment, to look at it more closely.
This isn't really the First Step. Nature is a big mess. To
learn anything about it you have to first pick a teensy little
area to start on and clean that up. Then mankind picks another
teensy little area; cleans that up. Of course, as in housework,
cleaning up the second mess can restore the first mess or
create five hundred more messes that need attention.
Not the First Step, but the first step when a new cleaner enters the
fray. It's already partly cleaned up; the first thing to do is to find a
nice tasty bit of dirt you can really get your teeth into.
... A
problem in theory, so you think about it for 7 days or 7 years, however
long it takes, and step sideways around the difficulty.
I suppose, if it takes 7 centuries one gets the reputation of
an Einstein.
The reputation depends on the result, of course. Einstein took 7 years. If
he could have done it in 7 hours, with the same result, and the same
understanding of the result, well ... Without spending a long time
thinking about and understanding the problem, you're unlikely to dream
about snakes eating their own tails, and even less likely to connect it to
the problem at hand.
.. Hard work either way.
Yea, and loads of sanity checks. That is one procedure your science
biz has established that my computer biz needs desparately. We
don't have much in place to institutionalize the sanity checks nor
teaching the ones that exist (and are soon to be forgotten).
The newest IEEE Spectrum was all about software failure. Nice feature on
the FBI's newest softflop. One of the people involved summarised it
nicely, "We wanted it real bad, and in the end, it was." How to Kill a
Project by Bad Management, in 2 Easy Steps.
While the idea of sanity checks is the same, what they're used for is
quite different. The best sanity checks in science are in medicine, with
double-blind trials being the standard. Ever heard of physicists using
blind researchers? Almost always, not needed. Rocks and atoms and
electrons don't know about placebos, and there're only a few cases where
observer bias resulted in crap data.
Engineering and the ccomputer biz have much in common. Is software
engineering, as practiced in the field, really engineering yet?
It's all about having just the right amount of obsession! Too little, and
you ignore the interesting stuff because it's unexpected. Too much, and
you get hung up on trivia, or become convinced that some experimental
error is a real effect, or an imagined theoretical error is a real error.
Very Buddhist middle road.
That's what you advisors are here for. right? Keep us young
and foolish things pointed in the correct direction?
In principle. In practice, the quality of supervision falls short of what
it should be far too often. Although having a student follow an
interesting but useless diversion for too many months or years is rarely
the problem.
This middle road is also formed by your publishing processes, too.
(which implies the info become public). Is it a trend that
this publicity vehicle is turning into the ad business?
No, not yet. Because most papers aren't especially readable or
interesting, even for scientists. But that's what the glossy magazines and
their www versions are for.
--
Timo Nieminen - Home page: http://www.physics.uq.edu.au/people/nieminen/
E-prints: http://eprint.uq.edu.au/view/person/Nieminen,_Timo_A..html
Shrine to Spirits: http://www.users.bigpond.com/timo_nieminen/spirits.html
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| User: "PD" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
03 Oct 2005 07:31:41 PM |
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Timo Nieminen wrote:
On Mon, 3 Oct 2005 wrote:
mmeron@cars3.uchicago.edu wrote:
writes:
One of the cool things about math is you start with nothing
and you can build anything you want. With science, you
gather a mess and then sort it out using the Scientific Method.
I exaggerate slightly here.
No, you don't exagerate, that's pretty much how it works. With the
slight correcton that in math you start with very little (instead of
"nothing"). But beyond this, it is just what you described.
The first step with math is to carefully pick a set of axioms and
then build from these few items. That was what I meant by "nothing".
I didn't mention that those couple of things chosen need to be
carefully chosen. ;-) One of the things I always wanted to do
was to take a set of established axioms and then tweak one
slightly, go throught the build process, and then see what differences
beween the two. And do this a thousand different ways.
The first step with science is to find something odd. Something funny in
some experimental/observational data; usually this is something that most
would dismiss without a closer look as merely an experimental error in
measurement. So you do a better experiment, to look at it more closely. A
problem in theory, so you think about it for 7 days or 7 years, however
long it takes, and step sideways around the difficulty. Hard work either
way.
Actually, there at least three kinds of scientific first steps I can
think of.
1. The one you mention, where there is an anomalous behavior that
doesn't fit in with the current description or understanding of things.
2. The sudden recognition of a regularity among a bunch of previously
disparate observations.
3. Synthesis: the applicaiton of a conceptual framework that is known
to work well in one set of circumstances, to a completely different set
of circumstances, yielding a common view to two disparate fields of
knowledge.
It's all about having just the right amount of obsession! Too little, and
you ignore the interesting stuff because it's unexpected. Too much, and
you get hung up on trivia, or become convinced that some experimental
error is a real effect, or an imagined theoretical error is a real error.
Very Buddhist middle road.
--
Timo Nieminen - Home page: http://www.physics.uq.edu.au/people/nieminen/
E-prints: http://eprint.uq.edu.au/view/person/Nieminen,_Timo_A..html
Shrine to Spirits: http://www.users.bigpond.com/timo_nieminen/spirits.html
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| User: "blackboab" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
30 Sep 2005 09:31:30 AM |
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http://www-groups.dcs.st-and.ac.uk/~history/HistTopics/Special_relativity.html
"Also in the paper Einstein mentions the clock paradox. Einstein called
it a theorem that if two synchronous clocks C1 and C2 start at a point
A and C2 leaves A moving along a closed curve to return to A then C2
will run slow compared with C1. He notes that no paradox results since
C2 experiences acceleration while C1 does not."
has this also been confirmed ? do clocks sent in circular trajectories
run slower than stationary clocks ?
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| User: "Androcles Androcles@ MyPlace.org" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
30 Sep 2005 12:19:45 PM |
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"blackboab" <blackboab@gmail.com> wrote in message
news:1128090690.601151.192610@o13g2000cwo.googlegroups.com...
|
http://www-groups.dcs.st-and.ac.uk/~history/HistTopics/Special_relativity.html
|
| "Also in the paper Einstein mentions the clock paradox. Einstein
called
| it a theorem that if two synchronous clocks C1 and C2 start at a point
| A and C2 leaves A moving along a closed curve to return to A then C2
| will run slow compared with C1. He notes that no paradox results since
| C2 experiences acceleration while C1 does not."
|
| has this also been confirmed ?
Of course not. It was shown to be wrong in 1913 by Sagnac.
http://www.britannica.com/eb/article-9038664
I cant draw it here very well, but here is the idea.
You can turn a dinner plate on the table to similate this.
AB
CD
A is 12 o'clock, B is 3, D is 6 and C is 9 o'clock.
The light in a fiber optic light guide on the plate
leaves A and goes to B and C, *AS* the plate turns,
one way forward, the other back.
BD
AC
Now the light continues on from B and Cand meets itself at D,
again as the plate turns.
DC
BA
So now the light has gone from A to D, one ray through B
and the other through C, meeting itself where it started at
the top left corner.
So....that's Sagnac effect. We've added the speed of the
plate to the speed of the light, one ray moved at c+v = 4 sides = 2+2,
the other moved at c-v = 0 sides = 2-2, as seen from the table.
As seen from the plate it is from A to D, c = 2 sides.
do clocks sent in circular trajectories
| run slower than stationary clocks ?
No. The clock on the plate has the same time as the clock on the table.
Einstein was a phuckwit, Sagnac knew it. So did Michelson.
Androcles.
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| User: "Sam Wormley" |
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| Title: Re: Has the speed of light emitted by a fast moving particle beenmeasured ? |
30 Sep 2005 09:45:53 AM |
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blackboab wrote:
http://www-groups.dcs.st-and.ac.uk/~history/HistTopics/Special_relativity.html
"Also in the paper Einstein mentions the clock paradox. Einstein called
it a theorem that if two synchronous clocks C1 and C2 start at a point
A and C2 leaves A moving along a closed curve to return to A then C2
will run slow compared with C1. He notes that no paradox results since
C2 experiences acceleration while C1 does not."
has this also been confirmed ? do clocks sent in circular trajectories
run slower than stationary clocks ?
See Physics FAQ
http://hermes.physics.adelaide.edu.au/~dkoks/Faq/Relativity/SR/TwinParadox/twin_paradox.html
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| User: "blackboab" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
30 Sep 2005 10:16:11 AM |
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dont be a parrot. the twins paradox is a thought
experiment. according to relativity if a clock is sent in a circular
orbit it should slow down.
has this been observed ?
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| User: "Sam Wormley" |
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| Title: Re: Has the speed of light emitted by a fast moving particle beenmeasured ? |
30 Sep 2005 11:31:05 AM |
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blackboab wrote:
dont be a parrot.
Don't be stooopid!
the twins paradox is a thought
experiment. according to relativity if a clock is sent in a circular
orbit it should slow down.
has this been observed ?
See Physics FAQ
http://hermes.physics.adelaide.edu.au/~dkoks/Faq/Relativity/SR/TwinParadox/twin_paradox.html
You'll find that twin_paradox deals with synchronous clocks C1 and C2
Hafele and Keating Experiment
http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/airtim.html
http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/airtim.html#c3
What is the experimental basis of Special Relativity?
http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html
What is the experimental basis of Special Relativity?
Index
1. Introduction
Domain of Applicability Test Theories of SR
2. Early experiments (Pre-1905)
Roentgen, Eichenwald, Wilson, Rayleigh, Arago, Fizeau, Hoek, Bradley, Airy.
3. Tests of Einstein's Two Postulates
3.1 Round-Trip Tests of Light Speed Isotropy
Michelson and Morley, Kennedy and Thorndike, Modern Laser/Maser Tests, Other.
3.2 One-Way Tests of Light Speed Isotropy
Cialdea, Krisher, Champeny, Turner & Hill.
3.3 Tests of Light Speed from Moving Sources
Cosmological Sources: DeSitter, Brecher; Terrestrial Sources: Alvaeger, Sadeh, ....
3.4 Measurements of the Speed of Light, and Other Limits on it
NBS Measurements, 1983 Redefinition of the Meter, Limits on Variations with Frequency, Limits on Photon Mass.
3.5 Tests of the Principle of Relativity and Lorentz Invariance
Trouton Noble, Other.
3.6 Tests of the Isotropy of Space
Hughes-Drever, Prestage, Lamoreaux, Chupp, Phillips, Brillet and Hall.
4. Tests of Time Dilation and Transverse Doppler Effect
Ives and Stilwell; Particle Lifetimes, Doppler Shift Measurements.
5. Tests of the Twin Paradox
Haefle and Keating, Vessot et al, Alley, Bailey et al., The Clock Hypothesis.
6. Tests of Relativistic Kinematics
Elastic Scattering, Limiting Velocity c, Relativistic Mass Variations, Calorimetric Test of SR.
7. Other Experiments
Fizeau, Sagnac, Michelson and Gale, g-2 Tests of SR, The Global Positioning System (GPS), Lunar Laser Ranging,
Cosmic Background Radiation (CMBR), Constancy of Physical Constants, Other.
8. Experiments Which Apparently are NOT Consistent with SR/GR
Experimenter's Bias Publication Bias
9. Acknowledgments
1. Introduction
Physics is an experimental science, and as such the experimental basis
for any physical theory is extremely important. The relationship
between theory and experiments in modern science is a multi-edged
sword:
1. It is required that the theory not be refuted by any undisputed
experiment within the theory's domain of applicability.
2. It is expected that the theory be confirmed by a number of experiments that:
- cover a significant fraction of the theory's domain of applicability.
- examine a significant fraction of the theory's predictions.
It is believed that Special Relativity (SR) meets all of these
requirements and expectations. There are literally hundreds of
experiments that have tested SR, with an enormous range and diversity,
and the agreement between theory and experiment is excellent. There is
a lot of redundancy in these experimental tests. There are also a lot
of indirect tests of SR which are not included here. This list of
experiments is by no means complete!
Other than their sheer numbers, the most striking thing about these
experimental tests of SR is their remarkable breadth and diversity. An
important aspect of SR is its universality -- it applies to all known
physical phenomena and not just to the electromagnetic phenomena it was
originally invented to explain. In these experiments you will find
tests using electromagnetic and nuclear measurements (including both
strong and weak interactions); gravitational tests are the province of
General Relativity, and are not considered here, see Experimental Tests
of GR.
There are several useful surveys of the experimental basis of SR:
Y.Z.Zhang, Special Relativity and its Experimental Foundations, World Scientific (1997).
G.Holton, "Resource Letter SRT-1 on Special Relativity Theory", Am. J. Phys., 30 (1962), p462.
D.I.Blotkhintsev, "Basis for Special Relativity Theory Provided by Experiments in High Energy Physics", Sov. Phys.
Uspekhi, 9
(1966), p405.
Newman et al. Phys. Rev. Lett. 40 no. 21 (1978), p1355.
Zhang's book is especially comprehensive.
Textbooks with good summaries of the experimental basis of relativity are:
M.Born, Einstein's theory of Relativity.
Bergmann, Introduction to the Theory of Relativity.
Moller, The Theory of Relativity.
M. von Laue, Die relativitätstheorie (in German).
Note, however, that SR is not perfect (in agreement with every
experiment), and there are some experiments that are in disagreement
with its predictions. See Experiments Which Apparently are NOT
Consistent with SR where some of these experiments are referenced and
discussed. It is clear that most, if not all, of these experiments
have difficulties that are unrelated to SR. Note also that few if any
standard references or textbooks even mention the possibility that some
experiments might be inconsistent with SR, and there are also aspects
of publication bias in the literature. That being said, as of this
writing there are no reproducible and generally-accepted experiments
that are inconsistent with SR, within its domain of applicability.
Domain of Applicability
The domain of applicability of a physical theory is the set of physical
situations in which the theory is valid. For SR this is basically
measurements of distance, time, momentum, energy, etc. in inertial
frames (coordinates); calculus can be used to apply SR in accelerated
systems, as can the more advanced mathematics of differential
geometry. A more technical definition is that SR is valid only in flat
Lorentz manifolds topologically equivalent to R4. In particular, any
experiment in which the effects of gravitation are important is outside
the domain of SR. Because SR is the local limit of General Relativity
it is possible to compute how large an error is made when one applies
SR to a situation that is approximately but not exactly inertial, such
as the common case of experimental apparatus supported against gravity
on the earth's surface. In many cases (e.g. most optical and
elementary-particle experiments on the rotating earth's surface) these
errors are vastly smaller than the experimental resolution, and SR can
be accurately applied.
Test Theories of SR
A test theory of SR is a generalization of the Lorentz transforms of SR
using additional parameters. One can then analyze experiments using
the test theory (rather than SR itself) and fit the parameters of the
test theory to the experimental results. If the fitted parameter
values differ significantly from the values corresponding to SR, then
the experiment is inconsistent with SR. But more normally, such fits
can show how well a given experiment confirms or disagrees with SR, and
what the experimental accuracy is for doing so. This gives a general
and tractable method of analysis which can be common to multiple
experiments.
See: http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html#Introduction
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| User: "blackboab" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
30 Sep 2005 11:01:53 AM |
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i think this is it
http://www.wonderquest.com/iss-sighting-and-clock.htm
Q: Since time and speed is relative, according to Einstein's theory of
relativity, will an atomic clock on the International Space Station be
slower than a synchronized atomic clock on the ground? (Yiu Wai Chan)
Proposed position (arrow) of the atomic clock aboard the ISS.
[NASA/JPL]A: Yes, the clock on the International Space Station (ISS)
will tick slower than the earthbound clock because of relativistic
effects. However, two effects compete and complicate the picture.
Position (arrow) of the atomic clock aboard the ISS. [NASA/JPL]
The dominant effect on the ISS clock is, as you surmised, a slow down
because the space station zings around Earth. Einstein figured out,
back in 1905, that the speed of light is a constant for all frames of
reference. Given that, an observer on Earth peering through a telescope
at the ISS clock would see it running slow compared with his own clock.
This is the same effect (the "time dilation" effect) that allows a
returning space farer twin to be much younger than her earthbound
sister, after the astronaut spends years blasting through space at near
light speeds.
Our genius of the last century, Einstein, however, didn't stop with
the Special Theory of Relativity. He went on to develop his General
Theory of Relativity, which includes gravity effects. In 1915, he
predicted that clocks run slower in high gr
avity fields. A clock on the Sun would run slower than an Earth clock,
for example. Thus, the gravity effect causes the ISS clock to speed up,
since the gravity field is slightly less for an object in orbit (more
distant) than at the Earth's surface. We have competing effects.
The question is: which effect wins out-the speed or the gravity
effect? Interestingly enough, the two effects cancel if you orbit Earth
at a radius of 1.5 times Earth's radius. This is pretty far out:
about 1,900 miles (3,100 kilometers) high. If the space station were to
orbit this high, an observer on Earth peering through his telescope
would see the ISS clock and his clock agreeing.
The lower the ISS, the faster it must orbit. Increased speed means a
slower clock. Thus, orbiting below that 1900-mile height, speed
dominates: the ISS clock ticks slower. Orbiting above 1900 miles high,
gravity dominates: the ISS clock ticks faster. The ISS actually orbits
only 220 miles (353 kilometers) high so the ISS clock does run slow:
About 0.0000000014 % slower.
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| User: "blackboab" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
30 Sep 2005 10:20:35 AM |
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{quote SW}
"Proofs" are found in mathematics.
In physics, one used observational (and experimental) data to
support or refute a hypothesis.
{/quote SW}
so why offer me a thought experiment as proof that a clock in a
circular motion runs slow ?
{quote SW}
Special relativity makes predictions. Observational data confirms
those predictions. There has never been a prediction of special
relativity that was contradicted by an observation.
{/quote SW}
so has a clock been observed to run slow when sent in a circular orbit
as relativity maintains ?
(no thought experiments please. hard empirical evidence) .
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| User: "Greg Neill" |
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| Title: Re: Has the speed of light emitted by a fast moving particle been measured ? |
30 Sep 2005 10:25:12 AM |
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"blackboab" <blackboab@gmail.com> wrote in message
news:1128093635.912162.57420@g44g2000cwa.googlegroups.com...
{quote SW}
"Proofs" are found in mathematics.
In physics, one used observational (and experimental) data to
support or refute a hypothesis.
{/quote SW}
so why offer me a thought experiment as proof that a clock in a
circular motion runs slow ?
{quote SW}
Special relativity makes predictions. Observational data confirms
those predictions. There has never been a prediction of special
relativity that was contradicted by an observation.
{/quote SW}
so has a clock been observed to run slow when sent in a circular orbit
as relativity maintains ?
(no thought experiments please. hard empirical evidence) .
Hafele and Keating Experiment.
http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/airtim.html
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| User: "Timo Nieminen" |
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| Title: Re: Has the speed of light emitted by a fast moving particle beenmeasured ? |
30 Sep 2005 01:19:32 PM |
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On Fri, 30 Sep 2005, blackboab wrote:
if a particle going close to the speed of light - eg in a particle
accelerator - emits a photon can its speed be measured ?
if so how ?
Sure, it can be measured. How? Time how long it takes to go from point A
to point B. That might not be easy. You already been pointed at Alvaeger
et al (I'll mention that you were being misinformed when told that the
beryllium block was the source. Of course, the beryllium block is not a
vacuum, but that's another matter. In any case, the gamma rays in question
don't interact significantly with it.)
However, there are some interesting and accurate, though indirect, ways to
find the speed of photons from a moving particle beam source. Such
radiation has real practical uses - read up on why synchrotron radiation
is good for many applications. The spectrum and angular distribution of
such sources is measured, and the applications often involve a wavelength
measurement (diffraction by crystals). Frequency and wavelength tell you
the speed. AFAIK, the spectrum is measured in terms of energy, since it's
rather difficult to directly measure frequencies in the X-ray range.
And since your question is about the constant-speed-of-light 2nd
postulate of SR, there are the Michelson-Morley type interferometer
experiments using light from moving sources (sun and stars). There's also
radar mapping of other planets which, since they rotate, constitute a
source for the reflected signal with different parts in motion at
different velocities. And GPS.
And, there's even more! Essentially the reason Einstein proposed the 2nd
postulate. The Maxwell equations appear to work very well. The
permittivity and permeability of free space appear to be constant (this
part really only applies to the other side of the 2nd postulate, that the
speed of light is independent of the speed of the "observer" (ie
coordinate system in which the speed is measured), while the apparent
correctness of the Maxwell equations suffices for speed of light being
independent of the speed of the source.) Basically, if the propagation of
electromagnetic radiation from a moving source is correctly described by
the Maxwell equations, then we know the speed of light emitted by moving
sources, and it's equal to c in free space. Quantum considerations don't
affect this, since the same equations - the Maxwell equations - are the
foundation of the quantised version of electromagnetic field theory.
If the speed of light depends on the speed of the source, then the Maxwell
equations are broken. This provides the possibility of a definitive test
of theories where the speed of light does depend on the speed of the
source (mostly "emission" theories or sometimes "ballistic" theories). I
think this is an interesting topic, but alas! - although there are 3
frequent posters to sci.physics who rather loudly support such theories,
none of them seem to be willing to discuss such things :(
--
Timo
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