The speed of light (relative to the observer) varies with the speed of the observer. This is an antirelativistic statement which, somewhat paradoxically, is commonplace in the scientific literature. Scientists often forget to worship special relativity and produce texts like this one:
http://physics.bu.edu/~redner/211-sp06/class19/class19_doppler.html Professor Sidney Redner: "The Doppler effect is the shift in frequency of a wave that occurs when the wave source, or the detector of the wave, is moving. Applications of the Doppler effect range from medical tests using ultrasound to radar detectors and astronomy (with electromagnetic waves). (...) We will focus on sound waves in describing the Doppler effect, but it works for other waves too. (...) Let's say you, the observer, now move toward the source with velocity vO. You encounter more waves per unit time than you did before. Relative to you, the waves travel at a higher speed: v'=v+vO. The frequency of the waves you detect is higher, and is given by: f'=v'/(lambda)=(v+vO)/(lambda)."
On Sep 12, 3:22 pm, Pentcho Valev <pva...@yahoo.com> wrote:
> The speed of light (relative to the observer) varies with the speed of the observer. This is an antirelativistic statement which, somewhat paradoxically, is commonplace in the scientific literature. Scientists often forget to worship special relativity and produce texts like this one:
> http://physics.bu.edu/~redner/211-sp06/class19/class19_doppler.html > Professor Sidney Redner: "The Doppler effect is the shift in frequency of a wave that occurs when the wave source, or the detector of the wave, is moving. Applications of the Doppler effect range from medical tests using ultrasound to radar detectors and astronomy (with electromagnetic waves). (...) We will focus on sound waves in describing the Doppler effect, but it works for other waves too. (...) Let's say you, the observer, now move toward the source with velocity vO. You encounter more waves per unit time than you did before. Relative to you, the waves travel at a higher speed: v'=v+vO. The frequency of the waves you detect is higher, and is given by: f'=v'/(lambda)=(v+vO)/(lambda)."
xxein: MM and PR are a step beyond Thor. I'll give you that. Even
Einstein could not reconcile his belief. It seemed to work, but then
again, it did not contain any physical reason for it to be so. Just a
math trying to explain an observation.
The complexity of Einstein's math matched no physical process. But
you are less than that with no physical process. MM and PR
interpretations included.
You can't base the understanding of the physic on Thor. But you seem
to base it on observational results that are only interpretations
based on old and incomplete theories (beliefs).
I've studied them and they don't have even a near completeness for the
physic that must provide.
Even I have not discovered the true physic but I can eliminate
Einstein as a contender. Even more much so with MM and PR
interpretations.
I am not suggesting that any theory in existence can do this. I am
saying that the way I think about it (on the macro scale and even to
some micro) is much more complete.
And then proof of what? An observation? You don't even know the
physic that PROVIDES for observation. It is much different than you
know. Been there, done that.
http://www.hep.man.ac.uk/u/roger/PHYS10302/lecture18.pdf Roger Barlow, Professor of Particle Physics: "The Doppler effect - changes in frequencies when sources or observers are in motion - is familiar to anyone who has stood at the roadside and watched (and listened) to the cars go by. It applies to all types of wave, not just sound. (...) Moving Observer. Now suppose the source is fixed but the observer is moving towards the source, with speed v. In time t, ct/(lambda) waves pass a fixed point. A moving point adds another vt/(lambda). So f'=(c+v)/(lambda)."
"In time t, ct/(lambda) waves pass a fixed point." That is, the speed of the waves relative to the fixed observer is c.
"A moving point adds another vt/(lambda)." That is, the speed of the waves relative to the moving observer becomes c'=c+v. The new frequency, f'=c'/(lambda)=(c+v)/(lambda), is consistent with c'=c+v.
http://www.cmmp.ucl.ac.uk/~ahh/teaching/1B24n/lect19.pdf Tony Harker, University College London: "The Doppler Effect: Moving sources and receivers. The phenomena which occur when a source of sound is in motion are well known. The example which is usually cited is the change in pitch of the engine of a moving vehicle as it approaches. In our treatment we shall not specify the type of wave motion involved, and our results will be applicable to sound or to light. (...) Now suppose that the observer is moving with a velocity Vo away from the source. (...) If the observer moves with a speed Vo away from the source (...), then in a time t the number of waves which reach the observer are those in a distance (c-Vo)t, so the number of waves observed is (c-Vo)t/lambda, giving an observed frequency f'=f(1-Vo/c) when the observer is moving away from the source at a speed Vo."
If "in a time t the number of waves which reach the observer are those in a distance (c-Vo)t", then the speed of the light waves relative to the observer is c'=c-Vo.
On Sat, 22 Sep 2012 08:57:54 -0700 (PDT), Pentcho Valev
<pva...@yahoo.com> wrote:
>http://www.cmmp.ucl.ac.uk/~ahh/teaching/1B24n/lect19.pdf >Tony Harker, University College London: "The Doppler Effect: Moving sources and receivers. The phenomena which occur when a source of sound is in motion are well known. The example which is usually cited is the change in pitch of the engine of a moving vehicle as it approaches. In our treatment we shall not specify the type of wave motion involved, and our results will be applicable to sound or to light. (...) Now suppose that the observer is moving with a velocity Vo away from the source. (...) If the observer moves with a speed Vo away from the source (...), then in a time t the number of waves which reach the observer are those in a distance (c-Vo)t, so the number of waves observed is (c-Vo)t/lambda, giving an observed frequency f'=f(1-Vo/c) when the observer is moving away from the source at a speed Vo."
>If "in a time t the number of waves which reach the observer are those in a distance (c-Vo)t", then the speed of the light waves relative to the observer is c'=c-Vo.
Wavelength remains the same, so the modified frequency is:
f' = V'/(lambda) = (V + Vr)/(lambda) = fo(1 + Vr/V)"
Pentcho Valev
Sound is emitted from a stationary source with a speed of Mach 1 and a wavelength of 1.116 feet.
If a car moves toward the stationary sound source with a speed of 30 mph, what frequency is heard? Explain your answer.
http://www.einstein-online.info/spotlights/doppler Albert Einstein Institute: "The frequency of a wave-like signal - such as sound or light - depends on the movement of the sender and of the receiver. This is known as the Doppler effect. (...) Here is an animation of the receiver moving towards the source: (...) By observing the two indicator lights, you can see for yourself that, once more, there is a blue-shift - the pulse frequency measured at the receiver is somewhat higher than the frequency with which the pulses are sent out. This time, the distances between subsequent pulses are not affected, but still there is a frequency shift: As the receiver moves towards each pulse, the time until pulse and receiver meet up is shortened. In this particular animation, which has the receiver moving towards the source at one third the speed of the pulses themselves, four pulses are received in the time it takes the source to emit three pulses."
That is, the motion of the observer cannot change the wavelength ("the distances between subsequent pulses are not affected") and accordingly the speed of light as measured by the receiver is (4/3)c.
> http://www.einstein-online.info/spotlights/doppler > Albert Einstein Institute:
> "The frequency of a wave-like signal - such as sound or light -
> depends on the movement of the sender and of the receiver.
> This is known as the Doppler effect. (...)
> Here is an animation of the receiver moving towards the source: (...)
> By observing the two indicator lights, you can see for yourself that,
> once more, there is a blue-shift - the pulse frequency measured at
> the receiver is somewhat higher than the frequency with which the pulses
> are sent out. This time, the distances between subsequent pulses are not
> affected, but still there is a frequency shift: As the receiver moves towards
> each pulse, the time until pulse and receiver meet up is shortened.
> In this particular animation, which has the receiver moving towards
>the source at one third the speed of the pulses themselves, four pulses
> are received in the time it takes the source to emit three pulses."
And to quote what follows in the next section:
"All our arguments so far were grounded in classical physics
[that is Galilean relativity].
Once we take special relativity into account, there is
an additional effect: time dilation."
And then the result would be different.
> That is, the motion of the observer cannot change the wavelength
> ("the distances between subsequent pulses are not affected") and accordingly
> the speed of light as measured by the receiver is (4/3)c.
Indeed.
In Galilean relativity, distances and wavelengths are invariant.
And if the speed of light is c in the rest frame of the source,
and the speed of the receiver v is c/3 towards the emitter,
then the speed of light measured by the receiver is c' = c + v = (4/3)c.
Did you have a point with stating this trivial prediction
of Galilean relativity?
You need to READ your sources. Further down they say explicitly: "All our arguments so far were grounded in classical physics." They then go on to describe the effects of relativity.
> That is, the motion of the observer cannot change the wavelength ("the
> distances between subsequent pulses are not affected") and accordingly the
> speed of light as measured by the receiver is (4/3)c.
Nonsense.
As I keep telling you, and you keep ignoring, the observation of the annual Doppler effect shows CONCLUSIVELY that "motion of the observer" (on earth) DOES "change the wavelength" [#].
[#] This is poorly worded -- the wavelength of the light wave is
not intrinsic, and what is changing is the MEASURED VALUE of the
wavelength BY THIS OBSERVER.
Pentcho Valev is one of the many fools and idiots around here who are unable to read, and who have proven themselves completely unable to learn anything. Readers who are interested in science would do well to ignore them.
> > "The frequency of a wave-like signal - such as sound or light -
> > depends on the movement of the sender and of the receiver.
> > This is known as the Doppler effect. (...)
> > Here is an animation of the receiver moving towards the source: (...)
> > By observing the two indicator lights, you can see for yourself that,
> > once more, there is a blue-shift - the pulse frequency measured at
> > the receiver is somewhat higher than the frequency with which the pulses
> > are sent out. This time, the distances between subsequent pulses are not
> > affected, but still there is a frequency shift: As the receiver moves
> towards
> > each pulse, the time until pulse and receiver meet up is shortened.
> > In this particular animation, which has the receiver moving towards
> >the source at one third the speed of the pulses themselves, four pulses
> > are received in the time it takes the source to emit three pulses."
> And to quote what follows in the next section:
> "All our arguments so far were grounded in classical physics
> [that is Galilean relativity].
> Once we take special relativity into account, there is
> an additional effect: time dilation."
> And then the result would be different.
How different, Clever Andersen? Will taking into account time dilation convert the original result, (4/3)c, to c? If yes, just show the calculations. If not, isn't your "time dilation" counterargument too silly?
On Monday, September 24, 2012 4:01:01 PM UTC+2, tjrob137 wrote:
> On 9/24/12 9/24/12 7:09 AM, Pentcho Valev wrote:
> > That is, the motion of the observer cannot change the wavelength ("the
> > distances between subsequent pulses are not affected") and accordingly the
> > speed of light as measured by the receiver is (4/3)c.
> Nonsense.
> As I keep telling you, and you keep ignoring, the observation of the annual
> Doppler effect shows CONCLUSIVELY that "motion of the observer" (on earth) DOES
> "change the wavelength" [#].
> [#] This is poorly worded -- the wavelength of the light wave is
> not intrinsic, and what is changing is the MEASURED VALUE of the
> wavelength BY THIS OBSERVER.
The crucial question, Honest Roberts: Does your "nonsense" refer to the text above it or the text below it?
http://www.takoi.edu.hk/~phy/0304_S6_webpage/Doppler%20effec1[1].2.htm
"Approaching observer with stationary source. The wavelength observed by the observer remains unchanged. (lambda)=c/f. Apparent speed of the wave relatively to the observer: c'=c+Vo. Apparent frequency observed by the observer: f'=c'/(lambda)=[(c+Vo)/c]f."
Contrary to naive expectations, the blasphemous equation c'=c+Vo provokes no reaction at all. High-ranking Einsteinians have already left the sinking ship:
>>> "The frequency of a wave-like signal - such as sound or light -
>>> depends on the movement of the sender and of the receiver.
>>> This is known as the Doppler effect. (...)
>>> Here is an animation of the receiver moving towards the source: (...)
>>> By observing the two indicator lights, you can see for yourself that,
>>> once more, there is a blue-shift - the pulse frequency measured at
>>> the receiver is somewhat higher than the frequency with which the pulses
>>> are sent out. This time, the distances between subsequent pulses are not
>>> affected, but still there is a frequency shift: As the receiver moves towards
>>> each pulse, the time until pulse and receiver meet up is shortened.
>>> In this particular animation, which has the receiver moving towards
>>> the source at one third the speed of the pulses themselves, four pulses
>>> are received in the time it takes the source to emit three pulses."
>> And to quote what follows in the next section:
>> "All our arguments so far were grounded in classical physics
>> [that is Galilean relativity].
>> Once we take special relativity into account, there is
>> an additional effect: time dilation."
>> And then the result would be different.
> How different, Clever Andersen?
> Will taking into account time dilation convert the original result, (4/3)c, to c?
Yes, stupid Valev.
> If yes, just show the calculations.
If you Google "Relativistic Doppler effect", you get 141 000 hits.
So why should I bother to repeat this trivial exercise?
> http://www.takoi.edu.hk/~phy/0304_S6_webpage/Doppler%20effec1[1].2.htm
> "Approaching observer with stationary source. The wavelength observed by the observer remains unchanged. (lambda)=c/f. Apparent speed of the wave relatively to the observer: c'=c+Vo. Apparent frequency observed by the observer: f'=c'/(lambda)=[(c+Vo)/c]f."
> Contrary to naive expectations, the blasphemous equation c'=c+Vo provokes no reaction at all. High-ranking Einsteinians have already left the sinking ship:
I note with amusement that Valev's naive expectation is that
"High-ranking Einsteinians" in this NG should bother to react on
the fact that relativity is not introduced in a physics web page
for students in a secondary school in Hong Kong. :-)
>>> "The frequency of a wave-like signal - such as sound or light -
>>> depends on the movement of the sender and of the receiver.
>>> This is known as the Doppler effect. (...)
>>> Here is an animation of the receiver moving towards the source: (...)
>>> By observing the two indicator lights, you can see for yourself that,
>>> once more, there is a blue-shift - the pulse frequency measured at
>>> the receiver is somewhat higher than the frequency with which the pulses
>>> are sent out. This time, the distances between subsequent pulses are not
>>> affected, but still there is a frequency shift: As the receiver moves towards
>>> each pulse, the time until pulse and receiver meet up is shortened.
>>> In this particular animation, which has the receiver moving towards
>>> the source at one third the speed of the pulses themselves, four pulses
>>> are received in the time it takes the source to emit three pulses."
>> And to quote what follows in the next section:
>> "All our arguments so far were grounded in classical physics
>> [that is Galilean relativity].
>> Once we take special relativity into account, there is
>> an additional effect: time dilation."
>> And then the result would be different.
> How different, Clever Andersen?
> Will taking into account time dilation convert the original result, (4/3)c, to c?
t_B-t_A = r_AB/(c-v) and
t_A-t_B = r_AB/(c+v) where r_AB denotes the length of the moving rodmeasured in the stationary system. -- Einstein
So how does measured c-v = c and measured c+v = c, measured in the moving system, clever Tusseladd? Oh wait, I know...
I want my weight to be 75 kg instead of 100 kg so I just
multiply what the bathroom scale says by 3/4, call it the Lorentz
weight loss and forget about dieting. Right, clever Tusseladd?
> If yes, just show the calculations.
If you Google "Relativistic Doppler effect", you get 141 000 hits.
So why should I bother to repeat this trivial exercise?
You wont because you know Id make you look like the drunken fool you are, clever Tusseladd.
-- This message is brought to you from the keyboard of Lord Androcles, Zeroth Earl of Medway
An observer who is at rest relative to the light source will see the
true or absolute frequency of the emitted light. For example, sodium
light is intrinsically yellow, so any observer who is at rest wrt a
sodium source will see sodium light as yellow. The reason for this is
shown by the following simple diagram:
O1 says, "I see yellow because any motion that I may have through
space will "compress" the waves back to yellow," and O2 says, "I also
see yellow because any motion that I may have through space will
"stretch" the waves back to yellow."
The yellow color is intrinsic and observer-independent because it is
caused by electrons in the source that return to their ground state.
Obviously, no observer has anything to do with this.
The observers are not measuring anything but are merely looking at
color.
Also, after the light leaves the source, it is disconnected from it
because light is source-independent. The source is "out of the
picture," only the light is left.
Given all of the above, it is clear that whenever observers see
different, non-yellow colors from a sodium source, then the observers
are moving differently relative to the light.
And since relative motion is reciprocal, we see that light is moving
differently relative to said observers.
And of course, this runs counter to special relativity "theory."
(Note that frequency is the only directly-measured parameter of the
equation wavelength = c/frequency, and a possibly slowed clock is used
to make this measurement. Also note that c is an assumed value. Only
after the frequency has been measured with a slowed clock and the
speed "c" is assumed can you then calculate the wavelength.)
On Wednesday, September 12, 2012 3:22:00 PM UTC-4, Pentcho Valev wrote:
> The speed of light (relative to the observer) varies with the speed of the observer. This is an antirelativistic statement which, somewhat paradoxically, is commonplace in the scientific literature. Scientists often forget to worship special relativity and produce texts like this one:
> Professor Sidney Redner: "The Doppler effect is the shift in frequency of a wave that occurs when the wave source, or the detector of the wave, is moving. Applications of the Doppler effect range from medical tests using ultrasound to radar detectors and astronomy (with electromagnetic waves). (...) We will focus on sound waves in describing the Doppler effect, but it works for other waves too. (...) Let's say you, the observer, now move toward the source with velocity vO. You encounter more waves per unit time than you did before. Relative to you, the waves travel at a higher speed: v'=v+vO. The frequency of the waves you detect is higher, and is given by: f'=v'/(lambda)=(v+vO)/(lambda)."
> Shift in Frequency Implies Shift in Speed of Light
That's right....a new theory of relativity called IRT is based on the above concept. A paper on IRT is available in the following link:
http://www.modelmechanics.org/2011irt.dtg.pdf
> If an observer moves behind light slightly below C in space
> what kind of seperation of the two shall take place?
> Mitchell Raemsch
Light's relative motion is the same* as that of any other entity in
space, such as a plain old asteroid (with the only - irrelevant -
difference being light's faster speed), so the separation of which you
spoke is the same as that of an observer in one car going 49 mph who
is following another car that is going 50 mph.
*the only reasons for round-trip light speed invariance are the
improper instruments used, namely, slowed clocks and shrunken rulers,
and if we use undistorted instruments with the clocks being correctly
synch'd, then light's one-way speed, just as will an asteroid's, will
vary with frame vel.
SR errs by trying to make light different. Light is the same as it was
before, during, and after the MMx. It ain't changed a bit.
> You need to READ your sources. Further down they say explicitly: "All our
> arguments so far were grounded in classical physics." They then go on to
> describe the effects of relativity.
> > That is, the motion of the observer cannot change the wavelength ("the
> > distances between subsequent pulses are not affected") and accordingly the
> > speed of light as measured by the receiver is (4/3)c.
> Nonsense.
> As I keep telling you, and you keep ignoring, the observation of the annual
> Doppler effect shows CONCLUSIVELY that "motion of the observer" (on earth) DOES
> "change the wavelength" [#].
No it doen't the incoming light becomes a new light source and the grating defines a new wavelength for this new light source. The correct interpretation is that the change in the incoming frequency is due to a change in the inconming speed of light when the wavelength of the source is assumed to be universal.
> An observer who is at rest relative to the light source will see the
> true or absolute frequency of the emitted light.
There is nothing "true" or "absolute" about that. This is just the frequency measured in the rest frame of the source.
You keep making claims like this, but have NEVER described how to make an "absolute" measurement.
> For example, sodium
> light is intrinsically yellow,
Not at all. It is yellow IN THE REST FRAME OF THE SOURCE. Observers moving relative to the source will see other colors -- which PROVES that color is not intrinsic to the light.
Make no mistake, an intrinsic property is one that is the same to
all observers. For light, color fails miserably.
Note: Human eyeballs are not very good at resolving different colors (compared to modern instruments), and they often make mistakes (the frequency response of the pigments in the retina are not uniform, or even monotonic). So in physics we universally mean frequency of the light when we mention "color" (sometimes wavelength is meant) -- eyeballs are too easily fooled.
Have you ever seen a color Polaroid photograph? Doesn't it
LOOK like all colors are present? -- they aren't; Polaroid
photography uses just a black-and-white image and a red image;
the "colors" you see are a sophisticated illusion to your
eyeball (and brain, which is where the deception really
happens).
> so any observer who is at rest wrt a
> sodium source will see sodium light as yellow.
Yes, that is true.
> The yellow color is intrinsic and observer-independent
This is just not so. Observers moving relative to the source see other colors.
Your hopes and dreams are not conditions the world must obey.
The color of a light ray is NOT intrinsic, because that is
WHAT WE OBSERVE. SR has nothing to do with it.
> because it is
> caused by electrons in the source that return to their ground state.
Yes, IN THE REST FRAME OF THE SOURCE. Not in any other frame.
Hint: those atoms and their electron clouds are at rest
in one and only one frame.
> Obviously, no observer has anything to do with this.
Sure. But observers' motion relative to the source has A LOT TO DO WITH WHAT THEY OBSERVE.
> The observers are not measuring anything but are merely looking at
> color.
That _IS_ a measurement. See above about the limitations of human eyeballs. Still, identifying the color of a light ray most definitely _IS_ a measurement of its color (and therefore its frequency and/or wavelength).
> Also, after the light leaves the source, it is disconnected from it
> because light is source-independent. The source is "out of the
> picture," only the light is left.
Hmmm. The source has "imprinted" itself on the light, in the sense that the events of constant phase are independent of frame, and were determined by the source; the frequency and wavelength between such events depends on the motion of the measuring instruments; that is conventionally phrased as "relative to the source", because that is in general the only reference available.
"Speed relative to light" has no meaning, because one cannot
put rulers and clocks at rest relative to the light.
> Given all of the above, it is clear that whenever observers see
> different, non-yellow colors from a sodium source, then the observers
> are moving differently relative to the light.
Only in your dreams. If "moving differently relative to the light" means the light has different speeds relative to the observers, then this is wrong (for light in vacuum). Indeed, "moving relative to light" has no real meaning, as light cannot make measurements; and no observer can make herself come to rest relative to the light, so this is impossible IN PRINCIPLE, and not merely because there happens to be no observer there.
Given all the above, it is clear that whenever observers see different, non-yellow colors from a sodium source, then the observers are moving RELATIVE TO THE SOURCE (no gravity).
> And since relative motion is reciprocal, we see that light is moving
> differently relative to said observers.
Again, only in your dreams. The real world does not correspond to your dreams. Too bad for your dreams.
You REALLY need to learn to stop attempting to dictate to nature how to behave. She won't listen. Essentially everything of substance that you said is contradicted BY EXPERIMENT.
Since the light path you perceive to be a straight line, is in actuality orthogonal due to the "fact" you and everything in this octave are in a hyper cube that is traveling inward at c, c is escape velocity around the corner of the hyper cube and the actual orthogonal path of light which is the explanation of c squared and empty space and the interference pattern and the invariant speed if light.
