The Doppler shift is most simply defined as the apparent wavelength differences observecd from photons emitted from a source that is either moving toward he observer, wavelength compression, or wavlength extension when the source moves away from the direction of the emitted photons. If these wavelength changes are physically due to the physical interaction of source and photon along the direction of motion of the photon there are two aspects of Doppler that makes me wince . The first, though least significant is inconsidering the relative motion of source frame and photon, where in compression the source is supposed to compress a light beam, moving away from the source at the speed of light . This certainly sounds like a lot to swallow right, SR theory? The second are all conditions of motions.D Discussing the blue compression shift will satisfy a discussion for the case of extension of wavelength. If there is an actual physical compression, there must necessarily have been a force applied along the direction of motion opf the light beam. Otherwise the compression process would necessily have to mave been a resistence less process, which would require some drastic overhaul of what little we know about the complex structure of photons of light For instance, is the photon subject to comression from a force applied in one direction only?, When the photon strikes an object from the front, by its own motion the phioton delivers a force. It is unlikely that there are these two unique and ambiguous charteristics of light. The compression must have been due to the force the moving source applied to the light beam. If this is the case and using the sinusoidal nature of photons, there is a naturall built in accelerator as the photon also pushes againt the source along the line of the photon direction. A general question here: If a photon, moving at the speed of light is goven a very measureable kiick in the ass would this tend to: increase the velocity of the light?,or decrease the velocity of the light?, or, have no affect on the velocity of light?. from lack observavtion we must conclude there is no measurable affect on the speed of light fronm the motion of the source. If there was no change of photon speed then what are possible measured reaction forces of the light when responding to the specific impulse of the source? If anything? wavelength compression with an absence of measured recoil is indicative of no applied force; the law of inertia that defines the application of af force requiring a perturbation of uniform motion which requires either, acceleration or, variation of direction of travel, or both. none of which are observed. the lack of measured velocity increase such C' = C + Cs and C' . C., wher C' is the velocity due to the specific impulse of the source on the photon.and indicates no accelration force and lack of any direction ivariations in the the beam's motion[ is fairly conclusive proof that the compression/extension model of Doppler shift. is not due to the application of a force on the photons, and finally, the lack of any reaction forces, or affects, due to source and photon interaction is implicate proof that the source-photon interaction model of Doppler shifts as far from the standard model describing any physical parallels to the nature of Doppler wavelength changes. Conclusion: Doppler shifts due to source - photon inteactions are not supported by fact, experimental results, or physical law .
geistkiesel: You need to go back to basics. First understand Doppler shift as it applies to sound waves, since that is a familiar and obvious example. Then, work your way through to understanding the Doppler shift of light in the non-relativistic sense. The final step is to incorporate time dilation into the Doppler shift, since this obviously affects the wave frequency. Once you've understood what you're trying to criticise, then we can talk.
Yes, I expected some response elike this. I am just talking about the application of force and the claim that the compression of wave length is due to the interaction of source and photon. Quite franmkly I think I was as basic as one can be. Does the light get compressed by physical matter as observed in the blue shifts and streched in the red shift? Yea Nay Dunno I diodn't mention acoustics, you did. You may see some one-to-one correlation , but O don't. Vertainly there is not experiemntal evidence that can equate motion of sound to that of light by compaing relaive velocitesd of sound and light. In otehr words it is not true that a function of the speed of the source of sound to the speed of sound is proportional to the speed of tthe source of light to the speed of light. Any engineering student with a book of Reynolds numbers in her briefcase can tell you that the speed of sound is a function of temperature, is variant and requires a medium. for motion to occur. The speed of sound is not the rock solid constant speed of light that would allow anything but the most rudimentary, really rude, compaison.. Simply put James R, does Doppler theory have anything to say regarding the source of light compressing the outgoing photons? Doppler is not force driven as advertiswed by SR. SR just assumed pecedence. Somebody with a thesis stuck in their butt needed a line or two to publish ere they too into the dust descend, and as they say, the rest is history.. James R, just once would you try to counter something someione has to say on the merits of what they have to say instead of bringing an SR mantra to the surface? Yes, work one's way up the chain of information to time dilation, let the moving observer assume a state pf motion at rest and begin to live.
No. Doppler shift is an effect of changing reference frames. Classically speaking, both sound and light are waves. The Doppler shift is a wave phenomenon. It works the same way for light waves, sound waves, water waves... in fact any kind of wave you want to look at. Yes, sound requires a medium to travel, while light does not. But the speed of light in a medium doesn't change, just as the speed of light in space doesn't change. Much that can be said about sound applies equally to light. Do you understand how the Doppler effect arises for sound waves? Do you understand how the Doppler effect would still apply for light even if relativity was false? I have no idea what you're talking about here. SR says nothing about the Doppler effect being due to any "force". I haven't begun to counter what you've said. I said you ought to understand the non-relativistic Doppler shift before you start looking at the relativistic shift. That was friendly advice, not argument. You're not making sense.
JamesR, Of course, you are absolutely right: the Doppler effect is a pure kinematics phenomenon and occurs due to observation of wave from the two reference frames moving in respect of each other. And every textbook says the same. But I do not know any book, which would emphasize that the reference to wave at the discussions on Doppler effect is only and only because of historical "memorabilia" and a simplicity of object. But the Doppler effect is attributed to the observation of any chain of events, no matter have these events a regular frequency of appearance, or an irregular one, or even a random one. And it is important to know for the many of applications. And sorry for interruption, guys…
I can't argue with you at the moment amd I must agree with your statement that the effect is considered of a relativistic origin. So then radiated light from a distants star, galaxy etc, moving at 200 - 500 km/sec is fast enough to measure the relaivity effect? i can understand the sound wave analogy that James R wanted me to consider but I see no direct analogy at this time. Before I mumble myself to sleep in this post I must give the problem some grok time, so don't whack this thread prematurely, for as Douglas MacAarthur was reported to have said, "'l shall return," or was that Arnie Schwazenegger? I always get these two mixed up.
GeistKiesel: Perhaps it would help if you imagined water waves on a pond that was flash frozen. Imagine walking slowly across the frozen pond and measuring the time interval between wave crests. Next imagine running across the pond and measuring the time intervals. You encounter the crests at shorter time intervals when you run. If you move swiftly toward the source of a sound you encounter peak air pressures at shorter time intervals. Your sensory apparatus perceives a higher pitched sound. There no force affecting the sound waves. If I move away from the sound source and you move toward it, we perceive different pitches. Which pitch is the real pitch? Neither. Does our motion exert a force on the waves? No. It is the same for light waves. The above does not involve relativity, although relativity and Newtonian analysis come up with different measurements of time and distance. These differences are not noticed by our senosry apparatus. The effect of motion on sound waves cannot be refuted. Ride on a train and record the sound of the whistle. Then stand on the tracks as the train approaches and record the sound of the whistle. Make sure you move off the tracks before the train arrives. Compare the two recordings. They will sound different unless you are tone deaf.
For all of you following this post: My statement that the motion of the source of the light measured with a Doppler shift, I agree that no credible experimental evidence indicates any force is applied by the source to the radiated light. However, in the case of the motion of sound there is such an force, at least inferentially determined, and as the sound motion is often used as a comparison to light Doppler phenomena, when offered as an instructional device, I made an unmeasured inference of the two measured velocity perturbations that share little, perhaps no more than the measured relative ether velocity of 8 km/sec determined by Michelson-Morely and Daytom Miller for two consistent measurment processes Geistkiesel
How do we know that its the wave that is compressed and not that the speed of light that has increased due to the fast approaching sourece ? So how much can U compress a wave ? Does that require energy ? Is that energy stored in the wave ? Can light have inertia ? Why cant light speed up faster than speed of light ?
Forget the approaching source. If I start moving rapidly towards the stationary source and achive a very high speed then that is absolutely not going to compress the wave at the source. Its me who is gona get more wave in a shorter periods compared to before I started moving. Humans r so dumb.
