Discussion in 'Natural Revelation and God's Creation' started by thbslawson, Jan 11, 2014.

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  1. Mushroom

    Mushroom Puritan Board Doctor

    No he doesn't, which is why it doesn't make any sense, but it makes the data fit. Just like wet sidewalks cause rain...
  2. Afterthought

    Afterthought Puritan Board Junior

    Thank you, that was very helpful. This might be the fellow to ask my own question of when I get the chance.

    Also, if there was a way to access actual scientific papers that those who promote these theories have written, that would be helpful (though I doubt it will be worth discussing them on this thread, it would satisfy at least my curiosity.).
  3. Logan

    Logan Puritan Board Junior

    I did not refer to the Doppler effect in the last several posts. That has nothing to do with the velocity of the wave or light you were asking about.

    Let me put it this way: in radar we make two general calculations: distance (based on the time it takes for the wave to travel out and back) and speed (based on the frequency shift of the received wave). The two are completely independent of each other. We can calculate distance to very, very fine accuracy and it is independent of the speed of the transmitter/receiver, or the object (thus the assumption of a constant speed appears to be correct).

    The speed of the object (or transmitter) is determined based on the frequency shift, which is unrelated to the velocity of the wave

    This understanding is wrong, and I tried to explain it before. There is no "offset", there is only perception of say, crests of wave coming closer together because of relative motion, and the Doppler effect is not created by the medium, it is created by the speed of the transmitter/receiver. The velocity of the wave is affected by the medium, which is why light will travel slower through water, or sound travels faster. And no, this is not a relativistic explanation, this all came before Einstein.

    The velocity of light (from the source) would be measured to be the same in all three instances. The frequency however would be different in the observed locations because of the Doppler shift caused by motion.

    It does not go against physics for other waves or wavelike motion. The analogy of a wave from an ambulance siren (with associated velocity and Doppler shift for the stationary observer) is exactly the same. A wave from a star has an associated velocity and Doppler shift. The velocity of the ambulance siren's wave will not change based on your velocity or the velocity of the ambulance. It is a constant. That's why there is a "sound barrier" for jets. Why does "common sense" dictate differently for electromagnetic waves?

    By the way, both the Sagnac and Airy experiments were designed to measure the flow of a hypothesized aether, so once again it does not (and cannot) prove a stationary earth except with certain assumptions. That no aether flow was detected has any number of explanations and to single out the one belies a presupposition that there is an unmoving aether unaffected by mass but that the earth is not moving through it.

    Please guys, criticizing models and theories is fine, I'm interested in new ones. I'm genuinely interested in the explanations a geocentrist model has, but not when the criticisms are based upon misunderstandings of the current model. I really need to back out of this, I've devoted a lot of time already.
  4. au5t1n

    au5t1n Puritan Board Post-Graduate


    You keep insisting that the velocity of a sound wave is constant even when the receiver is moving. That is true with respect to the medium (say, air) but not with respect to the receiver, which perceives a net velocity. If the calculation is performed relative to the medium or the earth, velocity is rightly held constant. But in a hypothetical c measurement based on starlight, the earth is the receiver, and before relativity, you could justifiably have expected to measure different net speeds relative to earth. It is you who have misunderstood.

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  5. Logan

    Logan Puritan Board Junior

    That is correct Austin, but that is not a misunderstanding, that is a definition. In a hypothetical situation where the observer is moving at the same speed and same direction as the source, the light would never reach him (net velocity of zero). But that's never been the question.
  6. Mushroom

    Mushroom Puritan Board Doctor

    Wait! You mean to say that a light beam traveling towards me, if I were traveling at the speed of light in the same direction, would have a net velocity of zero? So what if I were traveling say 50,000 mps less than the speed of light? Would said beam be traveling at net velocity 136k mps, or does that net zero thing only happen when I'm traveling at 'c'? Hmm... I think that has been the question all along. And now it seems more clouded than ever.

    But we don't see that, we see light always at 'c' except where affected by medium other than a vacuum. Einstein says that's the case no matter where we are in the universe. Others have long postulated an aether that acts as a medium that limits light to 'c'. Still others have postulated an absolute 'rest' that is that limit, as recorded on Earth and her proximity. And there are still other theories. I'm not an adherent of any single one, just skeptical of relativism. Your arguments concerning Doppler are based on an assumption that light is not traveling through a medium (or perhaps affected by an absolute rest), which is why you assume that the shift is only a factor of motion relative to the observer. That's the standard relativistic view, and it seems as though you can't conceive of any other possibility. That's fine. But I still would like to hear of a reliable experiment that proves both a) & b) above. If anybody can cite that, then we can dispense with the 'theory' part of ... The Theory of Relativity.
  7. au5t1n

    au5t1n Puritan Board Post-Graduate

    Surely we can agree that in relativity c is constant in a way that is different from the way the velocity of a sound wave is constant. The latter is constant with respect to the medium of propagation, and we used to suspect the same for light (the proposed medium being a "lumeniferous aether" before MM), but relativity posits that c is constant when measured from different reference frames - not with respect to a medium but with respect to the object from which it is measured. This is categorically different from the way sound behaves. I don't think your hypothetical example is consistent with special relativity. In SR, the net velocity of light should always be c when measured from anywhere.

    I do agree, however, that the predictions of special relativity cannot be abandoned without something that makes the same predictions replacing it. I am familiar with the mathematics of relativity, and there is no getting rid of those equations. A scientists who rejects special relativity needs to account for them some other way, and I'm not aware that this has ever been done.

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    Last edited: Jan 28, 2014
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