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The whole supernova 1A scenario is quite suspect. There are two things going on here.
1. These SN seem to be dimmer than expected from the application of Hubble's law. This has lead to the idea that the universe is accelerating in its expansion because the SN are presumably farther away than they would be if they were travelling away from us at a constant velocity. These distant objects are more distant than they "should" be from a constant velocity so they must have accelerated to get there. (Of course one could say that we are expecting (from Hubble's law) the SN to have a higher red shift for its distance and so it isn't travelling as FAST as it should be and so the universe is DECELERATING. It depends on how you look at it.) 2. These SN seem to have a longer time period of their brightness than we'd expect if they weren't moving away from us. This is somewhat consistent with an expected time dilation from a Doppler interpretation. But the time period of SN is not exactly correlated (although the correlation is strong) with the brightness and there may well be selection effects from absorption of photons or other mechanisms which cause dimming of the SN than acceleration. It's a quite complicated analysis and many effects need to be taken into account. For example at these high red shifts, there is doppler dimming if the red shift is doppler; namely the distance between the photons should be stretched by the same amount as the red shift and the photon flux is reduced. Namely the number of photons received per unit time is less so the source appears dimmer. (This is not the case for tired light, so a tired light SN1A is observed to be brighter than a Doppler SN1A. i.e., it is intrinsically dimmer to be at the same observed brightness.) This dimming effect for the doppler mechanism is compounded if there is acceleration in addition to Hubble's law. These differences in observed brightness between the two different mechanisms affects the expected time period of the SN1A. A tired light mechanism predicts that the SN1a is intrinsically dimmer than a doppler mechanism and so has a correspondingly different expected time period. So there are different expectations for the time period of the SN1A depending on whether the red shift is velocity doppler or acceleration doppler or tired light. It's also not at all clear that the supposed observed time dilation is not affected by selection effects. In fact, there was a paper presented at the Denver American Physical Society meeting that highly questioned the time dilation conclusions based on selection effects. |
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![]() Maybe ExpErdMann should drop the ananolgy and just describe what he's proposing directly. Are we talking about light losing energy as it traverses static space, or are we talking about space itself somehow disintigrating over time. I thought the tired light idea was the former, but it seems to me that EEM is talking about the latter.
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There are 10 types of people in the world. Those who understand ternary, those who don't, and those waiting for a bus. If logic doesn't work, then surely it does. |
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I don't want to suggest that the whole idea of tired light fails because this particular analogy isn't good, but he did specfically ask if anyone saw any problems with the analogy.Quote:
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I was also reminded that EEM hasn't mentioned the cosmological redshift since it since it was pointed that there was nothing extraordinary about it, despite initially calling it "the weak link in the mainstream argument". Sorry EEM, I keep talking about you in the third person. How about those details then? Not that I'm one of the practicing scientists here, but I'd like to follow the discussion ![]()
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There are 10 types of people in the world. Those who understand ternary, those who don't, and those waiting for a bus. If logic doesn't work, then surely it does. |
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ExpErdMann, are you trying to tie this in with the expanding earth idea that we discussed before? Not picking here, just wondering.
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Some try to tell me, thoughts they cannot defend,... - Moody Blues. |
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Since it is relevant to this thread, can you give some references? Quote:
This puts in serious doubt your own understanding of it. Quote:
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As mentioned above, the original prediction about time dilation in SNe was based on the classical Doppler shift, using supposed recessional velocities. In this case the time dilation factor is (1 + z). In SR, the time dilation factor is also (1 + z). Here the redshift has a term in v^2/c^2, unlike the classical Doppler, but the time dilation factor (1 + z) is the same. For the gravitational redshift, I'm not sure if the same relation holds as far as the Shapiro effect is concerned. Would appreciate it if anyone can clarify this one. My suggestion that the redshift could come about through weakening of spacetime is not developed enough to make this comparison as yet, but on the basis of the above I'm thinking that anywhere a redshift occurs a time dilation effect will also occur and that the former determines the magnitude of the latter. |
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