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Time relations

  1. Jan 23, 2006 #1


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    If quasars are appearing to travel at almost the speed of light from us, what would the relative time frames between us be.
  2. jcsd
  3. Jan 24, 2006 #2
    I'm not entirely sure what you mean by "relative time frames", but I think you're asking about time dilation?
  4. Jan 24, 2006 #3


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    Yes that is probably correct.
  5. Jan 24, 2006 #4


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    Would say a cepheid variable star in a galaxy moving at 150,000 mps away from us appear to blink slower and how would this slow blinking, if so, be related to the redshift at which it was detected?
  6. Jan 24, 2006 #5


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    Time would be severaly dilated in the case of a quasar moving away from us at nearly the speed of light. This means that we would observe the activity of the quasar as proceeding much more slowly than someone moving along with the quasar.

    In theory, a Cepheid variable would appear to vary in brightness more slowly if it were moving away from us at a significant fraction of the speed of light. Unfortunately, the light from any single star is quite feeble, and technology only exists to detect Cepheids only in our own galaxy and, in some select examples, in nearby galaxies. Thus, all Cepheids observed to date have very small, neglibible, redshifts. The technology necessary to resolve individual stars in quasars (which are nothing more than juvenile galaxies) is very far beyond our current technology.

    - Warren
  7. Jan 24, 2006 #6
    have a look please at
    Kurtiss J. Gordon
    Consideration of quasar redshifts
    am.j.phys. 48 514 (1980)
  8. Jan 24, 2006 #7
    Or were you asking about space dilation, that is the expansion of space itself between us and very distant parts of the universe?? A rapidly moving distant point appears as chroot describes, but if the distance is so great as to involve expansion of space itself then time not only appears relative but really is.
  9. Jan 24, 2006 #8


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    (emphasis mine)
    So where are the 10% quasars with blue shifts?

    This explanation just doesn't fit - it possibly did in 1980, but I certainly would not have considered it feasible back then.

    The quasar controversy arose during the 1960's when their observed evolution seemed to put another nail in the coffin of the steady state theory, together with the CMB. Explain away quasar cosmological red shift ("well at that distance they would have to be so bright") and the CMB ("the diffuse light of many galaxies in the far far distance, possibly even in another universe beyond our horizons") and you could still, just about, cling onto a non-evolving universe. However that 'flat earth theory' eventually lost credibility.

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