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Roman Cieciak

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How do the cosmologists account for the time gap of the distant galaxies' images?

First of all I am no phisycist of any kind, I am just a physics enthusiast.
The question that is bugging me in the notion of ever accelerating expantion of the universe is how do we know that the universe is accelerating right now. The images of the furthest galaxies are bilions years old and they are images of the younger universe, a universe that perhaps was 'still exploding', the force that caused the Big Bang was still effecting the matter in the universe. Hence it's only natural that those distant objects appear to be moving away from each other faster than the ones that are closer to us.
We don't and won't know what happens there 'now' and this might be the problem. Not "we're too late to see what happened" but "we're too soon to see what the outcome is/will be".
Please, let me know what is unclear and/or wrong in my reasoning, I'll try my best to lay out my idea.

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    May 2 2012: No it IS the case that we are too late to see what is happening there now. Now is Now everywhere in the universe what is happening in those distant galaxies is happening now... we are just able to to see those nows becuse what we use to see them in the first place is light. Light which takes time to get here so, the light that left the early universe, because it's takes so long to travel the vast distances is only just reaching us.
    When we look out at the distant parts of the universe we are basiclly looking back in time!
    • May 3 2012: Exactly. Hence the farther out we observe, the older the red shift. And since red shift increases with distance, one should conclude that over time expansion has been slowing down. But that's not the conventional wisdom, so where is the flaw in my thinking?
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        May 13 2012: Not too sure what you are thinking by your term "... the older the red shift"
        'Red shift' refers to how the light we observe is 'shifted' towards the Red end of the spectrum. Like the sound of a train as it goes pass, the waves get spread out lowering the pitch. Light also comes to us as waves. As the source speeds away from us we see these waves slowing down and therefor at a lower frequency (More reddy). The Red shift doesn't get older, what changes is the amount of Red Shift we measure.

        The Shift towards Red is greater at further distances because the further we look out we see those objects moving away from us faster than ones closer to us. The fact that the Red Shift has been mearsured as increasing is evidence that the expansion is speeding up, not slowing down... If it were slowing down the observed Red Shift would decrease.
        • May 18 2012: The question is how do we account for the time gap between distant objects measured.
          As you say "The Shift towards Red is greater at further distances because the further we look out we see those objects moving away from us faster than ones closer to us." but those objects are also more distant in time. Their red-shifted light was emitted earlier than the light of those closer objects.

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