Macros

Discussion in 'Photography' started by Alan Browne, Mar 16, 2013.

  1. Alan Browne

    PeterN Guest

    Ah! but are the gravitational fields random. According to Einstein, they
    are not.
     
    PeterN, May 3, 2013
    #81
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  2. So you're basically saying that the gravitational fields are
    ordered in such a way that photons from any random source stay
    parallel, at least in a sizeable number of cases.

    I'd like a single geometry designed by you where a bundle
    of parallel light rays from a single direction are bend by
    gravity sources in such a way that they remain exactly parallel.
    You can freely place the gravity sources.

    Kindly remember that any single gravity source will affect such
    a bundle of exactly parallel rays differently, depending on the
    mass of the gravity source and the (different!) distance from
    the individual ray to the gravity source. In other words:
    a bunch of parallel rays *will* be spread when it passes a
    gravity source ...

    Too hard?

    -Wolfgang
     
    Wolfgang Weisselberg, May 6, 2013
    #82
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  3. Alan Browne

    PeterN Guest

    I I precisely understood how gravitational forces interact, I doubt I
    would waste time responding to you.
     
    PeterN, May 8, 2013
    #83
  4. Alan Browne

    Martin Brown Guest

    Trouble is that stars for the most part tend to be heavily concentrated
    in galaxies, cluster of galaxies and super clusters of clusters.

    The net result is that you can get strong lensing effects of very
    distant sources by galaxies or clusters between us and the source.
    Einstein rings were predicted long before they were observed.

    http://hubblesite.org/hubble_discov...nstein_rings_natures_gravitational_lenses.pdf

    Probably by far the prettiest one is the Hubble image of the horseshoe
    ring around LRG 3-757 (sorry about the unromantic name for the latter)

    http://nasa-image.blogspot.co.uk/2011/12/horseshoe-einstein-ring-from-hubble.html

    That said most of the light rays from distant sources to an exceedingly
    good approximation do remain parallel.
     
    Martin Brown, May 8, 2013
    #84
  5. Alan Browne

    J. Clarke Guest

    It's not a matter of "approval", it's a matter of soliciting the advice
    of others to improve your own work. You're not obligated to take that
    advice, but having it can be helpful.
     
    J. Clarke, May 8, 2013
    #85
  6. If you precisely understood how gravitational forces
    (and matter and space) interacts, you'd probably on the list
    for the Nobel price.

    If you "merely"[1] had a working understanding of how
    gravitatonal forces act *and what that means* you'd be more
    careful about "in such a way that photons from any random
    source stay parallel", e.g. by making clear that they probably
    won't stay perfectly parallel. ('probably' only because I
    cannot guarantee that there can't be a setup where they *do*
    stay parallel.)

    -Wolfgang

    [1] not that that is something small in any way
     
    Wolfgang Weisselberg, May 8, 2013
    #86
  7. And that *keeps* the rays *parallel*?

    Yep, but the rays aren't parallel --- can't be, otherwise
    they must look like they came from the very same point (due
    to the distances involved).
    Only for distances that are very short compared to the distance
    from where they come.

    But we were getting theoretical, not real-world 'close enough'.

    -Wolfgang
     
    Wolfgang Weisselberg, May 8, 2013
    #87
  8. Alan Browne

    PeterN Guest

    Spot on. Many photographic masterpieces, would not score well in CC
    competitions. There are members who prepare images solely for CC
    competitions. If that is what they want, than I say fine, but as you
    correctly point out, there's a lot more to camera clubs than just
    competitions. Here is an image that I like, but did not do well in CC
    competition. But, I still like it.

    <https://dl.dropboxusercontent.com/u/97242118/swooper.jpg>
     
    PeterN, May 8, 2013
    #88
  9. Alan Browne

    PeterN Guest

    But the origins of the gravitational are not random. You certainly are
    free to speculate what would happen if they were, but I would rather
    concentrate on the far less esoteric topic, of how to improve my images.
     
    PeterN, May 9, 2013
    #89
  10. Did I get that right? You're basically saying that the
    objects are both random and not random?

    -Wolfgang
     
    Wolfgang Weisselberg, May 11, 2013
    #90
  11. Alan Browne

    PeterN Guest

    Np Read carefully
     
    PeterN, May 11, 2013
    #91
  12. Please explain "the gravitational", then. I carefully read
    it as meaning "the gravitational influence/the gravitational
    objects", because *that* makes sense, while "the gravitational"
    does not, at least with my very limited knowledge of English ...

    -Wolfgang
     
    Wolfgang Weisselberg, May 13, 2013
    #92
  13. Alan Browne

    PeterN Guest

    Read again.
    IF the objects were truly random, ......
    Then I said but, the objects are not random. Nothing contradictory
    there. But yes I should have said the origins of the gravitational
    fields are not random. I hope this clarifies.

    BTW the authority for my statement is Einstein, and that is what I
    remember him telling me. Since I was only about 11 at the time, I might
    have misunderstood.
     
    PeterN, May 14, 2013
    #93
  14. You started to talk about "theoretical" and "randomly
    distributed objects". Then you say "but they [the
    theoretical randomly distributed objects] are not random".
    Ok, the objects are not random, so your "If you want to get
    theoretical" claim has been abandoned as indefensible.

    So please construct a non-random arrangement of objects that
    do keep the rays in parallel as they pass through it. Have fun!
    Which statement? That "randomly distributed objects might
    very well equalize each other"? That "Therefore the rays would
    remain parallel"? That "the origins of the gravitational are
    not random"? That you are not contradicting yourself?

    -Wolfgang
     
    Wolfgang Weisselberg, May 14, 2013
    #94
  15. Alan Browne

    PeterN Guest

    Not worth replying to
     
    PeterN, May 15, 2013
    #95
  16. [PeterN moved the goalposts and can't even tell us which
    statement he claimed he had heard from Einstein himself]
    Sour grapes, Peter? Very sour grapes, eh?

    -Wolfgang
     
    Wolfgang Weisselberg, May 16, 2013
    #96
  17. Alan Browne

    PeterN Guest

    No just not replying to troll questions.
     
    PeterN, May 18, 2013
    #97
  18. Yep, asking you what exactly Einstein told you is a troll
    question *and* an insult.

    But still, I'd like a configuration where gravity sources
    (carefully placed by you) do *not* influence parallel light
    rays to become non-parallel.

    -Wolfgang
     
    Wolfgang Weisselberg, May 20, 2013
    #98
  19. Alan Browne

    J. Clarke Guest

    Wolfgang, I really do not understand why you are harping on this ad-
    nauseum. If you think it has some real relevance to the issue of
    starlight being treated as parallel rays then do explain the relevance.
     
    J. Clarke, May 21, 2013
    #99
  20. Alan Browne

    PeterN Guest

    Go back and read. If you don't believe me, that is your problem.

    I didn't say that in a random configuration that would be no influence.
    I said there could be offsetting influences. But we already went that
    route.
     
    PeterN, May 21, 2013
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