Palmer Conjecture

Seeing a picture of an Einstein Ring got me wondering. Do you suppose
that a light beam that departs something going one direction would
eventually pass a light beam that departs the same source in very
different direction? Both beams being effectively bent into a rough
circle by the mass of the entire universe. I'm thinking yes. If this
is true, and there was no dark matter in space, then the sky would have
to appear totally lighted if the time for a round trip by a light beam
were much smaller than the age of the universe itself because an object
would have to be visible everywhere. Since we don't see a completely
lighted sky at night there must either be lots of dark matter stopping
much of the starlight or the round trip time for a beam of light is
very long compared to the age of the universe itself.

If the universe was the right size and does not have too much dark
matter, we are potentially seeing the same objects many times each
today but don't know it. And if it is not true today, as Hubble extends
the distance of visible objects, the odds that this could happen are
growing. We might see an object that we think is 150 light years away
in one direction and the same object looking 8 billion light years away
in another. Of course, if this was true, our view of each image would
be from such a different direction that we could not recognize the
position of objects around it. And since the image we are seeing is
from such a different time, the characteristics of the object might be
quite different as well (an evolving star cluster in one and something
quite different in another).

So I'm a little perplexed with the question of how we might know that
this is what we're seeing, if it is. It would be a real shame if we
could theoretically see the same object many times but that the amount
of dark matter is so great that no light beam can actually make a round
trip.

.

Relevant Pages

  • Re: Riding on a photo
    ... > if he was riding on a light beam. ... > what the universe would look like from the point of view of a photon. ... Einstein trying to imagine what the universe would look like if he was ...
    (sci.physics.research)
  • Re: Palmer Conjecture
    ... > that a light beam that departs something going one direction would ... > circle by the mass of the entire universe. ... If space is infinite, and matter ...
    (sci.astro)
  • Re: Palmer Conjecture
    ... that a light beam that departs something going one direction would eventually pass a light beam that departs the same source in very different direction? ... Another way this is being examined is to see if there are actual repeating patterns in the background. ... I don't know if anyone's looked for repeating patterns in the 3D structure of the universe. ...
    (sci.astro)
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