Does the Universe have a Center of Gravity? Where is it?

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Chris Peterson
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Re: Does the Universe have a Center of Gravity? Where is it

Post by Chris Peterson » Sat Oct 22, 2011 6:08 am

Ann wrote:I absolutely understand what you mean, charlieo3. It's just that this beautiful lettering makes the words horribly difficult for me to read!!!
The written form of Danish doesn't help. Although this reads almost perfectly as modern Danish, it was written before the modern spelling conventions were adopted- so it looks a bit odd, even after the font is puzzled out.
Chris

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geckzilla
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Re: Does the Universe have a Center of Gravity? Where is it

Post by geckzilla » Sun Oct 23, 2011 12:04 am

At least at the time that the script was written people had advanced past uncials. :lol:

Would you believe that at some point in history there was no punctuation clearly guiding us from one sentence to the next and all letters were capital? Oh yeah, and all the words were connected, as well. Compared to that, this is a breeze!
Just call me "geck" because "zilla" is like a last name.

ErnieM
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How Large is the Universe

Post by ErnieM » Thu Jul 12, 2012 4:12 pm

I watched this video titled "How Large Is the Universe" http://www.youtube.com/watch?feature=pl ... EQouX5U0fc

In it, it is estimated that the whole universe is so large that my original questions "Does the Universe have a Center of Gravity" Where is It?" that opened this thread, I now admit, is irrelevant, meaningless and nonsense.

However, I am not sorry I asked because it sparked my imagination and started me on a trail leading to this point.

Thank you for all the replies.

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Chris Peterson
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Re: How Large is the Universe

Post by Chris Peterson » Thu Jul 12, 2012 4:52 pm

ErnieM wrote:I watched this video titled "How Large Is the Universe" http://www.youtube.com/watch?feature=pl ... EQouX5U0fc

In it, it is estimated that the whole universe is so large that my original questions "Does the Universe have a Center of Gravity" Where is It?" that opened this thread, I now admit, is irrelevant, meaningless and nonsense.
While I do think that the Universe cannot have a center of gravity in three dimensions, I don't see what the size of the Universe has to do with the question. Any massive three-dimensional structure of less than infinite size has a center of gravity. The reason the Universe doesn't have a center of gravity in the usual sense is because it isn't a three-dimensional structure, not because it is spatially large.
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neufer
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Re: How Large is the Universe

Post by neufer » Thu Jul 12, 2012 5:17 pm

ErnieM wrote:
I watched this video titled "How Large Is the Universe" http://www.youtube.com/watch?feature=pl ... EQouX5U0fc

In it, it is estimated that the whole universe is so large that my original questions
"Does the Universe have a Center of Gravity" Where is It?"
that opened this thread, I now admit, is irrelevant, meaningless and nonsense.
  • To perform the experiment: get yourself two eagles ....
http://en.wikipedia.org/wiki/Omphalos wrote: <<An omphalos (ὀμφαλός) is an ancient religious stone artifact, or baetylus. In Greek, the word omphalos means "navel." According to the ancient Greeks, Zeus sent out two eagles to fly across the world to meet at its center, the "navel" of the world. Omphalos stones used to denote this point were erected in several areas surrounding the Mediterranean Sea; the most famous of those was at the oracle in Delphi. It is also the name of the stone given to Cronus in Zeus' place in Greek mythology.

Most accounts locate the Omphalos in the temple adyton near the Pythia. The stone itself (which may have been a copy) has a carving of a knotted net covering its surface, and has a hollow centre, which widens towards its base. :arrow:

The Omphalos at Delphi came to be identified as the stone which Rhea wrapped in swaddling clothes, pretending it was Zeus. This was to deceive Cronus, his father, who swallowed his children so they could not grow up and depose him as he had deposed his own father, Uranus.

Omphalos stones were said to allow direct communication with the gods. Leicester Holland (1933) has suggested that the stone was hollow to channel intoxicating vapours breathed by the Oracle. Erwin Rohde wrote that the Python at Delphi was an earth spirit, who was conquered by Apollo, and buried under the Omphalos, and that it is a case of one god setting up his temple on the grave of another.

Christian destruction of the site in the fourth century at the order of Emperors Theodosius I and Arcadius makes all suggestions about its use tentative.>>
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ErnieM
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Re: Does the Universe have a Center of Gravity? Where is it

Post by ErnieM » Fri Jul 13, 2012 3:37 pm

Chris wrote:
While I do think that the Universe cannot have a center of gravity in three dimensions, I don't see what the size of the Universe has to do with the question. Any massive three-dimensional structure of less than infinite size has a center of gravity. The reason the Universe doesn't have a center of gravity in the usual sense is because it isn't a three-dimensional structure, not because it is spatially large.
When astronomers say "The expansion of Space is accelerating", how many dimensions of Space are they referring to? What do you mean with "because it isn't a three-dimensional structure"? Is the holographic 2D Universe universally accepted now?

I see this expansion making the already large Universe larger and the gravitational hold between galaxy structures weakening to inconsequential.

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Chris Peterson
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Re: Does the Universe have a Center of Gravity? Where is it

Post by Chris Peterson » Fri Jul 13, 2012 4:13 pm

ErnieM wrote:When astronomers say "The expansion of Space is accelerating", how many dimensions of Space are they referring to?
They are generally referring to the three spatial dimensions.
What do you mean with "because it isn't a three-dimensional structure"?
The Universe is a four-dimensional structure. Its geometric center contains t=0, a point that we can't observe. If the Universe if finite, its geometric center of mass will also be a four-dimensional point, which will not lie on the three-dimensional manifold we can observe.
I see this expansion making the already large Universe larger and the gravitational hold between galaxy structures weakening to inconsequential.
Gravity is a weak force to begin with. Certainly, its influence between points that are very far apart (but still causally connected) is likely to be very tiny. But not zero. Any bounded region of the Universe will have a center of mass.
Chris

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