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| Science Forum Index » Physics Forum » Scientific American: Misconceptions about the Big Bang |
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| Sam Wormley |
 Posted: Tue Mar 01, 2005 7:21 pm |
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| Dave P. |
| Posted: Tue Mar 01, 2005 11:42 pm |
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On Wed, 02 Mar 2005 00:21:59 GMT, Sam Wormley <swormley1@mchsi.com>
wrote:
[quote:1882f774a8]Scientific American: Misconceptions about the Big Bang
http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=0009F0CA-C523-1213-852383414B7F0147
[/quote:1882f774a8]
Actually... as a followup:
The article mentions at one point:
"Consequently, the current distance to the most distant object we can
see is about 3 times farther, or 46 light years."
Farther meaning farther than the distance light could have travelled
in the 14 billion years since the big bang, if space was not
expanding.
But then later in the article they talk about the event horizon of an
accelerating universe and say:
"The current distance to our cosmic event horizon is 16 billion light
years, well within our observable range"
I am confused by this. I understood the cosmic event horizon to be the
distance beyond which we could not see... yet they say it is within
our visible range, and that the most distant object we can see is 46
billion light years away.
I assume I am missing something about the concept of the cosmic event
horizon. Can anyone explain this in more detail?
Thanks.
Dave P. |
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| Jack Martinelli |
| Posted: Wed Mar 02, 2005 1:10 am |
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"AaronB" <amino_acid456@hotmail.com> wrote in message
news:1109725092.831688.211120@f14g2000cwb.googlegroups.com...
[quote:aca819dda8]
Sam Wormley wrote:
Scientific American: Misconceptions about the Big Bang
http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=0009F0CA-C523-1213-852383414B7F0147
One interesting point to pull out of this article:
"The term "at rest" can be defined rigorously. The microwave background
radiation fills the universe and defines a universal reference frame,
[/quote:aca819dda8]
....not universal. A unit of length in the CMBR is hard to define so that it
satisfies both the stochastic properties of QM and the determinism of GR.
I.e., a reference length is bound by two distinguishable objects (e.g.,
electrons). When these distinguishable object are virtual, you have to deal
with their popping into & out of existence. What does that imply about a
metric? (I don't even want to talk about the position of a photon.)
The CMBR is very complex & not fundamental & not smooth in space or time.
Try using the physics of the CMBR to describe gravity.
The CMBR is another kind of a reference frame. And like an electron, or
atom, it has its own proper/natural units of length & time. Its a useful
frame, but hardly universal.
Regards,
Jack Martinelli
http://www.martinelli.org |
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| Bjoern Feuerbacher |
| Posted: Wed Mar 02, 2005 5:48 am |
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Dave P. wrote:
[quote:ede49f387e]On Wed, 02 Mar 2005 00:21:59 GMT, Sam Wormley <swormley1@mchsi.com
wrote:
Scientific American: Misconceptions about the Big Bang
http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=0009F0CA-C523-1213-852383414B7F0147
Actually... as a followup:
The article mentions at one point:
"Consequently, the current distance to the most distant object we can
see is about 3 times farther, or 46 light years."
Farther meaning farther than the distance light could have travelled
in the 14 billion years since the big bang, if space was not
expanding.
But then later in the article they talk about the event horizon of an
accelerating universe and say:
"The current distance to our cosmic event horizon is 16 billion light
years, well within our observable range"
I am confused by this. I understood the cosmic event horizon to be the
distance beyond which we could not see... yet they say it is within
our visible range, and that the most distant object we can see is 46
billion light years away.
I assume I am missing something about the concept of the cosmic event
horizon. Can anyone explain this in more detail?
[/quote:ede49f387e]
I'm not sure about that, but I think they mean that we can see light
from objects which are up to 46 billion light years away *now* (but
left these objects long ago), but we will be unable to see light which
*leaves* objects which are more than 16 billion light years away *now*.
Bye,
Bjoern |
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| John C. Polasek |
| Posted: Wed Mar 02, 2005 10:53 am |
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On Tue, 01 Mar 2005 23:42:22 -0500, Dave P. <davep@home.com> wrote:
[quote:a3530406c4]On Wed, 02 Mar 2005 00:21:59 GMT, Sam Wormley <swormley1@mchsi.com
wrote:
Scientific American: Misconceptions about the Big Bang
http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=0009F0CA-C523-1213-852383414B7F0147
Actually... as a followup:
The article mentions at one point:
"Consequently, the current distance to the most distant object we can
see is about 3 times farther, or 46 light years."
Farther meaning farther than the distance light could have travelled
in the 14 billion years since the big bang, if space was not
expanding.
But then later in the article they talk about the event horizon of an
accelerating universe and say:
"The current distance to our cosmic event horizon is 16 billion light
years, well within our observable range"
I am confused by this. I understood the cosmic event horizon to be the
distance beyond which we could not see... yet they say it is within
our visible range, and that the most distant object we can see is 46
billion light years away.
I assume I am missing something about the concept of the cosmic event
horizon. Can anyone explain this in more detail?
Thanks.
Dave P.
[/quote:a3530406c4]
Dave, take a look at my expansion model at http://www.dualspace.net.
You will see there is a rationale for a radius/time 13BYR and distance
pi times that, which would be halfway around in the diagram (even more
if you don't mind seeing double). Take a look
John Polasek.
Mr. Dual Space
If you have something to say, write an equation.
If you have nothing to say, write an essay |
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| Guest |
| Posted: Thu Mar 03, 2005 8:32 pm |
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AaronB wrote:
[quote:b12caca5d4]"The term "at rest" can be defined rigorously.
[/quote:b12caca5d4]
That's because the vacuum is in a thermal state. A thermal state
breaks Poincare' invariance and also establishes an arrow to time
(future-pointing, if the temperature > 0; past-pointing, if the
temperature < 0). Ultimately, it resurrects the long-forgotten G field
in Maxwell's alphabet progressions A, B, C, D, E, F, G, H, I. |
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