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InkDark
Carpal Tunnel
Reged: 10/29/07
Posts: 1509
Loc: Montreal, Canada
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The Big Bang happened about 14 billion years ago. So why then does the Hubble ultra deep field observations doesn’t show a back ground of old (red shifted) very tightly packed galaxies. I’m thinking that since those observations go back in time almost 13 billion years ago, at a time when, as the Big Bang theory predicts, the galaxies of the Universe were close to each other, they should show up as young galaxies very near to each other (as seen by Hubble). The only explanation I can think of is that the incoming light from the oldest galaxies expanded with the Universe and this is why they don’t appear closer to each other than the nearer galaxies?
I must be missing something here which is obvious to most - which is a bit embarrassing. Thanks for your help.
Hubble ultra deep field
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Jimmy
"Rarely Have So Many Understood So Little About So Much" - Palle Yourgrau
"...since that time, I have not complained about the weather one single time. I’m glad there is weather." – Alan Bean, Apollo 12
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Pess
(Title)
Reged: 09/12/07
Posts: 1910
Loc: Toledo, Ohio
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Well, for one3 thing they are so far away that their light is too dim to see.
We have detected galaxies dating back to within 700 million years after the big bang. But these galaxies are so far away that their light is no longer in the visible wavelength and is so feeble in the infrared that we can only detect it because we got lucky and intervening galaxies provide a nice gravitational lens.
Pesse (Danger! Black Hole) Mist
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BillFerris
Carpal Tunnel
Reged: 07/17/04
Posts: 2582
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Actually, a Big Bang universe doesn't necessarily have to be "small" at the time when galaxies first formed. If the inflationary model is correct, the universe grew at an incredibly fast rate during the first, smallest fraction of a second. Following the initial inflation event, the universe would have continued expanding at a rate faster than the speed of light during its early history. The result would have been a universe that was already quite large when the first galaxies formed.
Bill in Flag
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Grand Canyon Adventure
Lowering the Threshold
18" Obsession
4.5" Meade 4500
10x50 Swift Audubon
Cosmic Voyage
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HiggsBoson
scholastic sledgehammer
Reged: 02/21/07
Posts: 809
Loc: Kal-li-fornia
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There first answer is that there were few galaxies at the time. Indeed your question is the mission statement of the James Webb Telescope. To view the formation of the earliest galaxies and see what ever there is to see at that time. This requires a large cold inferred telescope.
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Michael
ATM: 6" F/9 Newtonian Travel Scope
ATM: 12.5" F/4.5 Real Soon Now...
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InkDark
Carpal Tunnel
Reged: 10/29/07
Posts: 1509
Loc: Montreal, Canada
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Quote:
There first answer is that there were few galaxies at the time. Indeed your question is the mission statement of the James Webb Telescope. To view the formation of the earliest galaxies and see what ever there is to see at that time. This requires a large cold inferred telescope.
Looks like we'll have to wait then (come on 2013!  ). Thanks guys for your replies.
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Jimmy
"Rarely Have So Many Understood So Little About So Much" - Palle Yourgrau
"...since that time, I have not complained about the weather one single time. I’m glad there is weather." – Alan Bean, Apollo 12
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Qkslvr
Pooh-Bah
Reged: 06/23/06
Posts: 1054
Loc: NE Ohio, US
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I don't think there could be FTL inflation after photons decoupled, and the Universe became clear, otherwise the CMB would be outside out light cone.
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Mike
N8/CG-5/40D
Coming sometime/Maybe FrankenRebel
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