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Old 06-13-2012, 10:51 AM
 
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Quote:
Originally Posted by Glitch View Post
Reionization would not occur until 150 million to 700 million years after the Big Bang, so it is not likely we will be able to see anything earlier than that point.
I'm glad you brought that up. Dealing with age of events or epochs seem pretty tricky to me. Regardless, according to the NASA article in the OP, "The universe formed roughly 13.7 billion years ago in a fiery, explosive Big Bang. With time, it cooled and, by around 500 million years later, the first stars, galaxies and black holes began to take shape." If that's the case, then the longest figure of "...700 million years after the Big Bang" would have to be tossed out the window in terms of when Reionization occurred since galaxies much earlier have been seen. According to the Hubble Ultra Deep Field view, "The dim object is a compact galaxy of blue stars that existed 480 million years after the Big Bang..." Either galaxies that long ago are viewable to us, or there was a big error in stating that said galaxy existed "450 million years after the Big Bang". Any thoughts on that?
HubbleSite - NewsCenter - NASA's Hubble Finds Most Distant Galaxy Candidate Ever Seen in Universe (01/26/2011) - Release Images
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Old 06-13-2012, 11:08 AM
 
Location: Texas
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Or maybe we are seeing part of another universe?
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Old 06-13-2012, 01:07 PM
 
Location: Wasilla, Alaska
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Quote:
Originally Posted by NightBazaar View Post
I'm glad you brought that up. Dealing with age of events or epochs seem pretty tricky to me. Regardless, according to the NASA article in the OP, "The universe formed roughly 13.7 billion years ago in a fiery, explosive Big Bang. With time, it cooled and, by around 500 million years later, the first stars, galaxies and black holes began to take shape." If that's the case, then the longest figure of "...700 million years after the Big Bang" would have to be tossed out the window in terms of when Reionization occurred since galaxies much earlier have been seen. According to the Hubble Ultra Deep Field view, "The dim object is a compact galaxy of blue stars that existed 480 million years after the Big Bang..." Either galaxies that long ago are viewable to us, or there was a big error in stating that said galaxy existed "450 million years after the Big Bang". Any thoughts on that?
HubbleSite - NewsCenter - NASA's Hubble Finds Most Distant Galaxy Candidate Ever Seen in Universe (01/26/2011) - Release Images
It was my understanding that reionization could have occurred at any time from 150 million years after the Big Bang to 700 million years after the Big Bang. If they are finding discreet objects visible 450 million years after the Big Bang, then I would say that reionization could have occurred at any time from 150 million years after the Big Bang to 450 million years after the Big Bang. In time they may find even more distant objects, thus refining the timeline even further.

We know that the reionization process began after the Dark Ages, around 150 million years after the Big Bang. What we do not know is how long the process took. If we can see distinct objects that formed 450 million years after the Big Bang, then the reionization process would have had to be complete enough for us to see through the opaque plasma soup.
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Old 06-13-2012, 01:56 PM
 
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Quote:
Originally Posted by Brian.Pearson View Post
Or maybe we are seeing part of another universe?
I'm a bit doubtful about that for a number of reasons. If it was another universe, we should be seeing galaxies in that region of our own universe gravitationally influenced or attracted by it in a similar fashion as the galaxies observed in the Dark Flow anomaly. It's possible it could be remnant echoes of light from some of the earliest star formations, which might not have quite been actual stars at that time and would've been very short lived, and the reason they look so huge is because of the expansion of the universe over billions of years. it could also be ancient supermassive black holes pulling in matter to begin forming the earliest galaxies in the relatively cramped space of the universe at that time.

The view is not only looking at an enormous distance in space, but also looking back at an enormously distant period in time. At the present time though, it's just not clear enough to tell exactly what it represents.
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Old 06-13-2012, 02:18 PM
 
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Quote:
Originally Posted by Glitch View Post
It was my understanding that reionization could have occurred at any time from 150 million years after the Big Bang to 700 million years after the Big Bang. If they are finding discreet objects visible 450 million years after the Big Bang, then I would say that reionization could have occurred at any time from 150 million years after the Big Bang to 450 million years after the Big Bang. In time they may find even more distant objects, thus refining the timeline even further.

We know that the reionization process began after the Dark Ages, around 150 million years after the Big Bang. What we do not know is how long the process took. If we can see distinct objects that formed 450 million years after the Big Bang, then the reionization process would have had to be complete enough for us to see through the opaque plasma soup.
I completely agree with what you're saying that the reionization could have been shorter than originally thought. Still, the universe might be much stranger and contains a lot more surprises than is presently thought. It wasn't so long ago that we thought all the stars in the galaxy were all the stars there were in the universe. We now know that our galaxy is only one of billions and billions of other galaxies, and that the universe is not only expanding, but that the expansion is also accelerating. I think the evolution of the universe is generally sound and on the right track, but some of the details occasionally need to be revised.
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Old 06-13-2012, 02:34 PM
 
Location: Wasilla, Alaska
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Originally Posted by NightBazaar View Post
I completely agree with what you're saying that the reionization could have been shorter than originally thought. Still, the universe might be much stranger and contains a lot more surprises than is presently thought. It wasn't so long ago that we thought all the stars in the galaxy were all the stars there were in the universe. We now know that our galaxy is only one of billions and billions of other galaxies, and that the universe is not only expanding, but that the expansion is also accelerating. I think the evolution of the universe is generally sound and on the right track, but some of the details occasionally need to be revised.
I agree, and I think without any doubt that the universe is much stranger and contains a lot more surprises than is presently known. We are finding exoplanets with orbits that are "impossible" according to our understanding of planetary and solar system formation. We are finding new stars that are much more massive than we originally thought possible. Clearly our understanding needs to improve. That is what makes this particular time in our history so exciting.
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Old 06-13-2012, 02:41 PM
 
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Originally Posted by Glitch View Post
That is what makes this particular time in our history so exciting.
Yep! I'm right there with you on that. The changes are what makes it all, not only a challenge, but keeps it interesting and adds to our knowledge.
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Old 06-13-2012, 05:56 PM
 
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Originally Posted by NightBazaar View Post
Looks like the conclusion is that we'll have to wait to see what the James Webb Space Telescope reveals about these objects.

NASA - NASA's Spitzer Finds First Objects Burned Furiously

Wider image of the region
http://www.nasa.gov/images/content/6...-full_full.jpg
NB

Since your one of the Outer Space guru's on here my question is that in looking at that image with all those thousands upon thousands of stars in our observable sky which are just a small part of the Milky Way Galaxy how the heck then did astronomers happened to discover the Andromedia galaxy amongst all of them?
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Old 06-13-2012, 07:01 PM
 
Location: Wasilla, Alaska
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Originally Posted by 6 Foot 3 View Post
NB

Since your one of the Outer Space guru's on here my question is that in looking at that image with all those thousands upon thousands of stars in our observable sky which are just a small part of the Milky Way Galaxy how the heck then did astronomers happened to discover the Andromedia galaxy amongst all of them?
By accident. The Andromedia Galaxy was originally known as the Great Andromedia Nebulae within the Milky Way Galaxy before 1920. Edwin Hubble used the 100" mirror, on top of Mount Wilson in California, and found faint stars in the "nebula." In 1923 Hubble used Cepheid Variable stars as a standard candle to determine the distance of those faint stars and found that they had to be at least 1.5 million light years from the Milky Way Galaxy.

The Andromedia Galaxy was the very first object discovered that was known not to exist within our Milky Way Galaxy. It literally changed our understanding of the universe overnight.
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Old 06-13-2012, 07:22 PM
 
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Quote:
Originally Posted by 6 Foot 3 View Post
NB

Since your one of the Outer Space guru's on here my question is that in looking at that image with all those thousands upon thousands of stars in our observable sky which are just a small part of the Milky Way Galaxy how the heck then did astronomers happened to discover the Andromedia galaxy amongst all of them?
A guru?

The Andromeda galaxy is in the constellation of Andromeda and can be seen with the naked eye. As far as I can tell, it's the only deep space object that can be seen with the naked eye, although it looks very tiny and blurred. Astronomers certainly knew about it. It was thought to be a gas nebula existing in our galaxy. Of course, it will eventually exist in our galaxy in a few billion years from now.

I don't know who first spotted it, but it's been known for a very long time. The first long exposure photo of it was in 1887 showing it had a spiral pattern. It wasn't until 1920 that it was recognized as an external galaxy. That must've been quite a shock for the general public, or those interested in the cosmos.

A Persian astronomer knew about it in 974 CE. I wouldn't be surprised that the Egyptians were aware of it several thousands of years ago, but you'd be likely to know more about that than I would.
Andromeda Galaxy - Wikipedia, the free encyclopedia
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