Universe expansion rate question

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six_strings

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Hi, first post on this site <img src="/images/icons/smile.gif" /> <br />So, I am I bit confused about an article I read today ( http://www.cnn.com/2004/TECH/space/05/24/universe.wide/index.html )<br />In the article it states the universe is 156 billion light years across. And explains that expansion makes this possible even though the furthest galaxy we so far have observed is 13+ billion. So if i understand this right, that far galaxy was 13+ billion light years away when its photons left the galaxy but in actuality it is now 78 billion light years away? So the expansion of the universe is faster the the speed of light? I have a hard time grasping this.. heh.. I must be missing something or mis-understanding the article? <div class="Discussion_UserSignature"> </div>
 
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Saiph

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well, we can see to ~13 billion ly out, the age of the universe. There's no reason to say we have to be able to see everything that's out there. So calculations show the entire universe is some 156 billioni light years or so, but the <i>observable</i> universe is only a 13 billion ly radius sphere centered on us. <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>
 
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six_strings

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Mmmm.... Not exactly where I'm coming from with my Question.... The Article states: "the starting point of a photon reaching us today after traveling for 13.7 billion years is now 78 billion light-years away" <br />Now wouldnt that mean that space/the universe has expanded faster than light can travel? That is 5 times farther then light could travel on it own.... <div class="Discussion_UserSignature"> </div>
 
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yevaud

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Yes, it exactly means that spacetime has expanded at a rate much higher than the velocity of C. Since it's space itself that expanded, it isn't held to the same restriction as photons.<br /><br />This original expansion is known as "Inflation."<br /><br />Beyond the Big Bang: Inflation and the Early Universe<br /><br />Hope that answers your questions. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>
 
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alkalin

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OK, so another prediction of big bang is not found yet from this data. No surprise to me. Expansion predicts that it all came from a point 13.7 billion years ago, so if you were to look at this early universe, we should see similar features eventually.<br /><br />The article assures us that the universe size is far more than expansion from the universe 13.7 B years ago. Expansion is not the correct word. It should have said inflation. Expansion cannot put matter even close to the speed of light. But inflation is a math notion that can put everything were we see it far beyond the speed of light. What a dream.<br /><br />Don’t be surprised if this finding is swept under the rug so that the Doppler theory remains intact.<br />
 
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six_strings

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All I can say is whoa.... <img src="/images/icons/smile.gif" /> I read that article "Beyond the Big Bang: Inflation and the Early Universe " OMG! It must be beyond me.... I read it, comprehended most of it but still have trouble with the concept.... Thanks for the answers <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> </div>
 
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lukman

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I had the same question earlier, my understanding is that space expand first faster than speed of light, then after some distance, quark, electron, etc started to form. However, after reading the CNN news, it is very difficult for me to understand how they can come out with the idea that Universe is 156 billion light-years wide. The explanation seems to make me think that earth is the center of the universe. At least if my understanding was wrong, the explanation make me believe that they somehow should have an idea where about is the center of the universe. From what i've read, scientist believe that the way we see thing is 3 dimension will never make us know where is the center of the universe, just like ants on the ballon. Help me to understand please. <div class="Discussion_UserSignature"> </div>
 
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six_strings

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After more research on other sites and deep contemplation, I really think I lean alot towards being a "creationist" Please no one take offense <img src="/images/icons/smile.gif" /> It just feel in many ways our theorys to understanding our universe have gotten so unimaginably crazy that it seems we are just grasping more and more to explain how we should be here if theres no supreme being... Maybe we can't understand fully cause we were never meant too... Or to "know or understand" would mean confirming what many wish to deny.... <div class="Discussion_UserSignature"> </div>
 
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newtonian

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six_strings - No offense, I also believe in God, a supreme being, who intelligently designed our universe, and specifically fine tuned the expansion rate such that our universe coult contain stars, and life.<br /><br />I do not know if inflation models are correct or not - the other posters and the article do present accurately a popular model with inflation after the big bang.<br /><br />On how fine tuned the expansion rate is:<br /><br />"Even if we are neither professional astronomers nor amateurs, we can see that an expanding universe would have profound implications about our past—and perhaps our personal future too. Something must have started the process—a force powerful enough to overcome the immense gravity of the entire universe. You have good reason to ask, ‘What could be the source of such dynamic energy?’<br /><br />Although most scientists trace the universe back to a very small, dense beginning (a singularity), we cannot avoid this key issue: “If at some point in the past, the Universe was once close to a singular state of infinitely small size and infinite density, we have to ask what was there before and what was outside the Universe. . . . We have to face the problem of a Beginning.”—Sir Bernard Lovell.<br /><br />This implies more than just a source of vast energy. Foresight and intelligence are also needed because the rate of expansion seems very finely tuned. “If the Universe had expanded one million millionth part faster,” said Lovell, “then all the material in the Universe would have dispersed by now. . . . And if it had been a million millionth part slower, then gravitational forces would have caused the Universe to collapse within the first thousand million years or so of its existence. Again, there would have been no long-lived stars and no life.” - "Is there a Creatpr Who Cares About You?", pp. 12-14
 
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