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	<title>Comments on: The Universe is expanding at 74.2 km/sec/Mpc</title>
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	<link>http://blogs.discovermagazine.com/badastronomy/2009/05/07/the-universe-is-expanding-at-742-kmsecmpc/</link>
	<description>I am an astronomer, writer, and skeptic. I likes reality the way it is, and I aims to keep it that way. My real name is Phil Plait, and I run the Bad Astronomy blog.</description>
	<lastBuildDate>Mon, 23 Nov 2009 17:24:15 -0600</lastBuildDate>
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		<title>By: bruce</title>
		<link>http://blogs.discovermagazine.com/badastronomy/2009/05/07/the-universe-is-expanding-at-742-kmsecmpc/comment-page-3/#comment-222580</link>
		<dc:creator>bruce</dc:creator>
		<pubDate>Mon, 26 Oct 2009 23:42:58 +0000</pubDate>
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		<description>pardon my denseness, but given that the radius size of the observable universe at 14gpc, won&#039;t that make the &#039;expansion rate&#039; at 10,388,000 km per sec? about 34x faster than the speed of light?</description>
		<content:encoded><![CDATA[<p>pardon my denseness, but given that the radius size of the observable universe at 14gpc, won&#8217;t that make the &#8216;expansion rate&#8217; at 10,388,000 km per sec? about 34x faster than the speed of light?</p>
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		<title>By: Oz</title>
		<link>http://blogs.discovermagazine.com/badastronomy/2009/05/07/the-universe-is-expanding-at-742-kmsecmpc/comment-page-3/#comment-219421</link>
		<dc:creator>Oz</dc:creator>
		<pubDate>Mon, 12 Oct 2009 18:57:20 +0000</pubDate>
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		<description>The thought we were past the whole universe being flat...</description>
		<content:encoded><![CDATA[<p>The thought we were past the whole universe being flat&#8230;</p>
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		<title>By: Bendik Hansen</title>
		<link>http://blogs.discovermagazine.com/badastronomy/2009/05/07/the-universe-is-expanding-at-742-kmsecmpc/comment-page-3/#comment-207516</link>
		<dc:creator>Bendik Hansen</dc:creator>
		<pubDate>Thu, 20 Aug 2009 08:21:08 +0000</pubDate>
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		<description>Correction: is he suggesting that the universe is only a thin layer shaped like a sphere (or something similar), like the rubber of an inflated balloon?</description>
		<content:encoded><![CDATA[<p>Correction: is he suggesting that the universe is only a thin layer shaped like a sphere (or something similar), like the rubber of an inflated balloon?</p>
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		<title>By: Bendik Hansen</title>
		<link>http://blogs.discovermagazine.com/badastronomy/2009/05/07/the-universe-is-expanding-at-742-kmsecmpc/comment-page-3/#comment-207480</link>
		<dc:creator>Bendik Hansen</dc:creator>
		<pubDate>Wed, 19 Aug 2009 23:18:48 +0000</pubDate>
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		<description>Very interesting blog and comments.

I&#039;ve recently been bothered by the question: How in Hell can everything in the universe expand away from everything else in every direction, and even at an increased rate? In my logic, there would have to be a center where something moved slower, or clashed together. 

The inflation theory worked that out, but that leaves me with another question (it may be be that I take this balloon analogy a bit too biblically): Is he supposing that the universe is only a thin layer, like the rubber of an inflated balloon? (&quot;Thin&quot; like in 13,7 billion LY or something). 

And does he suggest that spacetime is curved like the outside of a globe to fit this inflated universe? Or are there simply &quot;walls&quot; that mark the outside and inside of the balloon which light (or anything else) cannot pass through?
If the former: The univerzal horizon doesn&#039;t make any sense, because light would be curved to reach us no matter where it came from.
If the latter: That&#039;d be weird, wouldn&#039;t it? ^^ That would imply that light can only pass through the matter of which the universe consists and that outside that it just...Idunno. 

One last thing: If my first question is answered with a &quot;yes&quot;, then shouldn&#039;t we be able to look further in one direction than the other (i.e. to the outside/inside of the balloon)? We&#039;re not very likely to be placed in the exast middle of those 13 billion LY of which it consist.

I&#039;ve no experience with cosmology or anything related, so I&#039;m sorry if this just seem like a load of rubbish to you (try to avoid the worst banter if you reply, thanks). I WILL purchase an introductionary book to cosmology, but my list of books to get is long, and I can&#039;t have this on my mind forever ^^</description>
		<content:encoded><![CDATA[<p>Very interesting blog and comments.</p>
<p>I&#8217;ve recently been bothered by the question: How in Hell can everything in the universe expand away from everything else in every direction, and even at an increased rate? In my logic, there would have to be a center where something moved slower, or clashed together. </p>
<p>The inflation theory worked that out, but that leaves me with another question (it may be be that I take this balloon analogy a bit too biblically): Is he supposing that the universe is only a thin layer, like the rubber of an inflated balloon? (&#8221;Thin&#8221; like in 13,7 billion LY or something). </p>
<p>And does he suggest that spacetime is curved like the outside of a globe to fit this inflated universe? Or are there simply &#8220;walls&#8221; that mark the outside and inside of the balloon which light (or anything else) cannot pass through?<br />
If the former: The univerzal horizon doesn&#8217;t make any sense, because light would be curved to reach us no matter where it came from.<br />
If the latter: That&#8217;d be weird, wouldn&#8217;t it? ^^ That would imply that light can only pass through the matter of which the universe consists and that outside that it just&#8230;Idunno. </p>
<p>One last thing: If my first question is answered with a &#8220;yes&#8221;, then shouldn&#8217;t we be able to look further in one direction than the other (i.e. to the outside/inside of the balloon)? We&#8217;re not very likely to be placed in the exast middle of those 13 billion LY of which it consist.</p>
<p>I&#8217;ve no experience with cosmology or anything related, so I&#8217;m sorry if this just seem like a load of rubbish to you (try to avoid the worst banter if you reply, thanks). I WILL purchase an introductionary book to cosmology, but my list of books to get is long, and I can&#8217;t have this on my mind forever ^^</p>
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		<title>By: The Universe is expanding at 74.2 km/sec/Mpc - The Michael Jackson Internet Fan Club MJIFC</title>
		<link>http://blogs.discovermagazine.com/badastronomy/2009/05/07/the-universe-is-expanding-at-742-kmsecmpc/comment-page-2/#comment-206524</link>
		<dc:creator>The Universe is expanding at 74.2 km/sec/Mpc - The Michael Jackson Internet Fan Club MJIFC</dc:creator>
		<pubDate>Sat, 15 Aug 2009 20:07:27 +0000</pubDate>
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		<description>[...] just by figuring out how bright some stars are?  Oh yeah, scientists did. That</description>
		<content:encoded><![CDATA[<p>[...] just by figuring out how bright some stars are?  Oh yeah, scientists did. That</p>
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		<title>By: Theresa MORRIS Mainpage &#187; Blog Archive &#187; GALAXY EXPANSE AND ESSENCE OF ALL</title>
		<link>http://blogs.discovermagazine.com/badastronomy/2009/05/07/the-universe-is-expanding-at-742-kmsecmpc/comment-page-2/#comment-195412</link>
		<dc:creator>Theresa MORRIS Mainpage &#187; Blog Archive &#187; GALAXY EXPANSE AND ESSENCE OF ALL</dc:creator>
		<pubDate>Sun, 28 Jun 2009 10:11:04 +0000</pubDate>
		<guid isPermaLink="false">http://blogs.discovermagazine.com/badastronomy/2009/05/07/the-universe-is-expanding-at-742-kmsecmpc/#comment-195412</guid>
		<description>[...]  The Universe is expanding at 74.2 km/sec/Mpc  (blogs.discovermagazine.com) [...]</description>
		<content:encoded><![CDATA[<p>[...]  The Universe is expanding at 74.2 km/sec/Mpc  (blogs.discovermagazine.com) [...]</p>
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		<title>By: telson</title>
		<link>http://blogs.discovermagazine.com/badastronomy/2009/05/07/the-universe-is-expanding-at-742-kmsecmpc/comment-page-2/#comment-191896</link>
		<dc:creator>telson</dc:creator>
		<pubDate>Mon, 15 Jun 2009 05:58:58 +0000</pubDate>
		<guid isPermaLink="false">http://blogs.discovermagazine.com/badastronomy/2009/05/07/the-universe-is-expanding-at-742-kmsecmpc/#comment-191896</guid>
		<description>http://koti.phnet.fi/elohim/howdideverythingbegin2.html

Concerning the Big Bang and expansion, it is an issue that we cannot detect with the naked eye or even with a telescope, no matter how much we look. Revolving and rotary movements of the bodies we can see – at least in the near space – but we cannot see expansion.

   Instead, some have thought that the best piece of evidence supporting the Big Bang is red shift, which can be observed in distant stars. It has been thought that when the spectrums of light in distant galaxies and stars move towards the red end of the spectrum, this indicates expansion. Red shift values of these celestial bodies should indicate their escape velocity and distance, so that all bodies are drawing away from us at a velocity proportional to their distance.

  However, using the red shift as evidence for expansion is questionable. It arises, for example, from the following factors:

 

The light of all stars is not red shifted. The first problem with the red shift is that the light of all stars is not red shifted. For example, the Andromeda Galaxy and certain other galaxies show blue shifted light, which means that they should be approaching us. (It has been estimated that the Andromeda Galaxy is approaching us at 300 kilometres a second! On the other hand, the escape velocity of the Virgin Constellation should be 1,200 km/s and that of Quasar PKS 2000 as much as 274,000 km/s. Where do these more than a hundredfold differences come from, if everything began at the same point?) These kinds of exceptions indicate that there may be some other explanation to the red shift values than drawing away from us. Maybe the values have nothing to do with their movements.

 

The values of adjacent galaxies. Another problem with the red shift is that some adjacent galaxies may have completely different red shift values, even though they are in connection with each other and quite close to each other. If the red shift value could be really used to tell the distance, there is no way these galaxies could be close to each other: instead, they should be far away from each other. This indicates that the red shift must be caused by some other facts, such as internal reactions and radiation of stars, which can also be detected from the Earth.

   Because of the same matter some researchers deny the importance of the red shift. They say or doubt it having anything to do with expansion. In fact, the whole Big Bang theory is then without its most important evidence:

 

I do not want to imply that everyone is of the same opinion regarding the interpretation of the red shift. We do not actually observe the galaxies rushing away from us; the only issue that is sure is that their spectrums have moved towards red. Famous astronomers doubt whether the red shift has anything to do with the Doppler shifts or with the expansion of space. Halton Arp of the Hale Observatory has emphasized that groups of galaxies can be found in space where some galaxies have quite different red shifts; if these groups are really composed of galaxies that are close to each other, they could hardly move at very different velocities. Furthermore, Maarten Schmidt noticed in 1963 that certain kinds of objects resembling stars had enormously high red shifts, up to more than 300 per cent! If these &quot;quasars&quot; are at the distances that can be deducted from their red shifts, they must radiate an extremely large amount of energy in order to continue being so bright. It is also very difficult to measure the correlation between velocity and distance when the objects are really far away. (Steven Weinberg, Kolme ensimmäistä minuuttia / The Three First Minutes, p. 40)</description>
		<content:encoded><![CDATA[<p><a href="http://koti.phnet.fi/elohim/howdideverythingbegin2.html" rel="nofollow">http://koti.phnet.fi/elohim/howdideverythingbegin2.html</a></p>
<p>Concerning the Big Bang and expansion, it is an issue that we cannot detect with the naked eye or even with a telescope, no matter how much we look. Revolving and rotary movements of the bodies we can see – at least in the near space – but we cannot see expansion.</p>
<p>   Instead, some have thought that the best piece of evidence supporting the Big Bang is red shift, which can be observed in distant stars. It has been thought that when the spectrums of light in distant galaxies and stars move towards the red end of the spectrum, this indicates expansion. Red shift values of these celestial bodies should indicate their escape velocity and distance, so that all bodies are drawing away from us at a velocity proportional to their distance.</p>
<p>  However, using the red shift as evidence for expansion is questionable. It arises, for example, from the following factors:</p>
<p>The light of all stars is not red shifted. The first problem with the red shift is that the light of all stars is not red shifted. For example, the Andromeda Galaxy and certain other galaxies show blue shifted light, which means that they should be approaching us. (It has been estimated that the Andromeda Galaxy is approaching us at 300 kilometres a second! On the other hand, the escape velocity of the Virgin Constellation should be 1,200 km/s and that of Quasar PKS 2000 as much as 274,000 km/s. Where do these more than a hundredfold differences come from, if everything began at the same point?) These kinds of exceptions indicate that there may be some other explanation to the red shift values than drawing away from us. Maybe the values have nothing to do with their movements.</p>
<p>The values of adjacent galaxies. Another problem with the red shift is that some adjacent galaxies may have completely different red shift values, even though they are in connection with each other and quite close to each other. If the red shift value could be really used to tell the distance, there is no way these galaxies could be close to each other: instead, they should be far away from each other. This indicates that the red shift must be caused by some other facts, such as internal reactions and radiation of stars, which can also be detected from the Earth.</p>
<p>   Because of the same matter some researchers deny the importance of the red shift. They say or doubt it having anything to do with expansion. In fact, the whole Big Bang theory is then without its most important evidence:</p>
<p>I do not want to imply that everyone is of the same opinion regarding the interpretation of the red shift. We do not actually observe the galaxies rushing away from us; the only issue that is sure is that their spectrums have moved towards red. Famous astronomers doubt whether the red shift has anything to do with the Doppler shifts or with the expansion of space. Halton Arp of the Hale Observatory has emphasized that groups of galaxies can be found in space where some galaxies have quite different red shifts; if these groups are really composed of galaxies that are close to each other, they could hardly move at very different velocities. Furthermore, Maarten Schmidt noticed in 1963 that certain kinds of objects resembling stars had enormously high red shifts, up to more than 300 per cent! If these &#8220;quasars&#8221; are at the distances that can be deducted from their red shifts, they must radiate an extremely large amount of energy in order to continue being so bright. It is also very difficult to measure the correlation between velocity and distance when the objects are really far away. (Steven Weinberg, Kolme ensimmäistä minuuttia / The Three First Minutes, p. 40)</p>
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