Another Question

[_Simon_]

<p>Hey!</p><p>I was thinking about a theory I heard a few years back. I remember hearing that Big Bang is destined to repeat itself over and over again. Meaning that the explosion made all matter in space fly in different directions as the debris in any explosion. But that gravity would eventually pull everyting back together and the whole thing would repeat itself all over again. I guess that would mean that at one time gravity would become more powerful than the current momentum of the debris.</p><p>&nbsp;What do you all think of this?</p><p>&nbsp;Have a nice day! <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-smile.gif" border="0" alt="Smile" title="Smile" /></p><p>&nbsp;//Simon </p> <div class="Discussion_UserSignature"> </div>

 

[neuvik]

<p>Thats assuming the model you mentioned is the most probably to occur in Friedmanns modle.&nbsp; The two others, indefinate expansion and aysmptote are still possible.</p><p>If that is true, then the singularites of black holes should also burst and reform.&nbsp;</p> <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">I don't think I'm alone when I say, "I hope more planets fall under the ruthless domination of Earth!"</font></strong></p><p><font color="#0000ff">SDC Boards: Power by PLuck - Ph**king Luck</font></p> </div>

 

[_Simon_]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Thats assuming the model you mentioned is the most probably to occur in Friedmanns modle.&nbsp; The two others, indefinate expansion and aysmptote are still possible.If that is true, then the singularites of black holes should also burst and reform.&nbsp; <br /> Posted by neuvik</DIV></p><p>&nbsp;</p><p>I have not heard about the aysmptote. Can you explaine it?<br /> </p> <div class="Discussion_UserSignature"> </div>

 

[neuvik]

<p>Well its not really an asymptote I just like calling it because it states everything is moving at a steady spead.</p><p>Basically the speraration between the galaxies started at some zero (on a space / time graph).&nbsp; Then it the galaxies are moving apart with a steady speed.&nbsp;&nbsp; Their speed is constat such that the universal graivty (prepared to be chewed by the physics grads) does not cause them to stop and come back, nor do they escape.</p><p>&nbsp;</p><p>Much like the explanation of gravity in LEO....your falling toward the Earth, but you keep missing it dueto your linerar speed.</p> <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">I don't think I'm alone when I say, "I hope more planets fall under the ruthless domination of Earth!"</font></strong></p><p><font color="#0000ff">SDC Boards: Power by PLuck - Ph**king Luck</font></p> </div>

 

[_Simon_]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Well its not really an asymptote I just like calling it because it states everything is moving at a steady spead.Basically the speraration between the galaxies started at some zero (on a space / time graph).&nbsp; Then it the galaxies are moving apart with a steady speed.&nbsp;&nbsp; Their speed is constat such that the universal graivty (prepared to be chewed by the physics grads) does not cause them to stop and come back, nor do they escape.&nbsp;Much like the explanation of gravity in LEO....your falling toward the Earth, but you keep missing it dueto your linerar speed. <br /> Posted by neuvik</DIV></p><p>Oh I see. So is there any theory that is widely considered to be the most probable?&nbsp;</p> <div class="Discussion_UserSignature"> </div>

 

[neuvik]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Oh I see. So is there any theory that is widely considered to be the most probable?&nbsp; <br /> Posted by _Simon_</DIV></p><p>&nbsp;</p><p>&nbsp;Theres just three models that fit.&nbsp; One, where the universe implode, explodes, and doesnt change. &nbsp; Quantum physics tells us which one is going to be more likely, but more reasearch is needed. &nbsp; They need a figure on the mass of the universe, but are having some trouble. &nbsp;&nbsp;&nbsp;</p><p>&nbsp;Thats all asumming that the universe did infact start from a singularity.</p><p>&nbsp;I don't know what they are leaning on, most galxies light is in the red shift spectrum to radio....saying that they are moving away. &nbsp; but its anyones guess still haha </p> <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">I don't think I'm alone when I say, "I hope more planets fall under the ruthless domination of Earth!"</font></strong></p><p><font color="#0000ff">SDC Boards: Power by PLuck - Ph**king Luck</font></p> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Hey!I was thinking about a theory I heard a few years back. I remember hearing that Big Bang is destined to repeat itself over and over again. Meaning that the explosion made all matter in space fly in different directions as the debris in any explosion. But that gravity would eventually pull everyting back together and the whole thing would repeat itself all over again. I guess that would mean that at one time gravity would become more powerful than the current momentum of the debris.&nbsp;What do you all think of this?&nbsp;Have a nice day! &nbsp;//Simon <br /> Posted by _Simon_</DIV></p><p>First, a common misconception is the the universe exploded.&nbsp; It did not.&nbsp; It expanded.&nbsp; An explosion would imply there is a center to the universe and that the universe has a preferred direction.&nbsp; Observations tell us otherwise.&nbsp; The Hubble redshifts tells us that the universe is expanding at a constant everwhere.&nbsp; From our location, we see everything expanding away from us.&nbsp; Places eslewhere in the universe would recognize the same thing.&nbsp; This is not typical of what you would see in an explosion.&nbsp;</p><p>According to the LambdaCDM model of the observable universe which is built from the Big Bang Theory (BBT), the current assessment is that we are in flat (or very nearly flat) universe.&nbsp; This tells us that the universe will expand forever... slowing down, but never quite stopping.&nbsp; They measure this by observing the Cosmic Microwave Background radiation (CMB) and determing the what the critical density is.&nbsp; </p><p>Using Friedmann's equations (as mentioned by Neuvik), the critical density (omega) is set to 1.&nbsp; The critical density is the ratio between the amount of mass in the universe required to keep it from collapsing and the actual observed mass.&nbsp; If the ratio is above 1 (too much mass), the universe collapses (closed or positive curvature).&nbsp; If the ratio = 1 (just the right amount of mass), it is expands forever, but never quite stopping (flat or zero curvature).&nbsp; If the ratio is below 1 (not enough mass), it expands at an ever increasing rate (open or negative curvature).</p><p>The curvature I'm talking about is due to mass curving spacetime.&nbsp; For example, the Earth curves spacetime around it and anything with in that curvature wants to collapse back onto the earth.&nbsp; The universe as a whole works the same way.&nbsp; Enough mass curving the manifold of spacetime and it collapses... not enough it expands forever being flat or having negative curvature.</p><p>By determining the total mass of the universe through observations of the CMB and the additional parameter of Lambda (aka dark energy causing an acceleration which is assumed to exist via observation of type 1a supernova), the current measurement is 1.02 +/- .02. &nbsp; </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>