Infinite Space

[SpeedFreek]

Well the concept (as described by Alan Guth and Brian Greene) describes the triggers for the different epochs as <i> phase transitions. </i><br /><br />It was the phase transition at the end of the grand unification epoch that triggered the inflation. One of the properties of inflation can be described as a scalar field which was settling down into a state of least energy and was generating a repulsive force which inflated the universe at the same time. When the scalar field reached its lowest energy state the process finished which initiated the next phase transition - reheating.<br /><br />Reheating is where the huge potential energy of the scalar field was released, filling the universe with the guark-gluon plasma. This phase transition marks the start of the electroweak epoch, the first epoch for which we have some experimental evidence for the conditions around at the time. This was a period of electroweak interaction, where exotic matter like bosons were created from the cooling expanding plasma. As the cooling expansion continued the creation of bosons ceased and they decayed as the four fundamental forces finally separated.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[weeman]

<font color="yellow"> I have a question. Is this "reheating" period the trigger that caused the inflation phase to slow down to the speed of light? Seems to me, that this would violate Newton's 1st Law: "An object in motion will remain in motion (FTL) unless acted upon by a force." </font><br /><br />There is also another theory as to why the expansion eventually slowed down, although it's not quite as in depth as Speedfreek's <img src="/images/icons/wink.gif" />. The universe, during inflation, could have been classified more as an open universe. An open universe is a situation in which there is not enough mass in the universe to halt its expansion, meaning it is doomed to expand forever. <br /><br />However, the mass of the universe at the end of inflation eventually reached the point of critical density; where critical density is the required density for the Universe to halt or slow its expansion, due to the pulls of gravity from all matter in the Universe. <br /><br />When the universe reached this density, it essentially would have gone from an open universe to a flat universe. A flat universe is when the universe will continually slow down but never come to a complete stop.<br /><br />However, recent observations made in the universe could put this theory to rest. If the universe is indeed accelerating, why would the universe inflate, then slow down, then speed up again? Inflation was a period of extreme velocity, then it slowed down to the speed of light, or less, then it started accelerating again. Why would this be?<br /><br />Either the theory I've stated is not true in any way, or the universe isn't accelerating and it just appears to us this way. <br /><br /> <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>

 

[kyle_baron]

<font color="yellow"><br />However, the mass of the universe at the end of inflation eventually reached the point of critical density; where critical density is the required density for the Universe to halt or slow its expansion, due to the pulls of gravity from all matter in the Universe. </font><br /><br />Thanks, I agree with your viewpoint. However, I would change one word. I would change the word matter to the word energy: "from all the energy in the universe". Since there was no matter durring inflation, but there was expanding energy, which has its own gravitational field.<br /><font color="yellow"><br />If the universe is indeed accelerating, why would the universe inflate, then slow down, then speed up again?<br /></font><br /><br />Inflation- relates to expanding energy.<br />Slowing down-relates to matter forming from the energy.<br />Accelerating- relates to both energy (dark) and matter. <div class="Discussion_UserSignature"> <p><font size="4"><strong></strong></font></p> </div>