The Omega Parameter

[weeman]

After recently learning about this, I find this simple equation to be quite interesting. The Omega Parameter deals a lot with the fate of our universe. One of the biggest questions asked today is, "How will the Universe end?" Omega is used today in relation to dark matter. Omega can simply be three outcomes, less than one, equal to one, or greater than one.<br /><br />Omega = Observable Density/Critical Density<br /><br />Where critical Density is the required density for the Universe to halt its expansion because of the pulls of gravity from all matter in the Universe.<br /><br />With these three outcomes gives us three different futures, and the eventual fate of our Universe. To our best knowledge today, Omega is most likely less than one. This means that there is not enough mass in the Universe for gravity to halt its expansion, it is doomed to expand forever.<br /><br />However, I firmly believe that if we can one day find the true answer to this equation, it will bring us a bit closer to the answer we seek, the answer to the ultimate theory. <br /><br />Lets say for a minute that one day in the near future we find a huge discovery in dark matter. We find that there is indeed enough of this matter to halt the expansion of the Universe. This means Omega is greater than one, and we live in a recollapsing Universe. Eventually, the Universe would stop expanding, then fall back in on itself in a massive crunch. Could this mean that another Big Bang might eventually happen? Could it mean that the Universe and Big Bang have already happened an infinite amount of times? <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]

<i><br />Omega = Observable Density/Critical Density <br /><br />Where critical Density is the required density for the Universe to halt its expansion because of the pulls of gravity from all matter in the Universe. <br /><br />With these three outcomes gives us three different futures, and the eventual fate of our Universe. To our best knowledge today, Omega is most likely less than one. This means that there is not enough mass in the Universe for gravity to halt its expansion, it is doomed to expand forever. </i><br /><br />From my Dec. Sky and Telescope magazine p.19: Omega is 1.003 with an uncertainty of 1%. This is from the Sloan Digital Sky Survey where they looked at 3 dimensional distributions of 60,000 giant elliptical galaxies. My question would be, is Omega = 1.003 close enough to 1, to render space infinitly flat? And then with Einsteins Cosmological Constant (dark energy), will cause the cosmic expansion to accelerate forever? Thats what the article proposes. <div class="Discussion_UserSignature"> <p><font size="4"><strong></strong></font></p> </div>