[continued from previous message]   
      
   >>>> for parts of the universe that are no longer visible to us.  Space   
   >>>> expanded and nothing really accelerated to faster than light, but they   
   >>>> are just too far away to observe.  There was the initial inflation when   
   >>>> space expanded much faster than the speed of light creating a "flat   
   >>>> universe" with just the right amount of mass and energy to keep it from   
   >>>> collapsing.  Dark energy is supposed to account for the continued   
   >>>> expansion of space within the universe.  One article that I recall   
   >>>> claimed that the visible universe extends out to around 45 billion light   
   >>>> years in all directions from where we are.  The visible light has to be   
   >>>> younger than the age of our universe (less than 14 billion years), but   
   >>>> space has expanded.   
   >>>   
   >>>   
   >>> An important point is, according to the evidence, there was a time   
   >>> before about 4bya when the universe was dominated by gravity, and its   
   >>> rate of expansion was actually slowing.  Now the universe is dominated   
   >>> by dark energy, and so its rate of expansion has become ever faster   
   >>> since then.   
   >>   
   >> The claim in the article is that the expansion of the universe continues   
   >> to be currently accelerating, but the rate of acceleration is   
   >> decreasing, so dark energy effects seem to have limits.   
   >   
   >   
   > What you say above is contrary to what I have read:   
   >    
   > ********************************   
   > In 1998, the High-Z Supernova Search Team published observations of   
   > Type Ia ("one-A") supernovae. In 1999, the Supernova Cosmology Project   
   > followed by suggesting that the expansion of the universe is   
   > accelerating. The 2011 Nobel Prize in Physics was awarded to Saul   
   > Perlmutter, Brian P. Schmidt, and Adam G. Riess for their leadership   
   > in the discovery.   
   > ********************************   
      
   The original article noted that the expansion of the universe is still   
   accelerating due to dark energy, but that the new measurements indicate   
   that the rate of acceleration is decreasing over time.  The expansion of   
   space is still accelerating, but there seems to be less pressure on the   
   gas petal so that the rate of accerleration is decreasing.  The   
   expansion is still going faster and faster, but the increased expansion   
   rate is decreasing.  If the decrease in acceleration continues there   
   will come a time when the expansion rate is no longer increasing.  The   
   claim is that there is enough mass to start the collapse of the   
   Universe.  My guess is that the expansion will continue, but start to   
   slow down instead of get faster and faster.  Once the expansion stops,   
   the universe can start to collapse.   
      
   >   
   >   
   >> I recall an article claiming that our current visible universe extended   
   >> out to around 45 billion light years in any direction (maybe it was 45   
   >> billion light years across, the light within visible space has to be   
   >> less than 14 billion years old) but there has to be a lot of the   
   >> universe that we can no longer see.  Kestrel indicated that this limit   
   >> applied to the points within our visible universe so that every location   
   >> had a different horizon and could see a different part of the existing   
   >> universe.  There would have to be a lot of matter that is not in the   
   >> visible universe.   
   >   
   >   
   > Correct.  This is something I pointed out to Peter Nyikos awhile ago,   
   > and I pointed out to you in my last post.  Every point in the cosmos   
   > is surrounded by its own Hubble Sphere.  The working assumption is   
   > that the cosmos outside our Hubble Sphere is largely similar to the   
   > space inside.  The problem is there is no way to know this for   
   > certain, even in principle.   
      
   So my original question was how do we know the amount of mass in the   
   universe when there may be a near infinite amount that we cannot observe?   
      
   The numbers on the internet that I have seen are that before the Big   
   Bang all the mass in the universe was contained within a volume of a   
   soccer ball.  Another claim is that inflation took something like the   
   size of a bacterium (1 to 10 microns) to the size of the Milky way   
   galaxy that is 100,000 light years across.  A soccer ball is 220,000   
   microns in diameter.  So my estimate would be that after inflation the   
   universe would have already been over 2 billion light years across.  The   
   claim that I have seen was that there may have been enough mass to   
   collapse the universe, but dark energy started an accelerated expansion   
   of the universe where the rate of expansion kept increasing, and   
   resulted in some of the universe to expand at a rate so fast that those   
   parts of the universe would no longer be visible to us.   
      
   We must have some type of mass estimate for the mass of the Big Bang,   
   but is the mass that we cannot observe in our calculations estimating   
   the mass of the universe based on what we can observe.  The total mass   
   of the universe has to be much greater than the visible mass we have   
   been using to make our estimates of whether or not there is enough mass   
   to cause a collapse.  I have never read any account that would take into   
   account that our visible universe is only a fraction of the volume of   
   the total universe.  Even the fact that there was a lot of the universe   
   that was beyond the visible horizon was new to me due to the Webb   
   telescope claims.   
      
   Ron Okimoto   
      
   >   
   >   
   >> Ron Okimoto   
   >>>   
   >>>   
   >>>> It doesn't matter, what I wanted was if the mass of the universe   
   >>>> estimate includes the mass that is not observable.  We have the   
   >>>> background radiation map of the universe, and estimates based on what we   
   >>>> can see (these are based on the observable universe).  The estimates   
   >>>> would have included what we could not see within the visible universe   
   >>>> because we lacked the ability to detect the light from the distant   
   >>>> objects.  Did this estimate also include the mass that was too far away   
   >>>> to be visible?  How do we know how much mass is no longer visible and is   
   >>>> beyond the horizon of what we can see?  We've been trying to estimate   
   >>>> the amount of dark matter within the visible universe, so how would we   
   >>>> measure the amount of matter further away than the visible horizon?   
   >>>> Even though we can't observe it, it is still part of our universe.   
   >>>>   
   >>>> Ron Okimoto   
   >>>   
   >   
      
   --- SoupGate-DOS v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)