An Older, Larger Universe
Josh Fink writes "Space.com has a very interesting article as part their weekly mystery Monday series about a new calculation that shows that the Universe is actually much older than than the 14.3 billion years old that was established in 2003. From the article, "...the universe is instead about 15.8 billion years old and about 180 billion light-years wide." The calculations were based off of a recalculation of the Hubble Constant which dictates how fast the universe is expanding, and they found it is actually 15% slower than previously thought. The findings will be printed in an upcoming edition of Astrophysical Journal."
Those are some huge numbers. What gets me going though is what is outside of those 180 billion light years of width? What happens when you hit the border? Is there a passport checkpoint?
My
The Hubble Constant is based on the idea that the redshift of spectrum of light reveals how quickly it is moving away from you. Similar to the Doppler effect with sound.
I am not a physicist but I recall another article that speculated that light may not always have traveled at the same speed. If this is true and we are measuring light that is ~90 billion years old, doesn't this drastically effect the red light shift that is so dependent on the constant of the speed of light?
They didn't go into detail in the article except that it is a new recalculation using a pair of stars instead of a single star. I do not believe this alleviates the problem of possible change in constants regarding light and its redshift, however.
My work here is dung.
The prolific mathematician Paul Erdos, towards the end of his life, used to say that he was about four billion years old. He explained: when he was a boy, the known of the age of the universe was about five billion years, but by the time he was older, the age of the universe was had grown to nine billion. Tack on another billion and change for all of us...
I believe that the 180B light years is just a MINIMUM, that is the universe could actually be much much larger. The 180B lyrs. would the minimum size that would be allowable under our current measurements (for example the cosmic background radiation) that dictate how much the universe grew as a result of "inflation". It it were smaller than that, we would start to see "reflections" of ourselves as the light in the universe would have gone all the way around like in a hall of mirrors (and we could see the earth of a long time ago!).
To illustrate how big the universe could be there was, I think, an interesting article (set of articles?) in Scientific American that described the various ways in which we would could have a "parallel (viewable) universe" to our own. One was the idea that the whole universe was so huge that if you went far enough you could find an exact same configuration of all of the particles that we can see in our own viewable (~30B lyr wide) universe.
Of course this would mean that the actual universe would be so unbelievably gigantic that 180B lyr. would be an unimaginably tiny speck within it!