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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?
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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.
How did they figure that out and what's outside of that?
If the universe is 15.8 billion years old and 180 billion light-years wide, wouldn't that mean that the outermost parts of the universe travel or have travelled around 5x faster than the speed of light?
...so what changes with this revelation? Did this change anything? Give us new insight? Did it support or crush any theories?
I mean, it's nice by itself and all, but I'd be highly interested whether that has any implications other than changing the universe from being old to being older than we thought.
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Sadly, according to TFA and Wikipedia, it is now believed to be about 71. These seem so far apart that I wonder if the same units were used for both estimates.
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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...
Not as cool Rabbi Yitzchak of Acca's (1250 CE) caculation of 15,340,505,767 years for the universe. There is a dispute if he meant earth years or synodic years. If that caculation is synodic years it will end about 14.8 billion earth.
So would this larger, older Universe affect the need for the particular volume of Dark Matter we've been searching? If this value is accepted, do we need less Dark Matter to explain the current state of universal expansion and possible contraction? What does this do for the various theories, a-la 'steady state', et. al?
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!
What then is the prevailing theory as to the disconnect between the 180 billion light year size and the 15.8 billion year age. If the universe was born out of a massive explosion 15.8 billion years ago, it would have had that long to spread out at the speed of light in every direction. So, then, you'd have a sphere with a radius of 15.8 billion light years that defines the maximum size of the universe.
So, the universe is 148.4 billion light years bigger than it ought to be (if the universe expanded from a singularity at the speed of light). So, do we believe the universe is expanding at much faster than the speed of light? Was space-time warped by the explosion? And if so, how can any guess made on spectral/telemetry data be considered meaningful?
The initial expansion was MUCH faster than the speed of light. c is the limit that governs speed in a vacuum. But by definition the early (first 400,000 years) expansion (or inflation) of the universe was expanding into NOTHINGNESS, not vacuum. For a period of time the universe expanded at many times the speed of light.
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So far, all the answers to all the questions seem to be making the same implicit assumptions:
- Hubble's Constant is constant
- The current size of the universe is known
I'm sure there are many equally important assumptions, but these two seem to form the basis for using the inverse of H-nought (dang, I'm British, now!) to calculate the age of the universe.If Hubble's Constant is actually Carpe Web's Variable (dang, I'm important, now!), then we'd have to know all the values of CW-i (index of Carpe Web's Variable over time, formerly thought to be Hubble's Constant) and then take one mother of an integral to calculate the age of the universe. Well, if we were smart enough to know all the values of CW-i over 6,000 years -- oops, I mean 15.8 billion years -- then maybe the integral wouldn't be too difficult.
But, we'd still need to know the current size of the universe to calculate the age. What if there's a little bit more beyond what we can currently "see"? What if there's some schmutz on the lens of the Hubble telescope? What if the invisible pink elephants only look invisible but are actually blocking our "view" of the real edge of the current universe (or maybe the edge of the universe 15.8 billion years ago, which is when the light from it started on its path to us)?
Anyway, my brain hurts, but either of the assumptions seems to swamp the margins of error mentioned in this thread.
A simpler way to think of it is that space is constant, but all of the matter in the universe is shrinking, including your measuring sticks. I don't know why physicists are reluctant to express it in these terms since it is mathematically equivalent.
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