VaultZero4Me said:
I am sorry, but those were all misreported. Something that many people know.
The 156 light years was gotten by mistaken the diameter for radius and doubling it.
The reports stemmed from the original work cited here
http://arxiv.org/abs/astro-ph/0310233
in 2004. Read the original work, and not what USA Today has to say about it.
Certainly I did not realize that Harvard was reporting the results wrong in 2005 -
76 billion is the lower boundary for the DIAMETER, not radius.
Yes I saw Wiki saying that too -
[quote:c93e5]
Misconceptions
Many secondary sources have reported a wide variety of incorrect figures for the size of the visible universe. Some of these are listed below.
13.7 billion light-years. The age of the universe is about 13.7 billion years. While it is commonly understood that nothing travels faster than light, it is a common misconception that the radius of the observable universe must therefore amount to only 13.7 billion light-years. This reasoning only makes sense if the universe is the flat spacetime of special relativity; in the real universe, spacetime is highly curved on cosmological scales, which means that 3-space (which is roughly flat) is expanding, as evidenced by Hubble's law. Distances obtained as the speed of light multiplied by a cosmological time interval have no direct physical significance. [5]
15.8 billion light-years. This is obtained in the same way as the 13.7 billion light year figure, but starting from an incorrect age of the universe which was reported in the popular press in mid-2006[6] [7] [8]. For an analysis of this claim and the paper that prompted it, see [9].
27 billion light-years. This is a diameter obtained from the (incorrect) radius of 13.7 billion light-years.
78 billion light-years. This is a lower bound for the size of the whole universe, based on the estimated current distance between points that we can see on opposite sides of the cosmic microwave background radiation, so this figure represents the diameter of the sphere formed by the CMBR. If the whole universe is smaller than this sphere, then light has had time to circumnavigate it since the big bang, producing multiple images of distant points in the CMBR, which would show up as patterns of repeating circles.[10] Cornish et al looked for such an effect at scales of up to 24 gigaparsecs (78 billion light years) and failed to find it, and suggested that if they could extend their search to all possible orientations, they would then "be able to exclude the possibility that we live in a universe smaller than 24 Gpc in diameter". The authors also estimated that with "lower noise and higher resolution CMB maps (from WMAP's extended mission and from Planck), we will be able to search for smaller circles and extend the limit to ~28 Gpc."[1] This estimate of the maximum diameter of the CMBR sphere that will be visible in planned experiments corresponds to a radius of 14 gigaparsecs, the same number given in the previous section.
156 billion light-years. This figure was obtained by doubling 78 billion light-years on the assumption that it is a radius. Since 78 billion light-years is already a diameter, the doubled figure is incorrect. This figure was very widely reported.[11] [12] [13]
180 billion light-years. This estimate accompanied the age estimate of 15.8 billion years in some sources; it was obtained by incorrectly adding 15 percent to the incorrect figure of 156 billion light years
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