Telescopes see 14 billion light years in all directions. Does this mean that the diameter is 28 billion?

Answer 1

no, the observable universe actually has a larger radius than 13.7 billion light-years. observations by nasa's microwave anisotropy probe suggest that the observable universe a radius of at least 78 billion light-years, but the observable universe is only a small part of the whole universe.
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read this:
http://www.sciam.com/print_version.cfm?articleID=0009F0CA-C523-1213-852383414B7F0147
http://en.wikipedia.org/wiki/Observable_universe

in addition, the universe seems to be something like the two-dimensional surface of a sphere. it is finite yet has no edge and no center. nothing exists, not even space and time, "outside" the universe. to quote a dead writer, "there's no there, there". space-time seems to have originated in the big bang (someone really needs to change that name.). the big bang was the whole universe, and everywhere in the universe was once the big bang.

http://universeadventure.org/
http://map.gsfc.nasa.gov/m_uni.html
http://www.astro.ucla.edu/~wright/cosmo_01.htm

Answer 2

As Physics_Dude has said, there is no diameter of the Universe to speak off. What the Universe is, is a surface of a multidimensional object. The sphere analogy is a good one. Anyway, what I explained to others in previous posts is that the distance across that surface is aprrox' 28-30 billion light years. It's edge is defined as the horizon created by the expansion of the Universe at that point reaching the speed of light. Anything beyond that horizon boundary is moving faster than the speed of light, relative to us, and therefore can't be seen. Why? the light anything emits there hasn't had the time to reach us. But one day, it will, and then we'll see those objects......but it'll be the object as it appeared there "X" billions of years ago. Not as it is, or where it is, now.

Although, some regions will never be visible to us because the Universe is presently accelerating its expansion....and has done so since 2 billion years after the Bang.

Answer 3

No it doesn't. First of all, to what "diameter" are you refering to? The Universe is NOT a 3-dimensional sphere. You doubled 14 billion to 28 billion seems to also assume that we are at the center of this 3-dimensional sphere. This is simply NOT correct.

A better analogy would be that we are on the surface of a 3-d sphere, and that every point on this sphere looks like it's the center. So if you look, the furthest you can see is the back of your head.

The fact that we can see 14 billion light-years out just means there were free photons moving in space 14 billion years ago. The Universe was expanding long before that. But let's for the moment assume that didn't matter, then the Universe is 14 billion light-years across period. No need to double it.

But what is the true size of the Universe? That we will never know, because the Universe is expanding at an accelerating pace, which implies that there are regions of space that is moving away at speed greater than the speed of light. We will never know about those places, and how far away they are.

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According to Warmsoapywaters' own source, and I quote:

"There is some disagreement as to exactly how large the observable universe in proper distance is: a study of the cosmic microwave background radiation by WMAP in May 2004 states the universe is at least 78 billion light years in radius, yet the March 2005 issue of Scientific American cites a figure of 46 billion light years in every direction. The ambiguity in size is dependent on the detailed models of the Hubble Law, especially the nonlinear nature of dark energy component of the universe which is causing the expansion of the universe to accelerate."

So like I said, we don't know what is the true size of the Universe, and we will never truly know because beyond 46 or 78 or whatever billions of light-years is the "Unobservable Universe", which is receding away at greater than the speed of light. We can never ever see it, detect it, do anything with it, so you can calculate all you want taking into account the nonlinear nature of dark energy or not. The fact is we can never verify any of our calculations.

Answer 4

Yes, it means the diameter of what we can view is 28 billion light years. (Of course, there is more beyond what we can't see)

Answer 5

Yep

Answer 6

No but that is the limmit from they can pick up the light anything further is toooooooooo far for them to pick it up.