How is the universe wider in diameter than it is old?

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steve h

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The universe is 14 billion years old so how come its more than 14 billion light years wide? Wikipedia claims is more than 80 B light years wide so it how is that possible? Don't say big bang inflation theory because that only lasted a few nanoseconds.
 
1) Yes, the universe is 14 billion years old.

2) When we see the farthest possible objects, the light has been traveling for 14 billion years (or nearly so). When the light left the object, it was a lot closer than 14 billion light years away. At the present time, however, the object is roughly 40 billion light years away.

3) Since we can see objects in all directions that are currently 40 billion light years away, we can say (in a certain sense) that the observable universe is 80 billion light years. (Some may give slightly different figures, such as 94, but let's not argue about that.)

4) The inflation phase of the universe lasted an extremely short time, but the expansion of the universe has occurred continuously (and, in fact, is accelerating) over the life the universe.

5) Finally, this volume of diameter 80 billion light years is an indication of the *current* size of what we can see. There might be much more to the universe than that, so you should really qualify this number as saying that it's the diameter of the observable universe, and not the whole shebang.
 
Steve,

Nobody can say how big the universe is.

We are able to see up to 16 billions light years away. That by no means implies that is the size of the universe.

Whoever claims such thing is in error!
 
Big bang inflation. It didn't last for a "few seconds", it lasted forever and is still going on. It was the acceleration (not speed) that lasted only a few nanoseconds.
 
Distant parts of the Universe can and do move apart faster than the speed of light. This does not violate Relativity or causality.

In fact the vast majority of the Universe is moving away from us faster than the speed of light.
 
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