Size of the Universe

[Perkinsjc12]

Question from a neophyte - If the Universe is 46 billion light years in diameter (Wikipedia) yet only 13.8 billon years old then is or has the universe expanded faster than the speed of light, does the outer 2/3 of the universe predate the big bang, does Wikipedia have it wrong, or is there one of those counterintuitive "warped or folding space phenomenon going on?

I'm sorry. 46 billion light year radius according to Wikipedia

[StringJunky]

At the early stages of the Big Bang the universe inflated faster than the speed of light. What this means is that space was created between any two points all over the universe simultaneously and not like an explosion, as the 'big bang' title suggests, radiating from a single point outwards. If you were stood in this expanding space you will see things moving away from you but you will feel stationary. The speed-of-light limit applicable in nearly all cases does not apply to the rate at which space (distance) can form. In case you ask, expansion only occurs now at the distances between superclusters ie 200MLYRS+ ...at distances less than this gravity wins and keeps things together.

[hoola]

is this inflation at the beginning of the universe and the speed of gravity have any co-relation? Both being supposedly super-luminal. I am not talking about gravity waves, which are held at C, but the straight line effects of gravity as being (near) infinite, so as to allow newton's gravity laws to work correctly.....edd

[Dekan]

"The Universe inflated faster than the speed of light" .

 

Wouldn't the electrons get left behind?

[Strange]

 

Question from a neophyte - If the Universe is 46 billion light years in diameter (Wikipedia) yet only 13.8 billon years old then is or has the universe expanded faster than the speed of light, does the outer 2/3 of the universe predate the big bang, does Wikipedia have it wrong, or is there one of those counterintuitive "warped or folding space phenomenon going on?

 

 

This is simply because the universe has been expanding since the light was emitted. The light was emitted 14 billion years ago, but since then the stars that emitted that light have been carried further away.

 

More here: http://www.astro.ucla.edu/~wright/cosmology_faq.html#DN

 

Note that the rate of expansion is not "faster than the speed of light" because it is not a velocity; the velocity depends on distance.

"For every million parsecs of distance from the observer, the rate of expansion increases by about 67 kilometers per second."

http://en.wikipedia.org/wiki/Metric_expansion_of_space#How_is_the_expansion_of_the_universe_measured_and_how_does_the_rate_of_expansion_change.3F

 

This means there will always be something far enough away that it is receding at greater than light speed.

"The Universe inflated faster than the speed of light" .

 

Wouldn't the electrons get left behind?

 

It wasn't an explosion pushing electrons through space; it was space itself that expanded. In other words, the distances between two points increased. There is no speed of light limit in this case, because that only applies to two objects in relative motion in the same frame of reference.

[Airbrush]

"The Universe inflated faster than the speed of light" .

 

Wouldn't the electrons get left behind?

Did the initial inflation occur BEFORE there were any electrons?

[Alan McDougall]

"The Universe inflated faster than the speed of light" .

 

Wouldn't the electrons get left behind?

 

Only space, which is mass-less, can move faster than light, there are galaxies at the edge of the universe(for lack of abetter word) that are moving faster than the speed of light, but they can only do this because they are imbedded in space. You cannot travel faster than light through the fabric of space, but you can travel with space faster than light. Within a galaxy nothing can exceed light speed, but the universe as a hypothetical cake and the galaxies as chips of impurities in the cake dough (Space) might rise very quickly, , however the chips, would separate, from each other at the rate of expansion of the cake dough (Space)

 

The impurities/chips (Galaxies) imbedded in the cake dough/space, cannot move through the dough (Space) at greater than light speed, but the dough,(Space) having zero mass can expand at any speed even exceeding the speed of light . Take a highly advanced space ship, it could never travel through the fabric of space, between, two galaxies at faster than light speed.

 

Summary, nothing can travel through the fabric of space faster than the speed of light.

 

Space which has no mass can expand faster than the speed of light, and take everything embedded in it at that speed, Like a fabric of infinitely stretchable cloth, with polka dots (Polka dots=Galaxies). Some great hypothetical hand could take the stretchable fabric and stretch it at almost infinite speed, taking the polka dots with it, only the dots get further and further apart, exactly at the rate the great hand stretches the fabric.

 

Sorry a bit long winded!

 

Einstein once said, "if you can explain your theory to your granny then you understand it yourself"