Warp wrote:
>   Galaxies do not expand because their gravity keeps them in shape. In
> other words, gravity inside (and near) galaxies is strong enough to
> "resist" the expansion. Consequently nothing inside galaxies expands.

Hmmmm.... I'll take this idea with a grain of salt. :-)

>   Another slightly difficult thing to grasp is that a constant expansion
> of the universe actually means that galaxies recede from us at an exponential
> rate. At each certain unit of time space distances double, which means that
> the distance between two galaxies grows exponentially with time. 

Yet, funny enough, the number of galaxies we see in an area is constant 
for a given volume, or close to it. This implies that perhaps the 
galaxies aren't receding at all, and space isn't growing at all.

I saw an interesting paper that postulated that what we observe would 
also be correct if further galaxies simply had a time axis pointing away 
from us. I.e., plot the universe on the surface of a sphere, and have 
time running perpendicular to the surface. The further apart two points 
are, the more red-shifted they will see each other, even if the sphere 
isn't expanding. It explains why we see a constant number of galaxies in 
a given space, and a number of other problems as well (like the "dark 
energy" expansion effect). It also explains the background radiation, 
the fact that it's flat everywhere, and that

I'm eager to hear about it coming out in a peer-reviewed journal.

>   Dark energy has been postulated as an explanation for this. It somehow
> causes an inflationary effect on the universe, making it to expand in an
> accelerated way.

Sounds ad hoc to me. :-)  Fortunately, none of this affects my life in 
even the most trivial way, until some scientist actually *does* 
understand it well enough to make predictions and hence technology. :-)

>   (All this is not based on professional literature, so don't take it
> for granted. It's just how I have understood it with me extremely limited
> understanding.)

Understood. Thanks for the lay interpretation.

-- 
   Darren New / San Diego, CA, USA (PST)
     It's not feature creep if you put it
     at the end and adjust the release date.

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