Galaxy Composition

"Once the distinct kinematic components of the Galaxy had been isolated, an interesting fact arose in that the chemical composition of the stars in those components also varied in a regular manner. Disk and bulge stars tend to be rich in heavy elements (above helium on the periodic table). Halo stars tend to be very poor in heavy elements"  (http://abyss.uoregon.edu/~js/ast123/lectures/lec10.html) emphasis mine.

So the hypothesis is at least supported in some way.  But what is it about the structure of our universe that results in the metallic or terrestrial bodies being closer to the source of gravity?  Simply gravity itself?  The heavier an object is, of course, the closer it will approach the gravity source, makes sense. Is there something more to this than just heavier elements gravitating toward the gravity core?

beyond yourself

Here is a place that is finally free of expectation.  I present my thoughts selfishly as a means of expression and contemplation.  However, the possibility of your benefit makes the prospect of this creation all the more compelling.

Did you know that the solar system is divided into two parts?  The gas giants (Jupiter, Saturn, Uranus, Neptune) are separated from the terrestrial planets (Mercury, Venus, Earth, Mars) by the asteroid belt.  Interesting.  Why is the solar system organized this way?  Planetary scientists would probably discuss its formation.  However, I'm interested in its thoughtful organization.  Is it mere coincidence that our home planet is set up like the solar system?  The outer layers are made of gas, the inner layers are made of rock, and finally, the core is molten.  If our own solar system has this pattern, and the earth also, could not the galaxy also be expected to have a similar composition?  Is the matter closest to the center of our galaxy more metallic in nature and the matter farthest from the center more gaseous?  I would hypothesize that this is true.  For those of you who may know something related to this, please comment and increase my knowledge.

From a distance, I see
the sun shine on the mountaintops.
It's cloudy here; it's raining here,
but in the distance, there are mountains.
It's muddy here; it's freezing cold,
but in the distance, there are mountains.
The birds take wing as if faith and will
are all the same,
And I am staring at my feet.
How does one step compare to
where I'm supposed to be?
How does one step help at all?
How does one step set me free?
Do I have the resources to get there?
Enough to enjoy it once I'm there?
Enough to come and get my family
and take them back again?
Is the distance just to be
viewed from here--an illusion
for the sake of hope
so that I'll remain,
so I'll maintain,
so I will not despair?
Or is it for to be there?