posted on Jan, 23 2012 @ 04:38 AM
As for galaxies in general, the majority of galaxies are actually so called "barred spiral galaxies".
In the past, there was the assumption that our own Milky Way should look similar to the Andromeda galaxy, with the typical oval and flat shape.
But recent findings suggest that the Milky Way is actually also a Barred Spiral Galaxy, looking more like:
Our own galaxy is a large disk-shaped barred-spiral galaxy about 30 kiloparsecs in diameter and a kiloparsec in thickness. It contains about two
hundred billion (2×1011) stars and has a total mass of about six hundred billion (6×1011) times the mass of the Sun.
I think i read that this shape is a result of the gravitational forces involved.
Looking at the Hubble pictures and some pictures of galaxies, i have an analogy:
Saying that our planet Earth is very unique and life is very unique is as silly as picking one random grain of sand from one beach somewhere on
Earth...and saying that this particular grain of sand is VERY unique and it cannot be that other grains of sand are similar in size and form. While
this one, randomly picked grain of sand is only one of trillions of grains
I mean, for me it's a given that the universe is full with life since the math alone doesn't allow another conclusion.
The bigger difficulty here is:
The involved distances...and the fact that stars/planets can be billions of years old. That means that if we look at at a planet...there is a
likelihood that a given moment life or civilization has not evolved YET...or is already gone.
Therefore this adds the difficulty that if two civilizations would want to meet - it also means that the two planets must be in the same state of
evolution when they have life and have created an "intelligent" civilization..and this could happen in a very tiny window compared to the total life
of a planet/planet system.
edit on 23-1-2012 by flexy123 because: (no reason given)