I think spiral galaxies are more "mature" than elliptical or irregular galaxies, but the arguement about how many old stars are in the galaxy is a good measuring stick too.

I saw a story on Universe Today that said the Milky Way was formed soon after the Big Bang. They could tell this by the amount of Beryllium in the stars of the Milky Way. That would make us "mature" I think, unless the entire Universe is not yet mature.

My avatar is of M51. All the red stars in the arms show that this is probably an "old" Galaxy.

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If the Universe is expanding, that should help with traffic.

The Earth is bi-polar.