Copernican principle

At the end of the day, the question of extraterrestrial life is based on two principles the Copernican principle and the mediocrity principle. The first states that the Earth is not in a central, specially favoured position. The mediocrity principle states that life on Earth is nothing special, so that life (in whatever form) could evolve in many places in the universe. 

How will we identify the extra astrophysics required to reconcile the properties of CDM dark haloes with those of luminous galaxies We can start by developing knowledge of the evolutionary history of at least one place in at least one galaxy. We would be unlucky if that place were far from the norm alternatively, any theory that predicts such a history to be very unusual might be suspect -the galaxian Copernican principle. Kinematics and current spatial location are of course critical parameters, so that traditional stellar populations analyses are... 

Synthesis of these notions leads to an alternative cosmology that has little in common with the standard model. It may not have the same dogmatic appeal as the big bang, but it unifies a growing body of discordant empirical evidence, based on all the matter and energy in the universe, the Copernican principle and sound mathematics, without singularities. It has the potential directly to address the basic notions of chirality, astronomical anomalies, holistic self-similarity and other cosmological puzzles, such as Zwicky s paradox, in addition to traditional celestial mechanics. In effect, it calls for the re-examination and re-interpretation of the cosmic whole. 

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