15 January 2015

Fine-tuned for observers?

To be fine-tuned for life isn’t the same as to be fine-tuned for intelligence and a Universe which is fine-tuned for observers is perhaps different from them (although not necessarily). It is an interesting question since our World isn’t optimal for observations, while there are imaginable universes more favorable for it. But to live in an older Universe would be even a more serious disadvantage.
According to Avi Loeb, the viewing conditions were optimal when the Universe was a mere half billion years old and the circumstances were excellent to study the cosmic perturbations. On the other hand, Lawrence M. Krauss and Glenn D. Starkman pointed out that in an ever-expanding universe “presently observable distant sources will disappear on a time-scale comparable to the period of stellar burning,” and we will forget the existence of our Universe within a hundred billion years. So our position in spacetime is between the two ends of the scale, but it is far from optimal. We can recall the words of King Alonso X who said that he had “some useful hints for” a Creator to produce a World.
To give a trivial example: it is impossible to decide directly whether light source is a distant and bright object or it is a weak source close to us [G. F. R. Ellis: Cosmology and Verifiability. In: Modern Cosmology and Philosophy 1998, p. 121.]. It is imaginable – theoretically at least – a physics where this kind of problem is eliminated, i.e. because every sources brightness is equal; or we could find other, more sophisticated solutions (Cepheids seems to be exceptions with the correlation between their light intensity and period).
All in all, it is a laborious and uncertain work to measure the distances in our Universe, and in the absence of real knowledge, we are willing to accept an “unproven cosmological assumption” about the homogeneity of space as an extension of the Copernican – Darwinian revolutions. Then this unproven assumption is used to interpret astronomical information (including distances) [ibid, p. 123.].
This problem is caused by the nature of our World, and is not a desirable situation for observers. But the worst scenario is a universe where one cannot able to observe anything – I strongly suspect that this world would be lifeless.
So there are two possible explanations. Perhaps we simply live in a Universe which is neither the best nor the worst from this point of view. It is imaginable as well, that a really observer-friendly Universe is impossible, and so this is the best one within the framework of our physics.

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