samedi 13 février 2016

Evidence against concordance cosmology

This thread is to discuss evidence against “concordance cosmology”. Concordance cosmology is the name used for the dominant model for cosmology.

The basic hypotheses of concordance cosmology are

1) The universe is expanding. This means the space between galaxies is expanding, not space within gravitationally (or electromagnetically) bound objects. This expansion accounts for the Hubble relationship between redshift and apparent luminosity.
2) The universe originated in a Big Bang. It went through a state of extremely high density and temperature. During this period, the light isotopes He-4, He-3, Li-7 and d were formed.
3) The expansion was initially driven by an “inflation” force field, which expanded the universe exponentially, accounting for the smoothness of the cosmic microwave background (CMB). This expansion also determines that the total energy density of the universe is the critical density. (The critical density is matter-energy density need to exactly balance gravitational energy)
4) The subsequent expansion, after inflation, was accelerated by a repulsive energy field, “dark energy” .whose energy density at the present is 70% of the critical density of the universe.
5) Five-sixths of the matter density in the universe is “dark matter” or non-baryonic matter, an unknown type of mater not consisting of nucleons and electrons. The remaining one sixth, or 5% of the critical density, consists of ordinary matter, or baryonic matter.

There are also a number of subordinate assumptions, and quite a few additional adjustable parameters in the model, but these are the core hypotheses. One thing to note right off is that neither the inflation field, dark energy nor dark matter have been observed in any experiments on earth or experiments conducted by spacecraft.

While in the past contradictions between this model and observations have been addressed by modification of the model, rather than questioning its underlying hypotheses, I would argue that those hypotheses are in fact testable and falsifiable. The universe is either expanding at a rate that explain the Hubble relation or it is not. It either went through a hot dense epoch, a Big Bang, or it did not. Dark energy exists or it does not. Dark matter exists or it does not.

I summarized the evidence against concordance cosmology in an invited presentation last June to a workshop at EWASS, a large astronomy conference. It is here. People should watch this presentation before posting to this thread.

I realize people tend to get excited about this subject. But please, no name-calling. Personally I’ll only respond to posts that raise actual scientific arguments or questions.


via International Skeptics Forum http://ift.tt/1Vd4XAF

Aucun commentaire:

Enregistrer un commentaire