Adam said: > Background microwave radiation, the red shift and many others that I > can't recall due to being tired from driving all day yesterday all > match the expected theories regarding the age and probable origin of > the universe.
The other important observation that the Big Bang model explains is the primordial abundances of light elements. There appears to be a primordial abundance of helium of around 23% by mass, but this can't all be accounted for by stellar nucleosynthesis because when stars have converted about 12% of their mass to helium they become red giants and subsequent nuclear reactions in the star consume rather than produce helium. Furthermore, the lower bound on the abundance of primordial helium seems quite homogeneous across the universe whereas if it was all produced in stars then there would be a much wider range of variation. The Big Bang also predicts synthesis of trace amounts of deuterium, helium-3 and lithium. The first two isotopes are fragile and are destroyed rather than consumed in stars, so their abundance in nature suggests a process other than stellar nucleosynthesis is responsible. In fact, the synthesis of these nuclei is very sensitive to the matter density in the universe, and a Big Bang with the right value of this parameter predicts just the observed amounts of each. As far as I'm aware, there is no known model that doesn't involved a hot big bang that can explain these three strands of observation: the microwave background, the red shift of distant galaxies and the abundances of light elements. Rich GSV Cosmology Lesson _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
