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Lithium in stars supports standard Big Bang

Alec MacAndrew

I am, as some will know, a supporter of the standard Big Bang model of cosmology. It seems to me that the more information we receive from very different sources, such as data from WMAPís measurement of the Cosmic Microwave Background and from galaxy surveys that independently verify the standard model, the more confident we can be that the Big Bang theory is right. I think it is time to reject models with much poorer empirical support such as Lernerís Plasma Universe and other steady state models (and of course the inanities of Young Earthers and others of their ilk).

This is not to say that all the issues around the standard model have been resolved Ė there are in fact some huge unresolved problems (for example, we canít explain the superabundance of matter over anti-matter; we donít know what the nature of dark matter or dark energy are, and so on). One of those problems was the fact in very old stars we expect the abundance of elements to be more or less the same as in the Big Bang nucleosynthesis, whereas the lithium in the surface of halo stars is three times less abundant than that.

Korn et al, published in Nature, have come up with a solution. The hypothesis is that complex combinations of processes such as atomic diffusion and turbulence transports lithium away from the surface of the star into its hotter core where it undergoes nuclear fusion. Good models exist for this process. Korn et al have observed stars of the same age but different stages of evolution in a globular cluster. They find that the lithium (and iron) abundance is different for different stages of evolution and thus temperatures of a star in a very good match to the model.

So it seems that the apparent shortfall of lithium in halo stars is caused by the transportation of lithium away from the surface into the interior of the star. If we extrapolate the process back to when the star was very young we can calculate the original abundance of lithium and lo and behold, it matches very accurately the abundance derived from the constraints imposed by observations of the CMB. Itís all coming together.

(First published on the evolutionpages blog.  Go here for the most recent posts on the blog)

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