It is so simple unfortunately it seems physicists will never recognise it. Plasma is a very good refractor ok? It is the 4th and most prevalent state of matter, (ions). It does of course make up the 'fine structure' surface of all matter (1/137th at rest) and the plasmasphere/ionoshpere of our planet. The heliosphere and galactic halo's seem to be made up of billions of solar masses of similar stuff (Dark matter). At the small end, even a single electron develops a plasma cloud when accelerated (at the LHC).
Fresnels refraction co-efficient 'n' rules for all media, including plasma.
Therefore light changes speed to the local 'c' of all plasma, i.e. all matter everywhere.
This explains about all the anomalies in physics and astrophysics. At last. (It actually also agrees with the postulates of SR).
Even more useful, it explains Equivalence and Gravity. Just ask for how, it's dead simple too. Confirming p = g. It's called the discrete field model, (DFM) and it's free to humankind.
Have a look on the FQXi essay competition site for a short aspect of the DFM with pictorial evidence;http://fqxi.org/community/forum/topic/803
Or here for a short video (it does take some brain power to fist handle the moving variables). http://fqxi.org/data/forum-attachments/1_YouTube__Dilation.htm
If you want a full version of where physics went wrong; http://wbabin.net/weuro/jackson.pdf
Or the latest paper exploring it's logical and exciting conclusion on the universe; Feb 2011 Helical CMBR Asymmetry, Pre-Big Bang State, Dark Matter and the Axis of Evil. Feb 2011 Helical CMBR Asymmetry, Pre-Big Bang State, Dark Matter and the Axis of Evil.
More papers and details available, explaining most anomalies and paradoxes in physics. That's for real!
Hello... anybody out there? ... hello?