Talk:Reionization

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[edit] Reionization and galaxy formation

The article says: reionization is the process that reionized the matter in the universe after the epoch of galaxy formation. But Graphical timeline of the Stelliferous Era shows the reionization phase starting at 100 million years after the Big Bang and completing before the formation of the first galaxies at 600 million years after the Big Bang. Which is correct ? Gandalf61 16:41, 23 January 2007 (UTC)

Never mind - found answer in Timeline of the Big Bang. Gandalf61 15:46, 27 January 2007

[edit] Recombination disambiguation

I added the link back to the disambiguation page for the time being, as it give some explanation. I may write create a recombination stub in the next few days and redirect the link there. James McBride 09:14, 15 August 2007 (UTC)

My bad. I went back and looked at the previous version, and I guess I had looked at the wrong recombination. I thought the link had been removed, instead of redirected to the Big Bang timeline. James McBride 08:36, 16 August 2007 (UTC)

[edit] Adding more images

I would like to see a few more images in the article. In particular, the graph of the CMB polarization angular anisotropy map and an example Gunn-Peterson trough. A non-copyrighted version of the first should be possible, as it was generated by WMAP, but I only was able to find the image at other sites. James McBride 09:14, 15 August 2007 (UTC)

[edit] Current image deletion

I think editors should give serious consideration to deleting the image given at http://imagine.gsfc.nasa.gov/Images/sats_n_data/exhibit/reion.diagram.jpg 1) The universe does not become opaque at the surface of last scattering. It's called that for a reason, and it's not because the universe suddenly starts scattering - the universe becomes transparent then, not opaque (exception being specific neutral hydrogen absorption features as mentioned in the GP trough sections) 2) The universe does not become neutral either for that matter. It was neutral already, but ionized. It becomes unionized at that point, which is not the same as neutral 3) The universe does not become transparent again at reionization. It'd be opaque again, except that the free electron density is low enough that the Thomson scattering cross section remains low and the universe stays opaque. In other words, that diagram from NASA is pretty badly wrong in a number of fundamental points. I'd get rid of it myself, but I'd probably be accused of vandalism for getting rid of something from a reputable source, even when it's got fundamental errors in it —Preceding unsigned comment added by 91.84.172.216 (talk) 00:29, 21 February 2008 (UTC)

I agree that the language used is rather poor. There is some use of opaque and transparent in the sense used in the diagram in some of the literature, but I was initially rather confused by that. Perhaps the article would be stronger without the diagram. James McBride (talk) 02:42, 22 February 2008 (UTC)