© Charles Chandler

 

Lloyd said:
Since hydrogen makes up most of the atoms in space, it's not clear to me how they would form into dust grains.

No, I don't think that the dust grains are hydrogen. To be honest, I can't recall ever hearing what they are actually are, but dusty plasmas definitely exist. Big stretches of the Milky Way are blotted out by them, and we can see them in images of stuff beyond our galaxy. But I need to learn more about their specific characteristics. Now that I have specific degrees of ionization in mind (i.e., 1 charged particle in 10^16 or 10^15), I want to see if the data confirm that. I "think" that the degree of ionization is detectable, since ions emit different photons from neutral atoms. I'm not sure what difference the composition of the dust grains would make. I'm just looking at the "like-likes-like" force, which is coming from the degree of ionization. But maybe if we knew the elemental composition, we'd knew the ionization energies. Then we could estimate how strong of a supernova it would take to photo-ionize how much of the dust cloud, and whether or not that degree of ionization would be sufficient to cause it to collapse into a star. I'm not sure if the data would support such conclusions, but I'm always looking for ways to cross-check assertions and assumptions.