Photospheric Opacity and Composition
... and we should probably start with a 90/10 percent mixture of neon/(standard model elements) in terms of the plasma with a density that matches the standard model at the surface of the photosphere. ... The umbra however is not neon. It's silicon with roughly the same density as the photosphere, so that part would need to be calculated separately in a similar 90/10 mixture of mostly silicon.
It sounds loony, but OK. 90% neon, 10% standard solar model elements. Since the standard solar model says the photosphere is around 90% H, 9% He, plus trace - shall we just say 90%Ne, 10%H? Is that what you meant?
Yes, that's exactly what I meant by the way. That works for me. You'll eventually need the metals and other elements to explain the "white light', but I doubt they'd have much effect on the opacity in any relevant way, whatever simplified scenario works for you is fine by me. FYI, I appreciate what you're doing actually, and I'm looking forward to your results.
I still need to know whether you mean 90%Ne by mass or by number. In other words, you might mean that if I weigh some plasma, 90% of the weight comes from Ne and 10% from H. Or, you might mean that if I count atoms, 90% will be Ne and 10% will be H. Those are very different, because a typical Ne atom weighs 20x as much as an H atom (i.e. a proton).
I meant mass assuming other elements present so use mass. It might be a bit heavy on the hydrogen since we're not including other (heavier) elements, but that's fine IMO.
It will be interesting to see what comes out of all this, but I have my reservations.
We already know, as a matter of fact, that the mixture of plasma Mozina wants to investigate, both for the general photosphere and sunspot umbrae, exists nowhere in or on the sun. We can look at the sun and see what it is made of. We know its chemical composition (by number about 92% hydrogen, 8% helium and less than 1% everything else; see, e.g.,
Solar Astrophysics by Peter Foukal, 2nd edition 2004 section 5.6 and table 5-3;
Asplund, et al., 2009). We have known that the sun is composed mostly of hydrogen since about 1930 (e.g.,
Russell, 1929;
Stromgren, 1932;
Eddington, 1932). The fact that the sun is made mostly of hydrogen is crucial, since we also know that, counterintuitively perhaps, the continuum opacity of stellar photospheres is dominated by the H
- ion (e.g.,
Wildt, 1939;
Massey & Bates, 1940;
Chandrasekhar, 1945, a 5-part paper, all parts linked from this page;
John, 1988;
John, 1994;
The Observation and Analysis of Stellar Photospheres by David Gray, 3rd edition 2005, pp. 154-157;
Solar Astrophysics by Peter Foukal, 2nd edition 2004 section 5.3.2, pp. 149-150). Finally, there is quite good enough agreement between helioseismological observations, solar neutrino observations, and the standard astrophysical models of the sun, such that all of Mozina's alternate hypotheses are excluded with confidence (see, e.g.,
Bahcall & Ulrich, 1988;
Bahcall, Pinsonneault, & Basu, 2001 and citations thereto for both papers).
Clearly, if we pick an unrealistic mix of elements, we get an unrealistic opacity as a result. 90% neon means a lot fewer H
- ions and, perhaps, a lot less opacity. So if we find that the Mozina mixture is indeed much more translucent than we are claiming for the photosphere here, so what? Since the chosen mixture is very unphysical, so will the low opacity be representative only of the Mozina sun, as opposed to the real sun we look at. It will still remain to show that there is observational support for the Mozina mixture, and some objective reason not to believe the standard mixture, which has been built up over 80 years of careful observations of the sun. I suspect that Mozina will be as incapable of supporting his alternate hypothesis for the solar chemical abundances as he is incapable of just about everything else, but we will see.
