There is a great deal of trickery involved in analyzing NMR spectra. Once you understand Fourier transforms and just how functions behave in time and in frequency space... couple that with convolution theory and then everything is simple. It's easy to zero-fill spectra to cheat the Fourier transform... or to apply window functions to filter spectra... And occasionally after a long day of staring at a bad spectra, it's fun to rediscover Nyquist sampling theory. All in all -- my idea of a nice quiet evening at home is to curl up with my Mathematica and my NMRSpectrumAnalysis and a few 2D spectra and transform my heart away. Love those Fourier transforms!
Similarly, chapter two - spectra of supernova, it seems that the observational astrophysicists have their bag of useful tricks. SN spectra can only come from at and above what's called the photosphere (which is the expanding edge of the ejected explosion) because the region prior to that is too optically thick. Basically in SN spectra, the line widths are so broad because of the doppler shift (ie, you get a velocity profile of the expanding matter too). They're also accompanied by a blueshift absorption. This is cool. The spectrum doesn't necessarily have a blackbody shape though instead depends on the wavelength dependence of the opacity and the extension of the atmosphere. But you can assume a blackbody distribution and you get a density law of rho ~ v^-7 in the outer half of the ejected matter (whoah!).
It's fascinating that astronomers can actually determine which lines belong to which elements. At the time this book was written, the statement was made that the in SN formation, the velocity profile is simple (hydrodynamical effects die out quickly after the explosion) and the velocity is proportional to the radius and matter for the most part expands homologously. I really wonder if that's still true. This book was written before 1990 and as far as I can tell doesn't take turbulence into account (is there any?).
So... one question if anyone really reads this... Why is there no Fe III in supernova spectra?
But thanks to you, I actually care now.