How exactly will DESI simultaneously capture individual spectra from 5,000 galaxies using optical fibers?
Why are the wings of many strong lines, including hydrogen lines and most metal lines, stronger in Dwarfs than in Supergiants?
Why are O III lines so prominent in the spectra of emission nebulae when the amount of oxygen relative to hydrogen is a million times smaller?
Is there a far away probe that has recorded the light spectrum from Earth as if it were an exoplanet?
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