Electronic/World Wide Web>Internet Article:  Siegel, Ethan (4/26/2014), Ask Ethan #34: Using up the Universe’s fuel, Retrieved on 2014-08-09
  • Source Material [medium.com]
  • Folksonomies: astronomy


    09 AUG 2014

     Hydrogen Levels in the Universe

    Our Sun is significantly enriched, having formed when the Universe was more than 9 billion years old in the plane of a spiral galaxy, one of the most enriched places in the Universe. Yet, when our Sun formed, it was still made out of — by mass — 71% hydrogen, 27% helium, and about 2% “other” stuff. If we convert that into “number of atoms” and treat the Sun as typical of the Universe, that means, over the first 9.3 billion years of the Universe, the fraction of hydrogen ha...
    Folksonomies: physics astronomy hydrogen
    Folksonomies: physics astronomy hydrogen
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