Nature1mon
Spectral Theory and the Origin of the Nebulium Lines
THE fact that the so-called nebulium lines are found to be associated with hydrogen and helium lines only ... in all places of which there appear spectral lines of unknown origin or under ...
What are stars made of? A century ago, this woman found out—and changed physics forever
In 1925, grad student Cecilia Payne first proposed that stars were mostly made of hydrogen and helium and shaped our ...