The Woman Who Discovered the Universe Is Mostly Hydrogen

Early twentieth century astronomers incorrectly believed stars shared the same chemical composition as Earth's heavy elements.

Cecilia Payne proved that stellar spectral differences are caused by temperature rather than different chemical recipes.

Stars are composed of seventy-five percent hydrogen and twenty-five percent helium rather than iron and silicon.

Henry Norris Russell dismissed Payne's nineteen twenty-five findings as impossible before claiming credit four years later.

Payne strategically included a disclaimer calling her own data not real to ensure her thesis was published.

This discovery redefined stars as laboratories of nuclear physics rather than simple qualitative descriptions.