Element Abundances in the Stars and Beyond, ca. 1925-1940

Explore the revolutionary shift in understanding stellar composition through this 23-minute conference talk examining the period from 1925-1940 when astronomers discovered that stars are predominantly composed of hydrogen and helium rather than Earth-like elements. Learn how Cecilia Payne's groundbreaking 1925 hypothesis challenged the prevailing consensus that stellar composition resembled Earth's, and follow the subsequent work by Arthur Eddington, William McCrea, and Albrecht Unsöld that established hydrogen's preponderance in the early 1930s. Discover how Bengt Strömgren's 1938 calculations showing the Sun as 60% hydrogen and 36% helium inspired Carl Friedrich von Weizsäcker's cosmogonic theory, and examine Victor Goldschmidt's pioneering compilation of cosmochemical data that produced the first graph of relative element abundances in the universe. Understand how this foundational work later proved instrumental to the Big Bang cosmology developed by George Gamow and his associates after World War II, and trace the coining of the term 'cosmochemistry' by Rupert Wildt in 1940, marking the emergence of this new scientific discipline that bridged astronomy and chemistry.