Hendrik Anthony "Hans" Kramers was a Dutch physicist who worked with Niels Bohr to understand how electromagnetic waves interact with matter and made important contributions to quantum mechanics and statistical physics.
Hans Kramers in c. 1928
Kramers (second row, fourth left) at Fifth Solvay Conference
Niels Henrik David Bohr was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922. Bohr was also a philosopher and a promoter of scientific research.
Bohr in 1922
Bohr as a young man
Bohr and Margrethe Nørlund on their engagement in 1910
The Niels Bohr Institute, part of the University of Copenhagen