Max Delbrück (1906-1981) is one of the guests and co-workers associated with Niels Bohr and the University Institute for Theoretical Physics (renamed the Niels Bohr Institute in 1965), who have 100-year anniversaries in 2006. Max Delbrück made his first longer stay of 6 months at the Institute in 1931. He was a frequent guest in the next 6-7 years, usually attending the annual Copenhagen Conference. Biographies can be found on the Delbrück page at the Cold Spring Harbor Lab website and at the Nobel Prize site

Paul Ehrenfest and Max Delbrück NBI balcony, 1933

Niels Bohr, Max Born and Max Delbrück NBI, 1936

Also in 1906, Physics Meeting at Sorø Academy Left in back row: Niels and Harald Bohr