Perhaps Heisenberg's most influential mentor, he headed the Copenhagen Institute and helped to refine the work of Heisenberg, among many other young scientists.
Another of Heisenberg's early mentors, he taught physics at Göttingen. Later on, he would recognize the matrix patterns of Heisenberg's work and help to establish quantum mechanics.
The most famous twentieth-century physicist, who differed from Heisenberg in two fundamental ways. First, Einstein never accepted uncertainty and believed that determinism was attainable. Second, he saw no justification for the separation of science and politics, and therefore used his international fame to campaign against the Nazis.
A physicist who came of age around the same time as Heisenberg and would remain a close collaborator throughout their careers.
One of Heisenberg's precursors in quantum theory, he would later collaborate with Heisenberg in attempts to save German physics at the onset of the Nazi regime. Planck encouraged Heisenberg not to resign his position and to instead wait out the Nazi reign to rebuild Germany after its inevitable defeat.
He showed how electron behavior could be understood in terms of waves. Schrödinger's theory yielded the same mathematical results as Heisenberg's quantum mechanics, but their pictures of the atom differed fundamentally.
Head of theoretical physics at Munich, he was Heisenberg's first mentor in science. Sommerfeld also tried to appoint Heisenberg as his successor, but was thwarted by Heisenberg's Nazi opponents.
The Munich professor who nearly failed Heisenberg during his oral examinations because he failed to demonstrate competence in experimental physics.