The most interesting thing about copenhagen (the Michael Frayn play, not the city) is the way it's typically staged.

Stage down is converted to a number of tiers of seats that, rather than sticking to the back wall, curve forward to the upstage parts of the wings. The playing area is extended out over the pit and in the shape of a flattened circle. The stage is also canted forward at a noticeable angle so that when a player is walking the perimeter of the stage their tread is noticeably affected by the pull of gravity. The seats at the back create the illusion of the play being played in the round, as well as reenforcing the almost atomic relationships between the characters, each other and the stage itself, the stage being a metaphor for both the universe (in a very literal sense - this is a play about quantum physics, people and memory after all) and the interior of an atom.

As the play progresses, its three characters each take turns at center stage with the two other characters orbiting around them. It's an incredibly energetic play and the players rarely stand still, constantly bouncing their thoughts off of each other. In the staging I've seen, Bohr and his wife intitially stuck to the center of the 'atom' while Heisenberg orbited around them. As the play progresses and they begin to trust each other once again, Heisenberg moves closer and closer to the center of the atom until Margarette is spun out to the orbit, effectively excluded from Heisenberg's relationship with her husband.

The other interpretation that could be brought to this is a cultural one - Heisenberg was a nationalistic German trying to stay afloat during World War II; Bohr and his wife were Danes and under German occupation. Regardless of their past affiliation Heisenberg was obviously not to be trusted and his initial hesitant orbits reflect that - he wasn't being cautious, he was being held at bay by the forces radiated from the core of this particular nucleus.