Some questions linger like a ghost
In the first conversations, when Margrethe asks about why did Heisenberg went to Copenhagen. Niels tries to convince his wife to drop the question but she refuses, comparing with a ghost that continues to hunt her. The comparison is used here to show just how much Margrethe wanted to find the answer to her question and how uneasy the question was making her feel, haunting her every step she took.
We operated like a business, like father and son
When the characters talk about the relationship which existed between Bohr and Heisenberg, it is compared with many other relations, both by Bohr and by Margrethe. Bohr described their relationship as being one which was operated like a business while Margrethe compared it with a father and son relationship. Both this comparisons have the purpose of showing just how close Heisenberg and Bohr was and how easily they were able to work with one another.
Not in our house
When Margrethe talks with Bohr about Heisenberg, Bohr admits that maybe Heisenberg expected to be invited into their home so they could have a private conversation, without fearing they were being listened. Margrethe refused without giving it a second thought, saying that their house was not the place for them to meet. The house becomes a metaphor here, being the place where no outside influence is allowed. Thus, the house becomes a metaphor for the beliefs and ideas Margrethe and her husband had and which could not be influenced and changed by anyone.
I carry my surveillance around like an infectious disease
This comparison is made by Heisenberg after Margrethe and Bohr discuss about him and the possibility that he is watched. Through this line, Heisenberg admits that many chose to stay away from him because he was being watched by German intelligence officers. Heisenberg was aware of this and so he was careful in what he did. This knowledge however made many beware of Heisenberg and even avoid him. Thus, the comparison has the purpose of showing just how isolated Heisenberg felt and how the surveillance affected his life.
Like lepers
During a conversation between Bohr and Heisenberg, the latter expresses his feelings of gratitude towards Bohr because he was among the only people who accepted him and other German scientists after the end of the First World War. The German people had a bad reputation because during the First World War, countries like France were attacked by Germany. At the end of the war, Germany lost and had to pay reparations to the attacked countries. Many still continued to see the German as the enemies even after the war was over and so they were treated as outsiders. The comparison between the way the Germans were treated and the way a leper may have been treated during those times shows just how isolated the German felt and how it affected their life in a negative way.
