Plain language
"Plain language" and "scientific language" both operate in the play. There are several instances when the two physicists start speaking too scientifically for many people to understand, and one of them will remark that they must revert to plain language, to explain it in a way that Margrethe will understand. Even for that effort, criticism arose about the complexity of the play and the difficulty for viewers to comprehend. A writer for "The Commonweal" commented on the Broadway premiere, saying that "the play's relentless cerebral forays can... be frustrating."