Norman Lloyd, who plays Professor Galen, was 78 years old at the time of production, making this performance the oldest age by any actor in the series. He has the greatest longevity of any performer on the series. In November 2020, he turned 106 years old. He is famous for being married to the same woman for 75 years, the longest continuous marriage in Hollywood history.
The first time that Humans, Klingons, Romulans and Cardassians all appear in the same episode.
Ocett is the only female with a rank of Gul ever mentioned or seen in any episode of any Star Trek series.
Jonathan Frakes was disappointed that he couldn't direct any outdoor scenes. They didn't have the money for it because it was being spent on Star Trek: Deep Space Nine (1993). The set designer Richard D. James said it wouldn't have made a difference anyway, because the crew couldn't find a salt flat without vegetation, as the episode demanded.
The episode's premise was inspired by Carl Sagan's novel Contact (later filmed as Contact (1997)), in which clues to the nature of the universe are discovered in a long calculation of Pi.