Trivia / Star Trek S1 E19 "Tomorrow Is Yesterday"

• Accidentally-Correct Writing: The first sign the Enterprise has traveled back in time is when Uhura intercepts a radio newscast saying that three astronauts will be launched in the first manned moon shot next Wednesday. Two years after the episode aired, Apollo 11 blasted off on July 16, 1969 (a Wednesday) carrying three astronauts (Neil Armstrong, Buzz Aldrin, and Michael Collins).
• Deleted Scene: Some portions of the interrogation scene between Kirk and Colonel Fellini were cut from the finished episode. In one, Fellini asks Kirk if he is an American citizen; in another, Kirk asks the colonel if he beats his wife.
• Recycled Set: The airforce base set appears to be the same set used by I Dream of Jeannie.
• Science Marches On: At the time this episode was written^note The episode aired January 26th, 1967, and was "in the can" for some time before that, there was no universally accepted term for a collapsed star of infinite density that had a gravity well so strong that even light could not escape it. The episode seems to be referring to this concept with the term "black star"; we would now know this as a "black hole"^note A term that was popularized by physicist John Wheeler in a lecture on January 18th, 1967, a mere 8 days before the episode aired—the term had existed before, but was not universally accepted until after this lecture.
• What Could Have Been: This episode was originally going to be the second part of a two part story that would have begun in "The Naked Time". In an earlier draft of the script, when Kirk ordered a hyperbolic course, he wanted the direction to be "Doesn't matter... the way we came... toward Earth."

---