When McCoy leaves the bridge, and later when he beams down to the planet, he isn't wearing a belt. When the landing party catches up to him on the planet he is wearing the standard utility-type belt.
The Guardian responds when Jim asks the question, "Then what is it?" But Jim asked another question a little earlier, "What is this thing, Mr. Spock?" Both questions are clearly directed to Spock, even if the second one doesn't include his name. So why does the Guardian respond to one but not the other?
Although Spock and Kirk are both present when the Guardian says it will show them "their" history, it only shows Earth's history.
The Guardian says it can only display the passage of time at a fixed rate. Fair enough, most VCRs only fast forward at one speed. But why can't it start at any given point? Once they've determined the speed it displays at, why not just tell it, "Start at 1900" and time from there? Instead the implication is it can only start displaying at the same single point over and over. If its users wanted to view the last days of a million-year-old civilizaton, this must have been very inefficient for such an advanced race.
Spock and Kirk have to enter the Guardian once it starts its second playback at the same time that McCoy did during its first playback (it says it can only play back time at one speed). They don't - they wait about 25 seconds longer then McCoy did.
McCoy is knocked out on the planet, then wakes up a few minutes later and makes it into the Guardian...with a phaser. Assuming the landing party intelligently decided to disarm him after they captured him, where'd he grab the phaser?
Set in New York in 1930, but a shot of front of building shows a fallout shelter sign.
Why does Spock "borrow" the fine tools by picking the lock instead of just asking permission? Edith Keeler already knew that he was working on a "radio" on his off-hours, was there some reason he thought she wouldn't let him use them?
What happened to Spock's superior Vulcan hearing? He was only a few feet away when McCoy first enters the mission and talks to Edith.
Spock clearly determines earlier that Edith dies in a street accident. However, when Kirk saves Edith from a fall inside a house, Spock says that might have been the accident he foresaw. Even with the various unpredictable factors Spock mentions earlier, there doesn't seem to be any way he could confuse a street accident for a house accident.
In the scene a deranged McCoy confronts the homeless man just after arriving in 1930, DeForest Kelley is wearing a ring on his left pinky. It wasn't there before and afterward.
Edith Keeler says to McCoy, "My young man is taking me to see a Clark Gable movie." In 1930, Clark Gable was an unknown bit player -- he didn't become a star until he appeared opposite Jean Harlow in Red Dust (1932).
When Edith stumbles down the stairs she still has both shoes. Kirk catches her and they go on up, and suddenly one of the shoes vanishes.
Why can't Spock play back his tricorder data on the tricorder screen? Instead he has to rig a computer to see what the tricorder says - this doesn't make much sense.
Trivia: This is the first time we see a transporter beam up more than six people. As is later demonstrated in "Day of the Dove," the transporter can hold some people in transit and materialize them separately from the main party.
McCoy: Better risk a few drops of cordrazine.
Kirk: Tricky stuff. Are you sure you want to risk...?
McCoy: You were about to make a medical comment, Jim?
Kirk: Who, me, Doctor?
Kirk: Then what is it?
The Guardian: A question. Since before your sun burned hot in space and before your race was born, I have awaited a question.
Kirk: What are you?
The Guardian: I am the Guardian of Forever.
Kirk: Are you machine or being?
The Guardian: I am both and neither. I am my own beginning, my own ending.
Spock: I see no reason for answers to be couched in riddles.
The Guardian: I answer as simply as your level of understanding makes possible.
Spock: A time portal, Captain--a gateway to other times and dimensions, if I'm correct.
The Guardian: As correct as possible for you. Your science knowledge is obviously primitive.
Kirk: Annoyed, Spock?
The Guardian: Your vessel, your beginning, all that you knew, is gone.
Kirk: I've seen old photographs of this period. An economic upheaval had occurred.
Spock: It was called Depression. Circa 1930. Quite barbaric.
Kirk: We seem to be costumed a little out of step with the time.
Spock: I'm afraid I am going to be difficult to explain in any case, Captain.
Kirk: Well, Mr. Spock, if we can't disguise you, we'll find some way of... explaining you.
Spock: That should prove interesting.
Kirk: You're a police officer. I recognize the traditional accouterments.
Spock: You were saying you'll have no trouble explaining it.
Kirk: My friend is obviously Chinese. I see you've noticed the ears. They're actually easy to explain.
Spock: Perhaps the unfortunate accident I had as a child?
Kirk: The unfortunate accident he had as a child. He caught his head in a mechanical... rice picker. But fortunately, there was an American missionary living close by who was actually a, uh... skilled plastic surgeon in civilian life.
Kirk: You were actually enjoying my predicament back there. At times, you seem quite human.
Spock: Captain, I hardly believe that insults are within your prerogative as my commanding officer.
Edith Keeler: Now, I don't pretend to tell you how to find happiness and love, when every day is a struggle to survive. But I do insist that you do survive, because the days and the years ahead are worth living for! One day soon, man is going to be able to harness incredible energy -- maybe even the atom. Energy that could ultimately hurl men to other worlds in some sort of spaceship. And the men that reach out into space will find ways to feed the hungry millions of the world, and to cure their diseases. They'll be able to find a way to give each man hope and a common future. And those are the days worth living for.
Edith Keeler: A lie is a very poor way to say hello.
Edith Keeler: Lots of people drink from the wrong bottle sometimes.
Edith Keeler: I still have a few questions I'd like to ask about you two. Oh, and don't give me that "questions about little old us?" look. You know how out of place you are around here.
Spock: Interesting. Where would you estimate we belong, Miss Keeler?
Edith Keeler: You? At his side, as if you've always been there and always will. (to Jim) And you... you belong... in another place. I don't know where or how. I'll figure it out eventually.
Spock: I'm finished with the furnace.
Edith Keeler: "Captain." Even when he doesn't say it, he does.
Spock: Captain, I must have some platinum. A small block would be sufficient--5 or 6 pounds. By passing certain circuits through there to be used as a duodynetic field core...
Kirk: Mr. Spock, I've brought you some assorted vegetables, baloney and a hard roll for myself, and I've spent the other 9/10ths of our combined salaries for the last three days on filling this order for you. This bag doesn't contain platinum, silver, or gold, nor is it likely to in the near future.
Spock: Captain, you're asking me to work with equipment which is hardly very far ahead of stone knives and bearskins.
Spock: If only I could tie this tricorder in with the ship's computers for a few moments.
Kirk: Couldn't you build some form of computer aid here?
Spock: In this zinc-plated vacuum-tubed culture?
Kirk: Yes, well, it would pose an extremely complex problem in logic, Mr. Spock. Excuse me. I sometimes expect too much of you.
Edith Keeler: What... what on earth is that?
Spock: I am endeavoring, ma'am, to construct a mnemonic memory circuit using stone knives and bearskins.
McCoy: This looks like old Earth around 1920 or '25.
Edith Keeler: Would you care to try for '30?
McCoy: I am unconscious, or demented.
Edith Keeler: I have a friend that talks about Earth the same way that you do. Would you like to meet him?
McCoy: I'm a surgeon, not a psychiatrist.
Edith Keeler: I think they're going to take all this money that we spend now on war and death...
Kirk: And make them spend it on life.
Kirk: A hundred years or so from now, a novelist will write a classic using that theme. He'll recommend those three words even over "I love you."
McCoy: Do you know what you just did?!
Spock: He knows, Doctor...he knows.
Kirk: Let's get the hell out of here.
The Guardian: Time has resumed its shape. All is as it was before. Many such journeys are possible. Let me be your gateway.
Ellison's first draft was written in 1966 when only the first two pilots had been produced. In this version, a crewman called Beckwith, suffering from drug addiction, travels back in time. Kirk and crew pursue him, meeting Edith, an innocent who would kill herself if she knew her destiny. Spock prevents Edith's rescue. Ellison's story won the Writer's Guild of America award for Outstanding Dramatic Episode Teleplay in 1967-68. The Transmitted episode was a final rewrite by Gene Roddenberry, it won the Hugo Award for Best Dramatic Presentation in 1968.
In the 2008 Emmy Awards, history being changed due to the time travel, was in the list of the Most Memorable Drama TV Moments. However, it didn't make it to the top 5.
This episode is listed on the Star Trek: Captain's Log Fan Collective DVD box set as being William Shatner's favorite episode.
According to Ellison, the idea for this story came to him while reading a biography of evangelist Aime Semple McPherson and he began toying around with the idea of what would happen if Kirk fell in love with a woman like this.
This episode ranked #92 on TV Guide's 1997 list of the "100 Greatest TV Episodes of All Time."
The lot where the NYC exteriors were filmed was the set for Mayberry on The Andy Griffith Show. Watch carefully as Kirk and Edith walk down the street, you will notice that Kirk and Edith walk right by the window sign which reads "Floyd's Barbershop."
The Star Trek: Voyager writers pay homage to this classic time travel episode in the Voyager episode "Futures End (Part 1)". Accidentally sent back in time to the 1990s, Captain Janeway at one point refers to 1990s technology as "stone knives and bearskins"--just as Spock and Kirk use that same term in this episode about 1930s technology.
In the 2006 digital remastering, the scene of the bum taking McCoy's phaser and destroying himself is edited out.
D.C. Fontana rewrote Ellison's script for the final screenplay.
Despite winning an Emmy, Ellison has pretty much disavowed the on-screen version of his story, writing various articles chastising Roddenberry for lying about the story about why his original script was rewritten, etc., as well as including his original script, which didn't have McCoy going nuts, featured a drug-dealing crewman and a different cube-shaped Guardian, and much more. Ellison's script has been republished in at least two different sources.
1968 WGA Award (TV) Winner: This episode garnered Harlan Ellison a Writers Guild of America award for best writing for an episode of a Dramatic Series.
The only time on the original series that Kirk uses an expletive.
Kirk: Well... we'll steal from the rich and give back to the poor later.
This paraphrases a line attributed to Robin Hood, a fictional folk hero from old England and the subject of numerous books, films and television shows.