Penny angrily rips on the guys' toy collections after their latest acquisition (a full-sized time machine prop from The Time Machine (1960)
) causes her to miss work.
- Answer Cut: Sheldon wonders why nobody bid on the time machine. One cut later, and we see it's life sized.
- Dirty Coward: When getting approached by Morlocks the second time, Sheldon begs the Morlocks to eat Leonard instead.
- Dream Within a Dream: The Stinger is Sheldon dreaming that he used the time machine to travel to the future, where he's attacked by Morlocks. He wakes up and tells Leonard about it, and Leonard informs him that he called movers to take away the machine... which turn out to be Morlocks. Sheldon then wakes up for real.
- Heroic BSoD: Leonard after Penny's scathing rant, to the point he was almost going to sell all of his collectibles without even giving thought to just giving them to his friends who were outright offering him money for those.
- Hypocrite: Sheldon angrily calls Penny one when Leonard wants to sell all of his collectibles because of what she said the previous day, pointing out that for her entire rant about how "grownups don't play with toys", she is also a collector of various girly toys and collectibles.
- Insane Troll Logic: Leonard wants to hurt Sheldon and punch him when Sheldon goes to insult him some more for the fact Penny's not in the mood to have sex with Leonard. Sheldon points out inflicting an attack on him would be meaningless because it won't change the past, when it would really change his future for the worse.
- It's All About Me: Leonard says he isn't going to sell any of his stuff to any of his friends, because if he does then the other two will be mad at him for not giving it to them. Sheldon immediately says who cares about that as long as Leonard gives it to him.
- "The Reason You Suck" Speech:
- Penny gave one to the guys for holding on to collectibles since it cost her a day's pay at work. She later admits that she didn't mean it, and was just in a bad mood.
- Sheldon gives her one near the end, calling her a hypocrite for keeping collectibles at her place as well.
- Time Travel Tropes: Several are discussed:
- Fantastic Time Management: Leonard jokes that he could use the time machine to drop Penny off at work yesterday.
- Field Trip to the Past: Leonard plans to travel back in time to see Alexander Graham Bell invent the telephone.
- Grandfather Paradox: Sheldon explains it when Leonard says he wants to go back in time to stop himself from buying the time machine.
- Our Time Travel Is Different: The gang does a humorous impression of the "Videocassette Time Travel" variation.
- Time and Relative Dimensions in Space: Raj mentions Leonard would logically end up in 1876 Pasadena, not in Alexander Graham Bell's Boston lab. (The show does not mention this, but Sheldon would probably be horrified to learn that present-day Pasadena was the site of a tuberculosis colony in 1876. It's also worth mentioning that they're not on the ground floor, and their building presumably wasn't built yet in 1876.)
- Time-Travel Romance: When Leonard says that girls like Penny don't go for guys with time machines, Sheldon points out examples of this trope.
- Undercrank: Parodied when Leonard plays in the time machine and the others run around as if sped up.
- You Shall Not Pass!: Sheldon at Leonard.