Near the end, Zimsky is, once again, waxing philosophic into his recorder. Suddenly, he stops and realizes that he's locked alone inside one of the Virgil's ejected sections, he's submerged in the molten core of the Earth, and he's next to a nuclear bomb that's seconds away from detonation. He lowers the recorder and says, "What the fuck am I doing?" He literally dies laughing moments later.
The film's epitome of faulty science, and depending on your view, possibly the biggest case of everyone/everything in the movie being in on the joke (more in Fridge Brilliance):
Josh (casually): So, we hotwire the nukes, as one does. We seed them through the core at locations that have to be accurate to the inch. We detonate them in a sequence that has to be accurate to the millisecond. Then we outrun the biggest nuclear shockwave in history. Zimsky: Right Braz: Yeah Josh: (beat) Well, that should be fairly simple.
Watch closely during the scene of pigeons going berserk in Trafalgar Square when a few of them are flying into windows: one of them is actually a flying fish!
While the space shuttle is crash-landing, it emits a sonic boom during a flyover of Dodger Stadium.
Zimsky's endless ribbing of Braz. It's unforgivably Jerk Ass, but it is funny.
Purcell: Doctor Brazzleton, I see you know Doctor Zimsky. Braz: Yeah. Twenty years ago he stole my research. After that we kind of lost touch. Zimsky: Research that was equally mine. Braz: That's funny, I never saw a check from any of the patents... Zimsky: All right, Braz. Twenty years in the desert makes you a prophet and a martyr...