When the center of the Earth stops spinning, it causes a disturbance in the electromagnetic field that protects humanity from cosmic radiation, sparking an apocalyptic sequence of events that builds to violent "superstorms" and ends with solar microwaves cooking the planet. Simple enough, right? Not for the makers of The Core, who are so worried about confusing people with scientific jargon that they demonstrate this principle by incinerating a piece of fruit (Earth) with a lighter and a can of air freshener (the sun). Stupidity on such a colossal scale brings no dignity to The Core's filmmakers or its audience, but it's still what makes disaster movies so shamelessly appealing. Before sobering up on moments of seriousness and loss, including the digi-destruction of major cities and monuments, The Core pelts Londoners with frenzied swarms of birds, lands the Space Shuttle in downtown Los Angeles during rush hour, and otherwise tries to be the biggest, most outrageous spectacle ever filmed. Which prompts the question: Is it willfully or unintentionally ridiculous? More importantly, does it really matter? With the exception of Hilary Swank, whose earnestness spoils the fun, a stellar cast seems in on the joke, including Aaron Eckhart as the wise-cracking geophysicist who takes leave from academia in order to save the planet. Asked to respond to a mysterious ecological incident that killed 32 people in a 10-block radius simultaneously–on "Green World Day," no less–Eckhart concludes that the Earth's core has stalled like an old Chevy, and everything on the surface will perish within a year. Lacking a giant set of jumper cables, the government employs a ragtag team of physicists and astronauts to plunge underground in a jerry-rigged $50 billion phallus built by Delroy Lindo. Joining Eckhart and Lindo on the project are Shuttle survivors Swank and Bruce Greenwood, fellow eggheads Tchéky Karyo and Stanley Tucci, and computer hacker DJ Qualls, who's asked to keep the secret mission off the Internet. As an egomaniacal Carl Sagan wannabe, Tucci suggests an inspired cross between an effete New York art critic and Dr. Strangelove, as he takes long drags from a cigarette while cherishing the secrets of his own Doomsday Device. So long as The Core stays in tune with his high silliness, it's a guilty pleasure, offering the kind of juvenile thrills provided by cheap old science-fiction movies with spaceships made of paper plates and thread (or, in this case, Earth's mantle, pictured as the inside of a New Age crystal shop). But once half a city gets flambéed, it becomes harder to enjoy the endless parade of MacGyver solutions to every little mishap, most of which involve a crew member being heroically jettisoned into fiery oblivion. If there's one thing dumb, breezy entertainment like The Core can't sustain, it's a reminder of fragile mortality.