According to Captain Beatty, why are people in the society of "Fahrenheit 451" so fascinated with fire?
Beatty has a short monologue on fire shortly after he and the rest of the firemen arrive at Montag's house, revealing that the alarm has been called on Montag and that Beatty knew what he was up to all along (although his blatant hints should have made it obvious).
Beatty rambles a bit in his speech, connecting an anthropological philosophy of fire to the specific benefit that it will grant him in this instance; fire will solve Beatty's problems, as it usually does. Beatty suggests that fire is the "perpetual motion" that mankind always sought to create but never could (because perpetual motion is impossible), and even though it seems to be perpetual, it will eventually consume everything if allowed to. The scientific explanation is unhelpful in Beatty's opinion ("gobbledygook") but the true purpose of fire is its ability to destroy "responsibility and consequences". At this point, Beatty is probably thinking about how Montag is his responsibility, and he will feel the consequences of Montag's betrayal as much as Montag does, unless he lessens the burden somewhat by forcing more of the responsibility and consequence onto Montag.
It is also insinuated that people in this society, in general, see the firemen, and fires themselves, as a spectacle, and that it is merely another form of entertainment to them.