9. Why Didn't The 500 Mile-Long Mothership Kill Everybody When It Exploded? - Independence Day (1996)
For all intents and purposes,
Independence Day is a big dumb action movie, one which contains a scene in which Jeff Goldblum somehow creates a virus on a Planet Earth computer that works aboard an alien mothership. Like I said, dumb, and hardly a movie that warrants close scrutiny. So whilst we can ignore the computer virus thing (c'mon! How did Goldblum write that thing, though?), there's a fairly large plot hole related to the defeat of the aliens themselves. Specifically, their ships. Because once the day is saved and victory is Will Smith's, lest we not forget that a colossal ship has just exploded (500 miles in length, mind) directly above the earth's atmosphere. That's more than 10 times longer than the city of London. Can you imagine the freakin' debris that would result from an explosion like that, and how many people it would kill as the bits and pieces re-entered Earth's atmosphere? That's going on the fact that an asteroid the size of a mere 20-story building has the power to destroy an entire city. Seriously. Hell, it need be only a mile in length to destroy
everything on Earth. And then there's all the other, 15-mile long ships that have been poised around Earth in populous locations - what happens when they land on top of hospitals and schools the world over? Likely this "happy" ending is far more depressing than whatever it was the aliens had planned for humanity. Geesh.