David Levinson (Jeff Goldblum)’s Timeline and Summary

David is a wise guy who's clearly very smart and funny.
However, according to his father, he's kind of flaming out in both the professional and personal departments.
When aliens attack the U.S., David figures out that the alien ships' signal is actually a countdown clock toward something, so he rushes to tell the White House so they can prepare for some kind of scheduled event.
Luckily, his kinda-ex-wife works there, so he has an "in."
Connie isn't really thrilled to have David around, since they're separated, but everyone finally realizes that David knows what he's talking about and starts listening to him.
David eventually figures out a way to disable the aliens' shields, but it involves a dangerous mission into the mother ship.
He and Steven make their way into space, and David successfully does his thing, which means militaries throughout the world are able to destroy the spaceships positioned around earth.
He ends the film a hero, and he gets the girl (a.k.a. his wife).