You've been warned - here's the ending... oh my god - they're aliens from another planet on a Noah's Ark rescue mission! Wow, revelation. Not.
Knowing anything in Knowing doesn't seem to make a bit of difference. Not to anyone. (And unfortunately that includes the audience.) Having advance knowledge of a possible planet ending crisis doesn't even suggest to anyone that they might, oh, say something about it to someone other than a family member.
Nicolas Cage's character, an astrophysicist, looks at a chart (written 50 years earlier by a child) with a colleague and points out a chronologically correct prediction of the date and number of dead in world wide tragedies over the last fifty years, and his colleague's response is "Systems that find meaning in numbers are a dime a dozen. Why? Because people see what they want to see." Well that would be a pretty neat trick. You could build a career on that in a Vegas showroom.
While Cage's brilliance supposedly illuminates this chart of catastrophe his kid has stumbled on, neither he or his brilliant colleague notice that the elusive numbers that are not part of the date and number of dead, are map coordinates. That is until his ever present GPS unit (which has been staring him in the face every day in his car) flashes his own location to him, just as a jet plane crashes next to the highway he's traffic jammed on. Being the hero type (at least as an actor), Cage jumps from his car and runs into the jet fueled flames while burn-gag stuntmen stagger all around him. (Since when do people walk away from utter destruction, their only piece of bad luck, after surviving a horrific jet crash with no apparent broken appendages, being that they are unfortunately engulfed in fire?) That is fire, by the way, that causes sporadic explosions and assorted mayhem, but not enough heat to prevent the actors from standing only yards away.
By the way, Cage's useless heroics come at the expense of his young son, one still suffering from the tragic loss of his mother, being left and forgotten in the rain on the steps of his school. It's OK, the kid gets ignored lots more even though the script is fond of pointing out that Dad and son "will be with each other forever". Well, except Dad will die a split-second fiery death along with planet Earth and son & new girl pal will reignite the human race on a distant, alien utopian planet.
Throughout the film, people behave as directed and written, with no attention paid whatsoever to how actual people do behave. Even director Alex Proyas' supernatural and sci-fi classics The Crow (1994) and the brilliant Dark City (1998) made more sense than this. Characters search a school building for a missing child with flashlights rather than simply turning on the building's lights. Black, shiny pebbles seem to portend some alien message but are completely ignored as anything more than a curiosity (that one's never explained). Cage's character, racing to rescue his son from an apparent kidnapping, stops to hold hands with a dead woman in the back of an ambulance to utter some profound thoughts, seemingly once again forgetting that his son may be in peril. The list is long and increasingly unforgivable.
Perhaps some forgiveness for illogical character behavior could be summoned if the story were even the least bit riveting, nail biting, suspense filled. Sorry. The words hack, cliched and recycled are far better descriptors. Close your eyes and picture an alien - yep, a humanistic swirl of pulsing blue light with some amber and red around the heart and brain. What's an alien spaceship look like? Now-a-days its some fractal geometry written into a computer rendering program, all sliding and intersecting, constantly moving angles backlit with bright, white light. And where does it land? Does a bear shit in the woods? Apparently so do aliens.
Knowing's tagline is "Knowing is everything". It made lots of cash last weekend and as I'm writing, it's still been number one each day this week. If Knowing remains on top next weekend and climbs to financial success, there will be proof that Knowing does indeed know at least one thing for certain. There are lots of dumb people without a wit of logic in their own brains who still have enough money to go to the movies.