While promoting After Earth, Will Smith said, “At heart, I’m a physicist.” Maybe, but only at heart, if the movie (which he was heavily involved in conceiving) is anything to go by.
Smith stars as Cypher Raige, a soldier from a civilization humans built on another planet 1,000 years after abandoning Earth. One day, he and his son Kitai, played by Smith’s real-life son Jaden, crash land on their ancestral home. Cypher is too seriously injured to light the distress beacon that landed miles away, so Kitai must trek across the wilderness to find it. It’s a dangerous mission — as Cypher warns his son, “Everything on this planet has evolved to kill humans.”
This line was featured heavily in the trailers because it sounds cool, but it falls apart the second you think about it. First and most obviously, why would everything evolve to kill something that hasn’t been there for 1,000 years? And 1,000 years may sound like a lot, but it’s a blip in evolutionary time. It would take thousands times thousands of years for the animals we know to develop into the giant monstrosities Kitai has to fight.
It gets worse. Somehow, over this relatively tiny timespan, the whole environment of Earth has changed — blazing hot all day, freezing cold all night — yet somehow the planet is covered in lush jungles even though the nightly freeze should kill them all off once every 24 hours.