Major Plot Hole: Most of this movie is a quest for a beacon to send a distress signal to Nova Prime. I repeat, a distress signal. You know, like the distress signal the two pilots are clearly shown sending before the crash. “Mayday, mayday…” That’s right. They already sent the distress signal! If a message could be sent from a handheld device on the top of a volcano surely it could be sent from a starship in outer space. Nova Prime already got the message. The General sent his son through all that hell for nothing. Thanks dad.
Super Plot Hole: We learn in After Earth that mankind has the technology to relocate our entire species across the galaxy through some sort of “worm-hole” creating hyperdrives. Suspend disbelief. Okay. We have the technology to terra-form a new planet (Nova Prime) and make it habitable. Suspend disbelief. I’ll buy that. But with this advanced technology the one and only weapon shown in the entire movie is a two-bladed retractable knife. WTF? The ursa attack with plain old claws and snapping jaws. So Will Smith and his space rangers fight back with… knives. Really?
We can travel faster than the speed of light but we decide to fight enemies like the Teenage Mutant Ninja Turtles ? Not a single long-range weapon? It seems implausible given the technology demonstrated. Even neanderthals had the good sense to fight predators at a distance with long spears and bows. You know, to avoid the claws. Would an advanced human race fight monsters hand to hand with knives? Even the Predators had missile launchers on their shoulders to go along with their blades!!
Super Plot Hole: Within Will Smith’s lifetime Earth was abandoned, Nova Prime was colonized and a war with aliens was fought. He cannot be more than 50 years old when he returns to Earth. In his 30 years away, all creatures on Earth “evolved” to kill humans. 2 problems with that:
1) Darwin taught us that evolution takes millions of years. The 3 decade jump from bald eagles and mountain lions to giant flying veloceraptors and sabre tooth tigers is impossible.
2) Darwin taught us that evolution occurs when species adapt to changes in their environment through natural selection. But humans abandoned Earth. How could a species “evolve to kill humans” if there are no humans to kill? This is so incredibly retarded.
Super Plot hole: But wait there’s more! Future humans do not have the monopoly on shit ideas ! Please welcome the unnamed alien adversaries from Planet Stupid. These trans-galactic warlords foregone blowing up Nova Prime with red-matter bombs, razing the planet with plasma canons or committing genocide via a genetically engineered Ebola virus. No, these Xeno-morons decided that their best path to victory over the mighty humans is to send shitty cgi monsters at them. Ursas are “genetically designed” by the aliens to wipe out all humanity with their highly advanced… teeth and claws. Brilliant. I’m sure this will work out well with a specie known in its long war history to have seemingly ditched the used of close-quarter combat a century ago.
And Ursas are a bad excuse of an enemy: they are giant hairless blind mole-rat lovechilden with razor sharp claws and excellent sense of smell. Yes, they can smell fear. Cool. But they are blind, so they cannot see odorless threats like spaceships with lasers, robotic drones, human rangers in hermetically sealed space-suits, claymore mines, snipers or any of the obvious ways humans could easily slaughter these bumbling blind rodents. The only reason this stupid threat is remotely effective is because it is used against humans who are also behaving in the most stupid possible way ever.
Plot Contrivance: Jaden Smith is sent on a deadly mission by his father the General. They calculate the exact number of lung-juice cans needed to survive the trip (5). A genius at strategy and survival, the General sends his only son into the wilderness with EXACTLY the number of cans needed for the trip. No extras. Just barely enough to make it. It’s not like he’ll be delayed by giant baboons, leeches, eagles, lions or that Ursa monster the General conveniently packed in the trunk. Thanks a lot, dad.