The Laws of Physics in Big Hero 6

Big Hero 6 is the latest animated movie from Disney animation studios. The 3D animated film takes place in the near future in a city called San Fransokyo. The main character, Hiro Hamada is a 14 year old robotics prodigy who uses his talents to create robots and participate in back-alley "bot-fights." His brother, Tadashi convinces him to go to his university, where he meets Tadashi's friends, Gogo, Honey Lemon, Wasabi and Fred.  Hiro also meets Baymax, Tadashi's invention created as a healthcare companion.  He presents his microbots, which impresses Professor Callaghan, who is head of the robotics program, and accepts him into the program. A fire causes the building to collapse, leaving Tadashi and, presumably, Callaghan dead. Tadashi's death causes Hiro to go into a great depression and lock himself in his room.

After accidentally activating Baymax, he follows him to the abandoned warehouse where he finds that someone is mass-producing his microbots.  They are attacked by a masked man who is controlling the bots. Hiro and Baymax escape.  Hiro resolves to catch the masked man and creates a suit of armor and upgrades Baymax. When Tadashi's friends offer their help, Hiro refuses at first but after their rescuing him he decides to create suits for them as well, forming the team Big Hero 6.

At first, the team suspects that Krei, owner of Krei Tech, is responsible for stealing the microbots because of video footage they find Krei testing teleportation technology. However, the masked man is actually Professor Callaghan. This infuriates Hiro, and he orders Baymax to kill Callaghan, but his friends stop him. Hiro angrily takes Baymax and leaves.

When Baymax plays clips of Tadashi test-running Baymax, Hiro realizes that killing Callaghan would make him no better than Callaghan, and decides to make amends with his friends.  They confront Callaghan, and it is revealed that he wants to use the microbots to kill Krei because Callaghan's daughter, Abigail, was the test pilot in the teleportation research and was lost in the portal. 

After unsuccessfully trying to convince Callaghan to stop, they destroy the microbots, enter the portal and rescue Abigail. Baymax sacrifices himself to get Hiro and Abigail back through the Portal. Callaghan is arrested.

Later, Hiro discovers that Baymax's healthcare chip is clenched in his rocket fist, and decides to create a new Baymax.  The six friends continue on taking on their new responsibility as superheroes.

The physics of Big Hero 6 is very similar and is almost mirror to our world's, and because it is set in the future, uses it to their advantage with advanced technology.  While the art and design is stylized, the physics and animation are realistic to present a world that is not too far off from ours. Because it a science fiction, Big Hero 6 adheres to the same laws of science of our world, and uses them to their benefit in order to create realistic futuristic technology to enhance the story.

Big Hero 6 makes effective use of different principles of animation to show the realistic physics of their world.   Slowing in and out is apparent throughout the film, especially while Baymax flies.  When Baymax turns off his thrusters while flying, this slowing in and out is much more apparent. Especially the first time when they fly, as Baymax flies straight up in the air. After Baymax turns off his thrusters, he slows into the peak of the arc, and, much like a rollercoaster, slowly tips over and slows out into a freefall, turning on his thrusters at the last second before hitting the water below. Parabolic arcs are also present during the car chase scene, when they jump the car over a ramp, causing it to fly through the air momentarily.

Instead of using stretch or smears to show action, Big Hero 6 goes the more realistic route and uses motion blur. Especially with flying or driving, or any movement that's too fast for us to see, motion blur is very apparent.  This is very effective for creating a world that is similar to ours.

Big Hero 6 also takes into account the way forces and inertia works as well. For example, during the scene where Hiro chases after Baymax, he often runs too fast and is unable to stop in time, causing him to slide past screen and run into things.  Of course, this is exaggerated for comedic effect, but the physics is still sound in the fact that Hiro is unable to stop moving abruptly when he runs quickly.  Baymax, being big in body in having short, stubby legs, cannot run very fast. Instead, he bounces around humorously, similar to a toddler trying to run. This was intentionally done to add to Baymax's "cute" factor, as both Baymax and toddlers are top-heavy, making it hard to run quickly and smoothly. But Baymax's vinyl body proves useful when he and Hiro are thrown out a window by Callaghan, and Baymax is able to break his fall by shielding him with his bouncy exterior.

In addition, the microbots' advanced technology allow for transportation.  By using the downward force of the human body walking combined with the upward force of moving microbots, the masked man uses the microbots to reach higher places and travel quickly, similar to a conveyer belt at an airport.  They also allow him to fall from great heights, as the upward force of the microbots creates a softer impact, breaking his fall without causing too much bodily harm.

The suits are designed with wind resistance in mind, minimizing surface area to allow the user to run quickly and move around without too much air resistance.  The differences in the suits become more apparent during the ending, when the magnetic portal is activated and begins sucking metallic objects towards it.  Wasabi, who has a big body, is able to stay grounded even though his suit has the most metal, because the heaviness and bulkiness of his body acts as an opposing force to the magnetic portal. However, he still feels "lighter" because the forces are not completely balanced.  This gives him somewhat of an advantage, allowing him to jump higher and move quicker.  Hiro's body is much too light to balance the force of the magnetic portal, so he compensates by using Baymax. However, Baymax's carbon-fiber skeleton is light, so he uses his thrusters to avoid getting sucked into the portal.  Gogo uses electromagnetic suspension and speed in order to cling to the microbots and use them to her advantage, effectively balancing the forces.  Neither Honey Lemon or Fred have enough metal in their suits to be affected by the portal.

Baymax's thrusters prove to be quite useful in balancing the different forces and gravity.  But when they enter the portal to save Abigail and find themselves in an abyss of zero gravity, they discover that Baymax's thrusters have become inoperable, leaving them stranded, because the forces are balanced.  Baymax uses his rocket-launching hand as a force to push Hiro and Abigail through the portal, but the force of the push thrusts Baymax in the opposite direction, tumbling deeper into the abyss.

In conclusion, while the technology in Big Hero 6 is more advanced than ours, being a futuristic movie, it is still realistic because of the adherence to the laws of physics and gravity. The movie is able to use those laws to their advantage, without stretching it into impossibility.  The movement and animation is realistic although the art is stylized to appeal to audiences.