In the world of film-making there are many freedoms for creativity, especially
when using CG components. This is prominent in many genres such as animated
films, action films and super hero films. In using computer generated images,
the creative teams are able to create different worlds, environments and push
the physics of human capabilities. However, pushing the laws of physics too far
can have its disadvantages. For this paper I will explore the pushing of some
of the laws in these following films: Tangled, The Spy Next Door and Marvel’s
The Avengers.
There are two laws of physics that are evidently incorrect in these films; the
Law of Inertia and the principle of Momentum & Impact. In physics, the Law
of Inertia and the principle of Momentum and Impact are incorrectly illustrated
in many films in order to create a sense of believe-ability, as opposed to a
completely correct representation.In 2011 Disney released a re-telling of the story of Rapunzel, in their animated film Tangled. In this version Rapunzel, daughter of the king and queen, is kidnapped as a baby by an elder woman who seeks the power of Rapunzel’s hair to keep her young. Rapunzel grown up in a tower hidden from the rest of the kingdom until one day a young man by the name of Flynn Ryder, frees her from the tower. Through many obstacles and turmoil, Flynn helps Rapunzel find her true parents and they live happily ever after. This example will focus on the character of Flynn Ryder. One of the obstacles he faces in the film is when he has to escape from the castle after he is taken into custody under false pretenses.
In this scene, Flynn Rider makes his great escape from the castle after being captured under false pretenses. He gets help from the “tough guys” of the film. He is catapulted from inside the castle courtyard, into the air/over the wall. As he’s “flying through the air” he remains in and upward/straight stance, simply rotating in the air.
When Flynn lands he lands perfectly on Maximus, a horse, who will take him to Rapunzel. However he lands perfectly, in the correct spot, without injuring neither the horse nor himself. What is important to note in this scene is the height of the castle walls, the weight of the “Viking looking guy” that does the catapulting, Flynn’s weight and the momentum with which he is falling. According to the principle of momentum, in order to stop an object of large or small momentum there needs to be a similar large force (applied quickly) or small force (applied slowly).
As seen in the first photo the castle wall is quite tall; about a little less than 100 feet (estimating). The second photo, you notice the character is pretty big and built and is jumping off the second story. In the third photo Flynn is at a significantly high height and manages to clear the wall. Even though the Viking is quite big in size and weighs a good number, the momentum in which he catapults Flynn would not have been such that Flynn would go entirely over the wall. Yes, he may “jump up” at a high height but not as far and as high as the wall. The second thing to notice is when Flynn lands on Maximus.
As mentioned Flynn is falling from a significant height and his momentum, though not too fast, is quick. Maximus was not a far distance from the apex of Flynn’s fall. This would mean that when Flynn lands on Maximus with that much force, he should have at least had some upward force moving him from the saddle, and the horse should have at least moved a little in reaction to Flynn’s force and weight. Neither of them have any reaction. A good example of incorrect usage of the physics principle of momentum.
Another film which has this same issue, in many parts of the film, is the 2010 kids’ action movie The Spy Next Door. Bob Ho is a simple man living a normal life and has a secret double life as a spy. Given some unplanned circumstances he takes on babysitting his neighbor/girlfriends’ kids. When his cover is blown, the kids soon join him in helping fight “the Russians”. As the movie progresses the youngest of the children, Nora, gets good at using some of the gadgets; without her knowing. The following scene is from the final fight scene of the movie in which Nora is face to face with the largest of the Russians.
Nora is in the hallway with the biggest Russian and he tries to come after her. She then shoots him with a small gun-like device. The gun shoots a “bullet” that catapults the Russian to the end of the hall, causing him to break the door and part of the wall. Both the Law of Inertia and the principle of Momentum & Impact are poorly used in this scene. The Law of Inertia states that an object moves with constant, uniform motion until acted on by an unbalanced force. In this case the “bullet” like device is shot with a fast speed however due to the size of the Russian is stopped; in this case disintegrates. This would be the first thing to notice. A “bullet” or bullet-like device would not disintegrate on contact, especially when made of metal or harder material.
In the second part of this sequence, we see the Russian being catapulted by the force of the bullet to the end of the hall. In this case the unbalanced force would be the wall that causes him to stop and fall to the ground. However, the momentum of the bullet versus the momentum in which he was “flying” across the hall is inconsistent. Again, the bullet would not have disintegrated and due to how fast it was going and its size the Russian would not have catapulted like he did. Another thing to notice is although the Russia is big in size and probably weighs quite a bit, the fact that he was able to break doorway and part of the wall is completely false. He may have been able to break a little bit given the force and momentum he was going at but not to the extent in the scene. This is not the only example in which the laws of physics are used incorrectly in this film. Although the physics are highly unbelievable, being that it’s a children’s film and live action it is understandable and more appropriate that such rules are broken in order to create a more fun and family friendly film.
The last film I wanted to look at is one of Marvel’s biggest move hits, 2012’s The Avengers. Unlike The Spy Next Door, this film has a lot more CG components in a live action setting. This film does deal with super hero characters that have supernatural abilities and powers, so it is expected that certain laws of physics will either be used incorrectly or completely ignored. However they still need to make it believable actions that the characters would actually have. The following example is from the final battle scene. In this particular part, Thor is joining the other avengers for the final battle.
He falls at lightning speed out of the sky, hits the ground, stumbles as he is getting up and suddenly walks perfectly when approaching the other avengers. Thor comes to a sudden stop after falling at such a high speed. In order to stop an object of large momentum, there needs to be a large force applied quickly or a small force applied more slowly. In this scene the large force would be the ground. Though it does apply force quickly, causing that sudden stop, the upward force that the ground exerts is not evident in Thor. Another thing to notice is the momentum in which Thor hit the ground. If he is falling at “lightning speed” and hits the ground that quickly, in reality he would have either been really critically injured (due to having almost no armor) or would have died.
For these three films, The Law of Inertia and principle of Momentum & Impact are purposely used incorrectly for the effect of comedy and visual enjoyment. This does not always mean that the action is believable even in the context of the film, but the suspension of disbelief required to experience films with exaggerated realities makes up for this fact. As we saw with The Spy Next Door. That is the beauty of filmmaking and television shows that use CG today; there is so much freedom to create such different, whimsical worlds and it is amazing to see how far we have come.
