Tuesday, April 20, 2010

Term Paper 2: Science Fact or Cinematic Fiction?

The laws of physics are absolute. There are no exceptions to these laws, because the laws reasons of why things are in this world. The only way we can defy the laws of physics is through the world of animation or computer-generated imagery.  Animation allows us to use our imagination to explore the world outside of the absolute laws of physics. Violating a law of physics may take many forms, including the obviously exaggerated or only slightly extended visions. This paper examines the violation of physics in jumping in the animated world. Different types of animation/CGI and different degrees of violations are examined to demonstrate the different effects bending a physics law can bring.

The Warner Brothers film Space Jam was released in 1996, combining live-action with cartoon animation and CGI. Michael Jordan starred in the film as himself, transitioning between the “real world” and the “looney world”.  Because the film took place in both the real world and a cartoon world, the creators made sure to differentiate the two worlds with obvious physics defiance in the animated world.  The film showed Michael Jordan going into the animated looney world, but also had scenes of Bugs Bunny and Daffy Duck traveling into the human world. When the cartoon characters were in the real world, it seemed that the normal law of physics applied to the characters as well, as seen when Bugs Bunny was retrieving Michael Jordan’s shoe high above the mantle and needed to use a chair as a step-ladder in order to reach it. With Michael Jordan in the looney world, it appears that the normal laws of physics stayed with him in the looney world. During the game against the Monstars, it was obvious that the monsters defied physics with their every move. Michael appeared normal until the last moment, with 10 seconds into the game, when Daffy hinted to Michael that “this is looney land” in response to Stan being filled with air like a hot balloon then deflating in the air, traveling like he had no weight. After Michael’s realization that he could follow the rules of the looney world, he jumped from the center of the basketball court, continued to rise after being caught by two monsters, and stretched his arms into a slam dunk that won the game. Prior to this jump, Michael ran and stepped on a Monstar’s back, bending his leg about 90 degrees, exerting his force downward onto the Monstar upon his launch with an estimated push height of 2 feet. At the height of this jump, Michael’s feet were off the air by the length of a basketball hoop, or about 10 feet.  Applying this estimation to the physics jump magnification equation, Michael’s jump magnification would be calculated at 5. However, by analyzing the jump frame-by-frame, the push time took 16 frames. The scene was shown in slow motion, making the actual push time about 8 frames. This analysis brings the jump magnification to just (9/16)*2ft = 1.125. The inconsistency suggests defiance in physics, which is clear in this case. Space Jam purposefully defies physics to bring contrast to the real world, teaching its audience to break out of the box.

In the live-action film Crouching Tiger Hidden Dragon, the jumping in the film defies physics constantly that it immerses the viewer into believing the unnatural jump is ordinary. Crouching Tiger allows its characters to jump with no jump magnification at extreme heights, such as jumping onto the roof of a building. Fifteen minutes into the movie, the thief enters to steal the legendary sword. She escapes by jumping onto the rooftop of the buildings with no push height. She is simply lifted into air, sometimes stepping in the air as if it was to gain height. By estimating the height of jump from floor to building to be 15 feet and push height to be 2 inches, the jump magnification is estimated to be 90. Further estimating the thief’s weight to be about 100 lbs, the jump force exerted by the thief in this case would be 900 times! However, the ease of these jumps does not make the viewer question the rules of physics in all other aspects of the film. Although the jumps are obviously unrealistic, the creators were able to make the audience believe in the jumps. The characters did not try to jump high, as they did not even swing their arms prior to their jumps, which would help a normal human jump almost 30% higher. Instead, the characters jumped at will with little to no push height, purposefully to lessen the obviousness of the defiance of physics. This way, the creators were able to make significant jumps as a part of the martial arts skill. Unlike the jump example of Space Jam, Crouching Tiger never mentioned an alternate rule in their world. The jump in Crouching Tiger was repeated throughout the film, and preserved most of all other physics laws. By doing so, Crouching Tiger was able to bend the physics laws of jumping without bending the laws of the world.

Another look at a different application of jumping can be seen from The Simpsons Movie. The Simpsons Movie is a fully animated/computer-generated film with no live-action scenes. At the scene where Homer dares Bart to ride to Krusty Burger on his skateboard naked, Bart travels downhill on his skateboard before his launch. He travels at about 1/5 of a driveway per frame; 24 inches, roughly 30 miles per hour. Based on the ehow.com video of “How to Jump Without a Ramp on a Skateboard”, it would be near impossible in physics for Bart to be able to get so much air without a ramp, as you can only lift the head of your skateboard and fall without a ramp. In the movie, Bart approaches a fence that is taller than he is – approximately 4 feet. His take-off is fast, but viewing frame-by-frame confirms that the road he travels on is continuously downhill and he does not have a ramp or any other object before he launches off on his skateboard. You can see Bart bend down on his skateboard as he approaches the jump, in order to have a greater jump force by maximizing his push height. As he goes into the air, he takes his skateboard with him, over the 4 ft. fence. As Bart exerts his force on the skateboard, it would be sound for him to jump away from his skateboard. However, the scene carries the skateboard with him. In order for this to be feasible, it would mean that Bart exerted the force on the skateboard, and the skateboard exerted its force on the ground as it was moving, and then translating the reaction force from the ground back up onto Bart. If we don’t take the skateboard into consideration, we can see that Bart’s push height is approximately 6 inches, and we estimate his jump height at 90 inches, for a jump magnification of 15 times. This jump scene from the Simpsons clearly defies normal physics with the presence of a skateboard, no ramp, unrealistic jump height and magnification. Furthermore, Bart’s hang time is about 5 seconds – 3 seconds ascending and 2 seconds descending, falling from the height of a 2-story building onto lower grounds. The creators were able to present this scene with such subtlety that a normal viewer would never think twice about the scene. The extra long hang time allows the creators to emphasize the moment of Bart’s glory and determination and add in the expressions of passing pedestrians to further add to Bart’s moment. This is yet another completely different way in the use of false physics, compared with Space Jam and Crouching Tiger.

In Space Jam, the defiance of physics was obvious as it contrasted the real world, and exaggerated with other false physics elements such as stretching of the arms. The creators wanted the viewers to understand that the law of physics doesn’t apply in the looney world, thus the obvious defiance of physics. The effect is light-hearted humor and teaches the viewer not to take the movie seriously. In Crouching Tiger, the jump was also obvious, but the result was different from that of Space Jam. The creators made the defiance normal, as if the characters were supposed to be able to jump that high and that easily. The result is the belief of a skill. Lastly, in the case of The Simpsons Movie, the physics-illegal jump was subtlety done. Bart Simpson’s jump was a fast scene that should not have brought attention to the physics for the viewers, even though the jump magnification is just as unrealistic as that of Crouching Tiger. The creators used this jump to extend the moment and emphasize with its surroundings. In conclusion, the defiance of physics in animations can be done in numerous ways to achieve numerous effects. We should not look into the absence of physics laws in animations, as they are normally absent on purpose in order to bring humor or lighten the moods of the viewers.

2 comments:

  1. This is to confirm that you posted your term paper on time. I'll try to get all the papers graded by the end of next week.

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  2. Intro & Conclusions: 20 points
    Main Body: 25 points (bonus points)
    Organization: 15 points
    Style: 15 points
    Mechanics: 20 points
    Total: 95 of 100 points

    For details on the grading rubric, go here:
    http://artphysics123.pbworks.com/Class-Structure-and-Grades

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