Wednesday, March 21, 2012
Sunday, March 11, 2012
First term paper
It isn't very often that we watch a movie to analyze the physics that operate in its universe. Most often, if the movie is made well, we accept everything that happens within the world of that film. The physics of the film may not coincide with the physics of our real universe, but if it makes sense in the story or is consistent throughout the film, we don't question it. However, when one analyzes the physics in a movie, certain hypotheses may be drawn from the observations. I have chosen to analyze the stop-motion animated movie “Chicken Run.” The interactions between the characters and their physical environment play a key part in the film, and those interactions work in a specific way.
My first hypothesis has to do with the air resistance in the world of the movie. I call it the “Power of the Air” hypothesis. In terms of our physical world, air resistance is dependent upon the size of an object and its speed. The larger the size or greater the speed, the more resistance there is. In this movie, we are dealing with chickens. They are not very large and they don't travel at fast speeds, but the way they move through the movie's world is a little different from the real world.
At the end of the movie, the chickens make a flying machine in order to escape the chicken camp. This machine uses a flapping motion to keep it suspended in the air. Judging by several clues in the film, it carries about fifty chickens. I estimate that each chicken weighs about five pounds. Also, during a certain part of the sequence, the aircraft carries an adult woman as well. In order for this machine to work, it would have to be very light or there would need to be a great amount of air resistance. Even if the chickens were not that heavy, having such a great number of them in the craft shows that it is not light. Also, in other parts of the movie, the same flapping motion is not able to lift the chickens themselves up off the ground. Therefore, the reason the aircraft is able to lift off the ground must be due to air resistance and not weight.
The chicken flying machine would only be able to lift off the ground if the force pushing it off the ground exceeded the force of gravity. There are a couple forces at work in this scene. First is the force of gravity in the world of “Chicken Run”. It is pulling the flying machine down to the ground and keeping it from going into the air. Then there is the force of the wings flapping. The wings exert a force pushing down on the air below them. There is also the force of the air resistance pushing back on the wings. Let's say that the majority of the force used to lift the machine up comes from the wings (as implied by this scene). In total, the estimated weight that the flying machine carries in this scene is about 300 pounds. That means the wings would have to exert a little over that in order to carry the craft upwards. At the same time, the air would have to resist that force with the same magnitude in order for the craft to get off the ground and stay off the ground.
The second hypothesis I want to talk about has to do with the way gravity works in this film. This is the “you don't fall till you're ready” hypothesis. The force of gravity in this film's world is not as strong as in the real world, and it acts a little bit differently. There is a delayed application of the gravitational force. Also, it is not as strong as in the natural world. It is counteracted by the air resistance principle I talked about before.
Let's look at a shot from the opening scene of the movie. The chickens are trying various ways to escape. One method they use is to disguise themselves as Mrs. Tweedy, the farm warden, and walk out of the camp on stilts. The two guard dogs see them and knock them down to the ground. In this shot, the chickens are hit off of two stilts. They take a moment in the air to be launched up and then fall to the ground at somewhat of a constant speed. A couple things might be concluded from this observation. One way to look at it is that the force of gravity is not very strong. It takes a lot more time for its force to counteract the upwards force of an object and even more time to accelerate that object downwards. Another way of looking at this example is that the chickens reached terminal velocity very quickly and maintained a constant speed down because of the powerful air resistance and weaker force of gravity.
Some other instances of this occurring are when the chickens are being trained by Rocky. He has them do a series of different exercises. In one of these the chickens spring off a trampoline into the air and fall back down. There is considerable hang time in the air once they have been launched and then they fall quickly back down. There are numerous examples of the chickens flying or jumping or falling through the air like this. There is also a scene in which one of the chickens knocks an R.A.F. medal out of another's hand and it flies through the air. Normally this kind of action would complete in a second or two, but the whole path of the medal through the air till it falls to the ground is about six seconds. These examples show how the force of gravity is weak and it takes a long time to act on an object in the air.
There are certain exceptions when an object is in the air in which it acts differently than normal (the first two hypotheses). When an object is launched, catapulted, or shot into the air by an active force such as a canon or slingshot, it does not follow a parabolic arc. In normal actions such as the character or object falling, they usually follow a parabolic arc. However, in certain circumstances such as when Rocky is shot out of a canon or Babs is flung out by a slingshot, these normal physical rules don't apply.
When Ginger first meets Rocky, he is flying through the air. In the first couple shots, he is traveling in a straight line. Then he hits a wind vane, bounces off of telephone wires, and travels in a diagonal path of motion to land in the chicken feed. In none of these actions or motions does he follow a parabolic arc, and hardly does he travel in any arcs at all. Then in the scene in which Babs is launched by a slingshot, she travels in a straight line as she leaves the cart and flies through the air. She doesn't fall to the ground until after she is redirected by the fence and lands on the rats.
In both of these scenes the character doesn't fall to the ground until after colliding and bouncing off of another object. They both travel initially in a straight line and hold it until being acted upon by an outside force. What can be suggested from these observations is that an active force such as a slingshot or canon causes objects to travel in a straight line or path of action. The force of gravity seems to have a delayed effect in other cases, but here it is not involved at all. Gravity does not act on such a catapulted object until it is first acted upon by an outside force, such as a wall, fence, or other object to collide with.
Another aspect of the universe of “Chicken Run” has to do with balance and the line of gravity. This observation is not so much a hypothesis, because it is an example of an inconsistent way things work in this film. In the end of the movie when the chickens have built their flying machine, they are taking off to leave. However, unfortunate for them, Mr. Tweedy comes and knocks down their ramp. They will crash into the fence if they continue their course, so they must make a turn. Fowler, the pilot, makes a hard turn to the right to turn the craft around. What the flying machine does is lean into the turn. This is an active pitch, and an example of the machine participating in active balance. The whole flying machine leans into the turn to maintain balance and lean with the line of gravity.
This would not be physically possible in reality. After making that turn, the flying machine turns around again at the end of the runway to make a second attempt. This time, however, the machine leans outward, with the force of the turn. This is a passive turn, the whole craft continuing in its path with inertia. In the first turn, the flying machine made an active lean to maintain balance. But in the second turn, it swung out as it would naturally do in real life. Just within a couple seconds of each other, the world of this movie contradicts itself.
Under normal conditions, when watching this film you are not analyzing the rules of its universe. You are only following the story and watching the action. If things are consistent or they make sense to the story, we normally accept it. Only by looking for them and observing the film do you find out certain “rules” of way things work. Some of these are specific to the story while others may be there only for consistency. Either way, the physics of the film's world play an important part in the movie watching experience.
My first hypothesis has to do with the air resistance in the world of the movie. I call it the “Power of the Air” hypothesis. In terms of our physical world, air resistance is dependent upon the size of an object and its speed. The larger the size or greater the speed, the more resistance there is. In this movie, we are dealing with chickens. They are not very large and they don't travel at fast speeds, but the way they move through the movie's world is a little different from the real world.
At the end of the movie, the chickens make a flying machine in order to escape the chicken camp. This machine uses a flapping motion to keep it suspended in the air. Judging by several clues in the film, it carries about fifty chickens. I estimate that each chicken weighs about five pounds. Also, during a certain part of the sequence, the aircraft carries an adult woman as well. In order for this machine to work, it would have to be very light or there would need to be a great amount of air resistance. Even if the chickens were not that heavy, having such a great number of them in the craft shows that it is not light. Also, in other parts of the movie, the same flapping motion is not able to lift the chickens themselves up off the ground. Therefore, the reason the aircraft is able to lift off the ground must be due to air resistance and not weight.
The chicken flying machine would only be able to lift off the ground if the force pushing it off the ground exceeded the force of gravity. There are a couple forces at work in this scene. First is the force of gravity in the world of “Chicken Run”. It is pulling the flying machine down to the ground and keeping it from going into the air. Then there is the force of the wings flapping. The wings exert a force pushing down on the air below them. There is also the force of the air resistance pushing back on the wings. Let's say that the majority of the force used to lift the machine up comes from the wings (as implied by this scene). In total, the estimated weight that the flying machine carries in this scene is about 300 pounds. That means the wings would have to exert a little over that in order to carry the craft upwards. At the same time, the air would have to resist that force with the same magnitude in order for the craft to get off the ground and stay off the ground.
The second hypothesis I want to talk about has to do with the way gravity works in this film. This is the “you don't fall till you're ready” hypothesis. The force of gravity in this film's world is not as strong as in the real world, and it acts a little bit differently. There is a delayed application of the gravitational force. Also, it is not as strong as in the natural world. It is counteracted by the air resistance principle I talked about before.
Let's look at a shot from the opening scene of the movie. The chickens are trying various ways to escape. One method they use is to disguise themselves as Mrs. Tweedy, the farm warden, and walk out of the camp on stilts. The two guard dogs see them and knock them down to the ground. In this shot, the chickens are hit off of two stilts. They take a moment in the air to be launched up and then fall to the ground at somewhat of a constant speed. A couple things might be concluded from this observation. One way to look at it is that the force of gravity is not very strong. It takes a lot more time for its force to counteract the upwards force of an object and even more time to accelerate that object downwards. Another way of looking at this example is that the chickens reached terminal velocity very quickly and maintained a constant speed down because of the powerful air resistance and weaker force of gravity.
Some other instances of this occurring are when the chickens are being trained by Rocky. He has them do a series of different exercises. In one of these the chickens spring off a trampoline into the air and fall back down. There is considerable hang time in the air once they have been launched and then they fall quickly back down. There are numerous examples of the chickens flying or jumping or falling through the air like this. There is also a scene in which one of the chickens knocks an R.A.F. medal out of another's hand and it flies through the air. Normally this kind of action would complete in a second or two, but the whole path of the medal through the air till it falls to the ground is about six seconds. These examples show how the force of gravity is weak and it takes a long time to act on an object in the air.
There are certain exceptions when an object is in the air in which it acts differently than normal (the first two hypotheses). When an object is launched, catapulted, or shot into the air by an active force such as a canon or slingshot, it does not follow a parabolic arc. In normal actions such as the character or object falling, they usually follow a parabolic arc. However, in certain circumstances such as when Rocky is shot out of a canon or Babs is flung out by a slingshot, these normal physical rules don't apply.
When Ginger first meets Rocky, he is flying through the air. In the first couple shots, he is traveling in a straight line. Then he hits a wind vane, bounces off of telephone wires, and travels in a diagonal path of motion to land in the chicken feed. In none of these actions or motions does he follow a parabolic arc, and hardly does he travel in any arcs at all. Then in the scene in which Babs is launched by a slingshot, she travels in a straight line as she leaves the cart and flies through the air. She doesn't fall to the ground until after she is redirected by the fence and lands on the rats.
In both of these scenes the character doesn't fall to the ground until after colliding and bouncing off of another object. They both travel initially in a straight line and hold it until being acted upon by an outside force. What can be suggested from these observations is that an active force such as a slingshot or canon causes objects to travel in a straight line or path of action. The force of gravity seems to have a delayed effect in other cases, but here it is not involved at all. Gravity does not act on such a catapulted object until it is first acted upon by an outside force, such as a wall, fence, or other object to collide with.
Another aspect of the universe of “Chicken Run” has to do with balance and the line of gravity. This observation is not so much a hypothesis, because it is an example of an inconsistent way things work in this film. In the end of the movie when the chickens have built their flying machine, they are taking off to leave. However, unfortunate for them, Mr. Tweedy comes and knocks down their ramp. They will crash into the fence if they continue their course, so they must make a turn. Fowler, the pilot, makes a hard turn to the right to turn the craft around. What the flying machine does is lean into the turn. This is an active pitch, and an example of the machine participating in active balance. The whole flying machine leans into the turn to maintain balance and lean with the line of gravity.
This would not be physically possible in reality. After making that turn, the flying machine turns around again at the end of the runway to make a second attempt. This time, however, the machine leans outward, with the force of the turn. This is a passive turn, the whole craft continuing in its path with inertia. In the first turn, the flying machine made an active lean to maintain balance. But in the second turn, it swung out as it would naturally do in real life. Just within a couple seconds of each other, the world of this movie contradicts itself.
Under normal conditions, when watching this film you are not analyzing the rules of its universe. You are only following the story and watching the action. If things are consistent or they make sense to the story, we normally accept it. Only by looking for them and observing the film do you find out certain “rules” of way things work. Some of these are specific to the story while others may be there only for consistency. Either way, the physics of the film's world play an important part in the movie watching experience.
Sunday, March 4, 2012
Outline of First Paper
Movie: Chicken Run (2000)
Intro- fun movie. Story themed around idea of chickens trying to fly. Many physical and environmental factors surrounding characters. The interaction between the characters and their physical environment plays a key part in the movie.
Hypothesis 1: Power of the Air
In this world, there is significant air resistance. Air resistance can suspend objects in the air, and decrease the effect gravity has.
Ex: the flying machine at the end of the movie.
Air resistance was used by wings to carry the craft through the air. Air craft was heavy.
The flying machine was also able to hold up an adult woman in the air.
Ex: when the guard dogs attack the chickens on stilts,
Hypothesis 2: You don’t fall till you’re ready
There is a delayed application of gravity. The force of gravity is not strong. It is counteracted by air resistance and it takes a while for gravity’s force to start pulling an object down.
Ex: The first time the chickens are in training, learning how to fly. The medallion that was hurled through the air. Chickens falling from being hit by guard dogs.
All these examples show how there is a time of hanging in the air. There is not a consistent rate at which objects fall back down after flying upwards.
Hypothesis 3: When an object is launched, catapulted, or shot into the air by a force such as a canon or slingshot, it does not follow a parabolic arc.
Ex: Rocky flying through the sky from a canon. Babs being shot out by a sling shot.
In these two examples, the characters follow a straight or diagonal line of action as they travel through the air. They don’t really fall. Gravity has a low effect of bringing them down. Where is has a delayed effect in other cases, here it seems to not be involved at all.
Hypothesis 4: Gravy is a very powerful force.
Ex. It causes explosions, enormous pressure builds up. The machine is overloaded by the pressure of gravy.
Conclusion- don’t realize the rules of the movie’s universe when watching. It is important to the story, but it is seamless in the world they inhabit.
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