Students should use the resources on the Comparing and Measuring Moving Objects student esheet to help them answer the questions on two Comparing Ways of Seeing student sheets. This sheet provides you with answers to the questions.
Comparing Ways of Seeing: Human Vision
1. Describe the functions of these optical elements:
Cornea: The cornea and the lens is where an object is first viewed.
Iris: The iris is the colored part of the eye. It is an adjustable diaphragm that controls the amount of light that is let into the eye.
Pupil: The pupil is controlled by the iris. When the iris is larger, the pupil gets smaller and less light is let into the eye.
Lens: The lens is a variable focus structure that changes shape as it fine-tunes your vision.
Retina: The retina is an optic nerve bundle that detects the image and translates it into electrical signals.
2. How is focus controlled by the eye?
Focus is controlled by the iris, lens, cornea, and muscle tissue. When the eyes are working properly, the eyes allow you to focus on objects that are close and far away. The lens allows objects to be focused properly.
3. What is refraction?
When light rays reach an angled surface of a different material, refraction causes the light rays to bend. Depending on what kind of lens the light hits, the light rays will bend toward or away from the center.
Functioning like a Camera
1. Match the eye parts to camera parts that perform similar functions.
2. What is myopia?
Myopia is nearsightedness. This condition is when the eye can only focus on objects that are close. Myopia can be caused by an eyeball that is too long or by a cornea with too much curvature.
3. Describe the cause and effects that occur when light passes through the eye.
a. The (iris) acts like the (diaphragm) of the camera, dilating and constricting the pupil to allow more or less (light) into the eye.
b. The (lens) is responsible for (focusing) light into the retina. It changes shape slightly to allow us to change (focus) between objects that are near and those that are (far).
c. The (retina) acts like (film) in a camera. The retina responds to (light rays) hitting it and converts them to electrical signals carried by the (optic nerve) to the brain.
d. The optic nerve is the structure which takes the information from the retina to the (brain), where this information is interpreted as a visual image. The optic nerve consists of a bundle of about one million (nerve fibers).
Comparing Ways of Seeing: Virtual Strike Zones
Look at the Ventura clip
1. How is the delivery of a pitch modeled through animation?
First, the pitch is shown in slow-motion, live action from two different camera angles. Then the same pitch is shown as an animated line that travels through a 3-D box that represents the strike zone.
2. How is the path of the ball shown?
A dotted line simulates the path of the pitch from the pitching mound to the plate. As it crosses the plate, the pitch is shown to be on the inside part of the plate, down in the strike zone.
3. Where do you think the electronic ump is located? How is the angle of the electronic ump different than the angle of a live umpire?
The live umpire is located directly behind the plate. Based on this clip, it is not possible to identify the location of the electronic umpire. The electronic umpire is actually a combination of video cameras and computers. The angle of the second live action pitch appears to be the same angle as the animated rendering of the electronic umpire system.
Note: The actual location of the cameras providing source data for the animation is over the first base and third base lines. The footage taken from these angles is then converted to animation.
4. Is there anything that the electronic ump can’t see from this angle?
The difficulty of using the first and third base angles to record the pitch is that the batter blocks the pitch from the camera’s view just as it crosses the plate. This means that the animation is “projected” rather than identically matched to the path of the ball recorded on the videotape.
Look at the Alfonso clip
1. Compare the two pitches shown on the clip. What makes it more difficult to call each of these pitches a strike or a ball?
In each case, the pitch is moving quickly and curving as it crosses the plate. On the first pitch, the batter backs away from the plate even though the pitch is called a strike. According to the animated replay, the pitch appears to be inside and off the plate.
The speed, angle, and curving motion of the balls as they cross the plate makes it difficult to evaluate when the pitches are balls or strikes.
2. What variables affect the electronic umpire’s ability to evaluate the pitch’s location?
The electronic umpire has to make adjustments for the height of each batter when deciding whether a pitch is a ball or a strike. The fact that the batter blocks the cameras’ view of the ball just as it crosses the plate makes the electronic umpire’s task of judging pitches more difficult.
Look at the Guzman clip
1. Compare what the live umpire saw and what the electronic umpire saw. The batter backs away. Why?
The pitch appeared to be curving towards the batter and he thought it might hit him.
2. Why does the live umpire make the wrong call? What is the pitch doing that makes it difficult to evaluate the pitch?
The pitch is approaching the plate at a fast speed and curves as it crosses the plate, making it difficult to evaluate.
3. Is this animated/simulated version of the path of the ball really accurate? What flaws might be in this system?
It is difficult to evaluate whether the animation is accurate, since the path shown appears somewhat different than the live action version of the pitch. The factors listed above might contribute to errors in the system.
4. One famous scientist who studies the physics of baseball movement says the system is 95% accurate, but that the last 5% is very expensive. This means the system is flawed to some degree. To what extent is it acceptable to live with a system with these flaws?
There are flaws in the human system of umpiring and also flaws in the electronic umpiring system. The degree to which any flaw is “fatal” is something that needs to be determined on a case-by-case basis.
5. Describe these aspects of the pitch shown on the clip:
trajectory: 5” down 4” away
curve: the pitch moves right to left and downward as it crosses the plate
speed: 87 MPH
How Pitch Traxx Works
1. From this description, what are some possible strengths and weaknesses of the design of this system?
Advantages: One possible advantage of the system is that it is electronic in nature and so human error might be lessened. There are multiple devices used to track the path of the ball. The picture that is taken as the ball crosses the plate is a good control to check the accuracy of the call that will be made by the system. Disadvantages: The system eliminates much of the human element that might be needed to review special circumstances (i.e., when a batter crouches to bunt, the system could misread this data). Another disadvantage is that the electronic system is not able to track the path of the ball through the batter’s box. This probably decreases the chances of 100% accuracy. Another possible disadvantage of the system is that the cameras are placed in different locations in each park, which also increases the chances that errors will occur in the evaluations of pitches.
2. What is the purpose of the electronic umpire system?
The purpose of the electronic umpire system is not to replace umpires. Nor is the purpose of the system to second-guess umpire calls during the game or overturn the umpires’ calls. Rather, it provides umpires with an opportunity to evaluate their strike and ball calls after the game.
3. What are some of the difficulties of calling strikes consistently?
One of the hardest things to do is call a pitch a ball or strike when the pitch is passing through different sections of the strike zone, often at very high speeds (i.e., 100 MPH).
4. What kinds of mistakes is the electronic umpire system prone to make?
The variable strike zone may pose unique challenges to the electronic umpire system. The system has to be able to tell when the pitcher has thrown a pitch that is a strike to one batter and a ball to another batter, based on their individual strike zones. Another area that may cause problems is in the 3-4 feet which blocks the camera view of the electronic umpire system. At this point, the system has to “project” the path of the ball and it may not be able to do so consistently.
5. Live umpires are “second-guessed” by fans and players. The umpire will never change the strike call, however. How does the electronic umpire second guess itself, and thereby give itself a chance to correct a bad call?
The picture that is taken just as the ball crosses the plate is a good control mechanism by which the electronic umpire system can “second guess” itself.
6. What pitch characteristics does the electronic umpire system measure?
MPH, break, and location.
7. What are some of the human considerations that have to come into play when considering an electronic umpire system?
In fact, the entire system was designed by a human. The end result of the design cannot be to take the fun out of the game. In other words, absolute perfection is not the goal of a baseball game. The video cameras have to be operated by humans. The projections that are done to predict the ball’s path during the last 3-4 feet also require human assistance.
8. Compare the flaws of a human umpire to an electronic umpire.
The flaws of the human system are inconsistency and possibly vision errors. In addition, the human factor enters into the equation when an umpire has to evaluate a pitch totally objectively. For the electronic umpire system, human error by camera operators also may be part of the process. Algorithms may or may not accurately reflect the curve of the pitch during the last 3-4 feet it travels. The fact that the electronic system is fully animated may create an illusion of perfect analysis, when in fact there is some element of translation and interpretation needed to render those animations.