Journal Entry 12/14

The bus is accelerating at +1 m/s2, which means that its velocity (change in position over a time interval) is increasing by +1 m every second. I know this because I know that acceleration is the change in velocity over a time interval.

If the bus accelerates from the intersection at +1 m/s2, it will be 15 m from the intersection after 5.0 seconds. I know this because due to the acceleration, the change in the velocity is increasing by 1 m each second. Over the first second, the bus moves 1 m. Then over the second second, the bus moves 2 m. Over the third second, the bus moves 3 m. This continues for 5 seconds. These distances add up to 15 m.

Journal Entry 11/22

"Constant velocity" is a term that depicts an unvarying change in the distance an object moves each second. "Constant acceleration" is a term that depicts an unvarying change in the distance an object moves each second over a time interval. As I previously stated, the unvarying change in the distance an object moves each second is its velocity, so constant acceleration is the change in velocity per second. When driving, constant velocity and constant acceleration can be seen. If I drive down a dirt road for 15 miles for one hour, that would be an example of constant velocity because each minute I am traveling 0.25 miles. If I drive down the same dirt road for 15 miles, but travel 0.25 miles in the first minute, 0.50 miles in the second minute, and 0.75 miles in the

third minute, this would be an example of constant acceleration because the velocity is changing constantly over time.

An object cannot have a constant velocity and a constant acceleration because acceleration only occurs when there is a change in velocity.

Car B will reach the end of the 100 m drag strip before Car A. Car B moves a farther distance between each pair of consecutive seconds because its velocity is increasing over those seconds (and velocity is the change in distance over time). If Car B has a constant acceleration of 10 m/s^2, that means that between seconds 0 and 1, it moves 10 m and then between seconds 1 and 2, it moves 20 m. Car A only has a constant velocity which means that it is moving 10 m per second.

Journal Entry 11/30 Continued

Positive and Negative Velocity are determined based on the coordinate system used to describe the movement of an object. If a number line is used, and a ball starts at zero, then movement to the right would be considered to have a positive velocity, while movement to the left would be considered to have a negative velocity. Now if the number line was flipped over with the positive numbers on the left side and the negative numbers on the right side, the balls movement to the the right would still have a positive velocity, while movement to the left would still have a negative velocity. When you decide that movement in one direction is positive, then movement in the opposite direction is negative.

Journal Entry 11/30

1. If an object is said to be moving in one dimension, its position can be determined by one coordinate system (aka a ruler).

2. Because motion is determined in terms of velocity (which takes into consideration the distance traveled and the speed of travel), a change can occur depending on the coordinate axis used to describe it. Practice Page 26 shows this. In coordinate axis A, the car starts at -100 m and moves to 0 m. In coordinate axis C, the car starts at 200 m and moves to 100 m. Although the speeds for both axis are 50, the velocities are 50 m/s and -50 m/s respectively. The cars may be covering the same number of meters, but they are moving in different directions.

3. When an object has a positive velocity, and is in one dimension, it is moving to the right. When an object has a negative velocity, and is in one dimension, it is moving to the left.

Journal Entry 11/16 Continued

I still think that the truck is the reference point for Dan. With my last sentence, however, I was trying to convey the idea that because Dan's car is moving at the same speed as the truck firing the baseball, the ball itself does not appear to be moving. I think my wording was just a bit awkward in the last sentence...sorry.

Journal Entry 11/16

Let's pretend that observer A and B are at the site of the Japanese experiment with the baseball and the truck both moving at 100 km/h. Observer A saw the ball moving and observer B saw the ball not moving and here is the reason why...

Let's call person A: Jen and person B: Dan

Jen hears that her friends are doing a physics experiment at the local race track. She has finished all her homework, so she decides to head over to the track and check out the experiment. Her friend Billy who is in charge of the experiment tells her to take a seat in the stands while he and his friends perform the experiment. Billy and his friends start the car, and they drive it around the track. When it reaches 100 km/ hr, Billy shoots a baseball out of a pitching machine (which is also rotating it 100 km/hr). Jen is amazed by what she sees. The ball whizzes past her and she is truly impressed by Billy's experiment. (Jen's object of reference is the pitching machine)

Billy also told his best bud Dan about the experiment he was performing after school. Dan really wants to see what happens when the ball is shot out of the machine, while the car is moving, so he tries really hard to be on time. Dan forgets his driver's license at home after he leaves the house however, so he has to drive carefully back and get it. Behind schedule, Dan races to the track so that he doesn't miss the experiment. He drives the entire trip at 100 km/hr, even on some of the residential streets between his house and the track. Luckily he doesn't get a ticket. Although he's driving above the speed limit in an attempt to make it to the track on time, the experiment is being performed right as he passes the location. He watches the truck on the track, but the ball does not appear to be moving. After many moments of puzzlement, he realizes that because he is traveling at the same speed as the truck on the track, the ball doesn't appear to be moving. (Dan's object of reference is the truck)

Although a little surprising, both Jen and Dan are correct about the motion of the ball. Based on each of their positions and actions, the ball appears to have different motion. Jen is seated and her object of reference is the ball and the pitching machine. In terms of this machine, the ball is moving at 100 km/hr. Dan is driving pass the track at the same speed as the truck, and his point of reference is that truck. In terms of the truck, the ball does not appear to be moving.

Journal Entry 11/2

Great Debates:
The Moon Landings: All Real or All Lies??

Host (Nicole): Hello and welcome to this weeks installment of Great Debates. Tonight, we will be considering the United States Space Program, and whether or not astronauts actually made it to the moon on July 20, 1969. Our special guest debaters tonight are Bryan and John, two noted scientists. Without further ado, let's get this debate started. Bryan you were the one to initiate this debate because you wanted to discredit NASA. How do you know that astronauts did not land on the moon?

Bryan: Well Nicole, as I'm sure you know, there are at least three aspects of the so-called moon landing that are contradictory. These contradictions are pretty full-proof if I do say so myself.

John: We'll have to see about that.

Nicole: Alright guys, before you get snippy with each other, Bryan what is the first point you would like to bring up?

Bryan: First of all, I would like to point out that in photographs of the supposed moon trip, no stars are visible. The moon is in the solar system, surrounded by stars, but they are surprisingly not seen in these photographs. I wonder how that could be. Actually I do know how that's possible. The moon landings were staged and by a basic human error, no stars were placed in the shots.

John: Bryan you are completely mistaken. If you knew anything about photography, you would realize that your assumption that there was a camera screw-up is wrong. Have you ever thought about how bright the moon actually is? The soil is practically glowing. And on top of this, the astronauts are in completely white suits. As they are standing on the moon, they are reflecting the sun's light from every point. The rays bouncing off of their suits and the soil are entering the camera lens and are preventing the stars from being seen. Imagine a light bulb sitting on a desk in a classroom. If you turned the bulb on, pointed your camera at it and took a picture, how much of the rest of the classroom do you think you would see? Not much, if anything. I'm sure you can understand this example, can't you?

Bryan: Well that may be a possible explanation, but even still, I know the landing was a fake. I have other proof. Don't you worry.

Brian holds up a picture of astronauts, Neil Armstrong and Buzz Aldrin, securing a US flag into the surface of the moon.

Bryan: If you're so sure that the astronauts actually went to the moon, how can you explain the movement of the flag in this picture? You have to know that there's no wind on the moon. What's going on John?

John: That's so simple Bryan. The astronauts themselves are causing the flag to move. Think about how you would put a flag into the ground. You have to twist and turn it so that it goes deep into the soil. The same thing is happening on the moon. Now if you can't come to terms with that, let's say that you decided to go to the park with your family one day. Now let's say that you stand in the middle of field and there is absolutely no wind blowing. It is the calmest day in the history of calm days. Your son and daughter decide to have a race. Your daughter starts to run and her long hair shifts around as if it is being blown by the wind. Don't forget that this is the calmest day in the history of calm days though. Clearly her own movement causes her hair to shift and flap around, as if it was being blown by the breeze.

Bryan: Hmpf. You think you're so smart. Well you're not. Show me some proof, some actual evidence that US astronauts actually went to the moon.

John proceeds to lift a moon rock out of his podium.

Bryan: What's that? Why would you bring a dumb rock to such a sophisticated debate?

John: I'm glad you asked Bryan. For your information this is no ordinary rock. This is a moon rock. Real scientists began extensive studies on these things when they were brought back from the moon by US astronauts. And do you know how we verified that these are not earth rocks? Probably not considering your other arguments. We analyzed their composition and came to see that there are no water molecules in these rocks. If they had been from Earth, there would be water molecules in them. Seriously Bryan, you should have done better research before coming on this show and embarrassing yourself.

Bryan storms off in a fit of anger and embarrassment.

Nicole: Well viewers, I hope you enjoyed today's episode of Great Debates. It certainly was interesting! Tune in next week for another Great Debate!

*** When you're looking at this Mr. D'Amato just keep in mind that I was not in class today. I looked at all the resources you provided and tried my best! ***

• The software I used to create this picture is "Paint".
• And honestly, the hardest part of drawing this was making the center and focal point darks circular. I don't use the "Paint" program that frequently, so I haven't mastered the manipulation of its tools. With a little more practice, I think my drawings could reach new levels.
  

PS: If this is too hard to read, let me know and I will print you a copy and give it to you in class.

Journal Entry 10/19

I would agree with Spud in so much as that an image of the orange is visible in the mirror, but it is not on the surface of the mirror. Through experiments and discussions in class I have learned that the location of the image is real, and behind the mirror, but the image itself is not on the surface of the mirror. In order to prove this to Spud, I would place an orange on the floor in front of the mirror. Then I would ask four people in the class to volunteer. I would give each person a ruler and ask them to place the ruler on the floor, pointed at the spot at which they see the orange. Each person would place their ruler in a different location, pointed at a different spot on the mirror, but towards a similar spot. I would then lift the mirror away and continue the line of each ruler with a line drawn with chalk. These lines would all meet at one point, which represents the location of the image. Linda's ideas about the image are wrong. In order to convince Linda that she is mistaken in her beliefs about the image, I would perform the same experiment as before, in front of her. I would place the orange in front of the mirror and then ask for four volunteers. I would give each volunteer a ruler and tell them to place the ruler on the floor, pointing at the image of the orange. If Linda was right, all of the rulers would be directed at the same point on the surface of the mirror. They would not be however. Each person sees the object from a different spot so when they direct their ruler it hits the surface in a different spot.

History of Discovery in Light and Vision

1. Euclid was an ancient Greek most noted for his contributions to geometry. He did contribute much to physics and light as well however. Euclid built off of Empedocles ideas and had the single greatest break through in light and vision history. He asked the question, Why do objects that are far seem so much smaller than they actually are? Through his studies, Euclid determined taht rays from the eyes must follow straight lines; rays of light travel in straight lines.

2. Empedocles was a Sicilian philosopher, doctor, and poet. He believed that we see objects because light streams out of our eyes towards them. An interesting story about Empedocles is that he threw himself into the volcano a Mount Etna in Sicily, in an attempt to prove that he was immortal. Unfortunately for Empedocles however, he was not immortal, and he died.

3. When Sicily fell to the rule of Islam, Islamic scholars translated, edited, and debated the optical and light ideas of the Greeks. al-Haytham was one of the leading scholars who worked with the ideas of the Greeks. He ultimately discovered how light and vision worked. He worked for al-Hakim, a powerful lord who encouraged learning because he wanted to control everything. He ordered al-Haytham to stop the Nile from flooding. But al-Haytham knew that this was impossible, so he pretened to be crazy to get out of the task. It didn't work however; he was thrown into jail. While in captivity, he bcame obsessed with light and dark. He refuted Empedocles ideas that rays come out of the human eye, because he realized that when he stared at the sun, his eyes hurt. This would not happen if rays came from the eyes. While in jail he studied light with the help of mirrors, and realized that light bounces like a ball. He said that rays travel through space in straight lines to our eyes. He ultimately estblished the laws of reflection and refraction. al-Haytham's works inspired future scientists like Roger Bacon, who built off his ideas about vision.

4. Roger Bacon was a 13th Century Fransiscan Friar who studied the al-Haytham's works. He studied the effect of light on glass and colors. He had a breakthrough when he realized that curved glassses can change the appearance of objects. This led to enhancement in spectacles. Roger Bacon was also obsessed with the rainbow, but his obsession borders on heresy. The rainbow represents an intense relationship between believers and god, and Bacon's work to replicate rainbows angered many religious people. Bacon was able to explain the miracle of the rainbow through natural law. He figured out that rainbows are a result of reflection and refraction in individual droplets of water. This discovery was religious suicide for Bacon. he was exiled for his works and placed in closed confinement in Paris.

"Light Fantastic" Movie Review

"Light Fantastic" was one of the best movies I've watched in school. I thought that Simon Schaffer was an exemplary host, who succeeded in providing the viewers with knowledge while bringing his own personality to the screen. I think what I liked the most about this film was the connection of both science and history; the physics behind light and the social impacts of light were represented simultaneously. I had never know that Impetecles, a Sicilian philosopher, doctor, and poet, was the first man to really contemplate the meaning of light, but learning of his discoveries was really interesting. Impetecles believed taht we see objects because light streams out of our eyes toward them. This idea probably seemed logical during the time of the Ancient Greeks, and even though it is not completely accurate, it was a great bounce point for future scientists to build off of. I think the best part of the movie began when Simon Schaffer talked about the Islamic takeover of the Greek views. Scholars of Islam translated, edited, and debated the optical and light ideas of the Greeks and Alhowzen (probably spelled wrong) was one of the most influential men in the history of light studies. I think Alhowzen became all the more interesting because I had never heard of him. He is definitely an underappreciated member of the physics community, who deserves a lot of respect. He refuted Impetecles ideas and established his own. Alhowzen discovered that rays travel through space in straight lines to our eyes. As he sat in jail, he studied light and established the laws of reflection and refraction. I thought it was interesting that the Islamic scholars were eager to understand light because it was a link to religion, but the militant Christians wanted it more to empower Europe. They believed taht light equaled divinity. When Simon Schaffer talked about the 13th Century Fransican Friar Roger Bacon, he did a superb job linking science and religion. Bacon was obsessed with the rainbow and he was able to explain this miracle through natural laws. His dedication to his field was religioius suicide; he was exiled to Paris for his works. During this segment of the film, I learned that rainbows are a result of reflection and refraction in individual droplets of water. This was extremely interesting because the awesomeness of the rainbow became more apparent. Overall, I would highly reccomend this film. I thought that the entire presentation was exceptional, and it really substantiated the light ray! I hope we continue to watch this film in class.

Good choice Mr. D'Amato!

Journal Entry 9/28 continued again

In a final attempt to understand the mystery of this scenerio, I turned to my notes. I think that the landscape does not appear because of diffuse reflection. A disturbance to the pond causes the surface to be rough and bumpy, which means that at each point, the normal line points in a different direction. This means that even if the rays that enter the water are parallel, they will be reflected in different directions. As a result of diffuse reflection, there aren't enough reflected rays concentrated in one direction, so no image appears on the surface of the pond.

Journal Entry 10/5

Conclusion To Today's Lab: To find the distance between the initial ray and the refracted ray, I used the trigonometric tool, SOH CAH TOA. I knew the distance between the wall and the laser adn the angle, after using Snell's law. Our equation was: tan 11.22 = x/670.56. When we solved for x, we got 133 cm. However, when we actually measured the distance between the two rays we got 126 cm. We then calculated our margin of error, again using SOH CAH TOA This time we knew the base of the triangle and the side and wanted to find the angle. Our equation was: arctan (126/670.56) = x. X equaled 10.64. This meant that our measurement of 11.22 degrees was off by 0.58 degrees. Looking at the protractor however, we concluded that a more precise measurement could not have been produced. Therefore, our measurement is accurate. I forgot to mention that in order to determine where the refracted point would hit the wall, we needed to set up another SOH CAH TOA equation. The triangle led us to the equation: tan 15 = x/61. X equaled 16.34 cm. We shifted the laser 16.34 cm and thus were able to continue the experiment.

Journal Entry 9/28 continued

1. Constant motion does not afford time for a light ray to reflect. When the pond is calm, it acts as a mirror for the rays to reflect off of, but when the water is moving, it is shifting as it is reflecting. Therefore, the reflected rays are being absorbed into the motion of the water, and fail to produce a picture of the landscape. 2. The portion of the spoon that is under water refracts light rays that hit it. Three-quarters of the spoon are underwater so a lot of rays are being refracted. When the refracted rays are all concentrated towards one area, that is the area where the image appears.

Journal Entry 9/28

1. When light reflects off of the water of a calm pond, the incident angle is the same as the reflected angle, with respect to the normal line at that point. If a light ray were to hit a rock at 60 degrees, that rock would then reflect the ray at 60 degrees. The reflected ray would hit the surface of the calm pond at 60 degrees and be reflected once more at 60 degrees. If that same pond was disturbed by a flock of birds, the motion of the water and the figures of the birds would be reflected, as opposed to the landscape of trees and such. 3. Rays reflect off of the handle of the spoon undisturbed (the incident angle is the same as the refracted angle), so when you look at the handle through the side, nothing is changed. In contrast, the rays that hit the surface of the water before touching the spoon experience refraction. When a light ray moves from air to water, it moves away from the normal. Let's say that a ray was entering the water at an angle of 35 degrees. A normal could be created at the point where the ray hits the water. Instead of continuing straight at 35 degrees though, the angle is refracted away from the normal. The refractive index for water is 1.33, and 1 for air, so to find the degree of refraction, you would take the sine inverse of the product of the refractive index for air multiplied by the sine of 35 degrees divided by the refractive index for water. Completion of this calculation results in 25.447 degrees. This means that a light ray entering the water at 35 degrees shifts 25.5 degrees away from its normal, upon entry into the water. The principle of refraction applies to the entire portion of the spoon under the water. As a result of so many refracted light rays, pieces of the spoon look distorted when looking through the side of the cup.

Journal Entry 9/21 continued

Upon further analysis of the article, "The Role of Light to Sight", I realized that light moves in all directions from each point is not mentioned in the article. The idea that rays move from a luminous source to an illuminated object is clear, but there is no discussion as to why every one in a room can see the illuminated object. It is impossible for 50 people to stand in the same place, but regarless of where they are standing, they are all able to see a spot from a laser on the way. This is a result of many rays being projected from te luminous source, then reflected off of the illuminated object, from numerous angles. If the article had discussed this more thoroughly, a better understanding would have ocurred.

Journal Entry 9/21

A. "We are able to see because light from an object can move through space and reach our eyes". This is wrong because light does not move directly from a luminous object to your eye, it is reflected off a surface. I know that an light rays must be reflected off of a surface in order to be seen as a result of the extensive work we did with laser beams. When a laser beam is shot at the wall, the only reason I can see it is because rays within that beam are reflecting off of the wall. If this wasn't the case, I would be able to see the light of the beam in between the laser emitter and the wall. If this sentence said, "We are able to see becasue light from an object moves through space, reflects off some surface, and then reaches our eyes", it would be accurate. I studied the article for about an hour, but I couldn't find anything else wrong with it. Could you give me a hint Mr. D'Amato?

Journal Entry 9/16 continued

I believe that light rays travel in straight lines because of the experiment we performed in class with the light bulb inside of the light proof box, with only a pinhole in it. Once we turned the light bulb on and shut the lights in the class room off, an image of the light bulb appeared on the wall, but it was inverted. The only way for the image to appear like so would be if rays traveled in a straight line from the base on the bulb, throught the pinhole, to the top of the wall, and in a straight line from the top of the bulb, through the pinhole, to the bottome of the wall. If the light rays were curved, they would not have made it through the pinhole as easily, and the inverted image would not have appeared.

Journal Entry 9/16

In a completely dark room, I would not be able to see anything. If no light ray is being projected, nothing is reflecting off any object in the room. Sight is a result of a light ray being reflected off of an object, and therefore without light rays, nothing is seen. Light travels in straight lines because it cuts straight through the air, moving from its point of emission to the point at which it will be reflected. A light ray draws your eye to focus on an object, and illuminates it. You can't see objects in a dark room because no light is being reflected off of said object. The inability to see an object in a dark room, coupled with the ability to see an object in a lighted room shows that you can see an object whena light ray enters your eye. Light rays are sent in all directions from an object because you can see an object from anywhere in a room. When we experimented with the laser, Mr. D'amato could see the laser from the front of the classroom, and I could see it from my desk. This means that the light bulb sent out rays from all directions, and these rays reflected off the wall in an equally large array of directions. p

Journal Entry 9/10

Questions: 1. What is the path of light rays from the laser to the screen? How can you tell? 2. Why can you see the spot on the wall? 3. Where can you stand to see the spot on the wall? What does this mean about the rays reflected from the wall? 4. Why can’t you see the beam of light before it hits the screen? 5. What do you observe when chalk dust is sprinkled in the beam? How can you explain this? 6. Summarize the conditions necessary for you to see something. My Answers: 1. The path of the light rays from the laser are all concentrated in a straight line. There is a single, intense light that shows up in only one spot. 2. The spot of light is visible because the laser being emitted hits the wall and is reflected off of it. 3. You could stand at any spot in ther room and still be able to see the spot on the wall. This means that the rays are being reflected in every direction from the way. 4. The beam of light is not visible before it hits the screen because there is nothing for it to reflect off prior to the screen. 5. When chalk dust is sprinkled on the beam of light, the light becomes visible. This is because the light is being reflected off of the tiny dust particles. 6. In order to see something, light must be reflected off of an object. For example, light rays from a bulb reflect off of your hand and make your hand visible to you.

3.