10/28/10 Science Blog

We started out class with what we did yesterday (shining lasers through triangles).

Yesterday for homework we had played a game that had lasers and "light splitters" in it, so we tested that out by pointing the laser at a tip of the triangle. Instead of seeing the laser split in half, we got a line on the table, but only viable when the laser wasn't touching the triangle. After that we shone a flashlight at the triangle, and there was a strange figure. The shadow had a lighter and darker spot with small rainbows on either side. But from different angles, the shadow would change a little bit. When we shone the flashlight though the side instead of the top, the shadow was a dark rectangle and a smaller , bright one inside it.

After doing that, we were told to put the materials away and discussed the ideas and hypotheses.

Someone went to the board and drew a triangle with laser beams bouncing all around in it and two beams coming out. The flashlight discussion started with showing everybody the rainbows would appear. The colors were blue, yellow, red, orange, a bit of purple and green. We talked about why the light would emit a rainbow. one hypothesis was that the lights were getting weaker and weaker and eventually, the weaker light would create the color (defusesion of light). We said the rays were somewhat similar to bouncy balls, but it didn't follow the rule of refraction, so we came up with waves.

We looked at a picture of Newton's experiment that had a white light entering a triangular prism and coming out as a laser. We said some rays bend more than others to create the rainbow because the light was slowing.

Wensday 10-27-10

Today in class we went over the take home quiz. We reviewed how light bends towards the normal when it is travelling through a dense material and bends away from the normal when it goes into a less dense material. We also discussed when our test would be and studysession would be. After that we made an experiment to see where a laser would go if we shined it through a triangular prism. We also learned the definition of the words defuse and propagate their definitions are:

Defuse: When light bounces off an object in all directions.

Propagate: When light leaves a source.

We also discussed some types of light that our eyes can't see. Some off them are x-rays, ultraviolet rays, cosmic rays, gamma rays, and infrared rays.

.

-TJ

A few days ago in science class we learned that this will happen if we shine the laser pointer into a block of water.

Today in class we conducted an experiment to see what would happen if we shined the laser on a glass rectangular prism. We used a pole and a rubber band to keep the laser pointer in place while we shined it onto the rectangular prism. Before we conducted the experiment we developed a hypothesis. my hypothesis was that the laser will bend toward the normal because the prism is more dense than the air.

- Prediction

Period 1

Today in class, we learned more about how light bends. We drew some models of this in class that showed slower light waves and faster light waves.

<-----------This picture is our model of a faster light wave.

This is a picture of our model of a slower light wave. ------------->

Also, we decided that speed is the amount of distance

traveled in a certain amount of time.

Then, we watched a video on when you attach two slinkies together and then you shine a light

through the slinkies. I predicted that when the light meets where the two slinkies meet together, there will be some sort of shock or the light will stop for a second. We also decided that when it meets from less dense to more dense, the light will become faster, and when it goes from more dense to less dense, it will become slower. When we actually watched the video, as soon as the light reached where the slinkies met, the light bounced back, then finished. Here's the model we came up with for this.

This proved that my prediction was not confirmed because instead of stopping for a second, it bounced back, then started up again.

-E.P.

Period 1 Blog

We started our class by Looking at our Homework. Our Homework assignment was to answer this question "What is it like to walk through air, water, quicksand, and wall? And why?"

Now we're discussing what a particle is. A particle is small, tiny, microscopic things.

The reason we need to know what a particle is, is because in air, water, quicksand, and the wall there are particles. This can help us figure out how it's like to walk through these items.

We can't walk through a wall because it has too many particles and less space, so you cant walk through.

The difference from walking through air and water is, water will take longer then walking trough air.

Hypothesis: The light slows down as it hits the water, thus causing it to bend and change its direction.

-Francesca

Period 1 10/20/10 Blog!!

Today in class...

First, we took attendance.


Next, Finley checked the homework. Our homework was to re-watch the video we saw in class. In the video, there is a laser. A block filled with water and nothing else is held up to the laser. When the laser hits the side of the block, the line no longer remains straight. Instead, the ray bends. Here is a link to the video: http://paer.rutgers.edu/pt3/movies/refraction.mov



We had to look for and discuss patterns:


Observations we made about the video-

• when the light hit the block it was no longer straight


• a faint ray was following the law of reflection and bounced off the block side


• some thought the light should not bend, but go straight

Did this activity follow the bouncy ball model (when the light hits an object, it bounces off at the same angle that it was shown) ? Why or why not? Why is the light doing this?

The light could slow down.

To figure this out, a student ran at Fin. When he approached Fin, he slowed down and tried to avoid him. When the collided, Fin pushed the student back.

Another example we used was if there was a bouncy ball launcher aimed at the water, and the water is pushing up, the ball would bounce back up and change paths. Although it should get pushed up, bounce off the water at equal angles (which it does a little bit), completely stop, go straight down in an unchanged path, or go down but get pushed up slightly, the ball actually got pushed down and rose back up.

The bending of the light inside the water and outside of the water are the same because it goes down and back up at the same angle. Why might this be happening?

Maybe water bends light because there could be some particles that change the light or the water could be more dense and is doing something to the light.

The light reflects off, but the bent line is not bouncing off at the same angle. So, part of this experiment works with the model, and part doesn't.

For homework tonight we have to compare these 4 scenarios: What is it like for YOU to walk through these things?

1. Air
2. Water
3. Quicksand
4. Wall

My advice for understanding today's lesson! For starters, the important thing we thought about today was why the light did what it did when hitting the water block. Finding the reason why is the hardest part. To figure it out, we have to consider the materials being used and all the different variables that are in play. If we combine new and old things we've learned, we can figure this out.

?

As for the homework, think about the density of the different items. Try to find a pattern by picturing yourself walking through the substances.


Hope this helps!

KV

10/19/10 Period 1

Today we reviewed what we did in class and for homework on Friday and the worksheet for Monday; the target practice. On Friday we went over what were some objects that were transparent, opaque and translucent

Transparent: some examples are windows, beaker and a petri dish

Opaque:floor, table, wall or a person.

Translucent: fishtank

AR

Period 1, with Sub

We read a reading about Huygens Vs. Newton in the fight for light and particles. The worksheet we did was drawing laser rays to a mirror, to targets. Also drawing reflections to the targets from other objects. Then we had to draw a ray to a mirror into Kenny's eyes. :) Sorry Kenny, we do still love you.

-Danielle, i hope i don't have to blog tomorrow :p

We had a sub. We had a pop quiz. Ask Mr. Finley for it. That is all!

October 12, 2010 Lasers and Reflections (Period 1)

Today we started with more trials of our experiment of seeing if lasers reflect off of the mirror at the same angle as they were shot. We needed to make a prediction on what would happen when the laser was shot through the protractor onto to the mirror and see where it reflected. Hleb, Thomas, and I came up with the prediction that the laser should reflect off of the mirror at the same angle as the laser was shot. After doing 8 trials with the mirror and protactor we determined that when the laser is shot through the protractor it reflected off the mirror at the same angle that they were shot at. When shot at 10 degrees, the laser was reflected at 10 degrees. When the laser was shot at 20 degrees. it reflected at 20 degrees and so on. These experiments lead to the confirmation of our hypothesis that lasers reflect off of a mirror at the same angle as they were shot.

(A picture of what I saw when I shot the laser through the protractor onto the mirror)



Later, Finley talked to us about a couple of things on our lab reports. Remember that there are no claculations necessary for today's lab. Then we talked about uncertainty, which is one half of the smallest increment, something else to think about for taday's lab report.

We walked out of class today with a proven hypothesis of lasers reflect off of a mirror at the same angle as they are shot and some things to consider for our lab reports tonight with uncertainty and no calculations.

KS

October 11, 2010 - Playing with Lasers and Mirrors [ Period 1 ]

Today, we first started off by taking attendence. Then, we got started on the experiment. Our main question: "When a laser hits off the mirror, is angle A and B equivilent? We began to find out. Students experimented with a laser and mirror (most of which, were using a protractor too.) to see what happens when a laser bounces off a mirror/protracter, and to test their hypothesis. Of course the protractor was clear. I noticed a group of people were testing with the fish tank It appears as if when they put the mirror behind the fish tank, and point the laser to it, the laser kind of goes into an angle. If I draw a picture, you might have a better understanding of what I am talking about. It is what I saw.


People, though, were playing and being somewhat foolish with lasers and pointing them to the wall and ceiling. Now this may be off topic, but, when the laser hit the ceiling light, the light spread out. As in, the one point would show, but then a glow of light would with a clearer red (kind of like transparency, you could still see the ceiling light) than the one point. This only went for when the lights were turn off. Our subsitute said we should do at least three trials, which most groups did, and we gave a little time for the people who didn't do three trials. When we turned the lights on, people began to write up what they saw, and gave back all the lasers and mirrors.


Tables discussed their hypothesis together, which caused some heated discussions at some tables. Afterwards, we discussed as a whole class if the statement was true, that laser A and B were notequivilent. A couple of groups thought no, they are not equivilent. At the end, groups wrote up their conculsions in their own opinion, but help from their groups.


Fun fact: Did you know that the laser was invented in New Providence? I bet you didn't. Our morning substitute was just so awesome to let us on this fun fact.


CP

Lasers and Mirrors -Period 1

Today in class we discussed our homework which was how an image would look in the back of your eye. We drew a ray diagram and we saw that all rays cross right as they go into the pupil, which was just like our cardboard experiment. The light rays, instead of crossing at the whole in the cardboard, cross at the pupil. The other part of our homework was how does your brain process the image and we learned that in the brain, the image gets flipped so that we see it right side up.

We also discussed why different colors affect the laser. We cam to the conclusion that some colors absorb more light and some colors reflect more. But then we had an idea. What does the light look like on different surfaces? So we got a mirror to see what would happen with the laser on it. My group saw that you can see the light in the mirror but you could also see it on some other object just as clearly because the light is reflected off of the mirror. Conor also had a good idea. His idea was that i you point the laser at a 35 degree angle onto the mirror, it will reflect off at a 35 degree angle so that the two angle would be congruent. The Finley told us that even though our hypothesis worked with a flat mirror, will it work with a curved mirror? Finley had another question for us which was does the laser hit more that one point on the mirror? Yolanda had a good idea that if we hit the laser at any point on the curved mirror, that it would work just like a flat mirror and reflect the laser off at the same angle just like a flat mirror. We all eventually agreed on that and Finley also told us that the laser only hits one place on the mirror. After that Finley gave us a new vocabulary word, normal. He said that the normal is perpendicular to the line that the laser is reflecting off of. So our conclusion for the class was that light bounces off of a mirror at the same angle that you pointed the laser, no matter if the mirror is flat or curved.

KM

Period 1

Today in class we light up a candle and put it next to the wall, we drew a ray diagram of where the light was going to go. We drew the rays of where the rays from the candle were going. We wrote on the board that the light went from the candle and went everywhere and it bounced off the wall and towards us. This happend because there was light shining off the wall from the candle that we could see.

Next we had the light and a piece of cardboard, there was a hole in the piece of cardboard. When the candle was shining there was a dot on the wall from the candle through the cardboard. The dot was the image of the candle uside down. We drew up how this happend with the rays from the light. Every table in the class had a different idea of how the candle was upside down when it went through the little hole through the cardboard. We said that the light from the bottom went through the hole and went to the top of the shadow on the wall.

Absorbing Lasers and Experiment Assumptions -Period 1

Today, we pointed lasers at different materials to for different in the way it reflects and if there is a difference, then why. We found out that the walls and floors "cling more too light, and meetal and laminated paper, reflected it more. We then also figured out that the color of the laser piont colored different when it was on a black background and on a white background. We then decided thatthe black absorbed the light. Then we still had to figure out what happened when the laser got pointed on the wall. We decided to come back on that later.

Then Mr. Finley told us that our experiment on Friday had gave data that he had never seen before. We then tried to figure out his assumption that he made.

We made three guesses:

• The size of the light bulb
• We all had the lights on at the same time
• The type of the light bulb

The type of the light bulb did affect the experiment. When we did the experiment again with a normal light bulb the light did spread out everywhere, and ther was no circle on the ceiling. When we used the flood light there was a circle on the ceiling. This makes sense because a flood light is made to send all the light out in one direction.

We then went over the homework. We started by drawing our idea. Ryan went up and drew his idea. His drawing showed the light bulb with a few rays coming out. We then a

sked ourselves what was wrong with Ryan's drawing, if there was anything wrong. We decided that, yes, there was something wrong . There should be an infinite amount of rays coming out of one spot on the light bulb, and an infinite amount of rays coming out of the ligh

t bulb.Then Mr Finley, and the class changed it to the light bulb having an infinite amounts of rays coming out it, and an infinite amount of rays coming out every spot on the light bulb.

We then reminded ourselves

what we did on Friday, which was we tried to find out how many rays came out of one spot on the light bulb. Mr. Finley

also pointed out that if we drew curved lines on our quiz in the near future we would lose points, because we have tested this and know that they are straight. Then we asked ourselves what is happening when we move the cardboard closer to the wa

ll. We decided it became more concentrated. Why is it

more concentrated? Because there is less space for it .

We also got our quizzes back today. We were told that we have to work on our scientific writing a bit more. There are different kinds of letters on your quiz, next to your answers. These correspond with the rubric you can find online under the tab Course Information on Mr Finley's teacher webpage.

DB

Period 1 - Light

For homework last night, we had to design an experiment including a lightbulb, a socket, an exacto knife, a piece of cardboard, and a wall. The three hypotheses we came up with in class were, one ray fans out, the light will spread out everywhere, and it varies for the various bulb strengths. My group decided to test the second hypothesis. We put the light bulb into the socket, and cut a hole in the cardboard with the knife. We turned the light on and put the carboard over it. The results were that the light fanned out. The hypthesis was proved.





During the class discussion, we talked about the results of our experiments. On the white board, Mr. Finley drew how the light fans out through the hole in the carboard. The main points of the discussion were that the the light on the wall is bigger than the hole in the cardboard. The other point that we discussed is that if there were no sides of the cardboard the light will go in all directions. The light will go all of the directions it can reach. Also, light on the wall as the surface gets farther away.

I found this link that explained the concept a little more: http://www.accessexcellence.org/AE/AEC/CC/vision_background.php

TR