Today we started out with Finley asking a question, "what would happen if light were to pass through a cube of water, a cube of glass, or a cube of helium?" We had to work and find out what would happen with our groups. After time was up, Fin asked 3 people to go up to the white board and draw out their ideas about the light passing through their assigned cube. The 3 people then sat down and waited for Fin's observation on their drawings. Fin asked other people to explain the drawings, and Fin said that they were all correct. Then he asked why the glass and the water was different. People said that the glass is more dense that water; when it's more dense, it moves toward the normal line. Then, people tried to explain the helium. JP drew that helium is less dense, so the light moves away from the normal line. After the explanations were done, Fin gave us 3 activities. First, he said we were going to experiment wth triangular prisms. We had a normal lazer pointer and a flash light. We had to shine the lights in all directions around the light. But with the flash light, he wanted to shine the flash light going down towards the triangle. We had to obsereve, describe, draw, explain and relate. In the drawings, he wants all the light rays coming out the flash light pic. Finally, we had to take a pen/pencil and put it in a pitcher of water, and draw a pic. of why the ruler was closer; that part was bonus. We then broke into our groups and started the experiment. Right when we start, the fire alarm goes off. The drill only took 3 minutes and we came back in and finally started to work. In my group, we predicted that when we shine the lazer from the top, the lazer will reflect off the sides, and come out the top. When we tested the lazer, our prediction was correct that the lazer would reflect back up, but there were numerous other lazers reflecting out of the triangle. We did a few more tests and recorded our observations. Then the period was over, handed in our materials, and left the room.

WR

We reviewed our hypothesis that light slows down at more dense objects.We also had the hypothesis that light goes towards the normal line when it slows down. We had to talk to our group about our hypothesis. My group(Emily, Claire, Anthony, and I) decided that it will slow down if it goes from a less dense to a more dense material. It was confusing deciding how to test to see if we were right. We concluded that we will take something like water and put a more dense object under it. We will use a protractor to see the angles that they come and go at. Jermey made a good point when he said we should point the laser at the wall with nothing in its way(on an angle), and then put a prism in its way and see how much it bent. I believe that this will be a very good representation for this. We decided to do the experiment multiple times to make sure we have an accurate conclusion. I liked this idea because it will give us an accurate responce. We used a metal rod to keep the laser pointer in place. Then, we marked where the laser was pointing. We then put the prism in its way. We saw it move differently when we move the prism. I think this experiment was a lot easier to set it up and do than I thought. Two points reflected off the prism as well. Only one was on the other side. It went about an inche away from the normal dot. This data supports our hypothesis.

MP

Friday, October 22nd

Our hypothesis from yesterday was that light moves slower in a denser area and faster in a less dense area. We also hypothesized that light is more stretched out when it is fast and it is more condensed when it is slower.

Next, we reviewed the homework from last night. The homework from last night was:

"Construct a prediction of what would happen to a slinky when it moves from a less dense area to a denser area. Then watch the video and say if your hypothesis supports

your prediction."

The video was of a slinky that had 2 parts to it. Half of it was made of a thicker material and the other part was a l

ighter mate

rial. There was a person on both ends of the slinky. First, a person on the right side shook the slinky and the ripple started off very fast, but once it reached the thicker part of the slinky, it slowed down and the ripples became more condensed.

Our prediction was that when the slinky starts off in the less dense area, it should start off straight and then have light, stretched out, ripples. Then when it gets to the denser area, the ripples in the slinky would be more condensed.

The results from the video supported my hypothesis so I may conclude that light travels slower in dense areas and it travels faster in less denser areas. When light travels faster, its waves are more stretched out and when it travels slower, its waves are more condensed.

-J.L.

Friday, October 22nd

Today in science class, we reviewed what we did yesterday first. We discussed the wave model with the slinky and how it moved (the slinky represented light).

fast- more distance

slow- less distance

When light moves faster, it's more stretched out and when it moves slower, it's more condensed.

October 21, 2010

Our hypothesis from yesterday was to answer why light bends. We realized that it bends because the light slows down. Another was our hypothesis from the homework from last night. It was asking how light will bend when it goes from less dense to more dense and more dense to less dense. In class today, we discovered the light will bend towards the normal line when it goes from more density to less density. When it is less to more, the light will slow down and it will bend towards the normal line.

In class, we also observed a container full of water, with playing cards taped to the sides. The bottom had a card, but from above looking down into the container you could see it. When you bend down and look from the side, it was not seen. The 3 of 4 sides had cards too. 2 sides had 2 cards, and 1 side only had 1. When you looked at 2 of the cards, you could only see 1/2 of it at some angles, but looking from the outside, the whole card was visible. You also couldn't see the cards from the outside, on the opposite side of the container.

After that observation was finished, we discovered the meaning of photon. Photon is the 2 ways that light can act. The first way is when light bounces off of a surface. This is called reflection. The other way, refraction, is when light bends. The Particle of Light is another meaning for reflection. It is like when we discovered the mirror experiment last week. The Wave Model of Light is also like refraction. This is the relation of when light slows down or speeds up.

We decided to make the Wave Model. So, we took a long, spring-like slinky and swung it, It looked like this (I could not find a good picture, but this is what was closest):

1 wave =

Refraction:

FAST: If light speeds up, it will look like this:

The wave legnths are closer together.

SLOW: If the light slows down, it will look like this:

The wave legnths are further apart.

Hypothesis of the day: Light moves through its speed and changes.

-A.L.

Period 2 Oct. 20

At the begining of class we talked about how we could walk through air, water, quick sand, and a 4 foot high wall. My group came up with this. For water we thought it would be harder because it is hard to put your foot in. Air it would be easy because we walk through it all the time. Quick sand would be very difficult because it is pulling you down. The wall we thought you could just climb over it since it is only 4 feet high. The class came up with as you go up it gets harder to go through, thenit becomes impossible. Then we talked about particles. We said it would look like a dot with one arrow. The arrow would be the direction and how fast the particle is going. We then drew how many particles would be in each. In the air there were little particles moving fast. Water there were more but moving slower. Quick sand there were also more but it was also moving slower. In the wall there were particles everywhere, and no movement. We can came up with the idea that the reason the water bent when we put water in it, the light literlly slows down. We then looked at a picture of light going into water. When the ray hit the water, some reflected, and some went in and bent. We siad that the bend in the light when it goes into water, it goes towards the normal line. Although when the light comes out of the water in bends away from the normal.
-MM

Mk Period 2 10/19/10

Today in class, we first got back our quiz corrections. Mr. Finley reminded us to look at the syllabus to see what should be included in them. Here is a link to the syllabus: http://www.npsd.k12.nj.us/20222069133223760/blank/browse.asp?A=383&BMDRN=2000&BCOB=0&C=60055

He said the biggest mistake was not including why you were mistaken. The next round of corrections is due a week from today, but Mr.Finley would rather you hand it in as early as possible.

Then Mr. Finley checked in our homework from the last two nights. (The questions on the video and the worksheets from yesterday) Then we went over the sheet. We decided that to correctly answer the question, we have to draw a straight line from the laser to the mirror. Then we measure the angle with our protractor and reproduce the same angle on the other side.

Below is a picture of the correct answers:

The back of the sheet was harder. We modeled it withe EC. She stood two feet away from the mirror. We called her Erin object. We called her reflection Erin Image. We established that because Erin object stood two feet from the mirror, Erin image looks like it is two feet from the mirror. In order to hit Erin object with the mirror, you have to be able to see Erin image. The same thing applies for the guy on our sheet. If Kenny object is where he is in the picture, then Kenny image is the same distance from the mirror. Eric has to be able to see Kenny image in order to hit Kenny. They increased in difficulty.

The correct answers are below

Then we went over two nights ago homework. We watched the video again.

We tried to figure out why it took the path it did. We realized that the rays on either side of the block are parallel. The reason some reflect is in JL's words escaping, is that it is reflecting off a little bit. It is going at the same angle. Some light passes through the block too. The only surprise, the direction changes. When it exited the the block, it went back up in the same amount it came down by.

Our bouncy ball model does not work for this case. The ball would bounce right back up, but the video shows the light go through and bend. A bullet might bend upward though because the water could be pushing it up. But in the video, the light went down

The whole video I thought was pretty confusing. Why does it bend? Why does some light reflect, but not all of it? The other sheets I thought were pretty straightforward. The best advice I could give you is to make sure you would be able to see the image in the mirror in order to hit the object. This will ensure you are accurately aiming. Also remember to draw straight lines, or the angles will be off. Finally remember to use a protractor, don't just eyeball it. Some answers are really close and you don't want to get a question wrong solely based on you forgetting to be accurate.

Mk

10/18/10

Today we had a sub. We started off with attendance. Then we read an article about light and did a work sheet. I'll probably blog again tomorrow.

-Yam

Period 2 October 15, 2010 JB

We changed seats so ask Finley where you sit if you were absent. We taked about analogies. An analogie is comparing things. We found analogies of light bouncing off a mirror. The laser is like a rain drop bounceing off a window, a bullet ricochaing off medal, and a bouncy ball bouncing off the floor. The bouncy ball hits the ground and bounces at the same angle. Another example is a basket ball hitting a backboard. In all of these examples the object goes at one angle, and hits something then, it goes off in the same angle on the other side. These are analogies, real life examples.



The simalarities of these situations are; that they are bouncing at the same angle, the surface changes, and the sources are different.



Some differences are; that they are at a different magnitued, the objects are aventually going to stop going straight and start heading down, they have different speeds, you can see the ball and not the light, they don't always travle in a straight line, and the bounce ball is solid matter, and the light is energy.



When using analogies you need to make sure it fits. For example, you can't use the bounce ball for explaning why we can see the light. A good analogy is a water balloon and how it hits the wall and explodes in every directing. Now were doing an experimeant that involes shinning a light into a beacher with water. We have found out that the laser, when shone through water, gets weaker.


We had a discussion in class on if a laser goes straight through when shone through water, or if it changes paths and bends when shone through water. We had HW to see if lights path changes direction. We have to watch a video and see if our bouncy ball model can explain whats happening.

JB

MA Period 2

Today in Period 2 Science we:
1. Talked about the scattering of light, otherwise known as why we don't see a concentreted reflected ray on some surfaces. The "some surfaces" in class was the wall. The wall was very rough, so we thought that the reason there is no concentrated ray because it was too rough. We also tested this on the mirror and whiteboard, confirming the fact that smooth and polished surfaces reflect a concentrated ray. We also used pond as an example; you can see your reflection in a pond when it is calm, then, when you throw a rock into it (making the surface rough, in a way), you can't see your reflection anymore.
2. However, when you point a laser at a window, which is smooth, it doesn't reflect off. So, we tested different surfaces with the laser to see which different surfaces reflect the laser.
Here's what we tested:
Window: not really, goes through
Wall: doesn't reflect
Glass test tube: not really, kinda goes through it
Plastic test tube: not really, just kinda goes through it
Person's jacket: no
An arm: no
Table: a little bit
Glossy poster: reflects off pretty well
Paper: sort of reflects and scatters at the same time

So, the light and the reflection is affected by the texture of the surface.
It is also affected by the color; for example: the black table, even though it was kinda shiny and flat, only reflected a little bit because the black color is absorbing some of the light.

There is a term for the idea that light can go straight through some surfaces; and that is transparency. This means that light can freely pass through it. An example of this is a glass beaker.
However, there is another term; it is translucent. This means that some light can pass through, but some also light also clearly reflects/absorbs some. An example of this is a window.
Opaque means that the object is solid, such as a shirt or something solid.

MA

Period 2 On 10-13-10 By MA

Hey people!!

So, today we had a sub, so we didn't do much.
But, we did:

1. Took a pop quiz on light
2. Had a word search to do

Ando no HW!

By the way,

Fin said he'd probably push the blogging schedule back a day,

so i'll blog again tomorrow.

MA Period 2

Period 2 10-12-10

Today in class we went over why when you shine the laser, only certain people at a certain angle can see it.

We had half the class stand at the front of the room, and the other half stay in their seats. The mirror was in between the two sections of people. Mr Finley shined the laser at the mirror, and some of the people in the front of the room could not see it. But the people sitting down could. Why so you think this is?

We could not see the laser on the mirror because the angle that the laser was shining at. It was bouncing off the reflective surface to the people who were sitting down.

The dot on the wall bounces off in every direction, but when we shine it at a reflective surface it will bounce off one ray at the same angle as the incident angle.

Don't forget to email Mr. Finley your lab if oyu have not all ready done so.

kk :)

Period 2 10-12-10

Today in class we we went over why when you shine the laser, only certain people at a certain angle can see it.

We had half of the class stand in front of the room, and the other half of the class stayed seated. Mr. finley shined the laser at the mirror, and some of the people in the front of the room could not see it. But the people sitting down could. Why do you think this is?

I think that because the the laser was reflecting off the the mirror and bouncing to the people on the other side of the rooms eyes, and we could not see it. The dot on the wall bounces off in every direction but when u shine it at a reflected surface it will bounce off one ray at the same angle as the incident angle.

Period 2 (10/11)

For all of the period we went over what goes into a lab report and redid any experiments we were unsure about.

Lab Report
What do you want in observations?
--Table of results, descriptions of results, general information (all 2 degrees of my prediction, etc..)
Make sure to include this in the conclusion.
--Claim, evidence, conclusion
**No need to add in curved mirror**
What would our calculations be?
--We didn't calculate anything.
What goes into the background?
--Other light experiments, things leading up to it (path of light and why do we see it(bounced off of different colors better), shone the light against the mirror, can include partner experiment with the background)
**Would be smart to include picture or drawing in results**

Uncertainty—half of the smallest division
This is helpful because when a football isn’t on the line but its half way.
Uncertainty is accurate but not precise.
Uncertainty was present in our experiment because when we measured the degrees, it was probably not exact (range). Include uncertainty in your table. **after some students were still uncertain about uncertainty, Mr. Finley did a quick drawing**

I measure something to be 45 degrees; the smallest increment is 5 degrees. What is the uncertainty?
--We find the uncertainty because it is half of the smallest increment (5/2=2.5)
+2.5 or -2.5

Does shining a laser against a mirror and it hits the opposite wall prove our hypothesis?

Law of Reflection= definitely proven
But nothing in science is proven?
--Many experiments were made, so many that it could no way be disproved.

Why can we see a dot on the mirror?
--The point on the mirror is an end point and reflects. It means that a new ray is started. (the end of one ray is also the starting point of another ray)
--The ray that hits the mirror is the strongest.

JF

Period 2 10/11/2010

Lab Report

What do you want in observations?

--Table of results, descriptions of results, general information(all 2 degrees of my prediction,etc..)

Make sure to include this in the conclusion.

--Claim,evidence,conclusion

**No need to add in curved mirror**

What would our calculations be?

--We didn't calculate anything.

What goes into the background?

--Other ligth experiemints,things leading up to it (path of light and why do we see it(bounced off of different colors better), shone the ligth against the mirror, )

**Would be smart to include picture or drawing in results**

Lasers and Light- period 2

Today we learned about how the laser reflects off of a curved mirror. How would the laser travel? The protractor has a invisible normal line, also known as 90 degrees. The formula we followed was m
Our procedures for finding the reflective ray is:

1. Place a mirror on a flat surface.

2. Put the protractor perpendicular to the mirror.

3. Shine the lazer at the mirror through the protector, perpendicular to the mirror.

4. Point the incident ray at the mirror through the protractor to get a reflective ray.

5. Repeat by starting at 10 degrees and increase by 10 degrees until you hit 90 degrees.

This was my prediction for:

10 degrees- 10 degrees

20 degrees- 20 degrees

30 degrees- 32 degrees

40 degrees- 40 degrees

50 degrees- 55 degrees

60 degrees- 63 degrees

70 degrees- 71 degrees

80 degrees- 87 degrees

90 degrees- 90 degrees



Our class data was for the actual measurement:

10 degrees- 12 degrees

20 degrees- 21 degrees

30 degrees- 30 degrees

40 degrees- 41 degrees

50 degrees- 52 degrees

60 degrees- 61 degrees

70 degrees- 70 degrees

80 degrees- 79 degrees

90 degrees- 90 degrees



S.D

Period 2

Today we went over what we did Friday and Friday's homework. We talked about what the possible outcomes were for the light going through the cardboard cut-out onto the wall. We came up with a hypothesis that it could travel in a straight line and cause the same size of the cut-out on the wall. Also, we concluded that it could fan out or just go everywhere. We found out that with just a single cut-out held against the light bulb that it goes everywhere.

Then, we visited the blog website to see how we could get to our period's blogs to see what are classmates said.

Next, we went back to Friday's homework to see how the image of the triangle cut-out got sharper as it got closer to the wall. One suggestion was that the reflection off the wall of the triangle caused the cut-out to get sharper as it got closer. We showed on the white board that one point on a single light bulb doesn't just have one ray but infinity.

Another suggestion of how the light causes the triangle cut-out to get sharper was that the light couldn't fan out once it it the cardboard which caused the triangle.

Afterwards, we went over why the candle light caused the light on the other side of the card board cut-out to appear upside down on the wall. We came up with that the rays from the candle that go through the cut-out cross each other to form itself upside down on the wall. Everything else is blocked and doesn't affect the appearance.

Today was just a review of Friday for the few people that were absent.

BB

Period 2 - Light

We needed to design an experiment for how much light can come out of one spot of a light bulb. Our materials were a knife, a light, a wall, and a piece of cardboard. We decided to cut a small hole in the cardboard, and clean it up. Then place the cardboard on the light and shine it at a wall/ roof. We would then be able to see the amount of light the comes from the one spot.



We had many ideas about how much light would come through. Some people thought 1 beam, 5 beams, 1,000 beams, 10,000 beams, 1,000,000 beams, or infinity. We believed that we would see a circle on the roof a little bigger than the cut we made in the cardboard. We thought this because the light would spread out as it came out.

As it turned out it lit up everything in a blur rather than a single focused light. It was not the circle I thought I would see. The only way we could tell any light was getting through was by holding our hand above the light to see shadows.

The light from one spot is not one single beam. It covered the whole roof. If it were one beam it would be just a dot. It was a blob covering everything. It did not slightly fan out because otherwise it would just be a circle bigger than the hole. We as a class have to agree that an infinite number of beams got through.

Towards the end of class Mr. Finley presented us with two problems to solve. The second of the two I can only guess at. The 1st is easier to understand.
1. Why when you hold the triangle there does the triangle show up and not become a blob?
I believe this happens because further from the bulb there are less beams crowded together going in all directions. This allows beams to go straight through. If they were at different angles the triangle would be distorted.
2. Why is the flame upside down.
JP

Period 2 - Light

For homework, our job was to draw pictures of ray diagrams. We had to draw a picture of someone looking at a puppy, watching a movie in a theater, and looking at your reflection in a lake.

• 
  
  Looking at a puppy - When we drew these pictures on the board, we drew a lot of arrows going to the dog and from the dog to your eye. It shows how the sun lights up the dog allowing our eye to see the dog's shape and the colors







• Watching a movie - The light is going to the movie and then back to your eye and detecting the color.







• Looking at your reflection - The arrows would bounce off the lake and the person and that would cause the lake to reflect your shape.

Why do our eyes hurt when we look at the sun?

Ideas

• Our eyes absorb the light and there is too much of it for our eyes to take





• The rays aren't bouncing off anything first to go to your eye





• Our eyes are adjusted to a certain amount of light so when we look at that light it's too bright.





• The sun's light is too strong





• It doesn't hurt our eyes when we look straight because the sun's rays are bouncing off things until it gets to your eye, so by then it isn't as strong.

Testing Experiment

Does light shine stronger when it hits different colors?

My group tested 4 colors - Pink, black, white, and clear

- We noticed that white and pink made the light shine the strongest, it was a bigger light. The black was the smallest light where it was just a little dot. The clear color made it big, but it was also kind of a fuzzy light almost as if it were faded.

We discussed that darker colors tend to absorb more light and lighter colors reflect more light. That is why they say if you wear a black t-shirt in the summer you will feel hotter because you are absorbing more heat from the sun.

How many rays come off a light bulb?

Ideas - - - -> -10,000 rays.........1,000,000 rays......1 ray......5 rays........infinity...

Which direction do the rays go?

1. Straight line





2. Fanned out





3. Everywhere

>>>>Conclusions<<<<

1. Light looks different on certain colors because the colors absorb them differently





2. There can be a number of rays in a light bulb





3. The sun's rays are too strong for our eyes to take, causing our eyes to hurt when we look directly at it

EE

Period 2 - Light Movie

Today, we watched a movie on light and how Harvard students underdatand what we are learning about right now. There was an idea:



Imagine you see yourself in a mirror. If you wanted to see your whole body in the mirror, would you walk backwards or forwards?



Just about everyone in the movie and in our class agreed you need to move back, which ended up being correct. Just like the movie pointed out, no one really thinks about a mirror, but instead uses one everyday.



Two students think that if they were in a totally dark room, objects lose their color when we look at them, but we can see their shapes. It is true that people don't really understand the circumstances because no one has really been in the situation where there was absolutely no light. As the room is still dark, they both think that after four or five minutes they will be able to see. However, after six minutes, they still can't see.



Main Points Of Video:



-To show that most people still think they can see in the dark. It is a common belief.

-To teach us how to work in a group and help us respect people's ideas.

-You need to test many ideas because you can never be sure until you test it.

-They already have their own ideas about what their discussing and they probably still think they have some supporting evidence.

-We have to be careful of bias. Biases are kind of leaning on one idea and not giving two ideas a main point. This is sometimes because of past assumptions.

-The assumptions in this experiment was that when people thought they had past experiences of complete darkness, when really, there was just a little bit of light to guide them.

-Always disprove hypthesis when testing.



*Lines that represent light are arrows and are straight lines.



Why do we see the apple in light?



Ideas:



-Colors of apples reflect off eyes.

-Light reflects off eyes.

-Eyes detect color.

-Our eyes detect shapes as well.


The above are the things we learned in class. This was important because we learned further information on what we have been learning about in this unit. We did the same experiment that the two seventh graders in the video did, so this movie was really relatable. It made everyone thoroughly understand this experiment and what occurs when we are in complete darkness.


For the past couple of days, we have used lasers as our light source and tested how they work in different circumstances. We use laser pointers like the one below to conduct our experiment:




Experiment <--- website.

Thanks for reading! Hope you learned a lot!


EC