Thursday, September 30, 2010

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



















Wednesday, September 29, 2010

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






Tuesday, September 28, 2010

Period 2


Today in class we discussed the question, Is the direction light is moving important? So as our hypothesis we decided that light travels in a straight line. Also make sure that when your taking about light you don' say that it goes in a line because a line could wiggle and curve and do all of that good stuff, but light goes in a straight line. We also drew pictures in class today in these pictures To show the light and what direction it was going we used an arrow.

In the diagrams we drew answers to the question Why can we see light? The first picture we came up with is the picture on the top left. That picture shows the laser's light beam coming from the laser and going to the wall. Once it hits the wall the light reflects off the wall and all around the room and in this case it hits the person's eye so then he could see it. So after that we wanted to draw a picture that described how we could see the laser's beam before it reached the wall. That picture is under the top picture.In that picture it shows that when the laser is traveling through the flour cloud it would hit some of the flour particles and then it would reflect off of them and into your eye.
So to conclude our class discussion we did an experiment to see if light reflects in every direction. Our hypothesis was that the light would reflect off the object and hit something else aslong as it had enough power to make it there. During the experiment I shined the lazers at one object that was positioned close to another. When I shined the laser at the object it did reflect off the first object and hit the second. Some of the things I did were that I shined the laser at my paper and it reflected off of that and hit the wall, I shined the laser on my hand and it reflected and hit the poster. I also shined it on the poster and it hit the ceiling.
So at the end of the experiment I concluded that light does reflect off the first object it made contact with and if it has enough power it will hit another object.
-DB

Monday, September 27, 2010

Period 2 - Lasers Experiment

Today we had a major prediction with the lasers;
  • clap flour in the air and shine the laser through it, and see if we can see the beam of the light.

Papi had a good idea, that water slowed the laser down which is true.

Next we turned the lights out and started to clap erasers with the flour all over them. Sasha and I went to the back of the room and started our experiment, then looked in front of me and then I realized that I could see the beam without any flour in the air. After we clapped the flour in the air, I tried to clap the rest out, we saw the beam at the strongest. Sasha and I wrote our observations from the experiment. All in all, some people could see the beam right in front of them, without the flour. Others needed the flour to see. I was not one of the people who needed the flour to see the laser beam.

The most confusing thing about this was probably figuring the experiment out. It wasnt the most challenging experiment, but trying to figure out how to see the beam was hard. Even though we used flour, we could have used a lot of different things.

Jenna G