Current Event

Name: Nadia

Subject: Science 7B

Teacher: Mrs. Medenica

Date: 30 January 2013

 

Current Event

Link to article: http://lightandcolorinnature.org/2011/10/continuing-press-for-triple-and-quadruple-rainbows/

Title of article: Continuing press for triple and quadruple rainbows

Both a rainbow and a double rainbow are beautiful sights, but a German photographer has captured both triple and quadruple rainbows. Triple and quadruple rainbows are an extremely rare sight, and there has been only 5 reports on triple rainbows over 250 years and none on quadruple rainbows! In fact, some scientists even think that these rainbows are just a myth. This is because the first and second rainbows are easy to see since they are farther away from the sun, while the third and fourth rainbow are located a lot closer to the sun causing them very difficult and even dangerous to see from the sun's glare. They can only become visible against a background which is darkened by thunderclouds or during very heavy rain. Also scientists found out that even though these rainbows are created the same way as normal rainbows are only the triple rainbow has three internal reflections and quadruple rainbows have four internal reflections.

I found this article very interesting because before I read this article I didn't know that double, triple or quadruple rainbows even existed! I also find it very interesting that scientists can find out information about such rare things. This article is connected to the unit we are studying in class now because we are studying "Sound and Light" and rainbows are made using light. 

Making Waves Lab

Making Waves Lab

Guiding Questions:

1. When water is dropped from a pipette into a pan of water, how does the wave behave?

2. What properties does a mechanical wave have?

3. How do waves interact with each other and with solid objects in their paths?

Hypothesis: (question 3)

I think that waves interact with each other by rolling one after another in a cycle. If there is a solid object in a waves path, if the object is big enough it can stop the wave and cause it to bounce back, but if the object is small then the wave will just continue its way over the object. 

When doing this lab we needed to drop water from a pipette into different parts of a container which was filled with water and see how the wave behaves. Also we needed to see how the cork that was in the container would behave when the waves were caused. Then we put different obstacles/objects into the container to see how the waves would react to them. 

Data Analysis:

I noticed that first when we were just dropping drops of water that the waves always began from the point/points where we dropped the water from and came one after another each farther away from the point where the water dropped and wider than the previous wave. When we dropped the water from two different pipettes the waves made by one drop of water reached the waves made by the other drop they crashed into each other but still continued going with less power than they had before. After this we repeated all this but with a cork to see how it would react to the waves. I noticed that the cork mostly followed the direction of the waves but didn't go very far because the waves didn't have enough power. When we used a paper towel as a barrier, the waves didn't stop but continued under the paper towel. Then, we put one stick of clay into two different positions and I saw the the waves didn't continue after the barrier but went through the gaps between the sides of the tray and the stick of clay. After we did this, we put in two and three sticks of clay each into two different positions and the waves stopped only where the barriers were and went through the gaps between them and the sides of the tray. 

Conclusion: 
In conclusion, I learned that waves become wider and less powerful from the point where they start, that two or more waves can interact with each other when they crashed into each other by entering the area of the other wave and that barriers can stop waves if they are big and dense enough but the wave will keep on going through the gaps between the barriers. I think that my hypothesis for question 3 was correct because this experiment proved that what I thought before doing the lab was correct.

Wave Interface Program:
In this program there is a tap and a pool of water where the water from the tap in dropping. The speed and size of the drops from the tap can be increased and decreased. I noticed that when the size of the drop is big than it creates a larger wave because there is more power in it. Also the waves become more frequent if the more drops of water are dropped. If there are two taps then the waves continue rolling in circles the way they would if there was only one tap and they interact by coming onto the area where the other tap's waves are forming. Also, on this program barriers can be formed which stop the waves from continuing so they can only continue going through the gaps between the barriers.