Using what they know about how light travels and interacts with materials, third graders are completing their last design challenge--trying to get a Lego person to illuminate with just a series of mirrors and everyday materials.  

How does the light bounce off of each mirror?  What happens as the light has to travel a greater distance?  Can the series of mirrors cover the length of a table and get the Lego person to light up brightly?  What happens as the angle of the mirror changes?  

What a great time they had exploring and solidifying their understanding of how light travels and interacts with materials.  Hats off to  you optical engineers!

Why does an apple appear red?  Or a leaf green?  Mrs. Brinza's shirt black?

Third graders are learning about how light is made up of many colors, and appears white to us.  In fact, white light is comprised of all the colors of the rainbow (red-orange-yellow-green-blue-indigo-violet) and when light is passed through a medium, it can break or refract.  This is why we see a rainbow of colors during a rainstorm, because visible light is "breaking" through the water droplets in the air.

Knowing that white light is made of many colors, this helps to explain why we see different colors.  The visible light from the sun is white light.  When it shines to the apple, the red wavelengths bounce off to our eyes, and the apple appears red.  All the other wavelengths of light (orange-yellow-green-blue-indigo-violet) are absorbed.  Why do we see green leaves then?  The green wavelengths are reflected into our eyes, and all the other wavelengths of light are absorbed into the grass (red-orange-yellow-blue-indigo-violet).  When we see the color black, all the wavelengths of light have been absorbed, and when we see the color black, all the wavelengths of light are reflected back into our eyes.  How cool!

Now that third graders have seen how different materials interact with light, they are making claims based on the evidence they gather.  Based on what they see on both walls, they are expanding their scientific vocabulary to provide evidence that support their claims.

Light can...

1.  Be reflected off a surface!  This means light bounces off it.  Technically, anything we see has light reflecting off of it into our eyes.  This enables us to see. 

2.  Be absorbed into a material!  This means that light is soaked up (or blocked from going through).  A shadow is cast on the opposite side of a material because light cannot pass through it.

3.  Be transmitted through a material.  This means that light goes through a material and is not altered in any way.  It continues to travel in a straight line.

Check out the third graders claims and evidence from their walls experiments!  Way to go third grade!

In our introductory activity to our optical engineering unit, third graders are discovering how light can interact with different materials.  Using everyday materials like transparencies, black paper, tissue paper, and mirrors, they are seeing how light can be blocked, bounced off, or go through materials.  We'll be officially defining what these science-based terms are next week!