In the morning when the sun shines all around, you are seeing light, which is “a form of energy.” Here on Earth the sun is the most important “natural source of light” for us. There are many other natural sources of light that we might not think about, including fireflies, lightning, and fire. There are also manmade sources of light that we call “artificial light.” Long ago there was no such thing as electricity and people had to use “candles or oil lamps for light.” All around us we see light sources that have been created by electricity. Perhaps you see many around you, including the light cast by your computer screen.
When light travels it moves in waves. These waves travel in “straight lines until they hit an object.” When light hits an object the waves bounce off it. When this happens the process is called “reflection.” If you’ve ever hidden under the covers and read a book with a flashlight, the light will reflect off the pages and into your eyes. Some objects “stop light waves from moving through them” as they are opaque. You’ll see some examples of this and you’ll also find out why shadows are made. You’ll learn about light and transparent materials, translucent materials, how light waves change when passing through some materials (refraction), you’ll get to take a look at rainbows, and you’ll learn about the different colors that light is made up of.
I was quite impressed with the way this book presented the elementary concept of optics, an important part of physics. Each concept was nicely explained in the text and accompanied by photographs that visually explained the concept as well. For example, when reflection was explained children were shown playing ping-pong. The caption said, “Light waves move like ping-pong balls. They bounce off objects and keep moving.” All the captions added a brief informative vignette to assist the young student’s comprehension of the material. This is one in a series of “Exploring Physical Science” books. In the back of the book is an index, a glossary, instructions for making an “Indoor Rainbow,” and additional recommended book and website resources to explore.
Quill says: This is an excellent overview of the science of light for the young student.
