What objects emit their own light? What objects need a light source to be seen?


Targets
At the end of this unit, you should be able to answer the following questions:

1. Where is light found in our world? (sun, electric lights, objects that glow)

1.1 What objects emit their own light? What objects need a light source to be seen?

1.2 How is looking at the sun or bright light dangerous?
2. How does light interact with other materials?

2.1 How can we use light to classify objects as transparent, translucent, or opaque?

2.2 How do objects create shadow?
3. How does light travel?

3.1 What happens when light hits a surface? (absorbed, reflected, or refracted)

3.2 How can light be broken into colours or combined to make a new colour?

3.3 How do various optical devices work?
Targets
Before you examine what light is or what it can do, consider where light comes from.  These are called sources of light.  Things that are luminescent are considered sources of light, and many of these occur in our world.  Some objects might appear to give light, but they are not actually producing their own light.  In this section, you will identify where the light in our world comes from.