1. The History of Light & Optics
Lesson 1 - The Histroy of Light & Optics
The History of Light & Optics

2. What do we Know? What things do you know about “Light” all ready?
What can you tell me about the properties of light?

3. History of Light
In groups, open up the Science in Action 8 textbooks to page
As we read through the next couple of pages, think about how our knowledge of light has evolved and how this has lead to new discoveries in our present day?

4. Pythagoras Theory
Pythagoreans believed that light came from our eyes and that where we looked dictated where light was and what we could see.
WHY WAS THIS OBVIOUSLY NOT THE CASE?

5. Pythagoras Theory
Pythagoreans believed that light came from our eyes and that where we looked dictated where light was and what we could see.
WHY WAS THIS OBVIOUSLY NOT THE CASE?
This theory was obviously wrong because then why couldn’t we see in the dark

6. Euclid’s & Ptolemy
Euclid suggested that light traveled in a straight line… beams of light
Ptolemy described how light would bend when it travelled from objects of different densities (i.e. from air to glass)

7. Haytham & Newton
Al – Haytham figured out that it was our eyes that absorbed light that was reflected off of objects to them so that we could see
Newton was able to show how white light was a mixture of several different colors of light

8. Galileo & Michelson
Galileo was interested in optical devices such as the telescope. He made several discoveries in astronomy as he fine-tuned and improved upon his telescopes.
Michelson was able to figure out the speed of light. He did this by placing two mirrors on two different mountain tops and timing how long it took for light to travel back and forth.

9. Your Assignment
Again, In groups, open up the Science in Action 8 Textbooks to page 181
In a small group discussion… please answer the “Check & Reflect” questions on that page.
We will go over these questions as a class in 5 minutes.

10. Today’s Understanding
Today we know that light has certain properties
The properties of light are:
- Light is a Form of Energy
- Light can be reflected
- Light travels in straight lines
- Light can be bent
- Light has a top speed (300,000 km/s)
- White light is a combination of different colours

11. So the big questions is “How do we see”?

12. The Big Idea!!! We can see because…
Light is emitted from a light source
Light then travels to & strikes an object
Light is reflected off of that object to our eyes
Our eyes gather that light to make an image out of it

13. We Can See Because…

14. Next Class!!!
We will talking about rays, ray diagrams, casting shadows, and the difference between:
- Translucent
- Transparent
- Opaque