Light And Optics
CPO Science
Key Questions
 What is light? How can we
make light?
 Why are there different colors
of light?
 How does light behave in a
prism?
Let it glow, let it glow, let it
glow
 Take white board and keep white side
facing up. Don’t look at the bottom!
 When I say go, flip board over so white
side is down. Place part of a hand over
the square. Keep hand there!
 When lights go out, remove hand and
observe.
Atoms
absorb and then emit energy
with their electrons
When
the energy emitted falls within
the visible spectrum we see it as light
Charge it up with color
 Take out the red, blue, and green LED
lights, plug them in, and use them to
energize the phosphorescent paper
 Remove the colored lights and observe
the paper with the room lights off
 How can you explain your observations?
Light and Color
 How does a TV or computer monitor display
many, many different colors when they start
with only red, blue, and green pixels?
 Mix blue and green light. What color do you
see?
 Mix red and blue light. What color do you see?
 Mix red and green light. What color do you
see?
 Mix all three lights!
Overview
 Simple Optical System
(Beaker Funhouse)
 Reflection/Refraction in a Prism
(Secret to Tic-Tac-Toe Invincibility
and
Prismatic Name Enlightenment)
 Critical Angle/Total Internal Reflection
(Laser Proving Ground)
What does
Transparent mean?
 What happens?
 What are some examples
of transparent materials?
What Is an
Optical System?
Anything that involves
light
Used to study how light
behaves
Simple Optical System
 Observe the Beaker with the
water and pencil in it
 Look at the Beaker from many
different vantage points
 What strange or interesting
things can you see involving the
image of the pencil?
OBSERVATIONS
 The pencil is bent
 There are two pencils
 There are three pencils
 The pencil is Magnified
 When you look straight down into the
beaker, the pencil doesn’t seem bent
Color Teaching Tool Slides
Color Teaching Tool Slides
Refraction/Reflection
in a Prism
 See Page 112 in the
Investigation Guide Handout
for written directions
 Take out Prism from CPO
Optics kit
OBSERVATIONS
 I can see the X at first
 When I move my head up and down the
X vanishes
 When the X vanishes the O takes its
place
 This seems to be happening at the same
angle, the “magic angle”
Prismatic Name
Enlightenment
1. Repeat the process for the X and O
but instead of the X write your first
name.
2. Also write your first name in place
of the O but this time underline
your name.
3. What information do you now see
that can help us explain what is
going on?
OBSERVATIONS
 I can see my name upside-down
 When I move my head up and down my
name vanishes
 When my upside-down name
vanishes the underlined name takes its
place, and it isn’t upside-down any
more
 This seems to be happening at the
same angle, the “magic angle”
Time to Experiment
 Use a Simple Model- Laser and Prism
 Build Upon What You Have Learned –
This Magic Angle is Critical to what is
going on
Setting Up Laser/Prism
Experiment
 See Page 113 in the Investigation
Guide for written directions
 Take out Laser from CPO Optics kit
 Use Graph Paper we have provided
OBSERVATIONS
 The exiting beam exits at a different
angle for each trial
 When I move the laser up the paper,
the exiting beam angles more in the
downward direction
 At a certain point the exiting beam
disappears
 This seems to be happening at the
same angle, the “magic angle”
Conclusions from Experiment
 At a certain angle the beam is refracted in a direction
that doesn’t exit the prism
 This happens at a specific angle-The CRITICAL
ANGLE
 When the angle is bigger than the CRITICAL ANGLE
the beam experiences TOTAL INTERNAL
REFLECTION
How We Can Use Optics
in Everyday Life
 Fiber Optics
 Laser Scanners
 Surgical Lasers
 Information Storage-CDs, DVDs
 High precision Distance Measuring