The document discusses light and its properties. It begins by asking how to light up the world and introduces a presentation on light. It then covers what light is, common sources of light like the sun, how light travels, and how it interacts with different materials by being absorbed, reflected, or passing through. It provides examples of transparent, translucent, and opaque objects and discusses how light is detected by the human eye.

1. How do you LIGHT Up
your world ?

2. Welcome to a power point
presentation on LIGHT.
• We will investigate the following:
• 1. What is light?
• 2.What are some sources of light around us?
• 3. What are opaque, transparent, and translucent
objects?
• 4. What is a light wave?

3. Light
• Our primary source of light is the sun.
• Light travels in straight lines at a speed of
186,000miles per second.
• *Light waves travel faster than sound waves!
• Light energy from the sun travels through space,
reaches earth, and some of it turns to heat energy
and warms the earth’s air.
• Light from the sun also travels to the cells of green
plants (producers) and is stored as energy.
• When light reaches an object, it is absorbed,
reflected, or passes through it.

4. Sensing Light
• Humans have two light
detectors.
• Do you know what
they are called?

5. How many sources of Light can you
list and explain?
• SUN=warms air,
water, and land.
• Fire=provides heat, light, and
cooking fuel.
• Lightning=
• Firefly=
• Flashlight=
• Light bulb=
• Laser beams=
• Optical
telephone
fibers=
*Traffic lights=
*

6. Can you answer these 6th grade
questions?
• 1. A person will see a flash of lightning before they
hear the thunder that goes with it because?
• 2.Can you draw a long wavelength and a short
wavelength next to it?
• 3. Can you contrast objects that are transparent,
translucent, and opaque?

7. “Just Passing Through:”
What happens when light strikes glass? Or
waxed paper? Or a book?
• If light travels through an
object it is =transparent
• If light is blocked by an
object and a dark shadow
is cast it is= opaque.
• If some light passes
through but not all and a
light shadow is present it
is=translucent.

8. What happens when light
hits these objects?
• Glass of water
• School bus window
• Notebook paper
• Waxed paper
• Plastic wrap
• Tissue paper
• Cardboard
• Textbook
• Hand lens…

9. Transparent objects:
• The windows on a school bus,
• A clear empty glass,
• A clear window pane,
• The lenses of some eyeglasses,
• Clear plastic wrap,
• The glass on a clock,
• A hand lens,
• Colored glass…
• ALL of these are transparent. Yes,
we can see through them because
light passes through each of them.

10. Translucent objects
• Thin tissue paper,
• Waxed paper,
• Tinted car windows,
• Frosted glass,
• Clouds,
• All of these materials
are translucent and
allow some light to
pass but the light
cannot be clearly seen
through.

11. Opaque objects:
• Heavy weight paper,
• Cardboard
• Aluminum foil,
• Mirror, bricks, buildings,
• Your eyelids and hands,
• Solid wood door,
• All of these objects are
opaque because light cannot
pass through them at all.
• They cast a dark shadow.

12. Let’s find out how light travels?
• Simple Activity: 1 working flashlight
• 1. Shine a flashlight on a wall.
• 2. Does light from the flashlight reach the
wall? How do you know?
• 3. What evidence do you have showing light
travels in a straight line?
• 4.Move closer with the flashlight. Any
changes?

13. What is light really?
Electromagnetic radiation waves
• The waves have high points
called “crests.” wavelength
• Waves also have low points
called “troughs.”
• *The distance from one
crest to the next crest is
called a “wavelength.”
• *The number of waves
passing a given point in
one second is called the
“frequency.”