Download October 19

What is light energy and how is it
used?
Learning Objectives




I will know what light energy is.
I will know how light energy can be used.
I will know how light travels.
I will know that light energy can be reflected or refracted.
Refracting Telescope
Hey, my father let me use
his refracting telescope. I
wanted to get a better look
at the moon.
I read
about telescopes while
I was writing a report
on Galileo. He used a
refracting telescope over
400 years ago. This
type of telescope uses
lenses to refract light
and magnify the image,
making it
seem larger.
How Light Travels
Light can pass through some materials and not others.
opaque
transparent
translucent
Light Changes Direction
reflected
Light is ___________ by a mirror.
refracted
Light is ___________ by a lens.
Reflection and Refraction
Look around the classroom. Which objects reflect and
which refract?
Object
Reflect or Refract?
window
desk
bowl of water
window
eyeglasses
refract
reflect
refract
book
reflect
t-shirt
reflect
reflect
refract
Light Waves and Color
Visible light has wavelengths between violet and red.
R
O
Y
G
wavelength
B
V
The Electromagnetic Spectrum
Optical Instruments
microscope
to view faraway
objects like stars
telescope
to reflect a
person’s image
mirror
to improve a
human’s vision
optical lens
to magnify very
small things