Light and color

​Optical Telescope

Focuses Light (MUST HAVE LIGHT)

​

​Used in space and on Earth

​

​To get photos of deep space

​Refracting Telescope

​Uses Lenses to BEND light

​

​Difficult to use

​Reflecting Telescope

Uses Mirrors to BOUNCE light

​Can be made VERY large

Multiple Choice

What is used to get the light to the eyepiece in a Reflecting Telescope?

• Lens

• Mirror

• Net

• Tube

Convex Lens

• Thicker in the middle than on the edges

• Bends light inward toward a point called the focus

Multiple Choice

Convex lenses are thicker in the middle than on the edges.

• True

• False

Concave Lens

• Thicker at the edges than in the middle

• Bends light outward

NOTE:

Both telescopes uses CONVEX LENS at eye piece to magnify the image

Multiple Choice

A ______ telescope uses a mirror to focus light onto a small area.

• reflecting
• refracting
• radio
• spectrum

Multiple Choice

A ______ telescope uses lens to focus light.

• reflecting
• refracting
• radio
• spectrum

Electromagnetic Spectrum Review

Multiple Choice

All waves carry...

• Energy

• Matter

• Light

• Particles

Multiple Choice

The type of wave that can travel through both matter AND empty space:

• Mechanical Waves

• Electromagnetic Waves

Multiple Choice

Which of the following electromagnetic waves has the lowest energy?

• Gamma Ray

• Visible Light

• Infrared

• Microwave

Multiple Choice

As the frequency of an electromagnetic wave increases, the amount of energy in that wave...

• Increases

• Stays the same

• Decreases

Multiple Choice

Which section of the spectrum is the ONLY one we can see?

• X-Rays

• Gamma Rays

• Visible Light

• Ultraviolet Rays

​Scientists believe that there are 18 to 20 sensory receptors

Multiple Choice

What do you think photoreceptors respond to .................

• Sound

• Taste

• Light

• Temperature

Neurons in the retina of the eye that change visible light from the electromagnetic spectrum into signals that are perceived as images or sight. Rods and cones are two types of photoreceptors located at the back of the eye..

​

​Photoreceptors

​

​Photoreceptors

Cone: allow us to see the colors.

Rods: Activated by the light​

​The human eye has about 120 million rod cells and six million cone cells.

Rods sense black and white and work in low light.

L

-

cones

sense long wavelengths in the

red range

M

-

cones

sense mid

-

range wavelengths in

green range

S

-

cones

sense short wavelengths in the

blue range

Cones sense
color and must
have more light
than rods to
work. Three
kinds of cones:

Primary colors!

• Red

• blue

• yellow

Secondary colors

• orange

• green

• purple

Multiple Select

What are the primary colors!

• Red

• yellow

• blue

• white

Multiple Select

What are the secondary colors!

• orange

• green

• purple

• black