Download Unit Two: Microscope and Light

Unit Two:
Microscope and Light
Microscope
What is Magnification?
 When objects are
made to appear
larger than they
really are A larger than life
image
What tools can you use to
magnify something?
Microscope
Who is Anton Van
Leewenhoek?
 One of the first to
discover microscopic
organisms
 He was one of the
first to use a
microscope to view
living cells and small
organisms
Anton Van Leewenhoek
What are
animacules?
Organisms he saw in
the pond water

Robert Hooke
•First to look at Cells
under the microscope.
•He used microscope to
look at everyday things
(cork, leaves, fleas!)
What is a lens?

Curved piece of glass that bends
(refracts) light
Convex
Concave
Electron
 Uses
electrons
(tiny
particles) to
magnify an
object
 Can magnify
100,000
times
 Particles
bounce off
the image

Types of Microscopes
Simple
 Uses 1 lens
 Uses light
 Example:
Magnifying
glass

Compound
 Uses at least
2 lenses
 Uses light
 Can magnify
1,000 times

Eyepiece
Nosepiece
Body Tube
Arm
Objective
Lenses
Diaphragm
Stage
Coarse focusing
Light
Fine Focusing
knob
Base
Calculating Magnification
How many times bigger are you making
the object?
 To calculate, Multiply the Eyepiece X
the Objective Lens

Ocular
objective
Calculating Magnification
TM =
Ocular Magnification X Objective Magnification
Ocular
objective
Prism
Refracts white light
into all of its colors.
 WHITE light is a
combination of ALL
colors of light

Light can be Transmitted
Transparent
 Objects are seen clear
 Transparency has NO color
Light can be Transmitted
Translucent
 Light transmitted through a substance
that scatters the light
 The image looks fuzzy and lacks detail

Examples: wax paper, etc.
Light can be transmitted
Opaque
 A substance that does not transmit
light.
 Doesn’t allow light to pass through it
 Examples: your hand, a piece of paper,
etc.
Light can be absorbed
Absorbed
 All of the light is collected in the object,
no light appears out of the object.

A pencil is yellow because yellow light
bounces off it while all other colors are
absorbed.
Light can be reflected

Reflected - The bouncing back of light
Light can be Refracted

Refracted – the bending of light
What is a lens?

Curved piece of glass that bends
(refracts) light
Convex
Concave
Who wears what lens?
Concave =
Nearsighted (can
not see far away)
Convex = Farsighted
(cannot see near)
Uses of light instruments
Natural light – Sun, Fire, Lightening
 Optical instruments – Cameras,
Telescopes, Microscopes
 Lasers – Intense beam of light of one color
(medicine, industry, communication)
 Fiber Optics – strands of glass that carry
more information than copper wires

The Eye

Label the parts of
the eye
The Eye
The Eye
1.
2.
3.
4.
5.
6.
CORNEA - transparent, outer layer
IRIS - colored portion of eye
PUPIL – “hole” in the iris that opens/closes
to allow more/less light
LENS – gets wider/thinner to focus
RETINA – membrane in back of eye
contains rods &cones
OPTIC NERVE –sends image from retina
to the brain