unit two: microscope and light. microscope what is magnification? when objects are made to appear...
TRANSCRIPT
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
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
Electron Uses
electrons (tiny particles) to magnify an object
Can magnify 100,000 times
Particles bounce off the image
Nosepiece
Objective Lenses
Stage
Light
Base
Fine Focusing knob
Coarse focusing
Diaphragm
Arm
Body Tube
Eyepiece
Calculating Magnification
How many times bigger are you making the object?
To calculate, Multiply the Eyepiece X the Objective Lens
Ocularobjective
TM = Ocular Magnification X Objective
Magnification
Calculating 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
1. CORNEA - transparent, outer layer2. IRIS - colored portion of eye3. PUPIL – “hole” in the iris that
opens/closes to allow more/less light4. LENS – gets wider/thinner to focus5. RETINA – membrane in back of eye
contains rods &cones6. OPTIC NERVE –sends image from
retina to the brain
The Eye