Unit Two: Unit Two: Microscope and LightMicroscope and Light
MicroscopeMicroscope
What is What is Magnification?Magnification?
A larger than life A larger than life imageimage
What tools can you use to What tools can you use to magnify something?magnify something?
MicroscopeMicroscope
Who is Anton Van Who is Anton Van Leewenhoek?Leewenhoek?
One of the first to One of the first to discover discover microscopic microscopic organismsorganisms
He was one of the He was one of the first to use a first to use a microscope to view microscope to view living cells and living cells and small organismssmall organisms
Anton Van LeewenhoekAnton Van Leewenhoek
What are What are animacules?animacules?
Organisms he saw Organisms he saw in the pond waterin the pond water
Robert HookeRobert Hooke
•First to look at Cells under the microscope.
•He used microscope to look at everyday things (cork, leaves, fleas!)
What is a lens?What is a lens?
Curved piece of glass that bends Curved piece of glass that bends (refracts) light(refracts) light
Convex Concave
Types of MicroscopesTypes of Microscopes
SimpleSimple Uses 1 Uses 1
lenslens Uses lightUses light Example: Example:
MagnifyinMagnifying glassg glass
CompoundCompound Uses at Uses at
least 2 least 2 lenseslenses
Uses lightUses light Can Can
magnify magnify 1,000 times1,000 times
ElectronElectron Uses Uses
electrons electrons (tiny (tiny particles) particles) to magnify to magnify an object an object
Can Can magnify magnify 100,000 100,000 timestimes
Particles Particles bounce off bounce off the imagethe image
Nosepiece
Objective Lenses
Stage
Light
Base
Fine Focusing knob
Coarse focusing
Diaphragm
Arm
Body Tube
Eyepiece
Calculating MagnificationCalculating Magnification
How many times bigger are you How many times bigger are you making the object? making the object?
To calculate, Multiply the Eyepiece To calculate, Multiply the Eyepiece X the Objective LensX the Objective Lens
Ocularobjective
TM = TM =
Ocular Magnification X Objective MagnificationOcular Magnification X Objective Magnification
Calculating MagnificationCalculating Magnification
Ocular
objective
PrismPrism
Refracts white Refracts white light into all of its light into all of its colors.colors.
WHITE light is a WHITE light is a combination of combination of ALL colors of lightALL colors of light
Light can be TransmittedLight can be Transmitted
TransparentTransparent Objects are seen clearObjects are seen clear Transparency has NO colorTransparency has NO color
Light can be TransmittedLight can be Transmitted
TranslucentTranslucent Light transmitted through a Light transmitted through a
substance that scatters the lightsubstance that scatters the light The image looks fuzzy and lacks The image looks fuzzy and lacks
detaildetail
Examples: wax paper, etc.Examples: wax paper, etc.
Light can be transmittedLight can be transmitted
OpaqueOpaque A substance that does not transmit A substance that does not transmit
light.light. Doesn’t allow light to pass through Doesn’t allow light to pass through
itit Examples: your hand, a piece of Examples: your hand, a piece of
paper, etc. paper, etc.
Light can be absorbedLight can be absorbed
AbsorbedAbsorbed All of the light is collected in the All of the light is collected in the
object, no light appears out of the object, no light appears out of the object.object.
A pencil is yellow because yellow A pencil is yellow because yellow light bounces off it while all other light bounces off it while all other colors are absorbed.colors are absorbed.
Light can be reflectedLight can be reflected
Reflected - The bouncing back of Reflected - The bouncing back of lightlight
Light can be RefractedLight can be Refracted
Refracted – the bending of lightRefracted – the bending of light
What is a lens?What is a lens?
Curved piece of glass that bends Curved piece of glass that bends (refracts) light(refracts) light
Convex Concave
Who wears what lens?Who wears what lens?
Concave = Concave = Nearsighted (can Nearsighted (can not see far away)not see far away)
Convex = Convex = Farsighted Farsighted (cannot see near)(cannot see near)
Uses of light instrumentsUses of light instruments Natural light – Sun, Fire, LighteningNatural light – Sun, Fire, Lightening Optical instruments – Cameras, Optical instruments – Cameras,
Telescopes, MicroscopesTelescopes, Microscopes Lasers – Intense beam of light of one Lasers – Intense beam of light of one
color (medicine, industry, color (medicine, industry, communication)communication)
Fiber Optics – strands of glass that carry Fiber Optics – strands of glass that carry more information than copper wiresmore information than copper wires
The EyeThe Eye
Label the parts of Label the parts of the eyethe eye
The EyeThe Eye
1.1. CORNEACORNEA - transparent, outer layer - transparent, outer layer2.2. IRISIRIS - colored portion of eye - colored portion of eye3.3. PUPILPUPIL – “hole” in the iris that – “hole” in the iris that
opens/closes to allow more/less lightopens/closes to allow more/less light4.4. LENSLENS – gets wider/thinner to focus – gets wider/thinner to focus5.5. RETINA RETINA – membrane in back of eye – membrane in back of eye
contains rods &conescontains rods &cones6.6. OPTIC NERVEOPTIC NERVE –sends image from –sends image from
retina to the brainretina to the brain
The EyeThe Eye