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 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

Types of Microscopes

of the compound microscope Identify the parts of the compound microscope

of the compound microscope Identify the parts of the compound microscope 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 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