Unit 3 – Light and Optics Topic 1 – Light – Visible form of energy. Radiation is the energy transfer method for light. Natural light source – comes from nature. Artificial light source- man made Incandescent – burns so hot it glows Fluorescent – UV energy is absorbed by Particles Phosphorescent – energy absorbed and released later Chemiluminescent – Chemical reaction creates light Bioluminescent – Living thing creates light Cost of lighting: (Number of KW (divide W by 1000) X # of Hours) x cost per kWh Transparent – all light passes thru , translucent – some light passes thru, Opaque – Nothing Topic 2 – Reflection – light bounces off a surface. Normal line – perpendicular to the surface. On a plane mirror, Angle of reflection = Angle of Incidence. Concave mirror – light crosses over creates upside down image. Magnifies when really close. Convex mirror – spreads outs light. Topic 3 - Refraction – Light bends as it moves from one medium to another. Less more dense (bend toward normal) More less dense (Bend away from normal)

Cornea = Glass protection, Eyelid = Shutter, Pupil = Aperture. Topic 4 – Lenses  Concave lens – Spreads out light works for myopia (near sightedness) Convex lens – converges light (brings it together) works for hyperopia (far sighted) Retina = Film, Lens = Lens, Iris = Diaphragm, Ciliary Muscle = Focusing ring, Cornea = Glass protection, Eyelid = Shutter, Pupil = Aperture. Topic 5 – Refracting Scope – Light is bent and collected by an convex lens. Reflecting scope – light is collected by mirrors and a convex lens. Binoculars – light is collected by prisms and a convex lens. Topic 6-8 Spectrum (L to S) = Radio Waves – microwaves – infrared –ROYGBIV –UV – X-ray – Gamma Frequency (Hz) = # of cycles divided by Time. LASER – Light Amplification by the Stimulated Emission of Radiation (light is collected together to make a solid beam.)