Producing and Using Light

Producing Light Incandescent light: creating light by heating a piece of metal until it glows Example: Light bulbs

Producing Light Fluorescent Lights: lights that use phosphorous and other chemicals to convert ultraviolet radiation to visible light Last longer and use less energy

Producing Light Neon Lights: use glass tubes filled with gas to create light Neon: red Carbon dioxide: white Helium: yellow Mercury: blue

Producing Light Sodium-vapor lights: use neon, argon or sodium metals to produce light Example: street lights, outdoor lighting

Producing Light Tungsten-Halogen Lights: have a tungsten filament inside a quartz tube filled with gas to create intensely bright light Examples: movie sets, underwater photography, headlights

Producing Light Lasers: produce only one wavelength of light that can be concentrates so that the energy in a small area Uses: medicine, blue-ray players, gaming consoles Lasers smarter every day lasers laser vs baloon

Using Light Polarized light: light waves that vibrate in only one direction Uses: reducing glare in sun glasses and windows

Holography Holography: producing a hologram (a complete 3-D image) of an object Made by illuminating objects with a laser lights future of holograms holograms2 how holograms work

Lenses Lens: a transparent material with curved surfaces that refracts light Examples: camera, microscope, telescope, eye glasses, contacts

Lenses Optical axis: an imaginary line directly in the center of a lens

Lenses Focal point: the point on the optical axis where light rays pass through after they enter the lens

Lenses Focal Length: the distance from the center of the lens to the focal point

Lenses Convex lenses: light rays converge and pass through a single point Optical Axis

Lenses Concave Lenses: light rays diverge from the focal point away from the optical axis Optical Axis

Eye Sight Cornea: a transparent covering on the eye where light enters and bends Retina: the inner lining to the eye where the rods and cones are located and the image gets converted into electrical signals and sent to the brain how we see

Eyesight Far away objects: the lens of the eye becomes less convex Close objects: the lens of the eye becomes more convex

Eyesight Farsightedness (hyperopia): distant objects are seen clearly but close objects are out of focus

Eyesight Nearsightedness (myopia): close objects are seen clearly but distant objects are out of focus

Eyesight Astigmatism: when the surface of the cornea is uneven and light is scattered on the retina

Telescopes Refracting telescopes: uses 2 convex lenses to focus light from a distant object

Telescopes Reflecting Telescopes: uses a concave mirror, a flat mirror and a convex lens Telescopes telescopes 2 telescopes 2 searching for alien life astrobiology

Microscopes Microscopes: uses two convex lenses to magnify small objects microscopes

Cameras Cameras: gather and bend light with lenses then record the image