Behavior of light
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The document discusses various optical phenomena including: - Reflection - Light bounces off surfaces at the same angle it hits. Smoother surfaces reflect better. - Refraction - Light bends when passing through different materials, changing speed. This causes dispersion into colors. - Color - Each color has a different wavelength. Color perceived is the wavelength reflected, others are absorbed. - Vision - Eyes have rods and cones that detect light and send signals to the brain for color and shape recognition. - Light sources - Incandescent bulbs heat a filament, fluorescent uses phosphors and gas, neon signs use colored gases, lasers emit synchronized waves.
Behavior of light
- 2. Opaque- no light passes through; absorbs and reflects light Translucent- allows some light to pass through; cannot clearly see through the material Transparent- can see clearly through the material
- 3. Law of reflection- light reflecting off of a surface will reflect at the same angle that it came in at.
- 4. Smooth, even surface reflect light better than rough, uneven surfaces.
- 5. Mirror images- a reflection of the image, but will be reflected back opposite Image outside the mirror is the real image, one in the mirror is the reflected image
- 6. Bending of light due to a change in the speed because of the materials that the light is passing through.
- 7. Refracts light and projects a color The bending breaks the waves into the different colors Rain droplets can also diffused the light into different colors (Rainbows)
- 9. Each color has a different wavelength The color you see is the color that is being reflected back to you, the other colors are being absorbed Black absorbs all colors, white reflects Filters- the color of the filter is the color of the light that it transmits
- 10. Seeing color begins with the eye Light enters through the retina and is focused on the retina, the rods and cones take in the light and send impulses to the brain Rods- most effective in the day and are used for distinguishing colors and shapes Cones- used for nighttime vision and are sensitive to dim light
- 11. Color Blindness- one or more sets of your cones do not function properly Most are red/green color blind (cones either detect reds, greens or blues)
- 13. Primary colors (of pigment)- red, blue and yellow Other colors are a mixture of pigments PRIMARY COLORS OF LIGHT- red, blue and green
- 15. Incandescent Light- heat a piece of metal until it glows; small wire coil (filament) inside usually made of tungsten Also gives off thermal energy Fluorescent lights- filled with gas at low pressure, inside coated with phosphors that emit light when they absorb UV radiation, electrodes at each end that absorb electrons, electrons collide with the gases to produce UV radiation
- 16. Neon lights- glass tubes filled with gas molecules, electric current causes collisions that produce visible light Neon only lights up red, other gases are used to produce the other colors
- 17. Sodium vapor lights- street lights, inside is a tube filled with neon, argon and sodium metal, the gas mixture gets hot when turned on, the sodium turns to vapor which is a yellow color. Lasers- numerous light waves at the same energy and wavelength are emitted at the same time