Waves and Light 2024 PDF

© 2000 Microsoft Clip Gallery LIGHT  LIGHT: What Is It? © 2000 Microsoft Clip Gallery Light Energy As atoms absorb energy, electrons jump out to a higher energy level. Electrons release light when falling down to the lower ener...

© 2000 Microsoft Clip Gallery LIGHT  LIGHT: What Is It? © 2000 Microsoft Clip Gallery Light Energy As atoms absorb energy, electrons jump out to a higher energy level. Electrons release light when falling down to the lower energy level. Photons - bundles/packets of energy released when the electrons fall. © 2000 Microsoft Clip Gallery  Electromagnetic Waves Speed in Vacuum 300,000 km/sec 186,000 mi/sec Speed in Other Materials? © 2000 Microsoft Clip Gallery Slower in Air, Water, Glass Light is an Example of a Transverse Wave © 2000 Microsoft Clip Gallery Energy is perpendicular to direction of motion Moving photons create electric & magnetic fields  Electromagnetic Spectrum Visible Spectrum – Light we can see Roy G. Biv – Acronym for Red, Orange, Yellow, Green, Blue, Indigo, & Violet. Longest to Shortest Wavelength.  LIGHT: Refraction of Light Refraction – Bending of light due to a change in speed. Index of Refraction – Amount by which a material refracts light. Prisms – Glass that bends light. Different frequencies are bent different amounts & light is separated into different colors.  Color of Light Transparent Objects: Light transmitted because of no scattering Color transmitted is color you see. All other colors are absorbed. Translucent: Light is scattered and transmitted some. Opaque: Light is either reflected or absorbed. Color of opaque objects is color it reflects.  Pencil Demonstration Notice how the pencil appears bent or even split into 2 pieces at the point where it enters the water. This is because of refraction. RAINBOW: In a primary rainbow, the arc shows red on the outer part and violet on the inner side. This rainbow is caused by light being refracted when entering a droplet of water, then reflected inside on the back of the droplet and refracted again when leaving it.  Color of Light (Cont.) Color of Objects White light is the presence of ALL the colors of the visible spectrum. Black objects absorb ALL the colors and no light is reflected back. © 2000 Microsoft Clip Gallery  Color of Light (Cont.) © 2000 Microsoft Clip Gallery Primary Colors of Light Three colors that can be mixed to produce any other colored light Red , blue, green Additive Secondary Colors of Light Made by combining 2 of the primary colors; includes Magenta, Cyan and  Paint Pigments © 2000 Microsoft Clip Gallery A colored substance that absorbs or reflects light to give color to a substance Primary pigments Red, yellow and blue In digital media they are yellow + cyan + magenta = black Subtractive  How You See © 2000 Microsoft Clip Gallery Retina – Lens refracts light to converge on the retina. Nerves transmit the image to the optic nerve and then to the brain Rods – Nerve cells in the retina. Very sensitive to light & dark Cones – Nerve cells help to see light/color  Color Blindness About 8% of men and.5% of women have a problem with their color receptors (cones). This condition is sometimes called color blindness because it results in an inability to distinguish between certain colors. Most people are not blind to color, but have trouble distinguishing between colors, most commonly red & green.  Reflection Diagram Incident beam = beam striking the mirror Reflected beam = beam bouncing off the mirror Normal = line drawn perpendicular to the surface of the mirror  Law of Reflection Law of reflection states that the angle of incidence ( I ) is equal to the angle of reflection ( r ).  LIGHT & USES: Diffraction Diffraction – Bending of waves around the edge of a barrier. New waves are formed from the original. breaks images into bands of light & dark and colors.  LIGHT & USES: Diffraction © 2000 Microsoft Encarta A diffraction grating. Each space between the ruled grooves acts as a slit. The light bends around the edges and gets refracted.  LIGHT & ITS USES © 2000 Microsoft Clip Gallery Sources of Light Incandescent light – light produced by heating an object until it glows. © 2000 Microsoft Clip Gallery  LIGHT & ITS USES © 2000 Microsoft Clip Gallery Fluorescent Light – Light produced by electron bombardment of gas molecules Phosphors absorb photons that are created when mercury gas gets zapped with electrons. The phosphors glow & produce light. LIGHT & USES: Optical Instruments Cameras Telescopes Microscopes © 2000 Microsoft Clip Gallery © 2000 Microsoft Clip Gallery © 2000 Microsoft Clip Gallery LIGHT & USES: Optical Instruments LASERS Acronym: Light Amplification by Stimulated Emission of Radiation Coherent Light – Waves are in phase so it is VERY powerful & VERY intense. LIGHT & USES: Optical Instruments LASERS Holography – Use of Lasers to create 3-D images Fiber Optics – Light energy transferred through long, flexible fibers of glass/plastic Uses – Communications, medicine, t.v. transmission, data processing.