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Sound and Light. The Nature of Light. Constructive and Destructive Interference. Light Can Be Modeled As a Wave. Light Diffracts like a wave Light also reflects and refracts. Max Planck and Albert Einstein. Nobel prize winners in physics
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Sound and Light The Nature of Light Sound and Light
Constructive and Destructive Interference Sound and Light
Light Can Be Modeled As a Wave • Light Diffracts like a wave • Light also reflects and refracts Sound and Light
Max Planck and Albert Einstein • Nobel prize winners in physics • Discovered that light, which usually travels in waves, sometimes behaves as if it were made up of a stream of small quantities, or quanta, of energy Sound and Light
Photon • Small unit of light energy or electromagnetic radiation. “Packets” • No mass, bundle of energy. • The energy, E, of a photon is calculated using the equation E = hu, • Where h is Planck's constant and u is the frequency of the light. Sound and Light
Atoms Emit Energy As Photons Absorbs Energy Sound and Light
Sometimes Light is modeled as a Stream of Particles • Explains why light can travel through the vacuum of space • Light can knock electrons off a metal plate Sound and Light
Light Has a Dual Nature • Duality • Different characteristics depending on the situation • Scientists use different models depending on what they are studying Sound and Light
Photon Self-identity Problems Sound and Light
Energy of Light Is Proportional to Frequency • Light is a form of energy. • The energy, E, of a photon is E = hu, • Where h is Planck's constant and u is the frequency of the light. Sound and Light
The Speed of Light • In a vacuum it is called ‘c’ • Depends on the medium Sound and Light
The Brightness of Light Depends on the Intensity • The rate at which light energy flows through a given area of space is referred to as its intensity. Sound and Light
The Brightness of Light Depends on the Intensity • Light waves spread out spherically from the source • Therefore intensity will drop as distance increases Sound and Light
Exploring the Electromagnetic Spectrum Sound and Light
Radar • System that uses reflected radio waves • Determine distance, location, shape and speed Sound and Light
Sound and Light12.3 Reflection and Color Sound and Light
Light Can Be Modeled As a Ray • Light ray is a model of light • Represents light traveling through space in an imaginary straight line Sound and Light
When Light Rays Reflect off a Smooth Surface, They Are Reflected in the Same Direction. Sound and Light
When Light Rays Reflect off a Rough Surface, They Scatter in Many Different Directions. Diffuse reflection Sound and Light
The Law of Reflection • States that when light rays reflect off a surface the angle of incidenceequals the angle of reflection. Sound and Light
The Law of Reflection Ө = Angle of incidence Ө’ = Angle of reflection Sound and Light
Normal • The theoretical line perpendicular to the surface where light hits a mirror. Sound and Light
Virtual Image • An image that results from an apparent path of light rays • Appears behind a mirror • Or in front of a lens Sound and Light
Flat Mirror Sound and Light
RealImage • Light rays really exist at the point where the image appears. • Appears in front of a mirror. • Or through a lens. Sound and Light
Concave and Convex Mirrors Sound and Light
Concave Mirrors • Can create real images Sound and Light
Fun House Mirrors Sound and Light
Reflection of Green Light by Leaves Life Science, Holt Science and Technology, California edition, Holt Rinehart and Winston, San Francisco, 2001 Sound and Light
Seeing Color • Objects have color because they reflect certain wavelengths of light • The object absorbs all the other colors • Your brain interprets each wavelength as color Sound and Light
Colored Filters Sound and Light
You look at a red tulip, with green leaves, under green light. What would you see? • A black flower with green leaves Sound and Light
The Primary Colors of Light and Pigment Light Pigment Additive Subtractive Sound and Light
Primary Colors of Printing Sound and Light
What are the True Colors? Sound and Light
Sound and Light 12.4 Refraction, Lenses and Prisms Sound and Light
Refraction • Bending of light rays • From one medium to another • Due to changing speeds Sound and Light
When light moves from a material in which its speed is higher to a material in which its speed is lower, it is… • Bent toward the normal. Sound and Light
If a light moves from a material in which its speed is lower to one in which its speed is higher, • The ray is bent away from the normal Sound and Light
Refraction in the Atmosphere • Creates mirages • Are a virtual image • Heat leads to diffraction that bends the light toward the sky Sound and Light
Total Internal Reflection • Light enters one end of a fiber optic cable and exits the other end • Complete reflection • Between two mediums • Angle of incidence exceeds the critical angle Sound and Light
Convex Lens Sound and Light
Convex Lens Sound and Light
Convex Lens Sound and Light
Concave Lens Sound and Light
diverging lenses • Concave Len. • It bends light outward and can only create a virtual image. Sound and Light
The Eye thecorneais responsible for the largest percentage of light refraction Sound and Light
