1. Students will learn about light.

2. Light
Light is a transverse electromagnetic wave. Consider the electric field portion as transverse up and down and the magnetic field portion as perpendicular side to side.
Light has many wave properties: reflection, refraction, diffraction, interference patterns, Doppler effect, color dependent on frequency, and intensity (or brightness) dependent on the amplitude of the waves.

3. Speed of light
The speed of light in a vacuum (and also in air) is 3 x 10^8 m/s.
Albert Einstein showed that nothing, nowhere, no how can ever every go faster than the speed of light = 3 x 10^8 m/s.

4. Light as a particle Sometimes light acts as a particle
Light “particles” are called “photons”
In very dim light, light appears as small pieces or bits
Light energy (as photons): E = hf
H = 6.63 x 10^-34 Joule seconds

5. Electromagnetic Spectrum
Gamma rays 10^19 – 10^21 Hertz 10^-12 m
X rays ^17 – 10^20 Hertz 10^-10 m
Ultraviolet 10^15 – 10^18 Hertz 10^-7 m
Visible 10^14 – 10^15 Hertz 10^-6 m
Infrared 10^12 – 10^14 Hertz 10^-5 m
Microwave 10^9 – 10^12 Hertz .01 m
FM /TV 10^8 Hertz 3 m
AM 10^6 Hertz m

6. Dispersion
Dispersion is the spreading of white light into the full spectrum. A prism separates white light into a rainbow of colors. This happens because the index of refraction of the material depends on the wavelength. Different wavelengths are bent to varying degrees.
Violet is bent the most; red is bent the least.
The sky is blue because it is bent the most as sunlight comes through earth’s atmosphere.

7. Examples of Dispersion
Prism
Rainbow
Diamonds

8. Polarized light
Ordinary light is unpolarized. It has many vibrations in many planes at once. The electric field vectors vibrate at all angles.
Light can be “filtered” or “polarized” by passing it through parallel slits. Long molecules can be arranged as long slits to achieve this purpose.