Characteristics of Light Light and Reflection Characteristics of Light

Electromagnetic Waves Electromagnetic waves – a transverse wave consisting of oscillating electric and magnetic fields at right angles to each other Electromagnetic spectrum – a continuum of electromagnetic waves

Electromagnetic Waves

Electromagnetic Waves Seven forms of electromagnetic radiation Radio waves, microwaves, infrared waves, visible light, ultraviolet light, x-rays, gamma rays Vary according to frequency and wavelength Radio waves have the longest wavelength and shortest frequency Gamma rays have the shortest wavelength and highest frequency All forms of electromagnetic waves move at the speed of light (2.99792458*108m/s in a vacuum and 2.99709*108m/s in air) We will use 3.00*108m/s in both situations c=fλ Speed of light = frequency * wavelength

Electromagnetic Waves

Electromagnetic Waves Waves can be approximated as rays (a straight line with an arrow head) Called ray approximation These lines represent wave fronts When they strike a boundary, they produce a spherical secondary wave called a wavelet Called Huygens’ principle in honor Christian Huygens who developed this approach to waves

Electromagnetic Waves

Electromagnetic Waves Brightness of light decreases by the square of the distance from the source The light spreads out, so less light is available per unit of area

Electromagnetic Waves