Light (aka electromagnetic radiation) ●stream of massless particles (photons) ●travel in a wave-like pattern called an electromagnetic wave ●speed of light (c=3*10^8) Electromagnetic Spectrum ●the vast range of energies that make up all types of light ●Divided by energy (and thus frequency and wavelength) of the light ●Radio, Microwave, Infrared, Visual, Ultraviolet, X-Rays, Gamma Rays ●Radio waves have the lowest energy and frequency and the longest wavelength ●Gamma Rays have the highest energy and frequency and the shortest wavelength Radio Waves ●Longest waves, lowest energy, lowest temperatures ●Non-Ionizing ●Wifi, remote controls, AM and FM Microwaves ●Longer microwaves used to cook food ●Shorter microwaves used for devices like cellphones ●Velocity = wavelength * frequency ●Microwaves are blocked by grids/walls ●Non-ionizing Infrared Light ●Far infared=thermal ●We emit infrared light ●Used to heat food ●
