The early theories of light were presented as being particles which passed from eye to object, and the opposing theory as particles passing from object to eye. The particle and wave theory of light was briefly discussed, along with the dual nature theory, light acting like particles at times, and like waves at other times. A changing electric current was shown to produce a magnetic field, and a changing magnetic field was shown to produce an electric current. The principle that light was an electromagnetic wave, which propagated itself by producing both a magnetic and electric part to the wave was presented using diagrams. That the electromagnetic wave could self propagate was used to explain why a medium is not needed for transmission.