A review of some introductory material involving the production of light energy, the electromagnetic nature of light, and the need not to have a medium for transmission. Transparent and opaque objects were defined in terms of electron vibrations, re-emission of light from the other side and absence of light being re-emitted. The conversion to heat from the loss of some energy passing through the glass was shown as a function of the frequency of the electro magnetic wave. The speed of light, once re-emitted, returned normal. The speed light passing through various substances was listed.