POWER WORDS (from the Yahoo! Kids Dictionary)
engineering The application of scientific and mathematical principles to practical ends such as the design, manufacture and operation of efficient structures, machines, processes and systems.
wavelength The distance between one peak or crest of a wave, such as of light, and the next corresponding peak or crest.
frequency The number of times a specified periodic phenomenon occurs within a specified interval. Waves per second is frequency, for example.
electric field A region of space characterized by the existence of a force generated by electric charge.
magnetic field A condition found in the region around a magnet or an electric current, characterized by the existence of a detectable magnetic force at every point in the region.
lens A ground or molded piece of glass, plastic or other transparent material with opposite surfaces either or both of which are curved, such that light rays are refracted so that they form an image.