Electromagnetic Spectrum: An electromagnetic spectrum is defined as the entire range of electromagnetic waves from low to high frequency. An example of an electromagnetic spectrum is the low frequency radio to the high frequency gamma ray waves.
Electromagnetic Wave: Electromagnetic waves are waves which can travel through the vacuum of outer space. Mechanical waves, unlike electromagnetic waves, require the presence of a material medium in order to transport their energy from one location to another.
Infrared: Having a wavelength just greater than that of the red end of the visible light spectrum but less than that of microwaves. Infrared radiation has a wavelength from about 800 nm to 1 mm, and is emitted particularly by heated objects.
Light year: a unit of astronomical distance equivalent to the distance that light travels in one year, which is 9.4607 × 1012 km (nearly 6 trillion miles).
Polarization: Polarization is a concept that comes from science, and it involves light, radiation, or magnetism moving in specific directions. Outside science, polarization usually refers to how people think, especially when two views emerge that drive people apart, kind of like two opposing magnets.
Ray: each of the lines in which light (and heat) may seem to stream from the sun or any luminous body, or pass through a small opening.
Ultraviolet: (of electromagnetic radiation) having a wavelength shorter than that of the violet end of the visible spectrum but longer than that of X-rays.
Speed of Light: The speed of light in vacuum, commonly denoted c, is a universal physical constant important in many areas of physics. Its value is exactly 299,792,458 meters per second, a figure that is exact because the length of the metre is defined from this constant and the international standard for time.