Light Light has its own characteristics that people should know. It travels in a straight line through a vacuum of space. Through its characteristics, you can detect different wavelengths and frequency to help you to study the Earth and the Universe. The electromagnetic (EM) spectrum is the term used by scientists to illustrate the entire range of electromagnetic waves that exists from radio waves to gamma rays. Visible light is one of the regions of the electromagnetic spectrum. It plays a vital role in our daily lives. It is the only region of the electromagnetic spectrum the human eye can perceive, thus, we can see the beautiful things around us. Characteristics of a Wave 1. Frequency (Symbol: f Unit: Hertz, Hz) - number of complete waves passing at a point every one second. 2. Amplitude (Symbol: A Unit: meter, m) - maximum height of a wave from its rest position. 3. Wavelength (Symbol: λ Unit: meter, m) - distance between two successive crests or troughs. 4. Speed of Light (Symbol: c Unit: meter per second, m/s) - distance travelled by light per unit time - all forms of electromagnetic radiation moves at exactly the same speed in vacuum - speed of light = 3.0 x 108 m/s (in vacuum) - formula: speed of light = wavelength x frequency symbol: c = λ f Characteristics of Light A. Color Visible light has wavelengths of 400 nanometer (nm) to 750 nanometer (nm). These wavelengths are represented by colors. Moreover, each color corresponds to a specific range of frequency. B. Intensity or Brightness is related to the wave’s amplitude. The height of the amplitude tells the brightness of light. Thus, the higher amplitude corresponds to a brighter light while lower amplitude corresponds to a dim light.
