No Title Flux and the Inverse Square Law Flux refers to the amount of energy crossing a given element of area in a given amount of time. The inverse square law describes how energy emitted in the form of light spreads out through space. A wave is characterized by wavelength and frequency .
Blue light has a shorter wavelength than red light.
Wavebands are subdivisions of the electromagnetic spectrum, such as visible light, ultraviolet, infrared, radio, or x-rays. The Earth possesses an atmosphere. The air acts to shield the ground from many different kinds of light, some of which is harmful to us. That is why space telescopes are important for astronomical studies in these wavebands. Note that the Earth's atmosphere is in constant motion.