Mass

Name:
Mass
Detailed information:
The quantity of matter contained in a particle or body regardless of its location in the universe. Mass is constant, whereas weight is affected by the distance of a body from the center of the earth (or of any other planet or satellite, e.g., the moon). At extremely high temperatures (for example the sun's interior), mass is converted into energy. According to the Einstein equation E = mc², all forms of energy, such as radiant energy and energy of motion, possess a mass equivalent, even though they have no independent rest mass (photons); thus there is no absolute distinction between mass and energy.See Energy; Matter.