Definitions for "Conservation of Energy"
The law in science that energy (or its equivalent in mass) can't be either created or destroyed Doppler effect - A shift in the wavelength of waves (such as light or sound waves) received from an object as it moves toward or away from the observer Electromagnetic radiation - Radiation made up of electromagnetic waves, including radio waves, visible light, gamma rays, and X rays
a fundamental law of physics which states that the energy of a system does not change unless an external force acts upon the system.
(first law)