Symptoms and effects. The illustration shows severe gall infection at the upper crown area on the roots of a peach seedling. Galls form on the crown of the plant (the point at the soil line where the main roots join the stem) and on the roots. They can also form on the main stem above soil level, or on the branches. Galls first appear as small, pale, roughened lumps of tissue. They enlarge, darken, and become convoluted.
Conservation of energy. Conservation of energy, principle of physics according to which the energy of interacting bodies or particles in a closed system remains constant. The first kind of energy to be recognized was kinetic energy, or energy of motion.
According to the principle of conservation of energy, energy is perpetual but can be transformed. During the process of transformation, part of the energy will be converted into heat in order to maintain its balanced condition. The resultant heat produced must then be dispersed through processes such as emission or radiation, and a portion of it is converted into energy.