On this day, 211 years ago, on November 25, 1814 (October 14, 1814, the lunar calendar), the German physicist Meier was born. Meier was born on November 25, 1814. He was a German physicist and one of the discoverers of the Law of Conservation of Energy. Energy is neither generated nor disappeared out of thin air. It can only be transformed from one form to another, or transferred from one object to another, and its total amount remains unchanged during the process of transformation or transfer. The law of conservation of energy is now widely accepted, but it has not been strictly proved. (1)Different forms of energy in nature correspond to different forms of motion: the motion of objects has mechanical energy, the motion of molecules has internal energy, the motion of charges has electrical energy, the motion inside atomic nuclei has atomic energy, and so on. (2)Different forms of energy can be transformed into each other: "Friction generates heat by overcoming friction and converting mechanical energy into internal energy; when the water in the kettle boils, the water vapor does work on the lid of the kettle to lift the lid, indicating that the internal energy is converted into Mechanical energy; current working through the electric heating wire can convert electrical energy into internal energy, etc." These examples illustrate that different forms of energy can be converted into each other and this conversion process is completed through work. (3)If a certain form of energy is reduced, there must be other forms of energy increase, and the amount of reduction and increase must be equal. If the energy of a certain object decreases, there must be an increase in the energy of other objects, and the amount of decrease and increase must be equal. Comments: Pioneers of thermodynamics and biophysics