Thermodynamics is a branch of physics that studies the movement of heat between different objects. Thermodynamics also studies the change in pressure and volume of objects. A branch of math called statistics is often used in thermodynamics to look at the motion of particles. Thermodynamics is useful because it helps us understand how the world of the very small atoms connects to the large scale world we see everyday. Thermodynamics also has two main branches called classical thermodynamics and statistical thermodynamics. An important idea in thermodynamics is that of a thermodynamic system. An...

Absolute zero is the lower limit of the thermodynamic temperature scale, a state at which the enthalpy and entropy of a cooled ideal gas reaches its minimum value, taken as 0. The theoretical temperature is determined by extrapolating the ideal gas law; by international agreement, absolute zero is taken as −273.15° on the Celsius scale (International System of Units), which equates to −459.67° on the Fahrenheit scale (United States customary units or Imperial units). The corresponding Kelvin and Rankine temperature scales set their zero points at absolute zero by definition. It is commonly thought...

Thermodynamic temperature is the absolute measure of temperature and is one of the principal parameters of thermodynamics. Thermodynamic temperature is defined by the third law of thermodynamics in which the theoretically lowest temperature is the null or zero point. At this point, absolute zero, the particle constituents of matter have minimal motion and can become no colder. In the quantum-mechanical description, matter at absolute zero is in its ground state, which is its state of lowest energy. Thermodynamic temperature is often also called absolute temperature, for two reasons: one, proposed...