Thermodynamics

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The word thermodynamics is derived from the Greek words therme, meaning heat and dunamis, meaning power. Thermodynamics is a branch of physics that studies the effects of changes in temperature, pressure, and volume on systems at the macroscopic scale by studying the motion of their particles. A system is the subject of study. Heat means energy in transit and dynamics relates to movement of particles; thus, in essence thermodynamics studies the movement of energy and how energy instills movement. Thermodynamics describes how systems respond to changes in their surroundings. This can be applied to a wide variety of topics in science (physics and chemistry) and engineering, such as engines, phase transitions of matter, chemical reactions, and transportation.

The study of thermodynamics is separated into two branches: the classical and the statistical thermodynamics.

Classical thermodynamics was the original study of thermodynamics in early 1800s. It was concerned with thermodynamic states, and properties as energy, work, and heat, and with the two laws of thermodynamics. However, classical thermodynamics lacked an atomic interpretation of the processes. Classical thermodynamics derives from the research done by physicist Robert Boyle. He developed the concept that the pressure P of a given quantity of gas varies inversely to its volume V at constant temperature. In other words this equation was derived: PV = k, a constant. From here, the thermo-science began to develop with the construction of the first successful atmospheric steam engines.

The first and second laws of thermodynamics emerged simultaneously in the 1850s.

With the development of atomic and molecular theories in the late 19th century, thermodynamics was given a molecular interpretation, which the classical thermodynamics lacked. This field is called statistical thermodynamics, which can be thought of as a bridge between macroscopic and microscopic properties of systems. Statistical thermodynamics is focused around the macroscopic results. The statistical approach is to derive all macroscopic properties (temperature, volume, pressure, energy, entropy, etc.) from the properties of moving particles and the interactions between them in the given system. Statistical thermodynamics was found to be very accurate and successful; therefore it is widely used by scientists around the world.

Thermodynamics is a branch of physics which deals with the energy and work of a system. It was born in the 19th century as scientists were first discovering how to build and operate steam engines. The term thermodynamics was first used by James Joule to express the relationship between heat and power.

The history of thermodynamics begins with a German scientist who designed and built the first vacuum pump.

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