Wednesday, December 2, 2009

Thermodynamics History

The word thermodynamics originates from the Greek words therme (heat) and dynamis (force). It is the branch of physical science that studies the physical properties of macroscopic systems of matter and energy including any spontaneous conditions, modifications or interactions that may occur between them. In other words, it deals with the mechanical actions or relations of heat. This science utilizes many variables such as pressure, volume, density, temperature and specific heat, to facilitate the description of macroscopic systems; the description of the behavior of an object and its relation to its environment.

Thermodynamics is considered one of the most important branches of physics due to the fact that it involves fundamental laws and principles that relate to all the different fields of engineering and science. It began developing in the XIX century when the study of heat and its ability to produce mechanical work became of great interest. However, the first thermodynamic term employed was "temperature" in the VII century. Galileo, an Italian physicist and astronomer, invented the first primitive thermometer. Then, Jean Ray and the grand duke Ferdinand II of Tuscany created other types of thermometers that employed different sources. The objective of these individuals was to manifest an instrument that would define the undefined; measure quantities that were unknown.
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Soon, many questions arised in the thoughts of a selected few. Questions concerning the transferring of energy from one body to another. Was it temperature that was being passed? This was a dubious inquiry that many hoped to answer. The best absolution was found in the study of a new science established by Joseph Black in 1770 called the calorimetry. It is the science of measuring quantities of heat expressed in calories. The calorimeter was a stirring device used to measure the amount of heat of a substance. This new science was based upon many postulates established by Black that were later, toward the end of the XVIII century, contradicted by an American colonial physicist and engineer, Benjamin Thompson. Nearly half a century, James Prescott Joule, an English physicist, later presented more refined theories.

Joule founded the first law of thermodynamics in the 1840s by demonstrating that the quantity of work necessary to cause a given change of state is independent of the type of work (electric, mechanical, etc.), the method of delivering or the rate of doing work. He also concluded that work could be converted into heat and heat into work.

Sadi Carnot, a French engineer who had created the Carnot engine in 1824, introduced the concept of the Carnot cycle. This conception distinguished the interactions of systems from the modifications of their states. In 1850, Rudolf Julius Clausius, a German physicist and mathematician who had enunciated two laws and contributed to the expansion of the study of this science, was intrigued by Carnot's notion. Consequently, it came to assertion that his principle is a postulate and, as a result, it became the second law of thermodynamics. Although in 1849 William Thomson, also known as Lord Kelvin, announced that there was a conflict between the conclusions carried out by Joule and the arguments on caloric Clausius settled this dilemma a few years later.

He established a property called entropy, which was included it in the second law and redefined the first and second law more explicitly.

After the flourishing of this new science, Lord Kelvin's interest in the study of temperature had grown. He, inclusively, instituted various definitions for thermodynamic temperature scales named after him. Not long after, a physicist of Edinburgh and Cambridge called James Clerk Maxwell asserted the zeroth law of thermodynamics.

Throughout the years, many other ingenious European and American mathematicians and physicist such as J. Willard Gibbs, Max Planck and Henri Poincaré, contributed notions and theorems that were very much valuable for the enhancement of the study of thermodynamics.

In the XVIII century, in 1918, a Nobel Prize winning German chemist, Walther Nernst, stated the Nernst theorem, which became the third law of thermodynamics.

Link about therm
odynamics
http://www.blueneptune.com/~xmwang/physDemo.html

http://didaktik.physik.uni-wuerzburg.de/~pkrahmer/home/thermo.html





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