

Ludwig Eduard Boltzmann was born February 20, 1844, in Vienna and died on September 5, 1906, in Duino, Italy. He was a physicist whose greatest achievement was in the development of statistical mechanics, which explains and predicts how the properties of atoms such as mass, charge, and structure determine the visible properties of matter such as viscosity, thermal conductivity, and diffusion. After receiving his doctorate from the University of Vienna in 1866, he held professorships in mathematics and physics at Vienna, Graz, Munich, and Leipzig. He contributed substantially to the foundation and development of statistical mechanics, a branch of theoretical physics. The Boltzmann constant, k, is a fundamental constant of physics occuring in nearly every statistical formulation of both classical and quantum physics. Having dimensions of energy per degree of temperature, the Boltzmann constant has a value of 1.38062 x 10^{23} joules per degree Kelvin (^{o}K), or 1.38622 x 10^{16} ergs per ^{o}K 

In the 1870s Boltzmann published a series of papers. He showed that the Second Law of Thermodynamics, which concerns energy exchange, could be explained by applying the laws of mechanics and the theory of probability to the motions of the atoms. In so doing, he made clear that the second law is essentially statistical and that a system approaches a state of thermodynamic equilibrium (equal energy distribution throughout) because equilibrium is overwhelmingly the most probable state in which matter occurs. During these investigations Boltzmann worked out the general law for the distribution of energy among the various parts of a system at a specific temperature.
He also derived the theorem of equipartition of energy known as the MaxwellBoltzmann law. This law states that the average amount of energy used for each different direction of motion of an atom is the same. He derived the integrodifferential equation for the change of the distribution of atoms due to collisions and laid the foundations and much of the structure of statistical mechanics. Boltzmann was also one of the first Europeans to recognize the importance of the electromagnetic theory proposed by James Clerk Maxwell of England. His work on statistical mechanics was strongly attacked by many who did not believe in the atomic theory and wanted to base all of physical science on energy considerations only. There was much misunderstanding of his ideas by those who did not fully grasp the statistical nature of his reasoning. His conclusions were finally supported by the series of discoveries in atomic physics that began shortly before 1900 and by the explanation of fluctuation phenomena, such as Brownian motion which is the random movement of microscopic particles suspended in a fluid. These phenomena in the physical world could be explained only by statistical mechanics. Tragically ill and depressed, Boltzmann took his own life in 1906.


 