Boltzmann constant

The Boltzmann constant (k or kB) is the physical constant relating temperature to energy.

Role in definition of entropy

In statistical mechanics, the entropy S of a system is defined as the natural logarithm of Ω, the number of distinct microscopic states available to the system given the macroscopic constraints (such as a fixed total energy E):

Related Topics:
Entropy - Natural logarithm

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:S = k , ln Omega.

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The constant of proportionality k is the Boltzmann constant. This equation, which relates the microscopic details of the system (via Ω) to its macroscopic state (via the entropy S), is the central idea of statistical mechanics.

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