Constant (Boltzmann)

The unit kelvin (K) is defined by fixing Boltzmann's constant k_B to be 1.380,649×10^-23 J/K (= kg·m²·s^-2·K^-1), where second, meter and kilogram are defined in terms of atomic clock, speed of light and Planck's constant.

Boltzmann's constant is named after the Austrian physicist Ludwig Eduard Boltzmann (1844 – 1906).

History

The German physicist Max Karl Ernst Ludwig Planck (1858 – 1947) introduced the constanrt k_B and gave the value 1.346×10^-23 J/K, about 2.5% lower than the current value.

Related concepts

• base units
• constant (atomic clock)
• constant (Avogadro)
• constant (electron charge)
• constant (Planck)
• constant (speed of light)
• kelvin
• temperature