| natural unit | unit | Unit of length, time, mass, etc. in which the fundamental constants c (the speed of light), h bar (Planck's constant) and kB (Boltzmann's constant) are equal to unity. That is, c, h bar and kB have the numerical value 1. (For example, if we measure length in light-years and time in years, then c = 1 light-year per year.) The use of natural units allows these constants to be omitted from mathematical equations, leading to less-cluttered calculations. In natural units, E = mc2 becomes E = m and E = kBT becomes E = T, so that both mass and temperature can be expressed in units of energy. (Of course, the correct factors of c, h bar and kB must be inserted at the end of a calculation to obtain measurable quantities.) |
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