In physics, the Planck charge, denoted by, is one of the base units in the system of natural units called Planck units. It is a quantity of electric charge defined in terms of fundamental physical constants.
The Planck charge is defined as:
- coulombs,
where:
- is the speed of light in the vacuum,
- is Planck's constant,
- is the reduced Planck constant,
- is the permittivity of free space
- is the elementary charge
- = (137.03599911)−1 is the fine structure constant.
The Planck charge is times greater than the elementary charge e carried by an electron.
The Gaussian cgs units are defined so that, in which case has the following simple form:
It is customary in theoretical physics to adopt the Heaviside-Lorentz units (also known as rationalized cgs). When made natural they are like the SI system with . Therefor it is more appropriate to define the Planck charge as
- coulombs,
When charges are measured in units of, i.e., when is set equal to 1, we obtain, which is commonly used in theoretical physics. In contrast, in (non-rationalized) natural cgs units where we have .
Famous quotes containing the word charge:
“I do the wrong, and first begin to brawl.
The secret mischiefs that I set abroach
I lay unto the grievous charge of others.”
—William Shakespeare (1564–1616)