Category:Definitions/Fine-Structure Constant

This category contains definitions related to Fine-Structure Constant.

The fine-structure constant is a fundamental physical constant which quantifies the strength of the electromagnetic interaction between elementary charged particles.

It is related to the strength of the coupling of an elementary charge $\E$ with the electromagnetic field, by the formula:

$\alpha = \dfrac {\E^2} {2 \pi \epsilon_0 h c}$

where:

$\E$ is the elementary charge: $1.60217 \, 6634 \times 10^{-19} \, \mathrm C$

$h$ is Planck's constant: $6.62607 \, 015 \times 10^{-34} \, \mathrm J \, \mathrm s$

$c$ is the speed of light: $299 \, 792 \, 458 \, \mathrm m \, \mathrm s^{-1}$

$\epsilon_0$ is the vacuum permittivity: $8.85418 \, 78128(13) \times 10^{-12} \, \mathrm F \, \mathrm m^{-1}$

$\ds \alpha$

$\approx$

$\ds 7 \cdotp 29735 \, 25693 \times 10^{-3}$

$\ds \dfrac 1 \alpha$

$\approx$

$\ds 1 \cdotp 37035 \, 99908 \, 4 \times 10^2$

Pages in category "Definitions/Fine-Structure Constant"

The following 6 pages are in this category, out of 6 total.