Fine-structure constant

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Numbers

α

0.0072973525675 +/- 1.09e-11

α^{- 1}

137.035999113 +/- 2.03e-7

Definition

The fine-structure constant

α

is the dimensionless physical constant defined as

α = e^{2} / (2 ε_{0} c h)

, where

e

is the elementary charge,

ε_{0}

the electric constant,

c

the speed of light in vacuum, and

h

the Planck constant.

Comments

(1)

α

may not be constant [3].

References

[1]

Arnold Sommerfeld, "Zur Quantentheorie der Spektrallinien", Annalen der Physik Ser. 4, Bd. 51 (1916).

Links

[2]

Wikipedia: Fine-structure_constant

[3]

Wikipedia: Is_the_fine-structure_constant_actually_constant?

[4]

Wikipedia: History_of_measurements

Data properties

Entries are of type: real number

Sources of data: [4]

Reliability: The given real intervals are chosen to contain all measurements up to five measurement uncertainties that are displayed in [4] in the years 2014-2020. Also note (1).