the fine-structure constant, also known as the Sommerfeld constant, commonly denoted by α (the Greek letter alpha), is a fundamental physical constant that...

Arnold Sommerfeld, introducing the fine-structure constant. The gross structure of line spectra is the structure predicted by the quantum mechanics of...

physical constant is sometimes used to refer to some universal dimensionless constants. Perhaps the best-known example is the fine-structure constant, α, which...

physical constants, such as the fine-structure constant α, which characterizes the strength of the electromagnetic interaction. Physical constants, as discussed...

specific tests of QED consist of measurements of the electromagnetic fine-structure constant, α, in various physical systems. Checking the consistency of such...

nature of physics. A physical theory that postulates a varying fine-structure constant can be express as either a variable speed of light or a variable...

The natural reactor of Oklo has been used to check if the atomic fine-structure constant α might have changed over the past 2 billion years. That is because...

is an experimentally determined constant, its value being proportional to the dimensionless fine-structure constant, which is known to a relative uncertainty...

bounds on their time-dependence. This concerns the fine-structure constant, the gravitational constant and the proton-to-electron mass ratio specifically...

NIST Reference on Constants, Units, and Uncertainty. NIST. May 2024. Retrieved 2024-05-18. "2022 CODATA Value: fine-structure constant". The NIST Reference...

is the speed of light, h is the Planck constant, α is the fine-structure constant, and R∞ is the Rydberg constant. As may be observed from the old values...

{\displaystyle 10\pi -{\frac {\pi }{10}}={\frac {99}{10}}\pi } . The fine-structure constant α {\displaystyle \alpha } is close to, and was once conjectured...

are pure numbers. An example of such a dimensionless constant is the fine-structure constant, α = e 2 4 π ε 0 ℏ c , {\displaystyle \alpha ={\frac {e^{2}}{4\pi...

into account the gravitational correction to the running of the fine structure constant α {\displaystyle \alpha } of quantum electrodynamics, Ulrich Harst...

thought to be the exact value of the fine-structure constant. The fine-structure constant, a dimensionless physical constant, is approximately 1/137, and the...

The fine-tuned universe is the hypothesis that, because "life as we know it" could not exist if the constants of nature – such as the electron charge...

These values are determined by the experimentally determined fine-structure constant α: ε 0 = 1 μ 0 c 2 = e 2 2 α h c   , {\displaystyle \varepsilon...

\varepsilon _{0}\hbar c}}\approx {\frac {1}{137}}} The fine-structure constant is the coupling constant of quantum electrodynamics (QED) determining the strength...

values of the other physical constants that define it. Since the Bohr model is not perfectly accurate, due to fine structure, hyperfine splitting, and other...

foundations of physics. Eddington argued that the value of the fine-structure constant, α, could be obtained by pure deduction. He related α to the Eddington...

provides an extremely precise independent determination of the fine-structure constant, a quantity of fundamental importance in quantum electrodynamics...

observations showing that the largest possible deviation of the fine-structure constant over much of the age of the universe is of order 10−5. The key...

alpha carbon and strength of electromagnetic interaction (as fine-structure constant). Alpha also stands for thermal expansion coefficient of a compound...

hydrogen and in muonium have been used to measure the value of the fine-structure constant α. Comparison with measurements of α in other physical systems...

fundamental constants. A nuclear clock has the potential to be particularly sensitive to possible time variations of the fine-structure constant. The central...

dimensionless constants and mass ratios. For example, Webb et al. reported detection of variation (at the 10−5 level) of the fine-structure constant from measurements...

dimensionless numbers like the Reynolds number in fluid dynamics, the fine-structure constant in quantum mechanics, and the Lorentz factor in relativity. In...

quantum number, magnetic quantum number. He also introduced the fine-structure constant and pioneered X-ray wave theory. Sommerfeld was born in 1868 to...

fundamental physics, including measurements of the gravitational constant, the fine-structure constant, and universality of free fall. Applied uses of atom interferometers...

natural nuclear fission reactor at Oklo, Gabon demonstrate that the fine-structure constant α has changed less than 10−17 per year over the last two billion...