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...

the dimensionful constants (the elementary charge, the Planck constant, and the speed of light) of which the fine-structure constant is composed is responsible...

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

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

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...

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...

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

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...

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...

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...

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

turn is determined by the experimentally determined dimensionless 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...

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...

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...

Creation of a Photon: A Heuristic Calculation of Planck's Constant ħ or the Fine Structure Constant α". Zeitschrift für Naturforschung A. 33 (8): 993–994...

order to reinsert physical constants (such dimensions uniquely determine the full formula). where: α is the fine-structure constant (α = e2 / 4πε0ħc ≈ 0.007297)...

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

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...

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

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

predicted for the photon structure function in the quark model to leading logarithmic behavior; where α is the fine-structure constant and the fractional quark...

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...

Physics portal Fine structure constant Rashba effect Dresselhaus effect Radwański, R. J.; Ropka, Z. (2001), "Fine Electronic Structure and Magnetism of...

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

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...