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

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

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

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

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...

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...

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...

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

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

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

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...

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...

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

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...

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...

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...

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...

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

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...

the fine-structure constant. The CODATA value of the Bohr radius (in SI units) is 5.29177210544(82)×10−11 m. In the Bohr model for atomic structure, put...