fine-structure constant
E590229
The fine-structure constant is a fundamental dimensionless constant of nature that characterizes the strength of the electromagnetic interaction between charged particles.
All labels observed (1)
| Label | Occurrences |
|---|---|
| fine-structure constant canonical | 3 |
How this entity was disambiguated
This entity first appeared as the object of triple T6396773 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: fine-structure constant Context triple: [ħ, relatedConcept, fine-structure constant]
-
A.
Fermi constant
The Fermi constant is a fundamental physical constant that quantifies the strength of the weak nuclear force in processes such as beta decay.
-
B.
Rydberg constant
The Rydberg constant is a fundamental physical constant that characterizes the limiting value of the highest wavenumber (or lowest wavelength) of any photon that can be emitted from the hydrogen atom, playing a key role in atomic spectroscopy and quantum theory.
-
C.
Planck constant
The Planck constant is a fundamental physical constant that quantifies the relationship between the energy of a photon and the frequency of its associated electromagnetic wave, forming a cornerstone of quantum mechanics.
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D.
Compton wavelength
The Compton wavelength is a fundamental quantum-mechanical length scale associated with a particle, characterizing the wavelength of a photon whose scattering off that particle produces significant relativistic and quantum effects.
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E.
Planck units
Planck units are a system of natural units in physics where fundamental constants like the speed of light, gravitational constant, and Planck constant are normalized to 1, providing a scale-free framework for describing physical laws.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: fine-structure constant Target entity description: The fine-structure constant is a fundamental dimensionless constant of nature that characterizes the strength of the electromagnetic interaction between charged particles.
-
A.
Fermi constant
The Fermi constant is a fundamental physical constant that quantifies the strength of the weak nuclear force in processes such as beta decay.
-
B.
Rydberg constant
The Rydberg constant is a fundamental physical constant that characterizes the limiting value of the highest wavenumber (or lowest wavelength) of any photon that can be emitted from the hydrogen atom, playing a key role in atomic spectroscopy and quantum theory.
-
C.
Planck constant
The Planck constant is a fundamental physical constant that quantifies the relationship between the energy of a photon and the frequency of its associated electromagnetic wave, forming a cornerstone of quantum mechanics.
-
D.
Compton wavelength
The Compton wavelength is a fundamental quantum-mechanical length scale associated with a particle, characterizing the wavelength of a photon whose scattering off that particle produces significant relativistic and quantum effects.
-
E.
Planck units
Planck units are a system of natural units in physics where fundamental constants like the speed of light, gravitational constant, and Planck constant are normalized to 1, providing a scale-free framework for describing physical laws.
- F. None of above. chosen
Statements (49)
| Predicate | Object |
|---|---|
| instanceOf |
dimensionless physical constant
ⓘ
electromagnetic coupling constant ⓘ fundamental constant of nature ⓘ |
| alsoKnownAs | Sommerfeld constant NERFINISHED ⓘ |
| appearsIn |
Breit interaction
NERFINISHED
ⓘ
Compton scattering formulas NERFINISHED ⓘ Dirac equation solutions for hydrogen ⓘ Thomson scattering cross section ⓘ atomic energy level splittings ⓘ atomic physics ⓘ quantum electrodynamics ⓘ quantum field theory ⓘ scattering cross sections ⓘ |
| approximateValue |
0.00729735257
ⓘ
1/137 ⓘ |
| category |
electromagnetism
ⓘ
fundamental physical constants ⓘ quantum electrodynamics ⓘ |
| characterizes | strength of electromagnetic interaction ⓘ |
| CODATA2018Uncertainty | 0.0000000000011 ⓘ |
| CODATA2018Value | 0.0072973525693 ⓘ |
| definedAs |
e²/(4πϵ₀ħc)
ⓘ
μ₀c e²/(2h) ⓘ |
| dependsOn |
Planck constant
NERFINISHED
ⓘ
elementary charge ⓘ reduced Planck constant ⓘ speed of light in vacuum ⓘ vacuum permeability ⓘ vacuum permittivity ⓘ |
| dimension | dimensionless ⓘ |
| governs | fine structure of atomic spectra ⓘ |
| introducedInContextOf | Bohr–Sommerfeld model of the atom NERFINISHED ⓘ |
| isApproximately | 1/137.035999084 ⓘ |
| isDimensionless | true ⓘ |
| isPositive | true ⓘ |
| isScaleIndependentInQED | approximately true at low energies ⓘ |
| isUniversal | true ⓘ |
| namedAfter | Arnold Sommerfeld NERFINISHED ⓘ |
| numericalValue | 0.0072973525693 ⓘ |
| relatedTo |
electromagnetic interaction
ⓘ
elementary charge ⓘ quantum of action ⓘ |
| roleIn |
Lamb shift
ⓘ
Rydberg constant expressions ⓘ anomalous magnetic moment of the electron ⓘ precision tests of quantum electrodynamics ⓘ |
| symbol | α ⓘ |
| usedFor |
determining other fundamental constants
ⓘ
testing Standard Model of particle physics ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: fine-structure constant Description of subject: The fine-structure constant is a fundamental dimensionless constant of nature that characterizes the strength of the electromagnetic interaction between charged particles.
Referenced by (3)
Full triples — surface form annotated when it differs from this entity's canonical label.
subject surface form:
ħ