Fizeau experiment
E204510
The Fizeau experiment was a pioneering 19th-century physics experiment that measured the speed of light using a rotating toothed wheel and helped establish light’s finite velocity.
All labels observed (7)
| Label | Occurrences |
|---|---|
| Fizeau experiment canonical | 3 |
| Fizeau effect | 2 |
| Fizeau–Foucault experiment | 2 |
| Fizeau experiment with moving water | 1 |
| Fizeau toothed-wheel experiment | 1 |
| Fizeau–Foucault apparatus | 1 |
| Fizeau–Foucault speed of light measurements | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T1811605 — 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: Fizeau experiment Context triple: [Hippolyte Fizeau, knownFor, Fizeau experiment]
-
A.
Michelson–Morley experiment
The Michelson–Morley experiment was a landmark 1887 physics experiment that attempted to detect the Earth's motion through the hypothesized luminiferous aether and whose null result helped pave the way for Einstein's theory of special relativity.
-
B.
Kennedy–Thorndike experiment
The Kennedy–Thorndike experiment is a classic test of special relativity that examined the constancy of the speed of light using an interferometer with unequal arm lengths and varying laboratory velocity.
-
C.
Ives–Stilwell experiment
The Ives–Stilwell experiment is a classic test of special relativity that measured the relativistic Doppler effect to confirm time dilation for fast-moving ions.
-
D.
Trouton–Noble experiment
The Trouton–Noble experiment was an early 20th-century test of the luminiferous aether that searched for a torque on a charged capacitor in motion and, by finding no such effect, provided support for the emerging theory of special relativity.
-
E.
Michelson interferometer
The Michelson interferometer is a precision optical instrument that splits and recombines light beams to measure extremely small differences in path length, widely used in fundamental physics experiments and metrology.
- 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: Fizeau experiment Target entity description: The Fizeau experiment was a pioneering 19th-century physics experiment that measured the speed of light using a rotating toothed wheel and helped establish light’s finite velocity.
-
A.
Michelson–Morley experiment
The Michelson–Morley experiment was a landmark 1887 physics experiment that attempted to detect the Earth's motion through the hypothesized luminiferous aether and whose null result helped pave the way for Einstein's theory of special relativity.
-
B.
Kennedy–Thorndike experiment
The Kennedy–Thorndike experiment is a classic test of special relativity that examined the constancy of the speed of light using an interferometer with unequal arm lengths and varying laboratory velocity.
-
C.
Ives–Stilwell experiment
The Ives–Stilwell experiment is a classic test of special relativity that measured the relativistic Doppler effect to confirm time dilation for fast-moving ions.
-
D.
Trouton–Noble experiment
The Trouton–Noble experiment was an early 20th-century test of the luminiferous aether that searched for a torque on a charged capacitor in motion and, by finding no such effect, provided support for the emerging theory of special relativity.
-
E.
Michelson interferometer
The Michelson interferometer is a precision optical instrument that splits and recombines light beams to measure extremely small differences in path length, widely used in fundamental physics experiments and metrology.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
historical scientific experiment
ⓘ
optics experiment ⓘ physics experiment ⓘ |
| aim |
to demonstrate that the speed of light is finite
ⓘ
to measure the speed of light in air ⓘ |
| approximateUncertainty | on the order of a few percent ⓘ |
| category |
Experiments on the speed of light
ⓘ
History of optics ⓘ |
| countryOfOrigin | France ⓘ |
| demonstrated | that light travel time over several kilometers is measurable with mechanical means ⓘ |
| distanceBetweenSourceAndMirror |
approximately 8,633 meters
ⓘ
approximately 8.6 kilometers ⓘ |
| era | 19th century ⓘ |
| field |
optics
ⓘ
physics ⓘ |
| followedBy |
Foucault experiment
ⓘ
surface form:
Foucault rotating mirror experiment
Michelson rotating mirror experiments ⓘ |
| inception | 1849 ⓘ |
| influenced |
Albert A. Michelson
ⓘ
surface form:
Albert Michelson
Michelson–Morley experiment ⓘ
surface form:
Michelson light-speed measurements
|
| location |
Montmartre
ⓘ
surface form:
Montmartre, Paris, France
Suresnes, France ⓘ |
| mainSubject | speed of light ⓘ |
| measuredValue |
approximately 3.13×10^8 meters per second
ⓘ
approximately 313,000 kilometers per second ⓘ |
| measurementType | one-way speed of light over a known distance ⓘ |
| medium | air ⓘ |
| method |
interruption of light by rotating toothed wheel
ⓘ
time-of-flight measurement of light ⓘ |
| namedAfter | Hippolyte Fizeau ⓘ |
| performedBy | Hippolyte Fizeau ⓘ |
| precededBy | astronomical measurements of light speed by Ole Rømer ⓘ |
| publicationYear | 1849 ⓘ |
| relatedTo |
Fizeau experiment
self-linksurface differs
ⓘ
surface form:
Fizeau–Foucault experiment
Foucault experiment ⓘ Hippolyte Fizeau ⓘ finite velocity of light ⓘ speed of light ⓘ |
| resultType | empirical measurement ⓘ |
| significance |
first terrestrial measurement of the speed of light using a mechanical method
ⓘ
improved accuracy of the known value of the speed of light ⓘ provided strong evidence that the speed of light is finite ⓘ |
| uses |
distant mirror
ⓘ
light source ⓘ rotating toothed wheel ⓘ telescope ⓘ timing mechanism ⓘ |
| year | 1849 ⓘ |
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: Fizeau experiment Description of subject: The Fizeau experiment was a pioneering 19th-century physics experiment that measured the speed of light using a rotating toothed wheel and helped establish light’s finite velocity.
Referenced by (11)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Fizeau–Foucault experiment
this entity surface form:
Fizeau effect
subject surface form:
Hippolyte Fizeau
this entity surface form:
Fizeau–Foucault apparatus
subject surface form:
Hippolyte Fizeau
this entity surface form:
Fizeau toothed-wheel experiment
subject surface form:
Hippolyte Fizeau
this entity surface form:
Fizeau experiment with moving water
this entity surface form:
Fizeau–Foucault experiment
subject surface form:
Armand Hippolyte Louis Fizeau
this entity surface form:
Fizeau–Foucault speed of light measurements