Kennedy–Thorndike experiment
E32550
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.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Kennedy–Thorndike experiment canonical | 5 |
How this entity was disambiguated
This entity first appeared as the object of triple T244336 — 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: Kennedy–Thorndike experiment Context triple: [Michelson–Morley experiment, relatedTo, Kennedy–Thorndike 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.
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B.
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.
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C.
Hanbury Brown and Twiss effect
The Hanbury Brown and Twiss effect is a quantum optical phenomenon in which correlations in the arrival times of identical particles, such as photons, reveal their underlying statistical and coherence properties.
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D.
On the Electrodynamics of Moving Bodies
"On the Electrodynamics of Moving Bodies" is Albert Einstein’s 1905 paper that introduced the special theory of relativity, fundamentally redefining concepts of space, time, and motion in physics.
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E.
Galilean relativity
Galilean relativity is the classical principle of relativity stating that the laws of mechanics are the same in all inertial frames related by Galilean transformations, assuming absolute time and Euclidean space.
- 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: Kennedy–Thorndike experiment Target entity description: 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.
-
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.
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.
-
C.
Hanbury Brown and Twiss effect
The Hanbury Brown and Twiss effect is a quantum optical phenomenon in which correlations in the arrival times of identical particles, such as photons, reveal their underlying statistical and coherence properties.
-
D.
On the Electrodynamics of Moving Bodies
"On the Electrodynamics of Moving Bodies" is Albert Einstein’s 1905 paper that introduced the special theory of relativity, fundamentally redefining concepts of space, time, and motion in physics.
-
E.
Galilean relativity
Galilean relativity is the classical principle of relativity stating that the laws of mechanics are the same in all inertial frames related by Galilean transformations, assuming absolute time and Euclidean space.
- F. None of above. chosen
Statements (47)
| Predicate | Object |
|---|---|
| instanceOf |
physics experiment
ⓘ
test of special relativity ⓘ |
| aim |
detect dependence of light speed on laboratory velocity
ⓘ
test time dilation independently of length contraction ⓘ |
| approach |
monitor fringe shifts over time
ⓘ
one arm parallel to Earth’s motion ⓘ one arm perpendicular to Earth’s motion ⓘ |
| assumes |
inertial laboratory frame
ⓘ
no preferred reference frame ⓘ |
| category |
experiments in special relativity
ⓘ
tests of the speed of light constancy ⓘ |
| comparedWith |
Michelson–Morley experiment with equal arms
ⓘ
linked to:
Michelson–Morley experiment
|
| constrains |
Lorentz-violating theories
ⓘ
ether-drift theories ⓘ |
| countryOfOrigin |
United States
ⓘ
linked to:
United States of America
|
| dependsOn | Earth’s changing velocity around the Sun ⓘ |
| designedBy |
Edward M. Thorndike
ⓘ
linked to:
Edward L. Thorndike
Roy J. Kennedy ⓘ |
| field |
physics
ⓘ
relativity ⓘ |
| historicalPeriod | early 20th century ⓘ |
| implies | time dilation must accompany length contraction ⓘ |
| influenced | development of precision tests of relativity ⓘ |
| inspired | modern resonator-based tests of Lorentz invariance ⓘ |
| measures | fringe shift in interferometer ⓘ |
| namedAfter |
Edward M. Thorndike
ⓘ
linked to:
Edward L. Thorndike
Roy J. Kennedy ⓘ |
| performedAt | Mount Wilson Observatory ⓘ |
| precision | high-precision test of Lorentz invariance ⓘ |
| publishedIn | Physical Review ⓘ |
| relatedTo |
Einstein’s special relativity
ⓘ
Ives–Stilwell experiment ⓘ Lorentz transformation ⓘ Michelson–Morley experiment ⓘ |
| result | null result ⓘ |
| status | experimentally confirmed ⓘ |
| supports | special relativity ⓘ |
| tests |
Lorentz invariance
ⓘ
constancy of the speed of light ⓘ isotropy of the speed of light ⓘ length contraction ⓘ time dilation ⓘ |
| theoreticalFramework |
Lorentz–Einstein transformations
ⓘ
linked to:
Lorentz transformation
|
| uses |
Earth’s orbital motion
ⓘ
optical interferometer ⓘ unequal arm lengths ⓘ |
| year | 1932 ⓘ |
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: Kennedy–Thorndike experiment Description of subject: 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.
Referenced by (5)
Full triples — surface form annotated when it differs from this entity's canonical label.