cesium atomic clocks

E116184

atomic clock timekeeping device

Cesium atomic clocks are ultra-precise timekeeping devices that use the microwave frequency of cesium atoms’ electron transitions to define and maintain the international standard for the second.

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All labels observed (8)

Label	Occurrences
NIST-F1	1
NIST-F1 cesium fountain clock	1
NIST-F2 cesium fountain clock	1
cesium atomic clock	1
cesium atomic clocks canonical	1
cesium fountain clock	1
cesium-133 atomic transition	1
cesium-beam atomic clock	1

How this entity was disambiguated

This entity first appeared as the object of triple T982966 — 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: cesium atomic clocks
Context triple: [International Atomic Time, basedOn, cesium atomic clocks]

A. International Atomic Time
International Atomic Time is a high-precision time standard based on the combined output of atomic clocks worldwide, serving as the fundamental reference for modern civil and scientific timekeeping.
B. Astronomical Clock
The Astronomical Clock in Prague is a medieval timepiece and astronomical instrument famous for its intricate mechanical design and hourly animated figures, making it one of the city’s most iconic landmarks.
C. Einstein synchronization convention
The Einstein synchronization convention is a method in special relativity for synchronizing distant clocks using light signals, forming the standard basis for defining simultaneity in inertial frames.
D. Deep Space Network
The Deep Space Network is NASA’s global system of large radio antennas used to track, communicate with, and receive data from distant spacecraft throughout the solar system and beyond.
E. MICROSCOPE satellite mission
The MICROSCOPE satellite mission was a French-led space experiment designed to test the validity of Einstein’s equivalence principle with unprecedented precision by comparing the free fall of different materials in orbit.
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: cesium atomic clocks
Target entity description: Cesium atomic clocks are ultra-precise timekeeping devices that use the microwave frequency of cesium atoms’ electron transitions to define and maintain the international standard for the second.

A. International Atomic Time
International Atomic Time is a high-precision time standard based on the combined output of atomic clocks worldwide, serving as the fundamental reference for modern civil and scientific timekeeping.
B. Astronomical Clock
The Astronomical Clock in Prague is a medieval timepiece and astronomical instrument famous for its intricate mechanical design and hourly animated figures, making it one of the city’s most iconic landmarks.
C. Einstein synchronization convention
The Einstein synchronization convention is a method in special relativity for synchronizing distant clocks using light signals, forming the standard basis for defining simultaneity in inertial frames.
D. Deep Space Network
The Deep Space Network is NASA’s global system of large radio antennas used to track, communicate with, and receive data from distant spacecraft throughout the solar system and beyond.
E. MICROSCOPE satellite mission
The MICROSCOPE satellite mission was a French-led space experiment designed to test the validity of Einstein’s equivalence principle with unprecedented precision by comparing the free fall of different materials in orbit.
F. None of above. chosen

Statements (48)

Predicate	Object
instanceOf	atomic clock ⓘ timekeeping device ⓘ
associatedWithOrganization	Bureau International des Poids et Mesures ⓘ linked to: International Bureau of Weights and Measures National Institute of Standards and Technology ⓘ National Physical Laboratory (UK) ⓘ linked to: National Physical Laboratory
basedOn	hyperfine transition of cesium-133 ground state ⓘ
comparedWith	optical atomic clocks ⓘ
controlledBy	atomic transition frequency ⓘ
defines	SI second ⓘ
developedFor	high-precision time standards ⓘ
enables	definition of the SI second since 1967 ⓘ
firstRealizedIn	1950s ⓘ
hasAccuracy	on the order of 10^-16 relative uncertainty for primary standards ⓘ
hasComponent	cesium beam tube ⓘ detector for atomic state ⓘ feedback control system ⓘ frequency synthesizer ⓘ magnetic shielding ⓘ microwave cavity ⓘ quartz oscillator ⓘ vacuum system ⓘ
hasLimitation	lower frequency than optical clocks ⓘ
hasProperty	long-term frequency stability ⓘ low drift over time ⓘ
hasVariant	cesium beam clock ⓘ cesium fountain clock ⓘ linked to: cesium atomic clocks space-qualified cesium clock ⓘ
maintains	international standard for the second ⓘ
measurementPrinciple	resonant interaction of microwaves with cesium atoms ⓘ
operatesAtFrequency	9,192,631,770 hertz ⓘ
operatesIn	microwave region of the electromagnetic spectrum ⓘ
requires	stable magnetic field ⓘ temperature control ⓘ ultra-high vacuum ⓘ
stabilizes	microwave oscillator frequency ⓘ
standardizedBy	International Committee for Weights and Measures ⓘ
usedFor	fundamental physics experiments ⓘ global navigation satellite systems timing ⓘ international timekeeping ⓘ metrology ⓘ realization of Coordinated Universal Time ⓘ realization of International Atomic Time ⓘ telecommunications synchronization ⓘ
usedIn	ground-based timing laboratories ⓘ satellite systems ⓘ time distribution networks ⓘ
uses	cesium atoms ⓘ microwave frequency transitions of cesium atoms ⓘ

How these facts were elicited