metre

Also known as metres, mètre, meter, meters

The metre (or meter in US spelling; symbol: m) is the base unit of length in the International System of Units (SI). Since 2019, the metre has been defined as the length of the path travelled by light in vacuum during a time interval of of a second, where the second is defined by a hyperfine transition frequency of caesium.

AI overview

The metre is the standard unit used to measure length or distance in the metric system, and it's used worldwide in science, industry, and everyday life. Since 2019, it has been precisely defined based on how far light travels through a vacuum in a tiny fraction of a second, which ensures consistent and accurate measurements everywhere.

AI-generated from the Wikipedia summary — may contain errors.

Key facts

Unit.name: metre
Unit.image: Metric standards Rijksmuseum.jpg
Unit.caption: Historical replicas of metric standards, including an iron metre
Unit.standard: SI
Unit.units2: Nautical units
Unit.inunits2: ≈
Unit.quantity: length
Unit.symbol: m
Unit.units1: Imperial/US units

via Wikipedia infobox

Wikidata facts

Image: Platinum-Iridium meter bar.jpg

Show 6 more facts

unit symbol: м
Commons category: Metre
conversion to SI unit: 1
Wikidata SPARQL query equivalent: wd:Q11573 p:P2370/psn:P2370 [wikibase:quantityAmount ?source; wikibase:quantityUnit ?base]. ?item p:P2370/psn:P2370 [wikibase:quantityAmount ?target; wikibase:quantityUnit ?base]. BIND(?source / ?target as ?value)
conversion to standard unit: 0.0006213711922373339
NCI Thesaurus ID: C41139

Sources (8)

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Article

9 sections

Contents

Spelling
Etymology
History of definition
SI prefixed forms of metre
Equivalents in other units
See also
Notes
References
Cited bibliography

The metre was originally defined in 1791 by the French National Assembly as one ten-millionth of the distance from the equator to the North Pole along a great circle through Paris, setting as that quarter of the Earth's polar circumference.