Metre - Wikipedia Where older traditional length measures are still used, they are now defined in terms of the metre – for example the yard has since 1959 officially been defined as exactly 0 9144 metre
Metre (m) | Britannica Metre (m), in measurement, fundamental unit of length in the metric system and in the International Systems of Units (SI) It is equal to approximately 39 37 inches in the British Imperial and United States Customary systems
Meter vs. Metre: Whats the Difference? - Grammarly The difference lies in the geographic or cultural preference: meter is the preferred spelling in American English, while metre is preferred in British English and other forms of English outside the United States
metre – Metric System The effect of this definition is that one metre is the length of the path travelled by light in vacuum during a time interval with duration of 1 ⁄ 299 792 458 of a second
- metre - BIPM The metre, symbol m, is the SI unit of length It is defined by taking the fixed numerical value of the speed of light in vacuum c to be 299 792 458 when expressed in the unit m s–1, where the second is defined in terms of the caesium frequency ΔνCs
History of the metre - Wikipedia Alongside his intercomparisons of artifacts of the metre and contributions to gravimetry through improvement of the reversible pendulum, Peirce was the first to tie experimentally the metre to the wave length of a spectral line