the.com/meter
the unit that started as a slice of Earth and became a beam of light
means A meter is the base unit of length in the metric system, equal to about 39.37 inches, used worldwide as the standard measure of distance.
from From French 'mètre,' borrowed from Greek 'metron,' meaning 'a measure.' When French scientists set out to define it during the revolutionary push for a rational system of measurement in the late 18th century, they fixed the meter as one ten-millionth of the distance from the equator to the North Pole — a slice of the Earth itself. That definition later gave way to a platinum bar, then to the wavelength of light, and finally to the distance light travels in a tiny fraction of a second, so the word's humble root 'to measure' now anchors itself in the speed of light.
- original definition
- one ten-millionth of pole-to-equator distance
- light-based now
- distance light travels in 1/299,792,458 second
- old standard
- a platinum-iridium bar locked in Paris
- poetry too
- governs rhythm in verse, not just rulers
- survey error
- early Earth measurement was slightly off
paris meridian — french standard meter bar defined in 1795 as 1/10,000,000 of earth's quadrant from equator to pole
international prototype meter — platinum-iridium bar kept at bipm in sèvres, france since 1889 as the official meter standard
speed of light definition — current standard since 1983: one meter is the distance light travels in 1/299,792,458 of a second