134 years have passed since the modern definition of the metro

2023-09-28 12:54:03

Subway pattern – WIKIMEDIA

MADRID, 28 Sep. (EUROPA PRESS) –

This September 28 marks 134 years since the First General Conference of Weights and Measures, in 1889, defined the meter as the distance between two lines on a platinum-iridium bar.

The history of the meter as a unit of length It started a hundred years ago. In the French Revolution of 1789, along with other challenges considered necessary for the new times, Scientific Commissions were appointed to standardize weights and measures, including length.

The task was arduous and complicated; The length of the pendulum in one second at the latitude of 45 degrees was considered as a standard, but it was eventually discarded because it was not a completely objective model. It would finally be agreed to measure a meridian arc to establish, on it and therefore on the Earth itself, the standard of the meter, whose etymology is the Greek word ‘metron’, which means measure.

Those in charge of said measurement were Jean Baptiste Joseph Delambre and Pierre Méchain, who between 1791 and 1798 and through a system of triangulation from Dunkirk to Barcelona, ​​established the measurement of said meridian arc on which the meter was established. informs Wikipedia.

Initially, this unit of length was created by the French Academy of Sciences in 1792 and defined as one ten millionth of the distance that separates the pole from the Earth’s equator, across the Earth’s surface. If this value were expressed in a manner analogous to how the nautical mile is defined, It would correspond to the length of the terrestrial meridian that forms an arc of 1/10 of a second of a centesimal degree.

Finally, on September 28, 1889, the International Commission on Weights and Measures adopted in its first conference new prototypes for the meter and, later, for the kilogram, which materialized in patterns of platinum and iridium alloy deposited in the underground of the Office of Weights and Measures in Sèvres, just outside Paris.

These standards were used until 1960. Since 1983, the current definition of the meter is the “distance traveled by light in a vacuum in 1/299792458 parts of a second”, given at the XVII General Conference of the International Bureau of Weights and Measures.