2019 revision of the SI
id:
2019-revision-of-the-si-189-16688611
title:
2019 revision of the SI
text:
In 2019, four of the seven SI base units specified in the International System of Quantities were redefined in terms of natural physical constants, rather than human artefacts such as the standard kilogram. Effective 20 May 2019, the 144th anniversary of the Metre Convention, the kilogram, ampere, kelvin, and mole are now defined by setting exact numerical values, when expressed in SI units, for the Planck constant (h), the elementary electric charge (e), the Boltzmann constant (kB), and the Avo
brand slug:
wiki
category slug:
encyclopedia
description:
Definition of the units kg, A, K and mol
original url:
https://en.wikipedia.org/wiki/2019_revision_of_the_SI
date created:
2011-01-02T17:52:36Z
date modified:
2024-09-09T21:50:54Z
main entity:
image:
{"content_url":"https://upload.wikimedia.org/wikipedia/commons/a/ab/Unit_relations_in_the_new_SI.svg","width":625,"height":600}
fields total:
13
integrity:
15