← All parts of this equation

Equation 4 · Part 2 · The Last Artefact: Redefining the Kilogram

Symbol e

KJ=2eh,RK=he2,KJ2RK=4hK_{\mathrm J} = \frac{2e}{h}, \qquad R_{\mathrm K} = \frac{h}{e^{2}}, \qquad K_{\mathrm J}^{2} R_{\mathrm K} = \frac{4}{h}
ee

What this part means

e is an input to the expression that computes the quantity on the left.

Its job in the formula

e is an input to the expression that computes the quantity on the left.

The passage around this formula

…the international uniformity of electrical measurements and their consistency with the SI” [ 9 ] . The consequence was a parallel electrical unit system, close to the SI but not identical to it [ 3 ] . Fixing h and e together dissolved the parallel system: KJ and RK are now calculated exactly from the defining constants, and the conventional values were retired [ 3 ] . A Kibble balance is therefore not merely an accurate balance. It is a mechanical quantity expressed entirely in quantum-referenced electrical…

Read this part in the article →

Learn the underlying idea

A variable is a named place for a value. Its letter is a local label: x can mean position in one formula and a data point in another.

Open the illustrated variables: a letter stands for a value guide →

See this notation across published equations →

Sources cited in the surrounding passage

These citations provide research context; check each source for the exact claim it supports.