Scientific Ontology

t_{1/2}

Quantum

Half-life

Time for half of a radioactive sample to decay.

second (s)

Dimension: $[\,T\,]$

How values of half-life span the physical world (in s, log scale).

Carbon-14

1.80 × 10¹¹ s

Uranium-238

1.40 × 10¹⁷ s

Lower limit10^-6 sUpper limit10¹⁷ s

Half-life and Decay Constant

\lambda = \dfrac{\ln 2}{t_{1/2}}