Exponential decay

Exponential decay is the decay of a physical property whose value goes as

$A=A_{0}e^{-(t-t_{0})/\tau }$

where $A_{0}$ is the value at time $t_{0}$ and $\tau$ expresses the rate of exponential decay. The quantity reaches one-half of its original value after a time interval equal to $\tau$ ln 2, which is called its half-life.

Examples

Examples of exponential decay include the radioactive decay of radioisotopes, the attenuation of sound or light through an absorber, and the decay of the magnetic fields of the planets.

See also

• Exponential growth