is the ability of a non-equilibrium
state to persist for a long period of time. Usually metastability is due to a relatively slow phase
transformation. For example at room temperature diamonds
are metastable because the phase transformation to the stable graphite
form is extremely slow. At higher temperatures the rate of phase transformation is increased and the diamond will transform to graphite. The bonds between the building blocks of polymers
such as DNA
are also metastable.
In electronics, the flip-flop is a device that suffers from metastability. It has two well-defined stable states, but under certain conditions it can hover between them for longer than the normal decision time.