Bifurcation

A bifurcation is any change in the qualitative form of the attractor of a dynamical system.

Bifurcations typically occur in dynamical systems as some control parameter is continuously varied and there is often something "bi" about it.

In Benard convection, heat from the surface of the earth simply conducts its way to the top of the atmosphere until the rate of heat generation at the surface of the earth gets too high. Then the atmosphere develops convection cells one rotating left and the other rotating right.

In a dripping faucet at low pressure, the drops come off the faucet with equal spacing. As the pressure is increased the drops begin to fall with two drops falling close together, then a longer wait then two drops falling close together again, a process described as "period doubling".