Order And Disorder (physics)
In physics, the terms order and disorder designate the presence or absence of some symmetry or correlation in a many-particle system.
In condensed matter physics, systems typically are ordered at low temperatures; upon heating, they undergo one or several phase transitions into less ordered states. Examples for such an order-disorder transition are:
- the melting of ice: solid-liquid transition, loss of crystalline order;
- the demagnetization of iron by heating above the Curie temperature: ferromagnetic-paramagnetic transition, loss of magnetic order.
The degree of freedom that is ordered or disordered can be translational (crystalline ordering), rotational (ferroelectric ordering), or a spin state (magnetic ordering).
The order can consist either in a full crystalline space group symmetry, or in a correlation. Depending on how the correlations decay with distance, one speaks of long-range order or short-range order.
If a disordered state is not in thermodynamic equilibrium, one speaks of quenched disorder. For instance, a glass is obtained by quenching (supercooling) a liquid. By extension, other quenched states are called spin glass, orientational glass. In some contexts, the opposite of quenched disorder is annealed disorder.
Read more about Order And Disorder (physics): Quenched Disorder, Annealed Disorder
Famous quotes containing the words order and/or disorder:
“He had discovered a great law of human action, without knowing it—namely, that in order to make a man or a boy covet a thing, it is only necessary to make the thing difficult to attain. If he had been a great and wise philosopher, like the writer of this book, he would now have comprehended that Work consists of whatever a body is obliged to do and that Play consists of whatever a body is not obliged to do.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)
“In a town-meeting, the great secret of political science was uncovered, and the problem solved, how to give every individual his fair weight in the government, without any disorder from numbers. In a town-meeting, the roots of society were reached. Here the rich gave counsel, but the poor also; and moreover, the just and the unjust.”
—Ralph Waldo Emerson (1803–1882)