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phase transition
subject			fact

phase transition	has inverse process
	has definition An abrupt change in the equilibrium state of a system. A sudden transition between one state of matter or energy and another state. For example, when hot water turns to steam or when ice crystallizes out of a liquid that has been cooled to below freezing, a phase transition has occurred. According to the grand unified theories of particle physics, the infant universe may have undergone one or more overall phase transitions. In this case, the energy uniformly filling all space corresponded to the supercooled liquid.
	is a kind of physical process
physical process	has domain physics

Kinds of phase transition :

• first order phase transition (7 kinds, 33 facts) - A phase transition which occurs in a manner similar to the way water boils. Bubbles of the new phase (steam) form in the midst of the old phase (water), so that temporarily the two distinct phases (steam and water) coexist.
• second order phase transition (2 facts) - A phase transition where one phase evolves into the other as the temperature changes, so the two phases never coexist.
• spontaneous symmetry breaking (3 facts) - The breaking of an exact symmetry of the underlying laws of physics by the random formation of some object. For example, the rotational in variance of the laws of physics can be broken by the randomly chosen orientation of an orthorhombic crystal that condenses as the material is cooled. In the standard model of particle physics, the symmetry between electrons and neutrinos is spontaneously broken by the values that are randomly chosen by the Higgs fields. In grand unified theories, the symmetry between electrons, neutrinos, and quarks is spontaneously broken by the values chosen randomly by the Higgs fields., Any situation in physics in which the ground state (i.e. the state of minimum energy) of a system has less symmetry than the system itself. For example, the state of minimum energy for an iron magnet is that in which the atomic spins are all aligned in the same direction, giving rise to a net macroscopic magnetic field. By selecting a particular direction in space. the magnetic field has broken the rotational symmetry of the system. However, if the energy of the system is raised, the symmetry may be restored (e.g. the application of heat to an iron magnet destroys the magnetic field and restores rotational symmetry).