Wiccan views of divinity the ancient Greek conception, where the elements correspond to matter (earth) and energy (fire), with the mediating elements (water, air) relating to the phases of matter (fire/earth mixtures). A more modern conception correlates the four elements to the four states of matter known to science: Solid (earth); Liquid (water); Gas (air); and Plasma (fire); with the akasha element corresponding to pure Energy. The Aristotelian system proposes a fifth or quintessential element, spirit (aether, akasha). The preferred version is a matter of ongoing dispute in the Wiccan community. There are other non-scientific conceptions, but they are not widely used among Wiccans.
Water atm, water boils at . At very low pressures (below about 0.006 atm), water cannot exist in the liquid state and passes directly from solid to gas by sublimation—a phenomenon exploited in the freeze drying of food. At very high pressures (above 221 atm), the liquid and gas states are no longer distinguishable, a state called supercritical steam. Water also differs from most liquids in that it becomes less dense as it freezes. The maximum density of water in its liquid form (at 1 atm) is ; that occurs at . The density of ice is . Thus, water expands