noun: the fact that something has two halves that are exactly the same

noun: the quality of being similar or of balancing each other

noun: (mathematics) an attribute of a shape or relation; exact correspondence of form on opposite sides of a dividing line or plane

noun: balance among the parts of something

noun: (physics) the property of being isotropic; having the same value when measured in different directions

**Keely**

"Macvicar's illustrations of assimilation "*Attraction, inertia, elasticity, heredity, reversion, symmetry, culminating in sphericity or symmetrical cellularity, chemical and electrical action, especially in voltaic action the influence and persistence of this law is most remarkably displayed.*" [JOHN ERNST WORRELL KEELY]

Music has a built-in **symmetry** and asymmetry such as with thirds (minor and major) which are unequal progressions.

**Symmetry** generally conveys two primary meanings. The first is an imprecise sense of harmonious or aesthetically pleasing proportionality and balance; such that it reflects beauty or perfection. The second meaning is a precise and well-defined concept of balance or "patterned self-similarity" that can be demonstrated or proved according to the rules of a formal system: by geometry, through physics or otherwise.

Although the meanings are distinguishable in some contexts, both meanings of "**symmetry**" are related and discussed in parallel.

The precise notions of **symmetry** have various measures and operational definitions. For example, **symmetry** may be observed

- with respect to the passage of time;
- as a spatial relationship;
- through geometric transformations such as scaling, reflection, and rotation;
- through other kinds of functional transformations; and

as an aspect of abstract objects, theoretic models, language, music and even knowledge itself.

This article describes these notions of **symmetry** from four perspectives. The first is that of **symmetry** in geometry, which is the most familiar type of **symmetry** for many people. The second perspective is the more general meaning of **symmetry** in mathematics as a whole. The third perspective describes **symmetry** as it relates to science and technology. In this context, **symmetries** underlie some of the most profound results found in modern physics, including aspects of space and time. Finally, a fourth perspective discusses **symmetry** in the humanities, covering its rich and varied use in history, architecture, art, and religion.

The opposite of **symmetry** is asymmetry. Wikipedia, Symmetry

See Also

**Balance**
**Concord**
**Depolar**
**Disturbance of Equilibrium**
**Equation**
**Equation of Forces**
**Equilibrium**
**Figure 13.14 - Equilibrium as Reciprocal Forces**
**Fulcrum**
**Harmony**
**Neutral**
**Reciprocal**
**Supersymmetry**
**Sympathy**