Over time, the symmetrical forms have to sign expedient organization of human things. The lack of symmetry in the structure of the individual elements of the environment (a tree branch, a man's hand, etc.) Is taken for granted as part of the whole subject and, consequently, its structure is dominated by the laws of the asymmetry arising from its functions, the laws of growth, etc.
Symmetry and asymmetry, complementing each other, are qualitative characteristic of the object, its law-building - the consistency, stability and beauty. The subject is called symmetric if, when it consists of geometrically or physically relatively equal parts, in a given order. The classification of main types of symmetry determines the geometric mirror (compatible) equality.
The simplest form of symmetry - mirror - is based on the equality of the two parts of the figure, located relative to one another, as an object and its reflection in the mirror. An imaginary plane that divides a figure in half called the symmetry plane and is denoted by t (from the French. Miroir-Mirror).
Another type of symmetry - the axial - due to the congruence, achieved by rotating the shape relative to the symmetry, i.e. line, when you turn around that figure can be repeatedly combined. The number of superimpositions for a complete revolution (360 °) is called the order of the axis and angle of each combination of shape - an elementary angle.
A typical variant of symmetry - screw - the result of the rotational motion of a point or line around a fixed axis with constant angular velocity and a simultaneous translational movement along this axis is also at a constant rate.
Household appliances, cars, clothes and many other objects are built according to the laws of mirror symmetry. Less common axial symmetry, it is typical for washing machines, vessels, etc. Screw symmetry found in the structural elements of aircraft, machinery, machine tools, ships, etc.
Symmetry helps to identify the main composition of predetermining its movement toward the center or plane of symmetry.
The composition and the static equilibrium (with respect to the axis of motion) of the vehicle provided by its symmetrical structure of the external. Dynamics and streamlining of its shape (or the axis of motion) generated by the laws of aerodynamics, help to increase speed and reduce fuel consumption. |