Snowflake unlikely that any two snowflakes are alike due to the estimated 10 (10 quintillion) water molecules which make up a typical snowflake, which grow at different rates and in different patterns depending on the changing temperature and humidity within the atmosphere that the snowflake falls through on its way to the ground. Snowflakes that look identical, but may vary at the molecular level, have been grown under controlled conditions. Although snowflakes are never completely symmetrical, a non-aggregated snowflake often grows so as to exhibit an approximation of six-fold radial symmetry. The symmetry gets started due to the hexagonal crystalline structure
Symmetrical components for three phase voltage components can be written as and decomposing the vector into three symmetrical components gives where the subscripts 0, 1, and 2 refer respectively to the zero, positive, and negative sequence components. The sequence components differ only by their phase angles, which are symmetrical and so are formula_3 radians or 120°. Define a phasor rotation operator alpha, which rotates a phasor vector counterclockwise by 120 degrees: Note that α = 1 so that α = α. The zero sequence components have equal magnitude and in phase with each other, therefore: and the other phase sequences have the