Rotation formalisms in three dimensionsIn geometry, various formalisms exist to express a rotation in three dimensions as a mathematical transformation. In physics, this concept is applied to classical mechanics where rotational (or angular) kinematics is the science of quantitative description of a purely rotational motion. The orientation of an object at a given instant is described with the same tools, as it is defined as an imaginary rotation from a reference placement in space, rather than an actually observed rotation from a previous placement in space.
Artistic canons of body proportionsAn artistic canon of body proportions (or aesthetic canon of proportion), in the sphere of visual arts, is a formally codified set of criteria deemed mandatory for a particular artistic style of figurative art. The word canon () was first used for this type of rule in Classical Greece, where it set a reference standard for body proportions, so as to produce a harmoniously formed figure appropriate to depict gods or kings. Other art styles have similar rules that apply particularly to the representation of royal or divine personalities.
Body proportionsBody proportions is the study of artistic anatomy, which attempts to explore the relation of the elements of the human body to each other and to the whole. These ratios are used in depictions of the human figure and may become part of an artistic canon of body proportion within a culture. Academic art of the nineteenth century demanded close adherence to these reference metrics and some artists in the early twentieth century rejected those constraints and consciously mutated them.
Soil functionsSoil functions are general capabilities of soils that are important for various agricultural, environmental, nature protection, landscape architecture and urban applications. Soil can perform many functions and these include functions related to the natural ecosystems, agricultural productivity, environmental quality, source of raw material, and as base for buildings. Six key soil functions are: Food and other biomass production Environmental Interaction Biological habitat and gene pool Source of raw materials Physical and cultural heritage Platform for man-made structures Soil acts as an anchor for plant roots.
ShoeA shoe is an item of footwear intended to protect and comfort the human foot. Though the human foot can adapt to varied terrains and climate conditions, it is vulnerable, and shoes provide protection. Form was originally tied to function but over time shoes also became fashion items. Some shoes are worn as safety equipment, such as steel-toe boots, which are required footwear at industrial worksites. Additionally, fashion has often evolved into many different designs, such as high heels, which are most commonly worn by women during fancy occasions.