3D printing3D printing or additive manufacturing is the construction of a three-dimensional object from a CAD model or a digital 3D model. It can be done in a variety of processes in which material is deposited, joined or solidified under computer control, with material being added together (such as plastics, liquids or powder grains being fused), typically layer by layer. In the 1980s, 3D printing techniques were considered suitable only for the production of functional or aesthetic prototypes, and a more appropriate term for it at the time was rapid prototyping.
CivilizationA civilization (British English: civilisation) is any complex society characterized by the development of the state, social stratification, urbanization, and symbolic systems of communication beyond natural spoken language (namely, a writing system). Civilizations are additionally characterized by other features, including agriculture, architecture, infrastructure, technological advancement, taxation, regulation, and specialization of labour.
Ancient EgyptAncient Egypt was a civilization in Northeast Africa situated in the Nile Valley. Ancient Egyptian civilization followed prehistoric Egypt and coalesced around 3100 BC (according to conventional Egyptian chronology) with the political unification of Upper and Lower Egypt under Menes (often identified with Narmer). The history of ancient Egypt occurred as a series of stable kingdoms, separated by periods of relative instability known as Intermediate Periods: the Old Kingdom of the Early Bronze Age, the Middle Kingdom of the Middle Bronze Age and the New Kingdom of the Late Bronze Age.
Art of ancient EgyptAncient Egyptian art refers to art produced in ancient Egypt between the 6th millennium BC and the 4th century AD, spanning from Prehistoric Egypt until the Christianization of Roman Egypt. It includes paintings, sculptures, drawings on papyrus, faience, jewelry, ivories, architecture, and other art media. It was a conservative tradition whose style changed very little over time. Much of the surviving examples comes from tombs and monuments, giving insight into the ancient Egyptian afterlife beliefs.
Complex geometryIn mathematics, complex geometry is the study of geometric structures and constructions arising out of, or described by, the complex numbers. In particular, complex geometry is concerned with the study of spaces such as complex manifolds and complex algebraic varieties, functions of several complex variables, and holomorphic constructions such as holomorphic vector bundles and coherent sheaves. Application of transcendental methods to algebraic geometry falls in this category, together with more geometric aspects of complex analysis.
Cradle of civilizationA cradle of civilization is a location and a culture where civilization was created independent of other civilizations in other locations. The formation of urban settlements (cities) is the primary characteristic of a society that can be characterized as "civilized". Other characteristics of civilization include a sedentary non-nomadic population, monumental architecture, the existence of social classes and inequality, and the creation of a writing system for communication.
Civilization stateA civilization state, or civilizational state, is a country that aims to represent not just a historical territory, ethnolinguistic group, or body of governance, but a unique civilization in its own right. It is distinguished from the concept of a nation state by describing a country's dominant sociopolitical modes as constituting a category larger than a single nation. When classifying states as civilization states, emphasis is often placed on a country's historical continuity and cultural unity across a large geographic region.
Silicon dioxideSilicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and most abundant families of materials, existing as a compound of several minerals and as a synthetic product. Notable examples include fused quartz, fumed silica, silica gel, opal and aerogels. It is used in structural materials, microelectronics (as an electrical insulator), and as components in the food and pharmaceutical industries.
Euclidean geometryEuclidean geometry is a mathematical system attributed to ancient Greek mathematician Euclid, which he described in his textbook on geometry, Elements. Euclid's approach consists in assuming a small set of intuitively appealing axioms (postulates) and deducing many other propositions (theorems) from these. Although many of Euclid's results had been stated earlier, Euclid was the first to organize these propositions into a logical system in which each result is proved from axioms and previously proved theorems.
Non-Euclidean geometryIn mathematics, non-Euclidean geometry consists of two geometries based on axioms closely related to those that specify Euclidean geometry. As Euclidean geometry lies at the intersection of metric geometry and affine geometry, non-Euclidean geometry arises by either replacing the parallel postulate with an alternative, or relaxing the metric requirement. In the former case, one obtains hyperbolic geometry and elliptic geometry, the traditional non-Euclidean geometries.