Lighting in the context of Show control

Theatre or theater is a collaborative form of performing art that uses live performers, usually actors, to present experiences of a real or imagined event before a live audience in a specific place, often a stage. The performers may communicate this experience to the audience through combinations of gesture, speech, song, music, and dance. It is the oldest form of drama, though live theatre has now been joined by modern recorded forms. Elements of art, such as painted scenery and stagecraft such as lighting are used to enhance the physicality, presence and immediacy of the experience. Places, normally buildings, where performances regularly take place are also called "theatres" (or "theaters"), as derived from the Ancient Greek θέατρον (théatron, "a place for viewing"), itself from θεάομαι (theáomai, "to see", "to watch", "to observe").

Modern Western theatre comes, in large measure, from the theatre of ancient Greece, from which it borrows technical terminology, classification into genres, and many of its themes, stock characters, and plot elements. Theatre artist Patrice Pavis defines theatricality, theatrical language, stage writing and the specificity of theatre as synonymous expressions that differentiate theatre from the other performing arts, literature and the arts in general.

Energy development is the field of activities focused on obtaining sources of energy from natural resources. These activities include the production of renewable, nuclear, and fossil fuel derived sources of energy, and for the recovery and reuse of energy that would otherwise be wasted. Energy conservation and efficiency measures reduce the demand for energy development, and can have benefits to society with improvements to environmental issues.

Societies use energy for transportation, manufacturing, illumination, heating and air conditioning, and communication, for industrial, commercial, agricultural and domestic purposes. Energy resources may be classified as primary resources, where the resource can be used in substantially its original form, or as secondary resources, where the energy source must be converted into a more conveniently usable form. Non-renewable resources are significantly depleted by human use, whereas renewable resources are produced by ongoing processes that can sustain indefinite human exploitation.

The control of fire by early humans was a critical technology enabling the evolution of humans. Fire provided a source of warmth and lighting, protection from predators (especially at night), a way to create more advanced hunting tools, and a method for cooking food. These cultural advances allowed human geographic dispersal, cultural innovations, and changes to diet and behavior. Additionally, creating fire allowed human activity to continue into the darker and colder hours of the evening.

Claims for the earliest definitive evidence of control of fire by a member of Homo range from 1.7 to 2.0 million years ago (Mya). Evidence for the "microscopic traces of wood ash" as controlled use of fire by Homo erectus, beginning roughly 1 million years ago, has wide scholarly support. Some of the earliest known traces of controlled fire were found at the Daughters of Jacob Bridge, Israel/Golan Heights, and dated to ~790,000 years ago. At the site, archaeologists also found the oldest likely evidence (mainly, fish teeth that had been heated deep in a cave) for the controlled use of fire to cook food ~780,000 years ago. However, some studies suggest cooking started ~1.8 million years ago.

An oil lamp is a lamp used to produce light continuously for a period of time using an oil-based fuel source. The use of oil lamps began thousands of years ago and continues to this day, although their use is less common in modern times. They work in the same way as a candle but with fuel that is liquid at room temperature, so that a container for the oil is required. A textile wick drops down into the oil, and is lit at the end, burning the oil as it is drawn up the wick.

Oil lamps are a form of lighting, and were used as an alternative to candles before the use of electric lights. Starting in 1780, the Argand lamp quickly replaced other oil lamps still in their basic ancient form. These in turn were replaced by the kerosene lamp in about 1850. In small towns and rural areas the latter continued in use well into the 20th century, until such areas were finally electrified and light bulbs could be used.

An electric light, lamp, or light bulb is an electrical device that produces light from electricity. It is the most common form of artificial lighting. Lamps usually have a base made of ceramic, metal, glass, or plastic that secures them in the socket of a light fixture, which is also commonly referred to as a 'lamp.' The electrical connection to the socket may be made with a screw-thread base, two metal pins, two metal caps or a bayonet mount.

The three main categories of electric lights are incandescent lamps, which produce light by a filament heated white-hot by electric current, gas-discharge lamps, which produce light by means of an electric arc through a gas, such as fluorescent lamps, and LED lamps, which produce light by a flow of electrons across a band gap in a semiconductor.

A light beam or beam of light is a directional projection of light energy radiating from a light source. Sunlight forms a light beam (a sunbeam) when filtered through media such as clouds, foliage, or windows. To artificially produce a light beam, a lamp and a parabolic reflector is used in many lighting devices such as spotlights, car headlights, PAR Cans, and LED housings. Light from certain types of laser has the smallest possible beam divergence.

A light fixture (US English), light fitting (UK English) or luminaire is an electrical lighting device containing one or more light sources, such as lamps and all the accessory components required for its operation to provide illumination to the environment. All light fixtures have a fixture body and one or more lamps. The lamps may be in sockets for easy replacement—or, in the case of some LED fixtures, hard-wired in place.

Fixtures may also have a switch to control the light, either attached to the lamp body or attached to the power cable. Permanent light fixtures, such as dining room chandeliers, may have no switch on the fixture itself, but rely on a wall switch.

A landscape is the visible features of an area of land, its landforms, and how they integrate with natural or human-made features, often considered in terms of their aesthetic appeal. A landscape includes the physical elements of geophysically defined landforms such as mountains, hills, water bodies such as rivers, lakes, ponds and the sea, living elements of land cover including indigenous vegetation, human elements including different forms of land use, buildings, and structures, and transitory elements such as lighting and weather conditions. Combining both their physical origins and the cultural overlay of human presence, often created over millennia, landscapes reflect a living synthesis of people and place that is vital to local and national identity.

The character of a landscape helps define the self-image of the people who inhabit it and a sense of place that differentiates one region from other regions. It is the dynamic backdrop to people's lives. Landscape can be as varied as farmland, a landscape park or wilderness. The Earth has a vast range of landscapes including the icy landscapes of polar regions, mountainous landscapes, vast arid desert landscapes, islands, and coastal landscapes, densely forested or wooded landscapes including past boreal forests and tropical rainforests and agricultural landscapes of temperate and tropical regions. The activity of modifying the visible features of an area of land is referred to as landscaping.

Energy economics is a broad scientific subject area which includes topics related to supply and use of energy in societies. Considering the cost of energy services and associated value gives economic meaning to the efficiency at which energy can be produced. Energy services can be defined as functions that generate and provide energy to the “desired end services or states”. The efficiency of energy services is dependent on the engineered technology used to produce and supply energy. The goal is to minimise energy input required (e.g. kWh, mJ, see Units of Energy) to produce the energy service, such as lighting (lumens), heating (temperature) and fuel (natural gas). The main sectors considered in energy economics are transportation and building, although it is relevant to a broad scale of human activities, including households and businesses at a microeconomic level and resource management and environmental impacts at a macroeconomic level.

Interdisciplinary scientist Vaclav Smil has asserted that "every economic activity is fundamentally nothing but a conversion of one kind of energy to another, and monies are just a convenient (and often rather unrepresentative) proxy for valuing the energy flows."

Darkness is the condition resulting from a lack of illumination, or an absence of visible light.

Human vision is unable to distinguish colors in conditions of very low luminance because the hue-sensitive photoreceptor cells on the retina are inactive when light levels are insufficient, in the range of visual perception referred to as scotopic vision.

A wheel chandelier is a lighting installment, in the form of a chandelier hanging from the ceiling in the form of a spoked wheel. The oldest and most important examples derive from the Romanesque period.

Wheel chandeliers were made for the practical purpose of lighting the great churches and other public areas, but in religion they also had symbolic significance, depicting the Garden of Eden or the Kingdom of God. The wheel, its gates, and its towers, which are usually decorated with Prophets and Apostles or inscribed with their names, symbolise the city walls of the New Jerusalem. The buttresses, towers, and candles number twelve or a multiple of twelve, after the numerology of the Book of Revelation. This symbolism is first found on two wheel chandeliers of Hildesheim Cathedral. The great wheel chandelier of the Church of the Holy Sepulchre was an inspiration.