luminous-flux density — noun : the luminous energy in a beam of light passing a unit normal section per unit time called also intensity of light … Useful english dictionary
Luminous efficacy — is a measure of how well a light source produces visible light. It is the ratio of luminous flux to power. Depending on context, the power can be either the radiant flux of the source s output, or it can be the total electric power consumed by… … Wikipedia
Orders of magnitude (specific energy density) — This is a table of specific energy densities by magnitude. Unless otherwise noted, these values assume standard ambient temperature and pressure. List of orders of magnitude for specific energy density Order of magnitude J/(kg) Specific energy… … Wikipedia
Energy — This article is about the scalar physical quantity. For other uses, see Energy (disambiguation). Energetic redirects here. For other uses, see Energetic (disambiguation) … Wikipedia
Orders of magnitude (energy) — Different orders of magnitude of natural energy production for solar, wind and geothermal versus average global consumption rate (1 W = 1 J/s) This list compares various energies in joules (J), organized by order of magnitude. List of orders of… … Wikipedia
Orders of magnitude (luminous flux) — To help compare different orders of magnitude, the following list describes various lumen, which is measured in lm. Factor (lm) Multiple Value Item 10 2 1 centilumen (clm) 0.025 lm One firefly[1] 101 10 lumen (lm) 12.57 lm One candle … Wikipedia
Radiant energy — Visible light (a form of radiant energy) scattered by fog in a forest. Radiant energy is the energy of electromagnetic waves.[1] The quantity of radiant energy may be calculated by integrating radiant flux (or power) with respect to time and … Wikipedia
Orders of magnitude (density) — Skylab measured several orders of magnitude of the Sun s density (top scale: 10−18 to 10−6 g⋅cm−3, equivalent to 10−15 to 10−3 kg⋅m−3) at different temperatures and heights above its surface. List of orders of magnitude for density less than … Wikipedia
Dark-energy star — A dark energy star is a hypothetical compact astrophysical object, which a minority of physicists feel might constitute an alternative explanation for observations of astronomical black hole candidates. Dark energy is invisible to the human eye;… … Wikipedia
Wireless energy transfer — or wireless power is the transmission of electrical energy from a power source to an electrical load without artificial interconnecting conductors. Wireless transmission is useful in cases where interconnecting wires are inconvenient, hazardous,… … Wikipedia
Exposure (photography) — Underexposure redirects here. For the 2005 film by Oday Rasheed, see Underexposure (2005 film). A long exposure showing stars rotating around the southern and northern celestial poles. Credit: European Southern Observatory … Wikipedia