Reference library
Foundations
Explore concepts, laws, equations and methods, with clear explanations of their use and sources. Choose an area of study or find a specific entry.
More filters
Reference entries
Showing 361–365 of 365 reference entries
Measurement · PhysicsRadiant flux, intensity, irradiance, exitance and radiance
Optical power, directional power and surface densities are different quantities.
DefinitionMeasurement · PhysicsPhotometric weighting, lumen, candela, lux and luminancePhotometry weights radiation with a specified standard visual response.
DefinitionMeasurement · Physics · ChemistryCommon non-SI units and exact SI conversionsCommon non-SI unit names require their correct SI scale factors.
DefinitionPhysics · ChemistryGas pressure as molecular momentum transferMolecular collisions link macroscopic pressure to random translational motion.
ModelChemistry · PhysicsOrdinary aggregate states and bulk behaviorSolid, liquid and gas describe bulk behavior rather than chemical identity.
Model