Physical quantities

quantification of the electrical interactions between ions in solution

product of a distance and a physical quantity

thumb|Chromaticity Diagram of the LCH color space

thermodynamic ratio of isobaric to isochoric specific heat capacities

thumb|upright=1.5|A family of hysteresis loops for grain-oriented electrical steel, a soft magnetic material. BR denotes [[retentivity and HC is the coercivity. The wider the outside loop is, the higher the coercivity. Movement on the loops is counterclockwise.]]

physical quantity that measures the rate of transfer of heat of a material from the hot side to the cold side

quotient of average sound pressure at a surface and sound volume flow rate through that surface

difference in energy of hydrogenic atom electron states not predicted by the Dirac equation

In radiometry, irradiance is the radiant flux received by a surface per unit area. The SI unit of irradiance is the watt per square metre (symbol W⋅m−2 or W/m2). The CGS unit erg per square centimetre per second (erg⋅cm−2⋅s−1) is often used in astronomy. Irradiance is often called intensity, but this term is avoided in radiometry where such usage leads to confusion with radiant intensity. In astrophysics, irradiance is called radiant flux.

property (of a system or substance) that is intensive or is extensive

generalization of electric charge (EM) adding color charge (QCD), mass-energy (gravitation), etc.; sometimes considered same as its charge quantum number

scalar physical quantity

measure of the ability of a porous material to allow fluids to pass through it

power carried by electromagnetic waves

physical quantity

'Delta-v''''' (also known as "change in velocity"), symbolized as {\Delta v} and pronounced , as used in spacecraft flight dynamics, is a measure of the impulse per unit of spacecraft mass that is needed to perform a maneuver such as launching from or landing on a planet or moon, or an in-space orbital maneuver. It is a scalar that has the units of speed. As used in this context, it is not the same as the physical change in velocity of said spacecraft.

in mathematics and theoretical physics, property of a system which remains unchanged under some transformation

thumb|Spectral reflectance curves for aluminium (Al), [[silver (Ag), and gold (Au) metal mirrors at normal incidence]]

complex number whose squared absolute value is a probability

In radiometry, radiance is the radiant flux emitted, reflected, transmitted or received by a given surface, per unit solid angle per unit projected area. Radiance is used to characterize diffuse emission and reflection of electromagnetic radiation, and to quantify emission of neutrinos and other particles. The SI unit of radiance is the watt per steradian per square metre (). It is a directional quantity: the radiance of a surface depends on the direction from which it is being observed.

the property that an increasing voltage results in a decreasing current

measurement of distance in which the change due to the expansion of the universe is factored out

thumb|right|A diagram comparing the size of an average human diver to the size of the modern great white shark, [[whale shark, and the prehistoric megalodon. The illustration also contains a linear measurement in meters in the middle.]] thumb|right|A size comparison illustration comparing the sizes of various planets and stars. In each grouping after the first, the last object from the previous group is presented as the first object of the following group, to present a continuous sense of comparison. thumb|right|A bat skull next to a ruler used to measure size. Size: thumb|right|A finch egg n

temperature difference per length

In spectroscopy, absorbance (abbreviated as A) is a logarithmic value which describes the portion of a beam of light which does not pass through a sample. Whilst the name refers to the absorption of light, other interactions of light with a sample (reflection, scattering) may also contribute to attenuation of the beam passing through the sample. The term "internal absorbance" is sometimes used to describe beam attenuation caused by absorption, while "attenuance" or "experimental absorbance" can be used to emphasize that beam attenuation can be caused by other phenomena.

Crystallinity refers to the degree of structural order in a solid. In a crystal, the atoms or molecules are arranged in a regular, periodic manner. The degree of crystallinity has a large influence on hardness, density, transparency and diffusion. In an ideal gas, the relative positions of the atoms or molecules are completely random. Amorphous materials, such as liquids and glasses, represent an intermediate case, having order over short distances (a few atomic or molecular spacings) but not over longer distances.

velocity of an object or observer B in the rest frame of another object or observer A

standard gravitational acceleration on Earth's surface

measure of the cancer risk to an organism due to ionizing radiation adjusted by tissue type factor

published ISO standard series

measure of how heavy or light a petroleum liquid is compared to water

In physics, an observable is a physical property or physical quantity that can be measured. In classical mechanics, an observable is a real-valued "function" on the set of all possible system states, e.g., position and momentum. In quantum mechanics, an observable is described by a linear operator. For example, these operators might represent submitting the system to various electromagnetic fields and eventually reading a value.

periodic vibration whose frequency is audible to the average human

logarithmic distance scale

dichroism involving circularly polarized light.

international standard

measure of the ability of a porous material to allow water to pass through it

spectral sensitivity of human visual perception of brightness

system describes the number of states per interval of energy at each energy level available to be occupied

physical quantity

Wikimedia list article

Wikimedia list article

ratio of the amplitudes of voltage and current of a single wave propagating along the line

physical quantity of interest in chemistry and electrodynamics

surface integral over the sound intensity

Imperial and US customary (non-metric) unit of volume

Wikimedia list article

areal density of exiting radiant flux

the total length travelled by all free neutrons per unit time and volume

astronomical measurand

physical phenomenon occuring when an object is largely immersed in a fluid, pushing it out of the way and taking its place

path integral of the fluid velocity around a closed curve

system of quantities based on seven base quantities: length, mass, time, electric current, thermodynamic temperature, amount of substance, and luminous intensity

property of photosensitive devices

of a galaxy

thermal quality

incident radiant energy per area

definitions for distance between two objects or events in the universe

concept in particle physics