Physical property

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A physical property is any aspect of an object or substance that can be measured or perceived without changing its identity. Physical properties can be intensive or extensive. An intensive property does not depend on the size or amount of matter in the object, while an extensive property does. In addition to extensiveness, properties can also be either isotropic if their values do not depend on the direction of observation or anisotropic otherwise. Physical properties are referred to as observables. It is not a modal property.

Often, it is difficult to determine whether a given property is physical or not. Color, for example, can be "seen", however, what we perceive as color is really an interpretation of the reflective properties of a surface. In this sense, many ostensibly physical properties are termed as supervenient. A supervenient property is one which is actual (for dependence on the reflective properties of a surface is not simply imagined), but is secondary to some underlying reality.

This is similar to the way in which objects are supervenient on atomic structure. A "cup" might have the physical properties of mass, shape, color, temperature etc, but these properties are supervenient on the underlying atomic structure, which may in turn be supervenient on an underlying quantum structure.

In the common sense, physical properties can be separated from nonphysical properties. Typically a nonphysical property is associated with a living being. Anger and love are not things which are part of the mechanics of the universe, but terms we use to discuss mental states.

Literally, the physical properties of an object are defined traditionally in a Newtonian sense, the physical properties of an object are absorption, acceleration, angle, area, capacitance, concentration, conductance, density, dielectric, displacement, distribution, efficacy, electric charge, electric current, electric field, electric potential, emission, energy, expansion, exposure, flow rate, fluidity, frequency, force, gravitation, impedance, inductance, intensity, irradiance, length, location, luminance, magnetic field, magnetic flux, mass, molality, moment, momentum, permeability, permittivity, power, pressure, radiance, resistance, spin, strength, substance, temperature, tension, thermal transfer, time, velocity, viscosity and volume. Note that there are more not listed here. In an Einstein-relative model, the physical properties of an object might differ.