|Quantities, physics: measurable properties of objects, processes or states. See also Scales, Proportions, Change, Motion, Processes, Flux, Space, Time, Spacetime, Metrisability.|
Books on Amazon
Quantities/Measure/Perdijon: size is connected to the property of quality, whereas the intensity is an expression of the amount, the quantity. - Size: quality - value: Quantity - Secondary quantities: not all physical quantities can be measured directly - E.g. interferometer: here, primary quantities have to be translated into secondary quantities: the invisible wavelengths into the movement of a pointer. - Mass: complex concept, needs experiments and interpretation.
Quantities/Measure/Perdijon: the value of most can be given by a simple number. But not vectors and tensors. However, they can be represented in the form of several scalar variables - measurable quantities: Example: speed in one point: three components - E.g. electric current: intensity and polarity - E.g. distribution. Number of individuals in different classes - e.g. sum of values: for most quantities no problem: E.g. two lengths or two masses can be added: this additive commutative qunantity is called measurable quantities. These include in the wider sense also not summable sizes but whose sum can be defined by a law of physics. E.g. resistance can be measured, even if it is not summable. - Against: relative quantities: with them one can only determine whether they are greater than or equal to others - e.g. temperature, E.g. hardness - X 74 - these quantities form an ordered set, they can be characterized - N.B.: E.g. a point of time can be marked, a period of time, however, is measurable - marked quantity: in extreme cases, the scale is reduced for them in such a way that there can only be expressed yes or no. We then speak of attributes - E.g. Fit - size is usually defined at all points of a body. - It is an average size that can be given as a common value for the entire volume.
Measure/quantities/Perdijon: measurable quantities: by numbers (Definition: summable!) - Relative quantities: only comparison: E.g. temperature, hardness (not summable) - extreme values: E.g. length, diameter: cannot be used arbitrarily, but at the outermost points.
|Link to abbreviations/authors|