"Physical dimension" redirects here. For the dimension of a physical quantity, see
Dimension (physics)
.
"Resizing" redirects here. For resizing of digital images, see image scaling.
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.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.A bat skull next to a ruler used to measure size. Size: 7 mm (0.28 in)A finch egg next to a dime; a person familiar with the size of a dime would thereby have a sense of the size of the egg.Forced perspective illusion wherein the perceived size of the Sphinx next to a human is distorted by the incomplete view of both, and the appearance of physical contact between the two.
).
Size can also be measured in terms of mass, especially when assuming a density range.
This animation gives a sense of the scale of some of the known objects in our universe.
In mathematical terms, "size is a concept abstracted from the process of measuring by comparing a longer to a shorter".
inches
.
The sizes with which humans tend to be most familiar are body dimensions (measures of anthropometry), which include measures such as human height and human body weight. These measures can, in the aggregate, allow the generation of commercially useful distributions of products that accommodate expected body sizes,[2] as with the creation of clothing sizes and shoe sizes, and with the standardization of door frame dimensions, ceiling heights, and bed sizes. The human experience of size can lead to a psychological tendency towards size bias,[3] wherein the relative importance or perceived complexity of organisms and other objects is judged based on their size relative to humans, and particularly whether this size makes them easy to observe without aid.
Human perception
Humans most frequently perceive the size of objects through
visual cues.[4] One common means of perceiving size is to compare the size of a newly observed object with the size of a familiar object whose size is already known. Binocular vision gives humans the capacity for depth perception, which can be used to judge which of several objects is closer, and by how much, which allows for some estimation of the size of the more distant object relative to the closer object. This also allows for the estimation of the size of large objects based on comparison of closer and farther parts of the same object. The perception of size can be distorted by manipulating these cues, for example through the creation of forced perspective
The sizes of objects that can not readily be measured merely by sensory input may be evaluated with other kinds of
field of vision may be measured using a telescope, or through extrapolation from known reference points. However, even very advanced measuring devices may still present a limited field of view
.
Terminology
Objects being described by their relative size are often described as being comparatively big and little, or large and small, although "big and little tend to carry affective and evaluative connotations, whereas large and small tend to refer only to the size of a thing".[5] A wide range of other terms exist to describe things by their relative size, with small things being described for example as tiny, miniature, or minuscule, and large things being described as, for example, huge, gigantic, or enormous. Objects are also typically described as tall or short specifically relative to their vertical height, and as long or short specifically relative to their length along other directions.
Although the size of an object may be reflected in its
gravity.[6] An object with a mass of 1.0 kilogram will weigh approximately 9.81 newtons (newton is the unit of force, while kilogram is the unit of mass) on the surface of the Earth (its mass multiplied by the gravitational field strength). Its weight will be less on Mars (where gravity is weaker), more on Saturn, and negligible in space when far from any significant source of gravity, but it will always have the same mass. Two objects of equal size, however, may have very different mass and weight, depending on the composition and density
of the objects. By contrast, if two objects are known to have roughly the same composition, then some information about the size of one can be determined by measuring the size of the other, and determining the difference in weight between the two. For example, if two blocks of wood are equally dense, and it is known that one weighs ten kilograms and the other weighs twenty kilograms, and that the ten kilogram block has a volume of one cubic foot, then it can be deduced that the twenty kilogram block has a volume of two cubic feet.
Conceptualization and generalization
The concept of size is often applied to ideas that have no physical reality. In
class
of objects to which it belongs. There are various other mathematical concepts of size for sets, such as:
cardinality (equal if there is a bijection), of a set is a measure of the "number of elements of the set"
for well-ordered sets: ordinal number (equal if there is an order-isomorphism)
In
false positives, denoted by α. In astronomy, the magnitude of brightness or intensity of a star is measured on a logarithmic scale. Such a scale is also used to measure the intensity of an earthquake, and this intensity is often referred to as the "size" of the event.[7] In computing, file size is a measure of the size of a computerfile, typically measured in bytes. The actual amount of disk space consumed by the file depends on the file system. The maximum file size a file system supports depends on the number of bits
reserved to store size information and the total size of the file system in terms of its capacity to store bits of information.
In
comoving distance – the distance as would be measured at a specific time, including the present – between Earth and the edge of the observable universe is 46 billion light-years (14×10^9 pc), making the diameter of the observable universe
, placing humans in a different context within their natural environment by depicting them as having physically been made exceptionally large or exceptionally small through some fantastic means.
^See, e.g., Robert A. Meyers, Extreme Environmental Events: Complexity in Forecasting and Early Warning (2010), p. 364, stating "[t]he corner frequency scales with the size of the earthquake measured by the seismic moment".
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Media related to Size at Wikimedia Commons