The macroscopic scale is the length scale on which objects or phenomena are large enough to be visible with the naked eye, without magnifying optical instruments.
When applied to physical phenomena and bodies, the macroscopic scale describes things as a person can directly perceive them, without the aid of magnifying devices. This is in contrast to observations (microscopy) or theories (microphysics, statistical physics) of objects of geometric smaller than perhaps some hundreds of .
A macroscopic view of a ball is just that: a ball. A microscopic view could reveal a thick round skin seemingly composed entirely of puckered cracks and fissures (as viewed through a microscope) or, further down in scale, a collection of in a roughly sphere shape (as viewed through an electron microscope). An example of a physical theory that takes a deliberately macroscopic viewpoint is thermodynamics. An example of a topic that extends from macroscopic to microscopic viewpoints is histology.
In statistical mechanics
In statistical mechanics, a macroscopic quantity refers to averages of many
particles, like
temperature or
pressure.
[ The boundary between microscopic and macroscopic scales is called the thermodynamic limit.]
In quantum mechanics
In early quantum mechanics, macroscopic scale distinguished a measurement apparatus from the quantum system being studied. These concepts were not clearly defined and were often conflated with macroscopic meaning a system treatable with classical mechanics while microscopic meant quantum mechanics was required. Numerous attempts to define the boundary between macroscopic and microscopic in quantum mechanics followed, notably work by Anthony Leggett in the 1970s and 1980s. Leggett sought quantum systems of macroscopic scale.
In pathology
In pathology, macroscopic diagnostics generally involves gross pathology, in contrast to microscopic histopathology.
In geology
In geology, megascopic refers to the study of rocks without the aid of a microscope, typically in the field.
See also
