**PHYSICS - (from
the Greek, φυσικός (physikos), "natural", and φύσις (physis), "nature") is the
science of the natural world dealing with the fundamental constituents of the
universe, the forces they exert on one another, and the results produced by
these forces. Physicists study a wide range of physical phenomena spanning all
length scales: from the sub-atomic particles from which all ordinary (i.e.,
baryonic) matter is made (particle physics) to the behavior of the material
Universe as a whole (cosmology).**

**Physics discoveries find applications throughout the
other natural sciences, since it studies the basic constituents of the natural
world. Some of the phenomena studied in physics, such as the conservation of
energy, are common to all material systems. These are often referred to as laws
of physics. Physics is sometimes said to be the "fundamental science", because
each of the other natural sciences (biology, chemistry, geology, etc.) deals
with particular types of material systems that obey the laws of physics. For
example, chemistry is the science of molecules and the chemicals that they form
in the bulk. The properties of a chemical are determined by the properties of
the underlying molecules, which can be described by areas of physics such as
quantum mechanics (called in this case quantum chemistry), thermodynamics, and
electromagnetism.**

Physics is closely related to mathematics, which provides the logical framework
where physical laws can be precisely formulated and their predictions
quantified. Physical theories are almost invariably expressed using mathematical
relations, and the mathematics involved is generally more complicated than in
the other sciences. The difference between physics and mathematics is that
physics is ultimately concerned with descriptions of the material world, whereas
mathematics is concerned with abstract patterns that need not have any bearing
on it. The distinction, however, is not always clear-cut. There is a large area
of research intermediate between physics and mathematics, known as mathematical
physics, devoted to developing the mathematical structure of physical theories.

While physics has a remarkably broad purview, it attempts only to describe those
aspects of the world that can be dealt with by the scientific method. It is not
concerned with issues that cannot be verified even in principle, such as those
studied in metaphysics.