 Acoustics
Acoustics is an interdisciplinary science that deals with the production,
control, transmission, reception, and effects of sound, having application
in the life sciences, the earth sciences, engineering, and the arts.
Acoustics is the physics of sound. The study of the science is applied to
noise control problems stemming from vehicle tires, home appliances,
office equipment, and power tools; the design of architectural structures
such as concert halls, lecture halls, and radio and television stations to
optimize sound; the detection and identification of hidden objects (e.g.,
objects submerged in the ocean); the nondestructive evaluation of the
performance and safety of critical components of equipment, such as jet
engines, by analyzing acoustic emissions of the components under stress
during use of the equipment; and the improvement of communication. Related Associations:
 Acoustical Society of America
Astronomy
Astronomy is the
science of the celestial bodies and of their location, magnitude, motions,
and constitution. The application of physics to astronomy for studying the
apparent and real motions of the sun, the moon, the planets, and the stars
is among the earliest contributions to the scientific method. Astronomy is
one of the oldest sciences. Astronomers of early civilizations performed
methodical observations of the night sky, and astronomical artifacts
have been found from much earlier periods. However, the invention of the
telescope was required before astronomy was able to develop into a
modern science. Astronomers use the principles of physics and
mathematics to learn about the fundamental nature of the universe and
its components, including the sun, moon, planets, stars, and galaxies.
As such, astronomy is sometimes considered a subfield of physics. They
also apply their knowledge to solve problems in navigation, space
flight, and satellite communications and to develop the instrumentation
and techniques used to observe and collect astronomical data.
Related Associations:
American Astronomical Society
Astrophysics
Astrophysics
is the branch of astronomy that deals with the physics of the universe,
including the physical properties (luminosity, density, temperature, and
chemical composition) of celestial objects such as stars, galaxies, and
the interstellar medium, as well as their interactions. The study of
cosmology is theoretical astrophysics at the largest scales where Albert
Einstein's general theory of relativity plays a major role. Because
astrophysics is a very broad subject, astrophysicists typically apply
many disciplines of physics, including mechanics, electromagnetism,
statistical mechanics, thermodynamics, quantum mechanics, relativity,
nuclear and particle physics, and atomic and molecular physics.
Related Associations:
American Astronomical Society
Atmospheric
Physics
Atmospheric
physics is the application of physics to the study of the atmosphere.
Atmospheric physicists attempt to model Earth's atmosphere and the
atmospheres of the other planets using fluid flow equations, chemical
models, radiation balancing, and energy transfer processes in the
atmosphere (as well as how these tie in to other systems such as the
oceans). In order to model weather systems, atmospheric physicists
employ elements of scattering theory, wave propagation models, cloud
physics, statistical mechanics and spatial statistics which are highly
mathematical and related to physics. It has close links to meteorology
and climatology and also covers the design and construction of
instruments for studying the atmosphere and the interpretation of the
data they provide, including remote sensing instruments. Divisions of
the U.S National Oceanic and Atmospheric Administration (NOAA) oversee
research projects and weather modeling involving atmospheric physics.
The US National Astronomy and Ionosphere Center also carries out studies
of the high atmosphere.
Related Associations:
International
Association of Meteorology and Atmospheric Sciences
Biophysics
Biophysics is the
application of physical concepts and techniques to the study of the
principles that underlie the structures and functions of living systems;
it is the study of the physical laws that create or affect biological
molecules and processes. Biophysics encompasses several levels of
biological organization, including the molecular level, the subcellular
and cellular level, and the organ level. Molecular biophysics considers
the structure of biological molecules such as enzymes, muscle proteins,
and nucleic acids and how these molecules interact with various forms of
energy. Study of biophysics at the subcellular and cellular level is
concerned with how molecules are organized into special cell structures
and how these structures perform their specialized functions.
Biophysicists also study the physical principles that underlie the
functioning of the ear, eye, and other body systems (e.g., the ear's
response to variations in air pressure that cause sound and the
transformation of energy received by nerve impulses from the eye into
visual sensations such as color, sharpness, brightness, and shape).
Biophysics research also has applications to medicine. For example, it
provides explanation of the functional relationship of body parts and has
potential impact on disease prevention through the study of the body's
defense mechanisms involving proteins at the cell-membrane level.
Related Associations:
Biophysical
Society
Chemical
Physics
Chemical
physics is a sub-discipline of physics that investigates physicochemical
phenomena using techniques from atomic and molecular physics and
condensed matter physics; it is the branch of physics that studies
chemical processes from the point of view of physics. While at the
interface of physics and chemistry, chemical physics is distinct from
physical chemistry in that it focuses more on the characteristic
elements and theories of physics. Meanwhile, physical chemistry studies
the physical nature of chemistry. Nonetheless, the distinction between
the two fields is vague, and workers often practice in each field during
the course of their research. Chemical physicists commonly probe the
structure and dynamics of ions, free radicals, polymers, clusters, and
molecules. Areas of study include the quantum mechanical behavior of
chemical reactions, the process of solvation, inter- and intra-molecular
energy flow, and single entities such as quantum dots. Experimental
chemical physicists use a variety of spectroscopic techniques to better
understand hydrogen bonding, electron transfer, the formation and
dissolution of chemical bonds, chemical reactions, and the formation of
nanoparticles.
Related Associations:
American
Physical Society Division of Chemical Physics
Cryogenics
Cryogenics (Low
Temperature Physics) is the study of matter at temperatures much colder
than those that occur naturally on Earth. Low temperature physicists are
concerned with phenomena such as superfluidity and superconductivity, and
Bose-Einstein Condensation. The field of cryogenics advanced during World
War II when scientists found that metals frozen to low temperatures
showed more resistance to wear. Cryogens, like liquid nitrogen, are used
for specialty chilling and freezing applications. Some chemical
reactions, like those used to produce the active ingredients for the
popular statin drugs, must occur at low temperatures of approximately
-100 °C. The freezing of foods and biotechnology products, like
vaccines, requires nitrogen in blast freezing or immersion freezing
systems. Certain soft or elastic materials become hard and brittle at
very low temperatures, which makes cryogenic milling (grinding) an
option for some materials that cannot easily be milled at higher
temperatures. Another use of cryogenics is cryogenic fuels. Cryogenic
fuels, mainly oxygen and hydrogen, have been used as rocket fuels. For
example, NASA's workhorse space shuttle uses cryogenic oxygen and
hydrogen fuels as its primary means of getting into orbit.
Related Associations:
Cryogenic
Society of America
Crystallography
Crystallography is the
subdivision of chemical physics that deals with the study of crystals
which compose solids and are made up of rigid three-dimensional
latticework of molecules that give rise to special properties such as
shape, hardness, electrical conductivity, and photoconductivity. Before
the development of X-ray diffraction crystallography, the study of
crystals was based on the geometry of the crystals. This involves
measuring the angles of crystal faces relative to theoretical reference
axes (crystallographic axes), and establishing the symmetry of the
crystal in question. Crystallographic methods now depend on the analysis
of the diffraction patterns that emerge from a sample that is targeted
by a beam of some type. The beam is not always electromagnetic
radiation, even though X-rays are the most common choice. For some
purposes electrons or neutrons are used, which is possible due to the
wave properties of the particles.
Related Associations:
American Crystallographic
Association
Electromagnetism
Electromagnetism is the
branch of science that deals with the physical relations between
electricity and magnetism. Light is electromagnetic radiation.
Electromagnetism is the physics of the electromagnetic field: a field
which exerts a force on particles that possess the property of electric
charge, and is in turn affected by the presence and motion of those
particles. The magnetic field is produced by the motion of electric
charges, such as electric current. The magnetic field causes the
magnetic force associated with magnets. The theoretical implications of
electromagnetism led to the development of special relativity by Albert
Einstein in 1905.
Related Associations:
American Institute of Physics
Energy
Energy, as defined by
physicists, is the ability to do work. Energy is one of the most basic
ideas of science. Energy occurs in many forms; physicists seek to find
relationships between the various forms of energy. All occurrences in the
universe can be explained in terms of energy and matter. Physicists
studying energy consider a system containing objects that have the ability
to transfer energy back and forth among themselves. Advances in physics
have had many applications in the area of energy efficiency, including the
development of energy efficient lighting, windows, heating and cooling
systems, and electrical power plants.
Related Associations:
American Institute of Physics
Engineering
Engineering is the
application of science and mathematics by which the properties of matter
and the sources of energy, or physical forces, in nature are made useful
to man in the form of structures, machines, products, systems, and
processes at a reasonable expenditure of time and money. Physics is
closely related to engineering in that engineering uses physical
principles in solving everyday problems and developing applications for
the improvement of the quality of human life. Find out more about
engineering.
Note: Some resources in this section are provided by the
American Institute of Physics.
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