Physicist

A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate causes of phenomena, and usually frame their understanding in mathematical terms. They work across a wide range of research fields, spanning all length scales: from sub-atomic and particle physics, through biological physics, to cosmological length scales encompassing the universe as a whole. The field generally includes two types of physicists: experimental physicists who specialize in the observation of natural phenomena and the development and analysis of experiments, and theoretical physicists who specialize in mathematical modeling of physical systems to rationalize, explain and predict natural phenomena.

Physicists can apply their knowledge towards solving practical problems or to developing new technologies (also known as applied physics or engineering physics).

The study and practice of physics is based on an intellectual ladder of discoveries and insights from ancient times to the present. Many mathematical and physical ideas used today found their earliest expression in the work of ancient civilizations, such as the Babylonian astronomers and Egyptian engineers, the Greek philosophers of science and mathematicians such as Thales of Miletus, Euclid in Ptolemaic Egypt, Archimedes of Syracuse and Aristarchus of Samos. Roots also emerged in ancient Asian cultures such as India and China, and particularly the Islamic medieval period, which saw the development of scientific methodology emphasising experimentation, such as the work of Ibn al-Haytham (Alhazen) in the 11th century. The modern scientific worldview and the bulk of physics education can be said to flow from the Scientific Revolution in Europe, starting with the work of astronomer Nicolaus Copernicus leading to the physics of Galileo Galilei and Johannes Kepler in the early 1600s. The work on mechanics, along with a mathematical treatment of physical systems, was further developed by Christiaan Huygens and culminated in Newton's laws of motion and Newton's law of universal gravitation by the end of the 17th century. The experimental discoveries of Faraday and the theory of Maxwell's equations of electromagnetism were developmental high points during the 19th century. Many physicists contributed to the development of quantum mechanics in the early-to-mid 20th century. New knowledge in the early 21st century includes a large increase in understanding physical cosmology.

The broad and general study of nature, natural philosophy, was divided into several fields in the 19th century, when the concept of "science" received its modern shape. Specific categories emerged, such as "biology" and "biologist", "physics" and "physicist", "chemistry" and "chemist", among other technical fields and titles. The term physicist was coined by William Whewell (also the originator of the term "scientist") in his 1840 book The Philosophy of the Inductive Sciences.

A standard undergraduate physics curriculum consists of classical mechanics, electricity and magnetism, non-relativistic quantum mechanics, optics, statistical mechanics and thermodynamics, and laboratory experience. Physics students also need training in mathematics (calculus, differential equations, linear algebra, complex analysis, etc.), and in computer science.

Any physics-oriented career position requires at least an undergraduate degree in physics or applied physics, while career options widen with a master's degree like MSc, MPhil, MPhys or MSci.

For research-oriented careers, students work toward a doctoral degree specializing in a particular field. Fields of specialization include experimental and theoretical astrophysics, atomic physics, biophysics, chemical physics, condensed matter physics, cosmology, geophysics, gravitational physics, material science, medical physics, microelectronics, molecular physics, nuclear physics, optics, particle physics, plasma physics, quantum information science, and radiophysics.

The three major employers of career physicists are academic institutions, laboratories, and private industries, with the largest employer being the last. Physicists in academia or government labs tend to have titles such as Assistants, Professors, Sr./Jr. Scientist, or postdocs. As per the American Institute of Physics, some 20% of new physics Ph.D.s holds jobs in engineering development programs, while 14% turn to computer software and about 11% are in business/education. A majority of physicists employed apply their skills and training to interdisciplinary sectors (e.g. finance).