Overview of Physicists: Who Are They? What Do They Do?

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 nature phenomena. 

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

HISTORY

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 word of ancient civilizations, such as the Babylonian astronomers and Egyptian engineers, the Greek philosophers of science and mathematics 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 emphasizing experimentation, such as the work of Ibn al-Haytham (Alhazen) in the 11^th 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 17^th century. The experimental discoveries of Faraday and the theory of Maxwell’s equations of electromagnetism were developmental high points during the 19^th century. 

Many physicists contributed to the development of quantum mechanics in the early-to-mid 20th^th century. New knowledge in the early 21^st 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 19^th 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.

EDUCATION

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, biological physics, 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 radio physics. 

CAREERS

The three major types of employers of career physicists are academic institutions, laboratories and private industries, with the largest employer being the last noted.

Physicists in academia or government labs tend to have titles such as Assistants, Professor, Sr./Jr. Scientist, or postdocs. As per the American Institute of Physics, some 20% of new physics Ph.D.s hold jobs in engineering development programs, while 14% turn to computer software and about 11% are in business / education. Most employed physicists apply their skills and training to interdisciplinary sectors (e.g. finance).

Job titles from graduate physicists include Agricultural Scientist, Air Traffic Controller, Biophysicist, Computer Programmer, Electrical Engineer, Environmental Analyst, Geophysicist, Medical Physicist, Meteorologist, Oceanographer, Physics Teacher/Professor/Researcher, Research Scientist, Reactor Physicist, Engineering Physicist, Satellite Missions Analyst, Science Writer, Stratigrapher, Software Engineer, Radar Developer, Technical Consultant, etc.

The majority of physicists with only Bachelor’s degrees are employed in the private sector. Other employment fields are academia, government and military service, nonprofit entities, labs and teaching. 

Typical duties of physicists with Master’s and Doctoral degrees working in their domain involve research, observation and analysis, data preparation, instrumentation, design and development of industrial or medical equipment, computing and software development, etc.

THE TWELVE LAWS OF PHYSICS

1, Newton’s Laws of Motion: These laid the foundation for classical mechanics and our understanding of motion: 

• An object at rest remains at rest. An object in motion continues to move at a constant velocity unless acted upon by an external force. 
• The force acting on an object is directly proportional to the mas of the object and acceleration produced. 
• For every action, there is an equal and opposite reaction. 

2. Law of Universal Gravitation: Every mass attracts every other mass in the universe with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. This is the reason celestial bodies like planets and moons are held in orbit around each other.
3. Electricity and magnetism are related phenomena, important to understand for the development of technologies such as radio, television and the internet.
4. Relativity: The laws of physics are the same for all non-accelerating observers. The speed of light in a vacuum is constant. Massive objects warp the fabric of spacetime, causing other objects to move along curved paths. 
5. Quantum mechanics describes the behavior of particles at the atomic and subatomic scales. This challenges classical physics by introducing probabilistic behavior, wave-particle duality and the ‘uncertainty principle’ which states that it is impossible to precisely know both the position and momentum of a particle simultaneously.
6. Laws of Thermodynamics govern the transfer of energy and the behavior of matter. 
7. Laws of Conservation: The total mass of an isolated system remains constant over time. Energy is neither created nor destroyed; it only changes forms. 
8. Law of Black-Body Radiation quantifies the spectral distribution of electromagnetic radiation from a perfect black body, which led to the development of quantum theory. 
9. Wave Equation describes how the quantum state of a physical system changes with time. 
10. Laws of Electromagnetic Induction describe how a changing magnetic field induces an electromotive force in a conductor. These laws are fundamental to the operation of generators, transformers and many other electrical devices.
11. Laws of Planetary Motion describe the orbits of planets around the sun, which played a crucial role in the development of modern astronomy and our understanding of celestial mechanics. 
12. Coulomb’s Law describes the electrostatic force between charged objects. 

This overview was prepared In June, 2024 from online sources including Wikipedia.