What does a physicist do?

1 Classical physics

Classical physics deals with the physical laws that describe the behavior of objects and forces at ordinary scales and speeds. For example, classical physics explains how gravity works, how projectiles move, how sound and light propagate, and how heat and energy are transferred. Classical physics is the foundation of many engineering disciplines, such as mechanics, civil engineering, and aerospace engineering. Physicists who work in classical physics may design and test structures, machines, vehicles, and instruments, or conduct research on topics such as fluid dynamics, acoustics, optics, and thermodynamics.

2 Quantum physics

Quantum physics deals with the physical laws that describe the behavior of objects and forces at the smallest scales and highest speeds. For example, quantum physics explains how atoms and molecules are formed, how electrons and photons behave, how nuclear reactions occur, and how superconductivity and superfluidity emerge. Quantum physics is the basis of many modern technologies, such as lasers, semiconductors, nanomaterials, and quantum computing. Physicists who work in quantum physics may develop and operate devices, materials, and systems that exploit quantum phenomena, or conduct research on topics such as quantum information, quantum cryptography, quantum metrology, and quantum simulation.

3 Relativistic physics

Relativistic physics deals with the physical laws that describe the behavior of objects and forces at the largest scales and highest speeds. For example, relativistic physics explains how space and time are distorted by gravity and motion, how black holes and gravitational waves are formed, how the universe began and evolved, and how the fundamental forces and particles are related. Relativistic physics is the frontier of cosmology and astrophysics, and requires the use of sophisticated telescopes, detectors, and accelerators. Physicists who work in relativistic physics may observe and analyze the phenomena and data from the cosmos, or conduct research on topics such as general relativity, string theory, dark matter, and dark energy.

4 Computational physics

Computational physics deals with the use of computers and algorithms to solve complex physical problems that cannot be solved analytically or experimentally. For example, computational physics can simulate the behavior of fluids, solids, plasmas, gases, and biological systems, or optimize the design and performance of devices, materials, and systems. Computational physics is an interdisciplinary field that combines physics, mathematics, computer science, and engineering. Physicists who work in computational physics may develop and apply numerical methods, software, and models to solve physical problems, or conduct research on topics such as machine learning, artificial intelligence, data science, and high-performance computing.

5 Applied physics

Applied physics deals with the application of physical principles and techniques to practical problems and innovations. For example, applied physics can create new sources of energy, improve medical diagnosis and treatment, enhance communication and information security, or develop new sensors and detectors. Applied physics is a broad and diverse field that overlaps with many other sciences and engineering fields. Physicists who work in applied physics may collaborate with other professionals and stakeholders to develop and implement solutions, products, and services that meet the needs and challenges of society, industry, and environment.