Physics Department

Overview

The Physics Department introduces students to the study of matter, energy, motion, forces, fields, waves, space, time, and the laws that govern physical reality. Physics is one of the foundation sciences because it explains how natural systems behave, how energy moves, how matter is structured, and how measurable relationships can be used to predict physical events.

Physics ranges from everyday motion to the structure of atoms, from electric circuits to black holes, from heat engines to quantum particles, and from sound waves to the expansion of the universe. Some branches of physics study familiar systems such as falling objects, machines, fluids, heat, sound, light, and electricity. Other branches study extreme or microscopic systems such as nuclei, particles, plasmas, spacetime, stars, galaxies, and the early universe.

This department page serves as the main entry point into the major areas of physics. The field is organized here into three large divisions: classical physics, modern physics, and applied and interdisciplinary physics. These divisions help students understand where each branch belongs before moving into specific lessons, reference pages, problem sets, and applications.

Department Divisions

• Classical Physics

  Classical physics studies motion, forces, waves, heat, fluids, light, electricity, magnetism, and other physical systems that can usually be explained without quantum mechanics or relativity.

• Modern Physics

  Modern physics studies physical systems that require quantum theory, relativity, nuclear models, particle models, or other twentieth-century and contemporary physical theories.

• Applied and Interdisciplinary Physics

  Applied and interdisciplinary physics connects physical laws to astronomy, Earth systems, medicine, biology, computing, engineering, technology, and other specialized fields.

Classical Physics

Classical physics includes the major branches of physics developed before the rise of quantum mechanics and relativity. These subjects remain essential because they explain most physical systems encountered at ordinary speeds, ordinary sizes, and everyday energy scales. Classical physics provides the first language of the discipline: motion, force, energy, momentum, fields, waves, pressure, temperature, and work.

• Mechanics

  Studies motion, forces, mass, acceleration, work, energy, momentum, collisions, gravity, rotation, torque, equilibrium, and mechanical systems.

• Electromagnetism

  Studies electric charge, electric fields, voltage, current, resistance, circuits, magnetic fields, electromagnetic induction, and electromagnetic waves.

• Thermodynamics

  Studies heat, temperature, thermal energy, energy transfer, internal energy, entropy, gases, phase changes, engines, refrigerators, and efficiency.

• Waves and Oscillations

  Studies vibration, periodic motion, frequency, wavelength, amplitude, wave speed, sound, resonance, standing waves, interference, and the Doppler effect.

• Optics

  Studies light, reflection, refraction, lenses, mirrors, ray diagrams, color, image formation, diffraction, interference, polarization, and optical instruments.

• Fluid Mechanics

  Studies liquids, gases, pressure, buoyancy, flow, viscosity, drag, lift, turbulence, surface tension, and aerodynamics.

Modern Physics

Modern physics studies systems that cannot be fully explained by classical models alone. It includes the theories and discoveries that transformed physics in the twentieth century, especially quantum mechanics and relativity. Modern physics is necessary for understanding atoms, nuclei, subatomic particles, high-speed motion, strong gravity, radiation, semiconductors, and many advanced technologies.

• Quantum Mechanics

  Studies matter and energy at atomic and subatomic scales, including quantization, wave-particle duality, probability, uncertainty, superposition, tunneling, and quantum states.

• Relativity

  Studies space, time, high-speed motion, gravity, mass-energy equivalence, spacetime curvature, gravitational time dilation, black holes, and gravitational waves.

• Atomic Physics

  Studies atoms, electron energy levels, atomic spectra, ionization, photons, spectroscopy, and the interaction between atoms and electromagnetic radiation.

• Nuclear Physics

  Studies atomic nuclei, protons, neutrons, isotopes, radioactive decay, half-life, fission, fusion, nuclear energy, and radiation.

• Particle Physics

  Studies fundamental particles, quarks, leptons, bosons, antimatter, neutrinos, particle accelerators, detectors, and the Standard Model.

• Condensed Matter Physics

  Studies solids, liquids, crystals, semiconductors, conductivity, magnetism, superconductivity, phase transitions, nanomaterials, and material properties.

• Plasma Physics

  Studies ionized gases, charged particle motion, plasma waves, magnetic confinement, fusion plasma, solar plasma, auroras, lightning, and space plasma.

Applied and Interdisciplinary Physics

Applied and interdisciplinary physics uses physical principles to study specialized systems and solve practical problems. These branches draw from classical physics, modern physics, mathematics, computation, engineering, biology, medicine, Earth science, and astronomy. They show how physics operates outside the classroom and laboratory, in technology, nature, health, industry, and the universe.

• Astrophysics

  Studies stars, planets, galaxies, black holes, stellar evolution, cosmic radiation, dark matter, dark energy, and physical processes in space.

• Cosmology

  Studies the universe as a whole, including the Big Bang, cosmic expansion, redshift, cosmic microwave background, large-scale structure, and the fate of the universe.

• Geophysics

  Studies Earth and planetary systems using physics, including seismic waves, gravity, magnetism, heat flow, plate tectonics, natural hazards, and planetary interiors.

• Atmospheric Physics

  Studies the physical behavior of the atmosphere, including air pressure, radiation balance, clouds, wind, storms, weather systems, greenhouse effects, and climate physics.

• Biophysics

  Studies living systems through physics, including diffusion, membranes, biomechanics, nerve signals, muscle motion, protein folding, biological energy, and fluid flow in the body.

• Medical Physics

  Studies the use of physics in medicine, including X-rays, MRI, CT scans, ultrasound, radiation therapy, nuclear medicine, dosimetry, medical imaging, and radiation safety.

• Computational Physics

  Studies physics through numerical methods, simulations, data analysis, mathematical modeling, Monte Carlo methods, computational fluid dynamics, and scientific computing.

Recommended Study Path

Students should usually begin with classical physics. Mechanics gives the first foundation because it introduces motion, forces, energy, momentum, and mathematical modeling. After mechanics, students can study waves, thermodynamics, electromagnetism, optics, and fluids. These subjects build the vocabulary needed to understand energy transfer, fields, circuits, vibration, light, pressure, and flow.

Modern physics should usually follow the classical foundation. Quantum mechanics and relativity introduce the two major limits of classical thinking: the microscopic scale and the high-speed or strong-gravity scale. Atomic physics, nuclear physics, particle physics, condensed matter physics, and plasma physics then show how modern theory explains matter, radiation, materials, nuclei, particles, and ionized gases.

Applied and interdisciplinary physics can be studied alongside advanced topics or after the main foundations are complete. These branches show how physics is used to understand stars, planets, Earth systems, weather, living organisms, medical tools, and computer simulations.