What is Modern Physics?
Modern Physics explores areas of Physics that help us understand atoms, subatomic particles, light, space, time, energy, and the fundamental nature of the universe.
Classical physics explains many everyday phenomena, but new theories are needed to describe matter at atomic scales, objects moving at extremely high speeds, and the behaviour of fundamental particles.
This chapter introduces quantum mechanics, relativity, and particle physics—theories that have transformed our understanding of matter, energy, space, and time.
Quantum Mechanics
Quantum mechanics describes matter and energy at atomic and subatomic scales.
It explains concepts such as photons, wave-particle duality, energy levels, and the unusual behaviour of particles such as electrons.
Quantum mechanics forms the foundation of technologies including lasers, transistors, computer chips, and many modern imaging systems.
Relativity
Relativity explains the behaviour of space, time, motion, gravity, and energy.
Special relativity describes objects moving at very high speeds and introduces effects such as time dilation, length contraction, and the relationship between mass and energy.
General relativity explains gravity as a consequence of the curvature of space-time caused by mass and energy.
Particle Physics
Particle physics studies the fundamental particles of matter and the forces acting between them.
It includes particles such as electrons, quarks, photons, and neutrinos. Protons and neutrons are made of smaller particles called quarks.
Particle physics helps scientists investigate the basic structure of matter and understand conditions in the early universe.