Physics
The fundamental laws governing matter, energy, motion, and the universe — from classical mechanics to quantum theory.
3 articles
What Is Quantum Mechanics? The Science of the Very Small
Quantum mechanics is the branch of physics that describes how matter and energy behave at atomic and subatomic scales. Learn about wave-particle duality, superposition, entanglement, the uncertainty principle, and why quantum theory is so strange.
How Nuclear Fusion Works: The Power of the Stars
Nuclear fusion is the process that powers the sun and stars, releasing enormous energy by fusing light atomic nuclei. Learn how fusion works, why it has been so difficult to achieve on Earth, and where recent breakthroughs stand.
What Is the Theory of Relativity? Einstein's Revolutionary Physics
Einstein's theory of relativity — both special and general — transformed our understanding of space, time, mass, and gravity. Learn how the theories work, what they predict, and why they are confirmed by experiments every day.