Start here · Essential guide
Key Concepts in Modern Physics
A plain-language tour of relativity, quantum theory and particle physics: the main ideas that reshaped physics after 1900 and the questions that remain open.
Universe and Matter
Physics and Matter
Modern physics, light, the elements and everyday math.
Breaking Down the Basics of Quantum Physics
Quantization, wave-particle duality, superposition and the uncertainty principle explained in plain words, with the everyday technology that depends on them.
From Crystals to Lasers: The Science of Light
How light interacts with crystals through refraction and band gaps, and how stimulated emission lets lasers produce a coherent, single-color beam.
Getting to Know the Periodic Table
How the periodic table arranges the elements by atomic number, what groups and periods mean, and how to read a single element's box and its trends.
Mathematics in Everyday Life
Practical, worked examples of everyday math: budgeting, scaling recipes, planning travel, comparing prices and estimating, with each calculation shown step by step.
What Are Atoms Made Of?
Atoms contain protons, neutrons and electrons, and protons and neutrons are made of quarks. Here is how the pieces fit, with sizes, charges and forces.
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More in universe and matter
Our Universe Space, the solar system and how we picture the cosmos. Stars and Galaxies How stars live and die and how galaxies and the early universe are understood. Planets and Space Exploration Missions, the Moon, eclipses and the search for life beyond Earth. Forces, Energy and Motion Classical physics that explains everyday motion, heat, sound and electricity. Chemistry and Materials Reactions, everyday substances and how common materials are made.