Physics, Astronomy & Engineering: Open Educational Resources (OER)

This electronic book is an adaptation and expansion by Don Smith of a printed text on the theory of Special Relativity written by Prof. Rex Adelberger before he passed.

Multiple free textbooks covering the following subject areas: Conceptual Physics; College Physics; University Physics; Classical Mechanics; Thermodynamics; Quantum Mechanics; Relativity; Electricity & Magnetism; Optics; Waves & Acoustics; Modern Physics; Nuclear Physics; Astronomy & Cosmology.

Free, customizable physics textbooks with additional resources for educators and students.

Last updated: July 31, 2025
The book can be used for either a one-semester or two-semester introductory course.

Lessons, articles, videos, simulations

Lessons, articles, videos, simulations, courses

Civil, Electrical & Computer, Mechanical, Manufacturing, Biomedical, Chemical, Energy, and more.

Explore the solar system, constellations, telescopes and optics, meteors, and more, with short descriptions and rich visuals: sky maps, images, diagrams, and more!

"Astronomy studies celestial objects and phenomena and combines mathematics, physics, and chemistry to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, and comets.
Cosmology is a branch of astronomy concerned with the studies of the origin and evolution of the universe, from the Big Bang to today and on into the future."