Albert Einstein is arguably the most famous physicist who ever lived. His name ranks among great thinkers who pushed forward radical new ideas like Sir Isaac Newton, Nicolaus Copernicus, Otto Hahn, and Andreas Vesalius. Einstein's work changed the way the world viewed physics, especially concerning relativity and quantum theory. He published hundreds of scientific papers during the course of his life, but in 1905, the year he turned 26, he published the four groundbreaking papers covered in this guide. These papers forever changed the way people view space, time, mass, and energy. This guide provides the papers themselves, in the original German and the English translations, as well as resources that give context of the time in which they were published and their meaning to future generations.