Frenchman Antoine Lavoisier is often called the father of modern chemistry. By observing an increase in weight when the chemicals sulfur and phosphorus were burned, he correctly deduced they must have combined during the combustion, providing a chemical explanation of fire. English scientist John Dalton contributed atomic theory a few decades later, which proposed that all matter is composed of atoms. By the 19th century Michael Faraday worked to make electrical power possible by describing electricity and magnetism.
Ancient Greek philosopher Artistotle was also the world's first notable biologist. He observed and classified the structure and behavior of plants and animals according to their common traits rather than their usability for humans. Much more recently Charles Darwin developed the modern theory of evolution in his "The Origin of the Species by Natural Selection." This 19th Century biological work describes how animals with variations that are beneficial for their environment have a better chance to survive and breed.
Galileo Galilei, a physicist pioneer in the 16th century, performed fundamental experiments in physics and made observations that paved the way for astronomy. A century later, Sir Isaac Newton invented differential calculus and developed theories in gravitation and mechanics. In the early 20th century, Albert Einstein published his General Theory of Relativity, which served as the first improvement on Newton's explanation of gravity. Just as Einstein's equations explained phenomenon in the universe on a large scale, physicists Richard P. Feynman and Julian Schwinger co-developed quantum electrodynamics later in the century to explain small-scale phenomenon.