The fundamentals of physics, from first principles

The story of how we figured out the universe.

A timeline of the discoveries that built physics, each one explained so a curious person can actually follow it. Every technical term is defined where it appears.

The Timeline of Physics

17 of 39 written. The rest are on their way.

Year Who The discovery
c. 1500 BCE Vedic hymns Early cosmology: order, fire, and the structure of the heavens soon
c. 1200 BCE Zoroaster A cosmos built on the opposition of light and dark soon
c. 600 BCE Thales of Miletus Rubbed amber attracts, and lodestone pulls iron soon
c. 530 BCE Pythagoras Musical harmony comes from simple ratios of vibrating strings soon
c. 450 BCE Empedocles Light is something that travels soon
c. 430 BCE Democritus All matter is made of indivisible atoms soon
c. 350 BCE Aristotle The first systematic Physics: motion, the elements, and the cosmos soon
c. 300 BCE Euclid The geometry of light rays and vision soon
c. 250 BCE Archimedes Buoyancy, levers, and the science of floating and balance soon
c. 240 BCE Eratosthenes Measured the size of the Earth from shadows soon
c. 77 CE Pliny the Elder Natural History: the ancient world catalogues nature soon
c. 150 CE Ptolemy Optics, refraction, and a mathematical model of the sky soon
c. 1021 Ibn al-Haytham The Book of Optics: how light and vision really work, by experiment soon
c. 1240 Grosseteste and Bacon Lenses, the rainbow, and the case for experiment soon
c. 1350 Buridan and Oresme Impetus: the seed of inertia and momentum soon
1543 Nicolaus Copernicus The Sun, not the Earth, at the centre soon
1600 William Gilbert The Earth itself is a magnet soon
1609 Johannes Kepler The planets move in ellipses, by precise laws soon
1610 Galileo Galilei Falling bodies, moons of Jupiter, and motion made measurable soon
1621 Willebrord Snell The exact law of how light bends soon
1643 Evangelista Torricelli The barometer, and the reality of the vacuum soon
1648 Blaise Pascal Air has weight, and pressure falls with altitude soon
1676 Ole Rømer Light has a finite, measurable speed
1687 Isaac Newton One law of gravity for apples, moons, and planets
1801 Thomas Young Light behaves as a wave
1820 Hans Christian Ørsted An electric current bends a compass needle
1820s André-Marie Ampère The force between two electric currents
1822 Joseph Fourier Any signal is a sum of simple waves
1824 Sadi Carnot The hard limit on every heat engine
1831 Michael Faraday A changing magnetic field makes electricity
1845 James Joule Heat and motion are the same currency: energy
1865 James Clerk Maxwell Light is an electromagnetic wave
1887 Heinrich Hertz Maxwell's waves, produced and caught in the lab
1898 Marie Curie Radioactivity comes from inside the atom
1900 Max Planck Energy comes in discrete packets
1909 Robert Millikan The charge of a single electron, measured
1911 Ernest Rutherford The atom has a tiny, dense nucleus
1931 Subrahmanyan Chandrasekhar A mass limit for white dwarf stars
today Helioseismology Reading the Sun's interior from its surface vibrations