Here’s our alphabetical list of the most popular scientists from ancient times on the Famous Scientists website.

An ancient scientific revolution: the first person in history to recognize that we live on a planet that is free in space and does not need to sit on something.

Founded the sciences of mechanics and hydrostatics, calculated pi precisely, devised the law of exponents, created new geometrical proofs, invented numerous ingenious mechanical devices, and more.

Promoted the idea that the earth follows a circular orbit around the sun eighteen centuries before Nicolaus Copernicus resurrected the idea.

A genius whose philosophical ideas are still taught, but his contributions to science retarded progress for almost two millennia.

Established zero as a number and defined its mathematical properties; discovered the formula for solving quadratic equations.

Devised an atomic theory featuring tiny particles always in motion interacting through collisions; advocated a universe containing an infinity of diverse inhabited worlds governed by natural, mechanistic laws rather than gods; deduced that the light of stars explains the Milky Way’s appearance; discovered that a cone’s volume is one-third that of the cylinder with the same base and height.

Known as the father of algebra; solved hundreds of algebraic equations in his great work

*Arithmetica*; first to use algebraic notation and symbolism.

An ancient theory of natural selection; mass conservation; and the four elements which are now often misattributed to Aristotle.

Accurately calculated Earth’s size 2,500 years ago; founded the science of geography; and devised the famous prime number sieve.

Authored the

*Elements*, the most famous and most published mathematical work in history; another great work,

*Optics*, explained light’s behavior using geometrical principles – the basis of artistic perspective, astronomical methods, and navigation methods for more than two thousand years.

Began his practice as a physician to gladiators and established a link between diet and health. Galen created a flawed doctrine that dominated Western and Arab medicine for 1,500 years.

One of classical antiquity’s greatest scientists: founded the mathematical discipline of trigonometry; measured the earth-moon distance accurately; discovered the precession of the equinoxes; and documented the positions and magnitudes of over 850 stars. His combinatorics work was unequalled until 1870.

The father of Western medicine: systematized medical treatments, disentangling them from religion and superstitions; trained physicians; produced a large body of medical textbooks. The famous Hippocratic Oath binds physicians to good ethical practices.

One of the most eminent mathematicians of late classical antiquity; scholars traveled from around the classical world to learn mathematics and astronomy at her school.

Began paradigm shifts: said projectiles keep moving after they are thrown because a force is impressed into them by the thrower; stated planets do not move because they are divine, but because, like on Earth, a force of motion had been impressed upon them; contradicted Aristotle’s claim that objects dropped from the same height fall at a rate proportional to their weights.

Produced the world’s first encyclopedia in 37 volumes and over a million words.

Produced an alternative statement of Euclid’s famously problematical parallel postulate: Proclus’s version came to be known as Playfair’s Axiom after it was restated by John Playfair in 1846. Much of what we know about the history of Ancient Greek geometry before Euclid comes from Proclus’s commentary on Euclid’s

*Elements*.

Author of the Almagest, which contained a catalogue of over a thousand stars with positions, relative brightnesses, and constellations; and a mathematical model predicting the movements of the planets that was unsurpassed for almost 1,500 years.

Believed the universe was constructed using mathematics and everything could be described with numbers; established a link between mathematics and music; proved Pythagoras’s theorem; discovered irrational numbers; discovered the Platonic Solids.

The first scientist in history, Thales looked for patterns in nature to explain the way the world works. He replaced superstitions with science. He was the first person to use deductive logic to find new results in geometry.

The father of Hypatia; Theon’s edition of Euclid’s

*Elements*supplanted all others, including the original – Theon simplified some of Euclid’s proofs and added new proofs of his own to the

*Elements*.