Scientific Revolution

What was the Scientific Revolution?

In the 16th and 17th centuries, a series of discoveries established a new view of the universe: that it was orderly and rational, and could be understood through observation and reason.^[1] Those ideas went on to shape the Enlightenment of the 18th century.^[1]

From an Earth-centred to a Sun-centred universe

Nicolaus Copernicus (1473–1543) concluded that Earth is a planet and that all the planets circle the Sun. His book On the Revolutions of the Celestial Orbs was published in 1543, the year he died.^[2]

Galileo’s telescope

Galileo Galilei (1564–1642) turned a telescope to the sky and found strong evidence for the new picture:^[2]

• Four moons orbiting Jupiter, taking from just under 2 days to about 17 days to go around.
• Phases of Venus, like the Moon’s, showing that Venus must orbit the Sun.
• A rugged Moon, with craters, mountain ranges, valleys and flat, dark areas.

Galileo also studied motion, and realised that a force is needed not just to start something moving, but also to slow it down, stop it, speed it up or change its direction.^[2] His ideas brought him into conflict with the Church. He was condemned to house arrest, and only in 1992 did the Catholic Church publicly admit that it had erred.^[2]

Kepler’s laws

Tycho Brahe recorded the positions of the Sun, Moon and planets for almost 20 years.^[3] His assistant, Johannes Kepler (1571–1630), spent more than 20 years analysing that data, and published his first two laws of planetary motion in 1609 in The New Astronomy.^[3] His first law states that each planet moves around the Sun in an ellipse, with the Sun at one focus.^[3] See Kepler’s Laws on the map.

Newton’s synthesis

Isaac Newton (1643–1727) brought it all together. His Principia, published in 1687 at Edmond Halley’s expense, set out three laws of motion meant to govern the motions of all objects.^[4]

New ways of knowing

The revolution was also about method. Francis Bacon championed inductive reasoning, reaching conclusions only after collecting evidence. René Descartes combined deductive reasoning with empiricism, helping establish the foundations of the scientific method.^[1]

A global inheritance

The Scientific Revolution did not come from nowhere. Medieval Persian mathematicians such as Muhammad ibn Musa al-Khwarizmi and Omar Khayyam provided intellectual tools, the Indian philosopher Aryabhata played a pivotal role in trigonometry, and the decimal number system from classical India and fractions in the Arabic numeral systems of North Africa made advanced calculation possible.^[1] The Enlightenment that followed was the result of cross-cultural networks of scholarship.^[1]