Key figures of the Scientific Revolution

What the Scientific Revolution was, and when

Textbooks usually run the Scientific Revolution from 1543, when Copernicus's On the Revolutions of the Heavenly Spheres and Andreas Vesalius's anatomy book On the Fabric of the Human Body were both published, to 1687, when Newton's Principia appeared, with a tail into the early 1700s. Before it, university science in Europe followed Aristotle on physics and Ptolemy on astronomy: a still Earth at the centre, perfect circles in the heavens, and different laws above and below the Moon. After it, educated Europeans increasingly accepted a moving Earth, one set of physical laws for the whole universe, and mathematics as the language for describing them.

Four things made it possible:

• Printing, which let astronomers share identical tables and diagrams, and spread errors that could then be corrected.
• Instruments: the telescope (first submitted for a patent in the Netherlands in 1608), the microscope, the pendulum clock, the barometer and the air pump.
• Better data, above all the Danish astronomer Tycho Brahe's naked-eye observations of the planets, the most accurate before the telescope.
• New institutions: the Royal Society of London (1660), whose motto Nullius in verba means roughly “take nobody's word for it”, the Paris Academy of Sciences (1666) and the first scientific journals, such as Philosophical Transactions (1665).

It did not start from nothing. Medieval scholars at Oxford and Paris had worked on the mathematics of motion, and Arabic scholars such as Ibn al-Haytham (on optics) and the astronomers of Maragha had criticised Ptolemy centuries earlier. See scholars of the Islamic Golden Age.

The key scientists, in order

Nicolaus Copernicus (1473 to 1543) was a canon of Frombork Cathedral in Royal Prussia, then part of the Kingdom of Poland, who also practised medicine and wrote on currency. He circulated a short handwritten sketch of a Sun-centred system around 1514 but held back the full book for decades, as he says in its dedication to Pope Paul III, for fear of scorn at so strange an idea. On the Revolutions appeared in Nuremberg in 1543, the year he died, with an unsigned preface by the Lutheran minister Andreas Osiander calling it only a hypothesis for calculation. His system still used circles, so it was not much more accurate than Ptolemy's.

Johannes Kepler (1571 to 1630) was a German Lutheran mathematician who went to Prague in 1600 to work with Tycho Brahe and inherited his observations, and his post as Imperial Mathematician, when Tycho died in 1601. Kepler found that Mars's orbit could not be a circle because Tycho's data differed from it by eight minutes of arc, a tiny amount he refused to ignore. In Astronomia nova (1609) he showed that planets move in ellipses and sweep out equal areas in equal times; in Harmonices Mundi (1619) he gave the third law, linking a planet's period to its distance from the Sun. From 1615 to 1621 he also defended his elderly mother, Katharina, in a witchcraft trial, and won her release.

Galileo Galilei (1564 to 1642) taught mathematics at Pisa and Padua. In 1609 he built a telescope of his own and in March 1610 published The Starry Messenger, reporting mountains on the Moon, many more stars than the eye can see, and four moons orbiting Jupiter. Later that year he saw that Venus shows phases like the Moon, which fits a Venus going round the Sun. In 1616 the Church ruled the Sun-centred view contrary to Scripture; his Dialogue Concerning the Two Chief World Systems (1632) made the case for it anyway, and in 1633 the Roman Inquisition forced him to abjure and kept him under house arrest for the rest of his life. There he wrote Two New Sciences (1638), on motion and the strength of materials, which shows that falling bodies cover distances in proportion to the square of the time. The line “And yet it moves” first appears in print more than a century after his death: see did Galileo say and yet it moves.

René Descartes (1596 to 1650) was a French philosopher who lived mostly in the Dutch Republic. When he heard of Galileo's condemnation in 1633 he held back his own book on the world, which assumed a moving Earth. His Discourse on the Method (1637) was written in French so that ordinary readers could judge it, and one of its appendices, La Géométrie, joined algebra to geometry: the x and y coordinates students use today grew from it. His Meditations (1641) start from the one thing he could not doubt, his own thinking. He pictured the universe as matter in motion, like a vast machine, which shaped how the next generation thought even when they rejected his details. He died in Stockholm in 1650, a few months after joining the court of Queen Christina of Sweden.

Isaac Newton (1643 to 1727 by the modern calendar) grew up in Lincolnshire, went to Trinity College, Cambridge, and did much of his early work on calculus, light and gravity in 1665 and 1666, when plague closed the university. He built the first working reflecting telescope and showed that white light is a mixture of colours. Prompted by Edmond Halley, who paid for the printing, he published the Principia in 1687: three laws of motion and a single law of gravitation that explained Kepler's ellipses, the tides and the paths of comets. He later ran the Royal Mint, became President of the Royal Society in 1703, and fought a bitter dispute with Gottfried Leibniz over who invented calculus. He also wrote far more on alchemy and theology than on physics, and kept most of it private. The falling-apple story comes from his own old age, told to William Stukeley in 1726: see did an apple fall on Newton's head.

A coda that shows how the new method spread: Benjamin Franklin (1706 to 1790) followed Newton's experimental model in his work on electricity. His Experiments and Observations on Electricity was published in London in 1751, proposed that lightning is electrical and led to the lightning rod, and the Royal Society awarded him its Copley Medal in 1753. The famous kite story is less certain than it looks: see did Franklin fly a kite in a storm.

Scientific Revolution timeline

Big themes and debates

• Was it a revolution at all? Some historians, such as Steven Shapin in The Scientific Revolution (1996), argue the term makes a slow, uneven change look sudden and unified. Others reply that the gap between Aristotle's physics in 1500 and Newton's in 1700 is real and enormous.
• Science against religion? Copernicus was a church official, Kepler and Newton were deeply religious, and Galileo saw himself as a good Catholic. The Galileo affair was about authority, politics and how to read Scripture as much as about astronomy. In 1992 Pope John Paul II accepted that the Church's judges had erred.
• Magic and science together. Kepler cast horoscopes for a living and Newton spent decades on alchemy. The people who built modern science did not sort ideas into our categories.
• Who gets left out? Instrument makers, printers, assistants and women such as the naturalist Maria Sibylla Merian and the philosopher Margaret Cavendish took part. Émilie du Châtelet's French translation of the Principia, published in 1759, is still used.
• Borrowed foundations. Copernicus used mathematical tools found earlier in the work of Islamic astronomers, and Kepler's optics built on Ibn al-Haytham. How the knowledge travelled is still being studied.

Primary sources to read

• Copernicus, the dedication of On the Revolutions to Pope Paul III (1543): why he waited, in his own words.
• Galileo, The Starry Messenger (1610): short, with his own drawings of the Moon.
• Galileo, Letter to the Grand Duchess Christina (1615): his argument, borrowing a cardinal's saying, that the Bible teaches how to go to heaven, not how the heavens go.
• Kepler, Astronomia nova (1609), chapter 19, where the eight minutes of arc appear.
• Descartes, Discourse on the Method (1637), Parts 2 and 4: four rules of method and “I think, therefore I am”.
• Robert Hooke, Micrographia (1665): the flea and the cork cells. Turn the pages for the engravings.
• Newton, Principia (1687), the Axioms or Laws of Motion at the start of Book 1, and the General Scholium added in 1713.
• Newton's notebooks and letters, digitised by Cambridge University Library.

If you are reading these for an essay, our guide on primary and secondary sources explains how to quote and cite them.

How to study the Scientific Revolution: projects

• Repeat Galileo's observations. With binoculars on a tripod you can see Jupiter's four large moons change position from night to night. Keep a log in Galileo's style and compare it with his drawings.
• Draw an ellipse with two pins and a loop of string, then mark where the Sun would sit. It explains Kepler's first law better than any diagram.
• Ramp experiment. Roll a ball down a long, gentle ramp and mark its position every second. The distances grow as 1, 4, 9, 16, as Galileo described in Two New Sciences.
• A trial with two scripts. Re-enact Galileo's 1633 trial using the Inquisition's sentence and his abjuration, then a second version where students argue the case as historians now understand it.
• Interview or debate. Use the questions to ask Galileo Galilei or questions to ask Isaac Newton, and compare the two in Newton vs Galileo. You can practise by voice with Galileo on Yuga, an AI recreation built from his books and letters. It is not the man and can get details wrong, so quote the books themselves in your work.