• c1600 – Galileo Galilei discovers the principle of inertia, building the stage for a rational view of motion.

• 1600 – William Gilbert finds that Earth has magnetic poles and acts like a huge magnet.

• 1600 – Galileo Galilei discovers that projectiles move with a parabolic trajectory.

• 1608 – Hans Lippershey invents the refracting telescope, which Galileo Galilei soon puts to use.

• 1609 – Galileo Galilei observes Jupiter’s four largest moons, disproving church dogma that all movement in the universe is centered on Earth.

• 1609 – Johannes Kepler publishes his first two laws of planetary motion showing that planets move in elliptical orbits around the sun.

• 1610 – John Napier publishes tables of logarithms, showing how they can be used to accelerate calculations.

• 1619 – Kepler publishes his third law of planetary motion relating the time taken for a planet to orbit the sun with its distance from the sun.

• 1621 – Willebrord Snell discovers the laws of light refraction.

• 1628 – Kepler publishes his planetary tables, the calculations for which would have taken years without Napier’s logarithms.

• 1629 – Niccolò Cabeo finds there are two types of electric charge and notes both attractive and repulsive forces acting.

• 1632 – William Oughtred invents the slide rule. With the combined power of logarithms and slide rules, calculation speeds explode.

• 1632 – Galileo Galilei finds that the laws of motion are the same in all inertial reference frames.

• 1637 – Rene Descartes invents the Cartesian coordinate system – i.e. the x-y axis for graphs, allowing changes in quantities with time to be plotted.

• 1645 – Blaise Pascal invents the adding machine.

• 1652 – Thomas Bartholin discovers the human lymphatic system.

• 1654 – Blaise Pascal and Pierre de Fermat invent the mathematics of probability and statistics.

• 1656 – Christiaan Huygens discovers Saturn’s rings after building a new telescope – the world’s best.

• 1657 – Pierre de Fermat uses the principle of least time in optics.

• 1658 – Jan Swammerdam discovers the red blood cell.

• c1660 – Otto von Guericke builds a rotating sphere from which sparks fly. Static electricity can now be generated. He demonstrates electrostatic repulsion.

• c1660 – Robert Hooke discovers that the extension of a spring or elastic material is directly proportional to the applied force.

• 1661 – Robert Boyle writes *The Skeptical Chymist*, with his manifesto for the science of chemistry, explaining the roles of elements and compounds, and telling scientists they must carefully observe, record and report scientific data.

• 1662 – Robert Boyle publishes his law of pressure and volume in gases.

• 1663 – James Gregory publishes his design for the world’s first reflecting telescope.

• 1664 – Robert Hooke uses a microscope to observe the cellular basis of life.

• 1665 – Isaac Newton invents calculus – the mathematics of change – without which we could not understand the modern world. He keeps it secret, using it to develop theories which he eventually publishes in 1687.

• 1666 – Isaac Newton discovers that light is made up of all of the colors of the rainbow, which are refracted by different amounts in a glass prism.

• 1667 – Isaac Newton builds the world’s first reflecting telescope.

• 1668 – John Wallis discovers the principle of conservation of momentum – one of the foundations of modern physics.

• 1669 – Hennig Brand becomes the first identifiable person to discover and isolate a new chemical element – phosphorus.

• 1674 – Antony van Leeuwenhoek discovers microorganisms.

• 1675 – Robert Boyle shows that electric repulsion and attraction act in a vacuum.

• 1676 – Ole Christensen Roemer measures the speed of light for the first time.

• 1676 – Christiann Huygens finds light can be refracted and diffracted and should be considered to be a wave-like phenomenon.

• 1684 – Gottfried Leibniz publishes his calculus, which he discovered independently of Isaac Newton. He has been working on calculus for the past decade.

• 1687 – Isaac Newton publishes one of the most important scientific books ever: *Philosophiae Naturalis Principia Mathematica*, revolutionizing physics and our understanding of gravity and motion.

This was a momentous century in which science moved from a state of knowledge that was in many ways little more advanced than third century BC Greece to a much more advanced, sophisticated position, paving the way for the industrial revolution in the 1700s, and many more famous scientists.

Probably the greatest advantages that Renaissance scientists had over their ancient Greek predecessors were:

• the invention of the movable type printing press in 1450 by Johannes Gutenberg. (Bi Sheng invented movable type printing much earlier, in about 1040 AD in China, but this does not appear to have influenced the Renaissance.)

• Leonardo Fibonacci brought the Hindu-Arabic number system to Europe in 1202 AD.

The Greek number system was primitive, making calculations cumbersome, and confining most Greek mathematical achievements to geometry. European scientists were using the Roman system, which was little better.

The familiar Hindu-Arabic system of 0,1,2,3,4,5,6,7,8,9… brought with it ease of calculation and the recognition that zero was a number in its own right. Mathematical rules for the correct use of zero were first written in 628 AD in Brahmagupta’s book *Brahmasputha Siddhanta*. This book also highlighted the use of negative numbers in, for example, solutions of quadratic equations.

Following the huge scientific advances of the 1600s, we have continued to take enormous strides in scientific knowledge, carrying us to where we are today.