Nicolaus Copernicus (1473-1543)
Copernicus was a Polish astronomer, best known for his theory that the Sun and not the Earth is at the centre of the universe.
Nicolaus Copernicus was born on 19 February 1473 in Thorn (modern day Torun) in Poland. His father was a merchant and local official. When Copernicus was 10 his father died, and his uncle, a priest, ensured that Copernicus received a good education. In 1491, he went to Krakow Academy, now the Jagiellonian University, and in 1496 travelled to Italy to study law. While a student at the University of Bologna he stayed with a mathematics professor, Domenico Maria de Novara, who encouraged Copernicus' interests in geography and astronomy.
During his time in Italy, Copernicus visited Rome and studied at the universities of Padua and Ferrara, before returning to Poland in 1503. For the next seven years he worked as a private secretary to his uncle, now the bishop of Ermland.
The bishop died in 1512 and Copernicus moved to Frauenberg, where he had long held a position as a canon, an administrative appointment in the church. This gave him more time to devote to astronomy. Although he did not seek fame, it is clear that he was by now well known as an astronomer. In 1514, when the Catholic Church was seeking to improve the calendar, one of the experts to whom the pope appealed was Copernicus.
Copernicus' major work 'De Revolutionibus Orbium Coelestium' ('On the Revolutions of the Celestial Spheres') was finished by 1530. Its central theory was that the Earth rotates daily on its axis and revolves yearly around the sun. He also argued that the planets circled the sun. This challenged the long held view that the Earth was stationary at the centre of the universe with all the planets, the Moon and the Sun rotating around it.
'De Revolutionibus Orbium Coelestium' was published in early 1543 and Copernicus died on 24 May in the same year.
Francis Bacon (1561-1626)
Bacon was an English philosopher and statesman, and a pioneer of modern scientific thought.
Francis Bacon was born on 22 January 1561 in London. He was the son of Sir Nicholas Bacon, keeper of the great seal for Elizabeth I. Bacon studied at Cambridge University and at Gray's Inn and became a member of parliament in 1584. However, he was unpopular with Elizabeth, and it was only on the accession of James I in 1603 that Bacon's career began to prosper. Knighted that year, he was appointed to a succession of posts culminating, like his father, with keeper of the great seal.
However, Bacon's real interests lay in science. Much of the science of the period was based on the work of the ancient Greek philosopher Aristotle. While many Aristotelian ideas, such as the position of the earth at the centre of the universe, had been overturned, his methodology was still being used. This held that scientific truth could be reached by way of authoritative argument: if sufficiently clever men discussed a subject long enough, the truth would eventually be discovered. Bacon challenged this, arguing that truth required evidence from the real world. He published his ideas, initially in 'Novum Organum' (1620), an account of the correct method of acquiring natural knowledge.
Bacon's political ascent also continued. In 1618 he was appointed Lord Chancellor, the most powerful position in England, and in 1621 he was created viscount St Albans. Shortly afterwards, he was charged by parliament with accepting bribes, which he admitted. He was fined and imprisoned and then banished from court. Although the king later pardoned him, this was the end of Bacon's public life. He retired to his home at Gorhambury in Hertfordshire, where he continued to write. He died in London on 9 April 1626.
Galileo Galilei (1564-1642)
Galileo was a hugely influential Italian astronomer, physicist and philosopher.
Galileo Galilei was born on 15 February 1564 near Pisa, the son of a musician. He began to study medicine at the University of Pisa but changed to philosophy and mathematics. In 1589, he became professor of mathematics at Pisa. In 1592, he moved to become mathematics professor at the University of Padua, a position he held until 1610. During this time he worked on a variety of experiments, including the speed at which different objects fall, mechanics and pendulums.
In 1609, Galileo heard about the invention of the telescope in Holland. Without having seen an example, he constructed a superior version and made many astronomical discoveries. These included mountains and valleys on the surface of the moon, sunspots, the four largest moons of the planet Jupiter and the phases of the planet Venus. His work on astronomy made him famous and he was appointed court mathematician in Florence.
In 1614, Galileo was accused of heresy for his support of the Copernican theory that the sun was at the centre of the solar system. This was revolutionary at a time when most people believed the Earth was in this central position. In 1616, he was forbidden by the church from teaching or advocating these theories.
In 1632, he was again condemned for heresy after his book 'Dialogue Concerning the Two Chief World Systems' was published. This set out the arguments for and against the Copernican theory in the form of a discussion between two men. Galileo was summoned to appear before the Inquisition in Rome. He was convicted and sentenced to life imprisonment, later reduced to permanent house arrest at his villa in Arcetri, south of Florence. He was also forced to publicly withdraw his support for Copernican theory.
Although he was now going blind he continued to write. In 1638, his 'Discourses Concerning Two New Sciences' was published with Galileo's ideas on the laws of motion and the principles of mechanics. Galileo died in Arcetri on 8 January 1642.
William Harvey (1578-1657)
Harvey was an English physician who was the first to describe accurately how blood was pumped around the body by the heart.
William Harvey was born in Folkestone, Kent on 1 April 1578. His father was a merchant. Harvey was educated at King's College, Canterbury and then at Cambridge University. He then studied medicine at the University of Padua in Italy, where the scientist and surgeon Hieronymus Fabricius tutored him.
Fabricius, who was fascinated by anatomy, recognised that the veins in the human body had one-way valves, but was puzzled as to their function. It was Harvey who took the foundation of Fabricius's teaching, and went on to solve the riddle of what part the valves played in the circulation of blood through the body.
On his return from Italy in 1602, Harvey established himself as a physician. His career was helped by his marriage to Elizabeth Browne, daughter of Elizabeth I's physician, in 1604. In 1607, he became a fellow of the Royal College of Physicians and, in 1609, was appointed physician to St Bartholomew's Hospital. In 1618, he became physician to Elizabeth's successor James I and to James' son Charles when he became king. Both James and Charles took a close interest in and encouraged Harvey's research.
Harvey's research was furthered through the dissection of animals. He first revealed his findings at the College of Physicians in 1616, and in 1628 he published his theories in a book entitled 'Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus' ('An Anatomical Study of the Motion of the Heart and of the Blood in Animals'), where he explained how the heart propelled the blood in a circular course through the body. His discovery was received with great interest in England, although it was greeted with some scepticism on the Continent.
Harvey was also the first to suggest that humans and other mammals reproduced via the fertilisation of an egg by sperm. It took a further two centuries before a mammalian egg was finally observed, but nonetheless Harvey's theory won credibility during his lifetime.
Harvey retained a close relationship with the royal family through the English Civil War and witnessed the Battle of Edgehill. Thanks to Charles I he was, for a short time, warden of Merton College, Oxford (1645 - 1646). He died on 3 June 1657.
Johannes Kepler (1571-1630)
Johannes Kepler was a German mathematician, astronomer, and astrologer. A key figure in the 17th century scientific revolution, he is best known for his laws of planetary motion, based on his works Astronomia nova, Harmonices Mundi, and Epitome of Copernican Astronomy. These works also provided one of the foundations for Isaac Newton's theory of universal gravitation.
During his career, Kepler was a mathematics teacher at a seminary school in Graz, Austria, where he became an associate of Prince Hans Ulrich von Eggenberg. Later he became an assistant to astronomer Tycho Brahe, and eventually the imperial mathematician to Emperor Rudolf II and his two successors Matthias and Ferdinand II. He was also a mathematics teacher in Linz, Austria, and an adviser to General Wallenstein. Additionally, he did fundamental work in the field of optics, invented an improved version of the refracting telescope (the Keplerian Telescope), and mentioned the telescopic discoveries of his contemporary Galileo Galilei.
Kepler lived in an era when there was no clear distinction between astronomy and astrology, but there was a strong division between astronomy (a branch of mathematics within the liberal arts) and physics (a branch of natural philosophy). Kepler also incorporated religious arguments and reasoning into his work, motivated by the religious conviction and belief that God had created the world according to an intelligible plan that is accessible through the natural light of reason. Kepler described his new astronomy as "celestial physics", as "an excursion into Aristotle's Metaphysics", and as "a supplement to Aristotle's On the Heavens", transforming the ancient tradition of physical cosmology by treating astronomy as part of a universal mathematical physics.
Isaac Newton (1642-1727)
Isaac Newton was born on Dec. 25, 1642, in Woolsthorpe, England. His father died before he was born, and when he was only three his mother, Hannah Newton, remarried and moved away, leaving him to be raised by an uncle. He was sent to the local grammar school, and for a time it was expected that he would grow up to manage his mother's property. But he nonetheless persisted in the pursuit of his wider interests, and after leaving the grammar school he enrolled at Trinity College, at the University of Cambridge, in 1661. He received his bachelor of arts in 1665, and was named a fellow of the College two years later.
Meanwhile, in the turbulent year of 1666, while England fought with Holland and suffered plague and a terrible fire in London, Newton made three of his greatest discoveries. In the field of optics, the study of light, he developed and proved his theory that white light is composed of a mixture of other colors of light, which, when split apart by a prism, form a band of color called a spectrum. This was a revolutionary advance, and equally revolutionary was his work in mathematics, where he developed a binomial theorem and worked out a method of calculating the slope of curves and the area under them, paving the way for the field of math known as calculus. But his most important innovation was the concept of gravity, the attraction between bodies in space that holds planets, moons and comets in orbit, and draws falling objects toward the earth. His theory of gravity, however, remained incomplete and unverifiable; it would not be published for two decades.
In 1669, Newton was appointed professor of mathematics at Trinity College. In January 1672, he was elected to the Royal Society, a loose organizations of scientists and intellectuals. Shortly thereafter, he presented a paper detailing his discoveries in optics, and developed a rivalry with the scientist Robert Hooke, who harshly criticized Newton's research. This rivalry would percolate throughout the 1670s, as Newton continued to work out the mathematics of gravity, and would flare up in the mid-1680s, when Newton finally published his work, some of which Hooke felt had been stolen from him. Newton's research was organized into a three-volume book, the Philosophiae Naturalis Principia Mathematica ("Mathematical Principles of Natural Philosophy"), known to posterity as the Principia. It set forth Newton's three laws of motion, and proceeded to set forth the theory of gravitation, and back it up with rigorous mathematical proofs. Although the theory had many detractors at first, the scientific community would ultimately embrace it, and the Newtonian world-view would dominate physics until the 20th century.
Principia made Newton an English celebrity. He was elected to Parliament in 1691, and after surviving a nervous breakdown in 1693, was appointed warden of the mint in 1696, and master of the mint three years later. He was elected president of the Royal Society in 1703, upon the death of Hooke, and was knighted in 1705. As his fame grew, he worked to buttress his own reputation, bringing the Society under his tight control and carrying on a feud with the German mathematician Leibniz over the issue of who had developed calculus first. Newton never married, and was tremendously pious: he dedicated his later years to the interpretation of scripture, and a mighty effort to understand the relationship between biblical prophecy and history. He died on March 20, 1727, and was buried with great honors in Westminster Abbey.