Nicolaus Copernicus Astronomer, Scientist, Mathematician (1473–1543)

SynopsisNicolaus Copernicus was born on February 19, 1473 in Torun, Poland. Circa 1508, Copernicus developed his own celestial model of a heliocentric planetary system. Around 1514, he shared his findings in the Commentariolus. His second book on the topic, De revolutionibus orbium coelestium, was banned by the Roman Catholic Church not long after his May 24, 1543 death in Frauenburg, Poland.

Early EducationFamed astronomer Nicolaus Copernicus (Mikolaj Kopernik, in German) came into the world on February 19, 1473. The fourth and youngest child born to Nicolaus Copernicus Sr. and Barbara Watzenrode, an affluent copper merchant family in Torun, Poland, Copernicus was technically born of German heritage—by the time he was born, Torun had ceded to Poland, rendering him a citizen under the Polish crown. German was Copernicus's first language, but some scholars believe that he spoke some Polish as well.

When Copernicus was 10 years old, his father passed away. His maternal uncle, Bishop of Varmia Lucas Watzenrode, generously assumed the paternal role, taking it upon himself to ensure that Copernicus received the best possible education.

In 1491, Copernicus entered the University of Cracow, where he studied painting and mathematics. Though he did not take astronomy classes at that time, he developed a growing interest in the cosmos, and started collecting books on the topic.

Upon graduating from Cracow in 1494, Copernicus returned to Torun, where he took a canon's position—arranged by his uncle—at Frombork's cathedral. Though the opportunity was only typically available to priests, Copernicus was able to hold onto the job for the rest of his life. It was a fortunate stroke for Copernicus: The canon's position afforded him the opportunity to fund the continuation of his studies for as long as he liked. Still, the job demanded much of his schedule; he was only able to pursue his academic interests intermittently, during his free time.

In 1496, Copernicus took leave and traveled to Italy, where he enrolled in a religious law program as the University of Bologna. There, he met astronomer Domenico Maria Novara—a fateful encounter, as the two began exchanging astronomical ideas and observations. Historian Edward Rosen described the relationship as follows: "In establishing close contact with Novara, Copernicus met, perhaps for the first time in his life, a mind that dared to challenge the authority of [astrologist Claudius Ptolemy] the

most eminent ancient writer in his chosen fields of study." The friends were so enthralled in their intellectual exchange, they decided to become roommates.

In 1500, after completing his law studies in Bologna, Copernicus went on to study practical medicine at the University of Padua. He did not, however, stay long enough to earn a degree, since the two-year leave of absence from his canon position was nearing expiration. In 1503, Copernicus attended the University of Ferrara, where he prepared to take the canon law exam. After passing the test on his first attempt, he hurried back home to Poland, where he resumed his position as canon and rejoined his uncle at a nearby Episcopal residence. Copernicus remained at the Lidzbark-Warminski residence for the next seven years, working and tending to his elderly, ailing uncle, and exploring astronomy whenever he could find the time.

In 1510, Copernicus moved to a residence in the Frombork Cathedral Chapter in hopes of clearing additional time to study astronomy. He would live there as a canon for the duration of his life.

Heliocentric Solar SystemThroughout the seven years he spent in Lidzbark-Warminski, Copernicus read several books on the subject of astronomy. Among the sources that Copernicus consulted was Regiomontus's Epitome of the Almagest, which presented an alternative to Ptolemy's model of the universe, and significantly influenced his research.

By 1508, Copernicus had begun developing his own celestial model, a heliocentric planetary system. During the second century A.D., Ptolemy had invented a geometric planetary model, which was inconsistent with Aristotle's idea that celestial bodies moved in a circular motion at different speeds around a fixed point, the earth. In an attempt to reconcile such inconsistencies, Copernicus's heliocentric solar system named the sun, rather than the earth, as the center of the solar system. Subsequently, Copernicus believed that the size of each planet's orbit depended on its distance from the sun.

Though his theory was viewed as revolutionary and met with some controversy, Copernicus was not the first astronomer to propose such a theory. Centuries prior, in 270 B.C., ancient Greek astronomer Aristarchus of Samos had identified the sun as the solar system's central unit. But a heliocentric theory was quickly dismissed in Copernicus's era because Ptolemy's theories were far more eagerly accepted by the influential Roman Catholic Church, which adamantly supported the earth-based solar system theory. Still, Copernicus's heliocentric solar system proved to be more detailed and accurate than Aristarchus's, including a more efficient formula for calculating planetary positions throughout the year.

After moving to the Frombork Cathedral Chapter in the early 1500s, Copernicus further developed his heliocentric model, and went on to design and apply a complex mathematical system for proving his theory. In 1513, his dedication prompted him to build his own modest observatory so that he could view the planets in action at any given time.

Copernicus's observations did, at times, lead him to form inaccurate conclusions, including his assumption that planets' orbit occurred in perfect circles. As German astronomer Johannes Kepler would later prove in the 17th century, planetary orbits are actually elliptical in shape.

'Commentariolus' and ControversyAround 1514, Copernicus completed a written work, Commentariolus (Latin for "Small Commentary"), a 40-page manuscript that he referred to as the "Sketch of Hypothesis Made by Nicolaus Copernicus on the Heavenly Motions." Commentariolus summarized Copernicus's heliocentric planetary system and strove to provide systematic proof—in the form of both astronomical observations and mathematical formulas—of the model.

The sketch set forth seven axioms, each describing an aspect of the heliocentric solar system: 1) Planets don't revolve around one fixed point; 2) the earth is at the center of the moon's orbit; 3) The sun is at the center of the universe, and all celestial bodies rotate around it; 4) The distance between the earth and sun is only a tiny fraction of stars' distance from the earth and sun; 5) Stars do not move, and if they appear to, it is only because the earth itself is moving; 6) Earth moves in a sphere around the sun, causing the sun's perceived yearly movement; and 7) Earth's orbit around the sun causes the planets to orbit in the opposite direction.

Commentariolus also went on to describe in detail Copernicus's assertion that a mere 34 circles could sufficiently illustrate planetary motion. Copernicus sent his manuscript to several friends and contemporaries, and while the manuscript received little to no response among his colleagues, a buzz began to build around Copernicus and his unconventional theories within two years of Commentariolus's release. Adding an air of mystery to Copernicus's growing reputation—and notoriety, for some—was his rejection to an invitation by the Lateran Council, which invited astronomers to provide advice in reforming the calendar.

Copernicus's written works, Commentariolus and, later, De revolutionibus orbium coelestium (Latin for "On the Revolutions of the Heavenly Spheres"), raised a fair share of controversy. Copernicus's critics claimed that he failed to solve the mystery of the parallax—the seeming displacement in the position of a celestial body, when viewed along varying lines of sight—and that his work lacked a sufficient explanation for why the earth orbits the sun.

In addition to drawing criticism from scholars, Copernicus's theories incensed the Roman Catholic Church; his model was considered heretical because it was contrary to the Church’s teachings. When De revolutionibus orbium coelestium was published in 1543, just before Copernicus's death, religious leader Martin Luther voiced his opposition to the heliocentric solar system model. His underling, Lutheran minister Andreas Osiander, quickly followed suit, saying of Copernicus, "This fool wants to turn the whole art of astronomy upside down."

Osiander even went so far as to write a disclaimer stating that the heliocentric system was a theory, not a fact, and add it to the book's preface, leading readers to assume that Copernicus himself had written it. By this time, Copernicus was ailing and unfit for the task of defending his work.

Ironically, Copernicus had dedicated De revolutionibus orbium coelestium to Pope Paul III. If his tribute to the pope was an attempt to cull the Catholic Church's softer reception, it was to no avail. The Church ultimately banned De revolutionibus posthumously, and the book remained on the list of forbidden reading material for nearly three centuries thereafter.

Death and LegacyIn May of 1543, mathematician and scholar Georg Joachim Rheticus presented Copernicus with a copy of a newly published De revolutionibus orbium coelestium. Suffering the aftermath of a recent stroke, Copernicus is said to have been clutching the book when he died in his bed on May 24, 1543 in Frauenburg, Poland.

In the 17th century, when the ban on De revolutionibus orbium coelestiumwas lifted, Kepler revealed to the public that the preface had indeed been written by Osiander, not Copernicus. As Kepler worked on expanding upon and correcting the errors of Copernicus's heliocentric theory, Copernicus became a symbol of the brave scientist standing alone, defending his theories against the common beliefs of his time.

Tycho BraheAstronomer, Scientist (1546–1601)

SynopsisAfter finding that Copernican tables were several days off in predicting the overlap of Jupiter and Saturn, Tycho Brahe decided to devote his life to correcting them. His observations—the most accurate possible before the invention of the telescope—included a full study of the solar system and accurate positions of more than 777 fixed stars, and what he accomplished remains remarkable today.

Youth and EducationTycho’s father was a privy councilor and later governor of the castle of Helsingborg, which controls the main waterway to the Baltic Sea. His wealthy and childless uncle abducted Tycho at a very early age and, after the initial parental shock was overcome, raised him at his castle in Tostrup, Scania, also financing the youth’s education, which began with the study of law at the University of Copenhagen in 1559–62.Several important natural events turned Tycho from law to astronomy. The first was the total eclipse of the Sun predicted for August 21, 1560. Such a prediction seemed audacious and marvelous to a 14-year-old student, but when Tycho witnessed its realization he saw and believed—the spark was lit—and, as his many later references testify, he never forgot the event. His subsequent student life was divided between his daytime lectures on jurisprudence, in response to the wishes of his uncle, and his nighttime vigil of the stars. The professor of mathematics helped him with the only printed astronomical book available, the Almagest of Ptolemy, the astronomer of antiquity who described the geocentric conception of the cosmos. Other teachers helped him to construct small globes, on which star positions could be plotted, and compasses and cross-staffs, with which he could estimate the angular separation of stars.In 1562 Tycho’s uncle sent him to the University of Leipzig, where he studied until 1565. Another significant event in Tycho’s life occurred in August 1563, when he made his first recorded observation, a conjunction, or overlapping, of Jupiter and Saturn. Almost immediately he found that the existing almanacs and ephemerides, which record stellar and planetary positions, were grossly inaccurate. The Copernican tables were several days off in predicting this event. In his youthful enthusiasm Tycho decided to devote his life to the accumulation of accurate observations of the heavens, in order to correct the existing tables.

Between 1565 and 1570 (or 1572?) he traveled widely throughout Europe, studying at Wittenberg, Rostock, Basel, and Augsburg and acquiring mathematical and astronomical instruments, including a huge quadrant. Inheriting the estates of his father and of his uncle Jørgen, Tycho then settled in Scania and constructed a small observatory on property owned by a relative. Here occurred the third and most important astronomical event in Tycho’s life. On November 11, 1572, he suddenly saw a “new star,” brighter

than Venus and where no star was supposed to be, in the constellation Cassiopeia. He carefully observed the new star and showed that it lay beyond the Moon and therefore was in the realm of the fixed stars. To the world at the time, this was a disquieting discovery, because the intellectual community protected itself against the uncertainties of the future by confidence in the Aristotelian doctrine of inner and continuous harmony of the whole world. This harmony was ruled by the stars, which were regarded as perfect and unchanging. The news that a star could change as dramatically as that described by Tycho, together with the reports of the Copernican theory that the Sun, not Earth, was the centre of the universe, shook confidence in the immutable laws of antiquity and suggested that the chaos and imperfections of Earth were reflected in the heavens. Tycho’s discovery of the new star in Cassiopeia in 1572 and his publication of his observations of it in De nova stella in 1573 marked his transformation from a Danish dilettante to an astronomer with a European reputation.

By marrying a peasant’s daughter, named Kirstine, in 1573, Tycho—as a nobleman’s son—scandalized most of his contemporaries. He seldom mentioned her in his extensive correspondence (which still exists), and it is probable that he was interested mainly in a companion who would superintend his household without being involved in court functions and intrigues. Tycho and Kirstine had eight children, six of whom survived him.

Mature Career

The new star in the constellation Cassiopeia had caused Tycho to rededicate himself to astronomy; one immediate decision was to establish a large observatory for regular observations of celestial events. His plan to establish this observatory in Germany prompted King Frederick II to keep him in Denmark by granting him title in 1576 to the island of Ven (formerly Hven), in the middle of The Sound and about halfway between Copenhagen and Helsingør, together with financial support for the observatory and laboratory buildings. Tycho called the observatory Uraniborg, after Urania, the Muse of astronomy. Surrounded by scholars and visited by learned travelers from all over Europe, Tycho and his assistants collected observations and substantially corrected nearly every known astronomical record.

Tycho was an artist as well as a scientist and craftsman, and everything he undertook or surrounded himself with had to be innovative and beautiful. He established a printing shop to produce and bind his manuscripts in his own way, he imported Augsburg craftsmen to construct the finest astronomical instruments, he induced Italian and Dutch artists and architects to design and decorate his observatory, and he invented a pressure system to provide the then uncommon convenience of sanitary lavatory facilities. Uraniborg fulfilled the hopes of Tycho’s king and friend, Frederick II, that it would become the centre of astronomical study and discovery in northern Europe.

But Frederick died in 1588, and under his son, Christian IV, Tycho’s influence dwindled; most of his income was stopped, partly because of the increasing needs of the state for money. Spoiled by Frederick, however, Tycho had become both unreasonably demanding of more money and less inclined to carry out the civic duties required by his income from state lands.At odds with the three great powers—king, church, and nobility—Tycho left Ven in 1597, and, after short stays at Rostock and at Wandsbek, near Hamburg, he settled in Prague in 1599 under the patronage of Emperor Rudolf II, who also in later years supported the astronomer Johannes Kepler.

The major portion of Tycho’s lifework—making and recording accurate astronomical observations—had already been done at Uraniborg. To his earlier observations, particularly his proof that the nova of 1572 was a star, he added a comprehensive study of the solar system and his proof that the orbit of the comet of 1577 lay beyond the Moon. He proposed a modified Copernican system in which the planets revolved around the Sun, which in turn moved around the stationary Earth. What Tycho accomplished, using only his simple instruments and practical talents, remains an outstanding accomplishment of the Renaissance.

Tycho attempted to continue his observations at Prague with the few instruments he had salvaged from Uraniborg, but the spirit was not there, and he died in 1601, leaving all his observational data to Kepler, his pupil and assistant in the final years. There was a struggle between Kepler and Tycho’s heirs regarding ownership of the data. When it was resolved, with those data Kepler laid the groundwork for the work of Sir Isaac Newton.

Joannes KeplerAstronomer (1571–1630)

Johannes Kepler, was a German astronomer who discovered three major laws of planetary motion, conventionally designated as follows: (1) the planets move in elliptical orbits with the Sun at one focus; (2) the time necessary to traverse any arc of a planetary orbit is proportional to the area of the sector between the central body and that arc (the “area law”); and (3) there is an exact relationship between the squares of the planets’ periodic times and the cubes of the radii of their orbits (the “harmonic law”). Kepler himself did not call these discoveries “laws,” as would become customary after Isaac Newton derived them from a new and quite different set of general physical principles. He regarded them as celestial harmonies that reflected God’s design for the universe. Kepler’s discoveries turned Nicolaus Copernicus’s Sun-centred system into a dynamic universe, with the Sun actively pushing the planets around in noncircular orbits. And it was Kepler’s notion of a physical astronomy that fixed a new problematic for other important 17th-century world-system builders, the most famous of whom was Newton.

Among Kepler’s many other achievements, he provided a new and correct account of how vision occurs; he developed a novel explanation for the behaviour of light in the newly invented telescope; he discovered several new, semi-regular polyhedrons; and he offered a new theoretical foundation for astrology while at the same time restricting the domain in which its predictions could be considered reliable. A list of his discoveries, however, fails to convey the fact that they constituted for Kepler part of a common edifice of knowledge. The matrix of theological, astrological, and physical ideas from which Kepler’s scientific achievements emerged is unusual and fascinating in its own right. Yet, because of the highly original nature of Kepler’s discoveries, it requires an act of intellectual empathy for moderns to understand how such lasting results could have evolved from such an apparently unlikely complex of ideas. Although Kepler’s scientific work was centered first and foremost on astronomy, that subject as then understood—the study of the motions of the heavenly bodies—was classified as part of a wider subject of investigation called “the science of the stars.” The science of the stars was regarded as a mixed science consisting of a mathematical and a physical component and bearing a kinship to other like disciplines, such as music (the study of ratios of tones) and optics (the study of light). It also was subdivided into theoretical and practical categories.

Besides the theory of heavenly motions, one had the practical construction of planetary tables and instruments; similarly, the theoretical principles of astrology had a corresponding practical part that dealt with the making of annual astrological forecasts about individuals, cities, the human body, and the weather. Within this framework, Kepler made astronomy an integral part of natural philosophy, but he did so in an unprecedented way—in the process, making unique contributions to astronomy as well as to all its auxiliary disciplines

Kepler’s Social World

There was no “scientific community” as such in the late 16th century. All schooling in Germany, as elsewhere, was under the control of church institutions—whether Roman Catholic or Protestant—and local rulers used the churches and the educational systems as a means to consolidate the loyalty of their populations. One means to this end was a system of scholarships for poor boys who, once having been trained in the schools of the duchy, would feel strong loyalty to the local ruler. Kepler came from a very modest family in a small German town called Weil der Stadt and was one of the beneficiaries of the ducal scholarship; it made possible his attendance at the Lutheran Stift, or seminary, at the University of Tübingen, where he began his university studies in 1589. It was expected that the boys who graduated from these schools would go on to become schoolteachers, ministers, or state functionaries. Kepler had planned to become a theologian.

His life did not work out quite as he expected. As he sometimes remarked, Divine Providence guided him to the study of the stars, while he retained a profound sense that his vocation was a religious one. As he later wrote, “I am satisfied…to guard the gates of the temple in which Copernicus makes sacrifices at the high altar.” It helped also that, at Tübingen, the professor of mathematics was Michael Maestlin (1550–1631), one of the most talented astronomers in Germany. Maestlin had once been a Lutheran pastor; he was also, privately, one of the few adherents of the Copernican theory in the late 16th century, although very cautious about expressing his views in print. Maestlin lent Kepler his own heavily annotated copy of Copernicus’s 1543 book, De revolutionibus orbium coelestium libri vi (“Six Books Concerning the Revolutions of the Heavenly Orbs”). Kepler quickly grasped the main ideas in Copernicus’s work and was tutored in its complex details by Maestlin. He sensed intuitively that Copernicus had hit upon an account of the universe that contained the mark of divine planning—literally a revelation. Early in the 1590s, while still a student, Kepler would make it his mission to demonstrate rigorously what Copernicus had only guessed to be the case. And he did so in an explicitly religious and philosophical vocabulary.

Kepler was not alone in believing that nature was a book in which the divine plan was written. He differed, however, in the original manner and personal intensity with which he believed his ideas to be embodied in nature. One of the ideas to which he was most strongly attached—the image of the Christian Trinity as symbolized by a geometric sphere and, hence, the visible, created world—was literally a reflection of this divine mystery (God the Father: centre; Christ the Son: circumference; Holy Spirit: intervening space). One of Kepler’s favourite biblical passages came from John (1:14): “And the Word became flesh and lived among us.” For him, this signified that the divine archetypes were literally made visible as geometric forms (straight and curved) that configured the spatial arrangement of tangible, corporeal entities. Moreover, Kepler’s God was a dynamic, creative being whose presence in the world was symbolized by the Sun’s body as the source of a dynamic force that continually moved the planets. The natural world was like a mirror that precisely reflected and embodied these divine ideas.

Inspired by Platonic notions of innate ideas in the soul, Kepler believed that the human mind was ideally created to understand the world’s structure.Astronomical work

The ideas that Kepler would pursue for the rest of his life were already present in his first work, Mysterium cosmographicum (1596; “Cosmographic Mystery”). In 1595, while teaching a class at a small Lutheran school in Graz, Austria, Kepler experienced a moment of illumination. It struck him suddenly that the spacing among the six Copernican planets might be explained by circumscribing and inscribing each orbit with one of the five regular polyhedrons. Since Kepler knew Euclid’s proof that there can be five and only five such mathematical objects made up of congruent faces, he decided that such self-sufficiency must betoken a perfect idea. If now the ratios of the mean orbital distances agreed with the ratios obtained from circumscribing and inscribing the polyhedrons, then, Kepler felt confidently, he would have discovered the architecture of the universe. Remarkably, Kepler did find agreement within 5 percent, with the exception of Jupiter, at which, he said, “no one will wonder, considering such a great distance.” He wrote to Maestlin at once: “I wanted to become a theologian; for a long time I was restless. Now, however, behold how through my effort God is being celebrated in astronomy.”

Had Kepler’s investigation ended with the establishment of this architectonic principle, he might have continued to search for other sorts of harmonies; but his work would not have broken with the ancient Greek notion of uniform circular planetary motion. Kepler’s God, however, was not only orderly but also active. In place of the tradition that individual incorporeal souls push the planets and instead of Copernicus’s passive, resting Sun, Kepler posited the hypothesis that a single force from the Sun accounts for the increasingly long periods of motion as the planetary distances increase. Kepler did not yet have an exact mathematical description for this relation, but he intuited a connection. A few years later he acquired William Gilbert’s groundbreaking book De Magnete, Magneticisque Corporibus, et de Magno Magnete Tellure (1600; “On the Magnet, Magnetic Bodies, and the Great Magnet, the Earth”), and he immediately adopted Gilbert’s theory that the Earth is a magnet. From this Kepler generalized to the view that the universe is a system of magnetic bodies in which, with corresponding like poles repelling and unlike poles attracting, the rotating Sun sweeps the planets around. The solar force, attenuating inversely with distance in the planes of the orbits, was the major physical principle that guided Kepler’s struggle to construct a better orbital theory for Mars.

But there was something more: the standard of empirical precision that Kepler held for himself was unprecedented for his time. The great Danish astronomer Tycho Brahe (1546–1601) had set himself the task of amassing a completely new set of planetary observations—a reform of the foundations of practical astronomy. In 1600 Tycho invited Kepler to join his court at Castle Benátky near Prague. When Tycho died suddenly in 1601, Kepler quickly succeeded him as imperial mathematician to Holy Roman emperor Rudolf II. Kepler’s first publication as imperial mathematician was a work that broke with the theoretical principles of Ptolemaic astrology. Called De

Fundamentis Astrologiae Certioribus (1601;Concerning the More Certain Fundamentals of Astrology), this work proposed to make astrology “more certain” by basing it on new physical and harmonic principles. It showed both the importance of astrological practice at the imperial court and Kepler’s intellectual independence in rejecting much of what was claimed to be known about stellar influence. The relatively great intellectual freedom possible at Rudolf’s court was now augmented by Kepler’s unexpected inheritance of a critical resource: Tycho’s observations. In his lifetime Tycho had been stingy in sharing his observations. After his death, although there was a political struggle with Tycho’s heirs, Kepler was ultimately able to work with data accurate to within 2′ of arc. Without data of such precision to back up his solar hypothesis, Kepler would have been unable to discover his “first law” (1605), that Mars moves in an elliptical orbit. At one point, for example, as he tried to balance the demand for the correct heliocentric distances predicted by his physical model with a circular orbit, an error of 6′ or 8′ appeared in the octants (assuming a circle divided into eight equal parts). Kepler exclaimed, “Because these 8′ could not be ignored, they alone have led to a total reformation of astronomy.” Kepler’s reformation of astronomy was of a piece with his reform of astrology’sprinciples and Tycho’s radical improvement of the celestial observations. Just as the spacing of the planets bore a close relation to the polyhedral forms, so, too, Kepler regarded only those rays hitting the Earth at the right harmonic angles to be efficacious.

During the creative burst of the early Prague period (1601–05) when Kepler won his “war on Mars” (he did not publish his discoveries until 1609 in the Astronomia Nova[New Astronomy]), he also wrote important treatises on the nature of light and on the sudden appearance of a new star (1606; De Stella Nova, “On the New Star”). Kepler first noticed the star—now known to have been a supernova—in October 1604, not long after a conjunction of Jupiter and Saturn in 1603. The astrological importance of the long-anticipated conjunction (such configurations take place every 20 years) was heightened by the unexpected appearance of the supernova. Typically, Kepler used the occasion both to render practical predictions (e.g., the collapse of Islam and the return of Christ) and to speculate theoretically about the universe—for example, that the star was not the result of chance combinations of atoms and that stars are not suns.

Kepler’s interest in light was directly related to his astronomical concerns: how a ray of light, coming from a distant heavenly body located in the outer regions of space, deflects when entering the denser atmosphere surrounding the Earth; and then, in turn, what happens to light as it enters the relatively denser medium of the human eye. These problems had some medieval precedent, but, as usual, Kepler treated them in his own individual way. Although a court astronomer, Kepler chose a traditional academic form in which to compose his ideas on light. He called it Ad Vitellionem Paralipomena, Quibus Astronomiae Pars Optica Traditur (1604; “Supplement to Witelo, in Which Is Expounded the Optical Part of Astronomy”). Witelo (Latin: Vitellio) had written the most important medieval treatise on optics. But Kepler’s analysis of vision changed the framework for understanding the behaviour of light. Kepler wrote that every point on a luminous body in the field of vision emits rays of light in all directions but that the only rays that can enter the eye are those that impinge on the pupil, which functions as a diaphragm. He also reversed the traditional visual cone. Kepler offered a punctiform

analysis, stating that the rays emanating from a single luminous point form a cone the circular base of which is in the pupil. All the rays are then refracted within the normal eye to meet again at a single point on the retina. For the first time the retina, or the sensitive receptor of the eye, was regarded as the place where “pencils of light” compose upside-down images. If the eye is not normal, the second short interior cone comes to a point not on the retina but in front of it or behind it, causing blurred vision. For more than three centuries eyeglasses had helped people see better. But nobody before Kepler was able to offer a good theory for why these little pieces of curved glass had worked.

After Galileo built a telescope in 1609 and announced hitherto-unknown objects in the heavens (e.g., moons revolving around Jupiter) and imperfections of the lunar surface, he sent Kepler his account in Siderius Nuncius (1610; The Sidereal Messenger). Kepler responded with three important treatises. The first was his Dissertatio cum Nuncio Sidereo (1610; “Conversation with the Sidereal Messenger”), in which, among other things, he speculated that the distances of the newly discovered Jovian moons might agree with the ratios of the rhombic dodecahedron, triacontahedron, and cube. The second was a theoretical work on the optics of the telescope, Dioptrice (1611; “Dioptrics”), including a description of a new type of telescope using two convex lenses. The third was based upon his own observations of Jupiter, made between August 30 and September 9, 1610, and published as Narratio de Jovis Satellitibus (1611; “Narration Concerning the Jovian Satellites”). These works provided strong support for Galileo’s discoveries, and Galileo, who had never been especially generous to Kepler, wrote to him, “I thank you because you were the first one, and practically the only one, to have complete faith in my assertions.”

In 1611 Kepler’s life took a turn for the worse. His wife, Barbara, became ill, and his three children contracted smallpox; one of his sons died. Emperor Rudolf soon abdicated his throne. Although Kepler hoped to return to an academic post at Tübingen, there was resistance from the theology faculty; Kepler’s irenic theological views and his friendships with Calvinists and Catholics were characteristic of his independence in all matters, and in this case it did not help his cause. Meanwhile, Kepler was appointed to the position (created for him) of district mathematician in Linz. He continued to hold the position of imperial mathematician under the new emperor, Matthias, although he was physically removed from the court in Prague. Kepler stayed in Linz until 1626, during which time creative productions continued amid personal troubles—the death of his wife and his exclusion from the Lutheran communion. Although he was married again in 1613 (to Susanna Reuttinger), five of his seven children from that marriage died in childhood. After the Counter-Reformation came in 1625, Catholic authorities temporarily removed his library and ordered his children to attend mass.

In 1615 Kepler used the occasion of a practical problem to produce a theoretical treatise on the volumes of wine barrels. His Stereometria Doliorum Vinariorum (“The Stereometry of Wine Barrels”) was the first book published in Linz. Kepler objected to the rule-of-thumb methods of wine merchants to estimate the liquid contents of a barrel. He also refused to be bound strictly by Archimedean methods; eventually he extended the range of cases in which a surface is generated by a conic section—a curve formed by the

intersection of a plane and a cone rotating about its principal axis—by adding solids generated by rotation about lines in the plane of the conic section other than the principal axis.

The Linz authorities had anticipated that Kepler would use most of his time to work on and complete the astronomical tables begun by Tycho. But the work was tedious, and Kepler continued his search for the world harmonies that had inspired him since his youth. In 1619 his Harmonice Mundi (Harmonies of the World) brought together more than two decades of investigations into the archetypal principles of the world: geometrical, musical, metaphysical, astrological, astronomical, and those principles pertaining to the soul. All harmonies were geometrical, including musical ones that derived from divisions of polygons to create “just” ratios (1/2, 2/3, 3/4, 4/5, 5/6, 3/5, 5/8) rather than the irrational ratios of the Pythagorean scale. When the planets figured themselves into angles demarcated by regular polygons, a harmonic influence was impressed on the soul. And the planets themselves fell into an arrangement whereby their extreme velocity ratios conformed with the harmonies of the just tuning system, a celestial music without sound.

Finally, Kepler published the first textbook of Copernican astronomy, Epitome Astronomiae Copernicanae (1618–21;Epitome of Copernican Astronomy). The title mimicked Maestlin’s traditional-style textbook, but the content could not have been more different. The Epitome began with the elements of astronomy but then gathered together all the arguments for Copernicus’s theory and added to them Kepler’s harmonics and new rules of planetary motion. This work would prove to be the most important theoretical resource for the Copernicans in the 17th century. Galileo and Descartes were probably influenced by it. It was capped by the appearance of Tabulae Rudolphinae (1627; “Rudolphine Tables”). The Epitome and the Rudolphine Tables cast heliostatic astronomy and astrology into a form where detailed and extensive counterargument would force opponents to engage with its claims or silently ignore them to their disadvantage. Eventually Newton would simply take over Kepler’s laws while ignoring all reference to their original theological and philosophical framework.

Galileo 

Astronomer, Scientist (1564–1642)

Early LifeGalileo Galilei was born on February 15, 1564, in Pisa in the Duchy of Florence, Italy. He was the first of six children born to Vincenzo Galilei, a well-known musician and music theorist, and Giulia Ammannati. In 1574, the family moved to Florence, where Galileo started his formal education at the Camaldolese monastery in Vallombrosa.

In 1583, Galileo entered the University of Pisa to study medicine. Armed with high intelligence and talent, he soon became fascinated with many subjects, particularly mathematics and physics. While at Pisa, Galileo was exposed to the Aristotelian view of the world, then the leading scientific authority and the only one sanctioned by the Roman Catholic Church. At first, Galileo supported this view, like any other intellectual of his time, and was on track to be a university professor. However, due to financial difficulties, Galileo left the university in 1585 before earning his degree.

Academic CareerGalileo continued to study mathematics, supporting himself with minor teaching positions. During this time he began his two-decade study on objects in motion and published The Little Balance, describing the hydrostatic principles of weighing small quantities, which brought him some fame. This gained him a teaching post at the University of Pisa, in 1589. There Galileo conducted his fabled experiments with falling objects and produced his manuscript Du Motu (On Motion), a departure from Aristotelian views about motion and falling objects. Galileo developed an arrogance about his work, and his strident criticisms of Aristotle left him isolated among his colleagues. In 1592, his contract with the University of Pisa was not renewed.

Galileo quickly found a new position at the University of Padua, teaching geometry, mechanics and astronomy. The appointment was fortunate, for his father had died in 1591, leaving Galileo entrusted with the care of his younger brother Michelagnolo. During his 18-year tenure at Padua, he gave entertaining lectures and attracted large crowds of followers, further increasing his fame and his sense of mission.

Controversial FindingsIn 1604, Galileo published The Operations of the Geometrical and Military Compass, revealing his skills with experiments and practical technological applications. He also constructed a hydrostatic balance for measuring small objects. These developments brought him additional income and more recognition. That same year, Galileo refined his theories on motion and falling objects, and developed the universal law of acceleration, which all objects in the universe obeyed. Galileo began to express openly his support of the Copernican theory that the earth and planets revolved around the sun. This challenged the doctrine of Aristotle and the established order set by the Catholic Church.

In July 1609, Galileo learned about a simple telescope built by Dutch eyeglass makers, and he soon developed one of his own. In August, he demonstrated it to some Venetian merchants, who saw its value for spotting ships and gave Galileo salary to manufacture several of them. However, Galileo’s ambition pushed him to go further, and in the fall of 1609 he made the fateful decision to turn his telescope toward the heavens. In March 1610, he published a small booklet, The Starry Messenger, revealing his discoveries that the moon was not flat and smooth, but a sphere with mountains and craters. He found Venus had phases like the moon, proving it rotated around the sun. He also discovered Jupiter had revolving moons, which didn’t revolve around the earth.

Soon Galileo began mounting a body of evidence that supported Copernican theory and contradicted Aristotle and Church doctrine. In 1612, he published his Discourse on Bodies in Water, refuting the Aristotelian explanation of why objects float in water, saying that it wasn’t because of their flat shape, but instead the weight of the object in relation to the water it displaced. In 1613, he published his observations of sunspots, which further refuted Aristotelian doctrine that the sun was perfect. That same year, Galileo wrote a letter to a student to explain how Copernican theory did not contradict Biblical passages, stating that scripture was written from an earthly perspective and implied that science provided a different, more accurate perspective. The letter was made public and Church Inquisition consultants pronounced Copernican theory heretical. In 1616, Galileo was ordered not to “hold, teach, or defend in any manner” the Copernican theory regarding the motion of the earth. Galileo obeyed the order for seven years, partly to make life easier and partly because he was a devoted Catholic.

In 1623, a friend of Galileo, Cardinal Maffeo Barberini, was selected as Pope Urban VIII. He allowed Galileo to pursue his work on astronomy and even encouraged him to publish it, on condition it be objective and not advocate Copernican theory. In 1632, Galileo published the Dialogue Concerning the Two Chief World Systems, a discussion among three people: one who supports Copernicus' heliocentric theory of the universe, one who argues against it, and one who is impartial. Though Galileo claimed Dialogues was neutral, it was clearly not. The advocate of Aristotelian belief comes across as the simpleton, getting caught in his own arguments.

Reaction by the ChurchChurch reaction against the book was swift, and Galileo was summoned to Rome. The Inquisition proceedings lasted from September 1632 to July 1633. During most of this time, Galileo was treated with respect and never imprisoned. However, in a final attempt to break him, Galileo was threatened with torture, and he finally admitted he had supported Copernican theory, but privately held that his statements were correct. He was convicted of heresy and spent his remaining years under house arrest. Though ordered not to have any visitors nor have any of his works printed outside of Italy, he ignored both. In 1634, a French translation of his study of forces and their effects on matter was published, and a year later, copies of the Dialoguewere published in Holland. While under house arrest, Galileo wrote Two New Sciences, a summary of his life’s work on the

science of motion and strength of materials. It was printed in Holland in 1638. By this time, he had become blind and in ill health.

Death and LegacyGalileo died in Arcetri, near Florence, Italy, on January 8, 1642, after suffering from a fever and heart palpitations. But in time, the Church couldn’t deny the truth in science. In 1758, it lifted the ban on most works supporting Copernican theory, and by 1835 dropped its opposition to heliocentrism altogether.

In the 20th century, several popes acknowledged the great work of Galileo, and in 1992, Pope John Paul II expressed regret about how the Galileo affair was handled. Galileo's contribution to our understanding of the universe was significant not only in his discoveries, but in the methods he developed and the use of mathematics to prove them. He played a major role in the scientific revolution and, deservedly so, earned the moniker "The Father of Modern Science."

Isaac Newton Philosopher, Astronomer, Physicist, Scientist, Mathematician (1643–1727)

SynopsisBorn on January 4, 1643, in Woolsthorpe, England, Isaac Newton was an established physicist and mathematician, and is credited as one of the great minds of the 17th century Scientific Revolution. With discoveries in optics, motion and mathematics, Newton developed the principles of modern physics. In 1687, he published his most acclaimed work, Philosophiae Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy), which has been called the single most influential book on physics. Newton died in London on March 31, 1727.

Professional LifeAs a professor, Newton was exempted from tutoring but required to deliver an annual course of lectures. He chose to deliver his work on optics as his initial topic. Part of Newton's study of optics was aided with the use of a reflecting telescope that he designed and constructed in 1668—his first major public scientific achievement. This invention helped prove his theory of light and color. The Royal Society asked for a demonstration of his reflecting telescope in 1671, and the organization's interest encouraged Newton to publish his notes on light, optics and color in 1672; these notes were later published as part of Newton's Opticks: Or, A treatise of the Reflections, Refractions, Inflections and Colours of Light.

However, not everyone at the Royal Academy was enthusiastic about Newton's discoveries in optics. Among the dissenters was Robert Hooke, one of the original members of the Royal Academy and a scientist who was accomplished in a number of areas, including mechanics and optics. In his paper, Newton theorized that white light was a composite of all colors of the spectrum, and that light was composed of particles. Hooke believed that light was composed of waves. Hooke quickly condemned Newton's paper in condescending terms, and attacked Newton's methodology and conclusions.

Hooke was not the only one to question Newton's work in optics. Renowned Dutch scientist Christiaan Huygens and a number of French Jesuits also raised objections. But because of Hooke's association with the Royal Society and his own work in optics, his criticism stung Newton the worst. Unable to handle the critique, he went into a rage—a reaction to criticism that was to continue throughout his life.

Newton denied Hooke's charge that his theories had any shortcomings, and argued the importance of his discoveries to all of science. In the ensuing months, the exchange between the two men grew more acrimonious, and soon Newton threatened to quit the society altogether. He remained only when several other members assured him that the Fellows held him in high esteem.

However, the rivalry between Newton and Hooke would continue for several years thereafter. Then, in 1678, Newton suffered a complete nervous breakdown and the

correspondence abruptly ended. The death of his mother the following year caused him to become even more isolated, and for six years he withdrew from intellectual exchange except when others initiated correspondence, which he always kept short.

During his hiatus from public life, Newton returned to his study of gravitation and its effects on the orbits of planets. Ironically, the impetus that put Newton on the right direction in this study came from Robert Hooke. In a 1679 letter of general correspondence to Royal Society members for contributions, Hooke wrote to Newton and brought up the question of planetary motion, suggesting that a formula involving the inverse squares might explain the attraction between planets and the shape of their orbits.

Subsequent exchanges transpired before Newton quickly broke off the correspondence once again. But Hooke's idea was soon incorporated into Newton's work on planetary motion, and from his notes it appears he had quickly drawn his own conclusions by 1680, though he kept his discoveries to himself.

In early 1684, in a conversation with fellow Royal Society members Christopher Wren and Edmond Halley, Hooke made his case on the proof for planetary motion. Both Wren and Halley thought he was on to something, but pointed out that a mathematical demonstration was needed. In August 1684, Halley traveled to Cambridge to visit with Newton, who was coming out of his seclusion. Halley idly asked him what shape the orbit of a planet would take if its attraction to the sun followed the inverse square of the distance between them (Hooke's theory).

Newton knew the answer, due to his concentrated work for the past six years, and replied, "An ellipse." Newton claimed to have solved the problem some 18 years prior, during his hiatus from Cambridge and the plague, but he was unable to find his notes. Halley persuaded him to work out the problem mathematically and offered to pay all costs so that the ideas might be published.

Publishing 'Principia'In 1687, after 18 months of intense and effectively nonstop work, Newton published Philosophiae Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy). Said to be the single most influential book on physics and possibly all of science, it is most often known as Principiaand contains information on nearly all of the essential concepts of physics, except energy.

The work offers an exact quantitative description of bodies in motion in three basic laws: 1) A stationary body will stay stationary unless an external force is applied to it; 2) Force is equal to mass times acceleration, and a change in motion is proportional to the force applied; and 3) For every action, there is an equal and opposite reaction. These three laws helped explain not only elliptical planetary orbits but nearly every other motion in

the universe: how the planets are kept in orbit by the pull of the sun’s gravity; how the moon revolves around Earth and the moons of Jupiter revolve around it; and how comets revolve in elliptical orbits around the sun.

The laws also allowed Newton to calculate the mass of each planet, calculate the flattening of the Earth at the poles and the bulge at the equator, and how the gravitational pull of the sun and moon create the Earth’s tides. In Newton's account, gravity kept the universe balanced, made it work, and brought heaven and earth together in one great equation.

Upon the publication of the first edition of Principia, Robert Hooke immediately accused Newton of plagiarism, claiming that he had discovered the theory of inverse squares and that Newton had stolen his work. The charge was unfounded, as most scientists knew, for Hooke had only theorized on the idea and had never brought it to any level of proof. However, Newton was furious and strongly defended his discoveries.

He withdrew all references to Hooke in his notes and threatened to withdraw from publishing the subsequent edition of Principia altogether. Halley, who had invested much of himself in Newton's work, tried to make peace between the two men. While Newton begrudgingly agreed to insert a joint acknowledgement of Hooke's work (shared with Wren and Halley) in his discussion of the law of inverse squares, it did nothing to placate Hooke.

As the years went on, Hooke's life began to unravel. His beloved niece and companion died the same year that Principia was published, in 1687. As Newton's reputation and fame grew, Hooke's declined, causing him to become even more bitter and loathsome toward his rival. To the bitter end, Hooke took every opportunity he could to offend Newton. Knowing that his rival would soon be elected president of the Royal Society, Hooke refused to retire until the year of his death, in 1703.

International ProminencePrincipia immediately raised Newton to international prominence, and he thereafter became more involved in public affairs. Consciously or unconsciously, he was ready for a new direction in life. He no longer found contentment in his position at Cambridge and he was becoming more involved in other issues. He helped lead the resistance to King James II's attempts to reinstitute Catholic teaching at Cambridge, and in 1689 he was elected to represent Cambridge in Parliament.

While in London, Newton acquainted himself with a broader group of intellectuals and became acquainted with political philosopher John Locke. Though many of the scientists on the continent continued to teach the mechanical world according to Aristotle, a young generation of British scientists became captivated with Newton's new view of the

physical world and recognized him as their leader. One of these admirers was Nicolas Fatio de Duillier, a Swiss mathematician whom Newton befriended while in London.

However, within a few years, Newton fell into another nervous breakdown in 1693. The cause is open to speculation: his disappointment over not being appointed to a higher position by England's new monarchs, William III and Mary II, or the subsequent loss of his friendship with Duillier; exhaustion from being overworked; or perhaps chronic mercury poisoning after decades of alchemical research. It's difficult to know the exact cause, but evidence suggests that letters written by Newton to several of his London acquaintances and friends, including Duillier, seemed deranged and paranoiac, and accused them of betrayal and conspiracy.

Oddly enough, Newton recovered quickly, wrote letters of apology to friends, and was back to work within a few months. He emerged with all his intellectual facilities intact, but seemed to have lost interest in scientific problems and now favored pursuing prophecy and scripture and the study of alchemy. While some might see this as work beneath the man who had revolutionized science, it might be more properly attributed to Newton responding to the issues of the time in turbulent 17th century Britain. Many intellectuals were grappling with the meaning of many different subjects, not least of which were religion, politics and the very purpose of life. Modern science was still so new that no one knew for sure how it measured up against older philosophies.

In 1696, Newton was able to attain the governmental position he had long sought: warden of the Mint; after acquiring this new title, he permanently moved to London and lived with his niece, Catherine Barton. She was the mistress of Lord Halifax, a high-ranking government official who was instrumental in having Newton promoted, in 1699, to master of the Mint—a position that he would hold until his death. Not wanting it to be considered a mere honorary position, Newton approached the job in earnest, reforming the currency and severely punishing counterfeiters. As master of the Mint, Newton moved the British currency, the pound sterling, from the silver to the gold standard.

In 1703, Newton was elected president of the Royal Society upon Robert Hooke's death. In 1705, he was knighted by Queen Anne of England. By this point in his life, Newton's career in science and discovery had given way to a career of political power and influence.

Newton never seemed to understand the notion of science as a cooperative venture, and his ambition and fierce defense of his own discoveries continued to lead him from one conflict to another with other scientists. By most accounts, Newton's tenure at the society was tyrannical and autocratic; he was able to control the lives and careers of younger scientists with absolute power.

In 1705, in a controversy that had been brewing for several years, German mathematician Gottfried Leibniz publicly accused Newton of plagiarizing his research, claiming he had discovered infinitesimal calculus several years before the publication of Principia. In 1712, the Royal Society appointed a committee to investigate the matter. Of course, since Newton was president of the society, he was able to appoint the committee's members and oversee its investigation. Not surprisingly, the committee concluded Newton's priority over the discovery.

That same year, in another of Newton's more flagrant episodes of tyranny, he published without permission the notes of astronomer John Flamsteed. It seems the astronomer had collected a massive body of data from his years at the Royal Observatory at Greenwich, England. Newton had requested a large volume of Flamsteed's notes for his revisions to Principia. Annoyed when Flamsteed wouldn't provide him with more information as quickly as he wanted it, Newton used his influence as president of the Royal Society to be named the chairman of the body of "visitors" responsible for the Royal Observatory.

He then tried to force the immediate publication of Flamsteed's catalogue of the stars, as well as all of Flamsteed's notes, edited and unedited. To add insult to injury, Newton arranged for Flamsteed's mortal enemy, Edmund Halley, to prepare the notes for press. Flamsteed was finally able to get a court order forcing Newton to cease his plans for publication and return the notes—one of the few times that Newton was bested by one of his rivals.

Final YearsToward the end of this life, Newton lived at Cranbury Park, near Winchester, England, with his niece, Catherine (Bancroft) Conduitt, and her husband, John Conduitt. By this time, Newton had become one of the most famous men in Europe. His scientific discoveries were unchallenged. He also had become wealthy, investing his sizable income wisely and bestowing sizable gifts to charity. Despite his fame, Newton's life was far from perfect: He never married or made many friends, and in his later years, a combination of pride, insecurity and side trips on peculiar scientific inquiries led even some of his few friends to worry about his mental stability.

By the time he reached 80 years of age, Newton was experiencing digestion problems, and had to drastically change his diet and mobility. Then, in March 1727, Newton experienced severe pain in his abdomen and blacked out, never to regain consciousness. He died the next day, on March 31, 1727, at the age of 84.

Isaac Newton's fame grew even more after his death, as many of his contemporaries proclaimed him the greatest genius who ever lived. Maybe a slight exaggeration, but his discoveries had a large impact on Western thought, leading to comparisons to the likes of Plato, Aristotle and Galileo.

Although his discoveries were among many made during the Scientific Revolution, Isaac Newton's universal principles of gravity found no parallels in science at the time. Of course, Newton was proven wrong on some of his key assumptions. In the 20th century, Albert Einstein would overturn Newton's concept of the universe, stating that space, distance and motion were not absolute but relative, and that the universe was more fantastic than Newton had ever conceived.

Newton might not have been surprised: In his later life, when asked for an assessment of his achievements, he replied, "I do not know what I may appear to the world; but to myself I seem to have been only like a boy playing on the seashore, and diverting myself now and then in finding a smoother pebble or prettier shell than ordinary, while the great ocean of truth lay all undiscovered before me."

Francis Bacon Scientist, Lawyer (1561–1626)

Early LifeStatesman and philosopher Francis Bacon was born in London on January 22, 1561. His father, Sir Nicolas Bacon, was Lord Keeper of the Seal. His mother, Lady Anne Cooke Bacon, was his father's second wife and daughter to Sir Anthony Cooke, a humanist who was Edward VI's tutor. Francis Bacon’s mother was also the sister-in-law of Lord Burghley.

The younger of Sir Nicholas and Lady Anne's two sons, Francis Bacon began attending Trinity College, Cambridge, in April 1573, when he was 12 years old. He completed his course of study at Trinity in December 1575. The following year, Bacon enrolled in a law program at Honourable Society of Gray's Inn, the school his brother Anthony attended. Finding the curriculum at Gray's Inn stale and old fashioned, Bacon later called his tutors "men of sharp wits, shut up in their cells if a few authors, chiefly Aristotle, their dictator." Bacon favored the new Renaissance humanism over Aristotelianism and scholasticism, the more traditional schools of thought in England at the time.

A year after he enrolled at Gray's Inn, Bacon left school to work under Sir Amyas Paulet, British ambassador to France, during his mission in Paris. Two and a half years later, he was forced to abandon the mission prematurely and return to England when his father died unexpectedly. His meager inheritance left him broke. Bacon turned to his uncle, Lord Burghley, for help in finding a well-paid post as a government official, but Bacon’s uncle shot him down. Still just a teen, Francis Bacon was scrambling to find a means of earning a decent living.

Counsel and StatesmanFortunately for Bacon, in 1581, he landed a job as a member for Cornwall in the House of Commons. Bacon was also able to return to Gray's Inn and complete his education. By 1582, he was appointed the position of outer barrister. Bacon's political career took a big leap forward in 1584, when he composed A Letter of Advice to Queen Elizabeth, his very first political memorandum.

Bacon held his place in Parliament for nearly four decades, from 1584 to 1617, during which time he was extremely active in politics, law and the royal court. In 1603, three years before he married heiress Alice Barnham, Bacon was knighted upon James I's ascension to the British throne. He continued to work his way swiftly up the legal and political ranks, achieving solicitor general in 1607 and attorney general six years later. In 1616, his career peaked when he was invited to join the Privy Council. Just a year later, he reached the same position of his father, Lord Keeper of the Great Seal. In 1618, Bacon surpassed his father's achievements when he was promoted to the lofty title of Lord Chancellor, one of the highest political offices in England. In 1621, Bacon became Viscount St. Albans.

In 1621, the same year that Bacon became Viscount St. Albans, he was accused of accepting bribes and impeached by Parliament for corruption. Some sources claim that Bacon was set up by his enemies in Parliament and the court faction, and was used as a scapegoat to protect the Duke of Buckingham from public hostility. Bacon was tried and found guilty after he confessed. He was fined a hefty 40,000 pounds and sentenced to the Tower of London, but, fortunately, his sentence was reduced and his fine was lifted. After four days of imprisonment, Bacon was released, at the cost of his reputation and his long- standing place in Parliament; the scandal put a serious strain on 60-year-old Bacon's health.

Philosopher of ScienceBacon remained in St. Alban's after the collapse of his political career. Retired, he was now able to focus on one of his other passions, the philosophy of science. From the time he had reached adulthood, Bacon was determined to alter the face of natural philosophy. He strove to create a new outline for the sciences, with a focus on empirical scientific methods—methods that depended on tangible proof—while developing the basis of applied science. Unlike the doctrines of Aristotle and Plato, Bacon's approach placed an emphasis on experimentation and interaction, culminating in "the commerce of the mind with things." Bacon's new scientific method involved gathering data, prudently analyzing it and performing experiments to observe nature's truths in an organized way. He believed that when approached this way, science could become a tool for the betterment of humankind.

Biographer Loren Eisley described Bacon's compelling desire to invent a new scientific method, stating that Bacon, "more fully than any man of his time, entertained the idea of the universe as a problem to be solved, examined, meditated upon, rather than as an eternally fixed stage upon which man walked." Bacon himself claimed that his empirical scientific method would spark a light in nature that would "eventually disclose and bring into sight all that is most hidden and secret in the universe."

During his young adulthood, Bacon attempted to share his ideas with his uncle, Lord Burghley, and later with Queen Elizabeth in his Letter of Advice. The two did not prove to be a receptive audience to Bacon's evolving philosophy of science. It was not until 1620, when Bacon published Book One of Novum Organum Scientiarum (novum organum is Latin for "new method"), that Bacon established himself as a reputable philosopher of science.

According to Bacon in Novum Organum, the scientific method should begin with the "Tables of Investigation." It should then proceed to the "Table of Presence," which is a list of circumstances under which the event being studied occurred. "The Table of Absence in Proximity" is then used to identify negative occurrences. Next, the "Table of Comparison" allows the observer to compare and contrast the severity or degree of the event. After completing these steps, the scientific observer is required to perform a short survey that will help identify the possible cause of the occurrence. Unlike a typical

hypothesis, however, Bacon did not emphasize the importance of testing one's theory. Instead, he believed that observation and analysis were sufficient in producing a greater comprehension, or "ladder of axioms," that creative minds could use to reach still further understanding.

Writing CareerDuring his career as counsel and statesman, Bacon often wrote for the court. In 1584, he wrote his first political memorandum, A Letter of Advice to Queen Elizabeth. In 1592, to celebrate the anniversary of the queen's coronation, he wrote an entertaining speech in praise of knowledge. The year 1597 marked Bacon's first publication, a collection of essays about politics. The collection was later expanded and republished in 1612 and 1625.

In 1605, Bacon published The Advancement of Learning in an unsuccessful attempt to rally supporters for the sciences. In 1609, he departed from political and scientific genres when he released On the Wisdom of the Ancients, his analysis of ancient mythology.

Bacon then resumed writing about science, and in 1620, published Novum Organum, presented as Part Two of The Great Saturation. In 1622, he wrote a historical work for Prince Charles, entitled The History of Henry VII. Bacon also published Historia Ventorum and Historia Vitae et Mortis that same year. In 1623, he published De Augmentis Scientarium, a continuation of his view on scientific reform. In 1624, his works The New Atlantis and Apothegmswere published. Sylva Sylvarium, which was published in 1627, was among the last of his written works.

Although Bacon's body of work covered a fairly broad range of topics, all of his writing shared one thing in common: It expressed Bacon's desire to change antiquated systems.

Death and LegacyIn March 1626, Bacon was performing a series of experiments with ice. While testing the effects of cold on the preservation and decay of meat, he stuffed a hen with snow near Highgate, England, and caught a chill. Ailing, Bacon stayed at Lord Arundel's home in London. The guest room where Bacon resided was cold and musty. He soon developed bronchitis. On April 9, 1626, a week after he had arrived at Lord Arundel's estate, Francis Bacon died.

In the years after Bacon's death, his theories began to have a major influence on the evolving field of 17th-century European science. British scientists belonging to Robert Boyle's circle, also known as the "Invisible College," followed through on Bacon's concept of a cooperative research institution, applying it toward their establishment of the Royal Society of London for Improving Natural Knowledge in 1662. The Royal Society utilized Bacon's applied science approach and followed the steps of his reformed

scientific method. Scientific institutions followed this model in kind. Political philosopher Thomas Hobbes played the role of Bacon's last amanuensis. The "father of classic liberalism," John Locke, as well as 18th-century encyclopedists and inductive logicians David Hume and John Mill, also showed Bacon's influence in their work.

Today, Bacon is still widely regarded as a major figure in scientific methodology and natural philosophy during the English Renaissance. Having advocated an organized system of obtaining knowledge with a humanitarian goal in mind, he is largely credited with ushering in the new early modern era of human understanding.