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Scientific Revolution

Scientific revolution

:This article is about the period in history, not the process of scientific progress via revolution, proposed by Thomas Kuhn and discussed at paradigm shift In the history of science, the scientific revolution was the period that roughly began with the discoveries of Kepler, Galileo, and others at the dawn of the 17th century, and ended with the publication of the Philosophiae Naturalis Principia Mathematica in 1687 by Isaac Newton. These boundaries are controversial, with some claiming that the proper start of the scientific revolution was the publication of De revolutionibus orbium coelestium by Nicolaus Copernicus in 1543, while others wish to extend it into the 18th century. Nevertheless, the basic themes of the revolution are readily recognised. The seventeenth century was a period of major scientific change. But at that time the word "science" did not have its current meaning, and "scientist" had not been coined; Newton was called a natural philosopher. Not only were there major theoretical and experimental developments, but even more importantly, the way in which scientists worked was radically changed. At the beginning of the century, science was highly Aristotelian; at its end, science was mathematical, mechanical, and empirical.

Emergence of the revolution

There is much scholarly debate as to the nature, emergence, and even the existence of the scientific revolution. This debate began with the work of Alexandre Koyré when he coined the term and definition of 'The Scientific Revolution' in 1939, which later influenced the work of traditional historians A. Rupert Hall and J.D. Bernal and subsequent historiography on the subject (Stevin Shapin, The Scientific Revolution, 1996). To some extent, this arises from different conceptions of what the revolution was; some of the rancor and cross-purposes in such debates may arise from lack of recognition of these fundamental differences. Since the time of Voltaire, many observers have considered that a revolutionary change in thought, called in recent times a scientific revolution, took place around the year 1600; that is, that there were dramatic and historically rapid changes in the ways in which scholars thought about the physical world and studied it. Science, as it is treated in this account, is essentially understood and practiced in the modern world; with various "other narratives" or alternate ways of knowing omitted. A striking case for this point of view is presented by the historian of science Howard Margolis as part of a larger (and controversial) theory of the causes of the revolution (Margolis, 2002). It may be summarized in the following lists of significant advances in science:

Early and Medieval Views of Science

2nd century
- Galen's work in anatomy
- Ptolemy's calculations of planetary motion. (This and Galen's anatomy, though largely superseded by later work, are none the less important contributions to science.) Ptolemy believed that the earth was the center of the universe.
- Aristotle's belief that God placed earth at the center of the universe with a hierarchical order to the Universe. The universe, according to Aristotle consisted of concentric spheres. All bodies naturally moved toward the center and moved toward rest, therefore a God must exist in order to move things into motion, which was later revoked by Newton's theories.
- Dante's view of the four elements: fire, earch, water, and air, which made up earth and purgatory.
- Galen believed that there were four bodily humors--blood, phlegm, yellow bile, and black bile. This idea was later revoked by Andreas Vesalius. Galen believed that sickness was caused by an inbalance of any of the humors.

New Scientific Thought

About 1600, Ideas and People who emerged:
- Uniform acceleration of falling bodies (Galileo)
- Inertia and inertial frames of reference
- The Earth as a magnet
- Theory of lenses
- Kepler's laws of planetary motion (Kepler), coupled with Copernicus' publication of Concerning the Revolutions of the Celestial Spheres.
- Telescopic discoveries: moons of Jupiter, lunar mountains, phases of Venus, etc. (Galileo)
- Laws of hydrostatics
- Constant period of the pendulum (Newton)
- Andreas Vesalius (1514-1564) published On the Fabric of the Human Body (1543), which discredited Galen's views. He found that the circulation of blood resolved from pumping of the heart. He also assembled the first human skeleton from cutting open cadavers.
- William Harvey (1578-1657) solved how blood circulates via disections.
- Tycho Brahe and Johannes Kepler searched for understanding of the stars. Although the Danish Brahe rejected the Copernican belief that the earth revolved around the sun, his assistant Kepler, a German, proved that Copernicus' theory had validity. He established, using trigonometry and geometric algebra, laws of planetary motion.
- William Gilbert (1544-1603), an English scientist, published a book describing the magnet in 1600.
- Sir Francis Bacon (1561-1626), whose greatest scientific experiment amounted to stuffing snow into a dead chicken, nevertheless penned inductive reasoning, proceeding from observation and experimentation. This contrasted with Rene Descartes who took a more theoretical approach to science.
- Galileo was tried for his belief of the Copernican system because he lived in Italy, a Catholic state at the height of an inquisition that prosecuted heresy. Because the pope was a personal friend of Galileo's, he fortunately escaped death and instead lived the rest of his life in house arrest if he chose to renounce his support for Copernicus's views, which he did. He is perhaps best known for his law of falling bodies, which he proved not only theoretically through a thought experiment, but also through experimentation, uniting both the inductive observational part of science with the theoretical and logical branch.
- René Descartes(1596-1650) and Isaac Newton(1642-1727): Descartes pioneered Deductive reasoning, publishing in 1637 Discourse on Method. He is widely known for issuing the statement, "I think, therefore I am" (Cogito, ergo sum). Newtonian Synthesis, on the other hand is built upon Kepler, Galileo and Descartes--Newton believed that scientific theory should be coupled with rigid experimentation. Newton postulated the theory of Universal Gravitation. Newton became a wealthy hero--knighted by the king and elected to Parliament in 1689 representing Cambridge University. However, Newton did clash with Goetfried Leibniz on various issues, including who first invented Calculus and on the question of whether or not God intervened in everyday affairs. It is not easy to find work of comparable importance, apart from that of Copernicus, to fill out the intervening period. Margolis reports that the most commonly suggested candidate for filling the gap is Alhazen's theory of intromission; that is, that vision is by means of light emitted from bodies, not rays from the eye. Giving this important work its full value (regardless of its antecedents in Aristotle), it still does not go far to fill fourteen centuries, and the other candidates are few:

[One may reasonably judge that] Gilbert and Stevin each discovered more that has proved important for modern science than the combination of everyone who lived during the fourteen centuries between them and Ptolemy. But for Kepler and Galileo a claim this bold is not merely arguable, but beyond real dispute. If you measure what either Kepler or Galileo discovered against everything discovered in the previous 1400 years, it is no contest. (Margolis, 2002; p. 139)

In this interpretation these extraordinary changes, beginning with Copernicus and extending to the early 17th century, are the raw data on which are built the theoretical studies of how and why the revolution took place, and what changes in society and thought resulted from it. Other accounts of what constitutes the revolution exist and lead to quite different studies.

Theoretical developments

In 1543 Copernicus' work on the heliocentric model of the solar system was published, in which he tried to prove that the sun was the centre of the universe. Ironically, this was at the behest of the Catholic Church as part of the Catholic Reformation efforts for a means of creating a more accurate calendar for its activities. For almost two millennia, the geocentric model had been accepted by all but a few astronomers. The idea that the earth moved around the sun, as advocated by Copernicus, was to most of his contemporaries preposterous. It contradicted not only the virtually unquestioned Aristotelian philosophy, but also common sense. For suppose the earth turns about its own axis. Then, surely, if we were to drop a stone from a high tower, the earth would rotate beneath it while it fell, thus causing the stone to land some space away from the tower's bottom. This effect is not observed. It is no wonder, then, that although some astronomers used the Copernican system to calculate the movement of the planets, only a handful actually accepted it as true theory. It took the efforts of two men, Johannes Kepler and Galileo, to give it credibility. Kepler was a brilliant astronomer who, using the very accurate observations of Tycho Brahe, realised that the planets move around the sun not in circular orbits, but in elliptical ones. Together with his other laws of planetary motion, this allowed him to create a model of the solar system that was a huge improvement over Copernicus' original system. Galileo's main contributions to the acceptance of the heliocentric system were his mechanics and the observations he made with his telescope, as well as his detailed presentation of the case for the system (which led to his condemnation by the Inquisition). Using an early theory of inertia, Galileo could explain why rocks dropped from a tower fall straight down even if the earth rotates. His observations of the moons of Jupiter, the phases of Venus, the spots on the sun, and mountains on the moon all helped to discredit the Aristotelian philosophy and the Ptolemaic theory of the solar system. Through their combined discoveries, the heliocentric system gained more and more support, and at the end of the 17th century it was generally accepted by astronomers. Both Kepler's laws of planetary motion and Galileo's mechanics culminated in the work of Isaac Newton. His laws of motion were to be the solid foundation of mechanics; his law of universal gravitation combined terrestrial and celestial mechanics into one great system that seemed to be able to describe the whole world in mathematical formulae. Not only astronomy and mechanics were greatly changed. Optics, for instance, was revolutionised by people like Robert Hooke, Christiaan Huygens and, once again, Isaac Newton, who developed mathematical theories of light as either waves (Huygens) or particles (Newton). Similar developments could be seen in chemistry, biology and other sciences, although their full development into modern science was delayed for a century or more.

Experimental developments

The development of telescopes in Holland and subsequent improvements by Galileo and others greatly expanded the accuracy and range of celestial observations. The emerging technology of the microscope brought the world of the very small within reach of the human observer, although it would take an additional two centuries before the instrument was perfected. Another notable invention was the air-pump, extensively used by Robert Boyle and others.

Methodological developments

The most important changes were in the way that science was done. Three main developments can be identified as mathematisation, mechanisation, and empiricism.

Mechanisation

Aristotle recognised four kinds of causes, of which the most important was the "final cause". The final cause was the aim or goal of something. Thus, the final cause of rain was to let plants grow. Until the scientific revolution, it was very natural to see such goals in nature. The world was inhabited by angels and demons, spirits and souls, occult powers and mystical principles. Scientists spoke about the 'soul of a magnet' as easily as they spoke about its velocity. The rise of the so-called "mechanical philosophy" put a stop to this. The mechanists, of whom the most important one was René Descartes, rejected all goals, emotion and intelligence in nature. In this modern view, the world consisted of matter moving in accordance with the laws of physics. Where nature had previously been imagined to be like a living entity, the scientific revolution viewed nature as following natural, physical laws.

Empiricism

"Look at the world, but don't experiment!"—such was the view of the natural philosophers before the scientific revolution. Nature, it was thought, should be looked at as it worked on its own. If one did an experiment, one was putting nature in "unnatural" circumstances, and hence the results of an experiment would not agree with the true way nature worked. Under the influence of philosophers like Francis Bacon, an empirical tradition was developed in the 17th century. The Aristotelian belief of natural and artificial circumstances was abandoned, and a research tradition of systematic experimentation was slowly accepted throughout the scientific community. Bacon's philosophy of using an inductive approach to nature -- to abandon assumption and to attempt to simply observe with an open mind -- was in strict contrast with the earlier, Aristotelian approach of deduction, by which analysis of "known facts" produced further understanding. In practice, of course, many scientists (and philosophers) believed that a healthy mix of both was needed -- the willingness to question assumptions, yet also interpret observations assumed to have some degree of validity. At the end of the scientific revolution the organic, quantitative world of book-reading philosophers had been changed into a mechanical, mathematical world to be known through experimental research. Though it is certainly not true that Newtonian science was like modern science in all respects, it closely resembled ours in many ways -- much more so than the Aristotelian science of a century earlier.

Literary criticisms

A recent trend in literary theory, "cultural materialism" questions whether there was a scientific revolution, or, if a revolution occurred, it questions whether it was important. Literary critics who hold this point of view have a special (and some would claim, mistaken), definition of what the term "revolution" means. These literary critics hold that if a scientific revolution did not occur instantaneously, and without historical precedent, then by definition it cannot be a revolution, and can only be an evolution. If the scientific revolution was only an evolution, then it would have little or no intelligibility as a single event, but nonetheless, like all evolutionary processes, "the scientific evolution" invites serious consideration as a process or group of processes, in order to understand if and how language, culture and society have changed and are changing as a result. The scientific revolution, as a change in theoretical outlook, is normally identified as a four step process (this is not true of 'scientific practice' which is much less clearly definable historically). First, Galileo is seen as the father of "theoretical experimentalism", in that he legitimised observation, as opposed to pure reason, as a route to authentic knowledge, and presented the observations (for instance, in his falling body experiments) with an analysis that had the rigour of Euclidean proof. Second (but not subsequent to, or, in direct conjunction with Galileo) Francis Bacon projects (what we would now think of as) the Galilean "experimental truth revealing process" onto the entire map of the natural universe, setting forth an agenda for every natural phenomenon then known, to be subjected to experimental scrutiny. Third, Robert Boyle sets about regularising Galileo's experimental work as characterised by his reports of "falling bodies experiments" into a practical method for ensuring that the observational process accumulates a body of knowledge which is public, thorough and "self-correcting" by the practice of publication, replication and review of scientific experiments. Fourth, Newton produces the first widely read works which purport to address the most significant fundamental natural processes with "Boylean rigour". Although cultural materialism doesn't necessarily dismiss the main thrust of these claims, it does not accept that they fully account for the changes which are attributed to them, or that they reflect the nature or even the points in time when the relevant changes occurred. If Boyle's "public science" model coexisted with "pre-scientific" disciplines, then the "revolution" was "romanticised" by their biographers, who wished to paint a picture of the 'new wisdom' being adopted at the same time as the abandonment of the "wicked, secretive and pagan" practices of the pre-scientific "mystics".

References

- Howard Margolis: It Started with Copernicus. New York: McGraw-Hill, 2002 ISBN 0-07-138507-X
- Shapin, Steven. The Scientific Revolution. Chicago: The University of Chicago Press, 1998. ISBN 0-266-75021-3
- This book suggests we re-examine and re-evaluate the mythology of 'The Scientific Revolution' to see if it was a cohesive or even real a historical event. The problem of the late 16th century to early 17th century was that while new methodologies were developed and used by a few, basic ideas remained relatively consistent - notably Newton reintroducing occult (hidden) forces (ie gravity) despite the want of a visibly mechanistic world system - while natural philosophers argued against others and amongst themselves over their legitimacy by using propagandized definitions of 'ancient' and 'modern'.

Science

- Barry Gower: Scientific Method. London: Routledge, 1997 ISBN 0-415-12281-3
- This book is concerned with the sequence of changes from which the modern understanding of science has developed and thus gives a useful grounding in the philosophical and historical basis of the scientific revolution

History

- I. Bernard Cohen: Revolution in Science. Cambridge, Mass.: Belknap Press of Harvard University Press, 1985 ISBN 0-674-76777-2
- Bertrand Russell: The Scientific Outlook. London: Allen & Unwin, 1931
- A highly influential work. The first chapter 'Examples of the scientific method' paints a history of the key developments in the scientific revolution, from the perspective of a devotee of 'scientific thinking'.

Literary criticism

- Richard S. Westfall: Never at Rest: A biography of Isaac Newton. Cambridge: Cambridge University Press, 1980 ISBN 0-521-23143-4
- A biography of Newton which begins the process of identifying the interplay between the 'theopolitical' issues and science which formed the basis of the 'actions and equal and opposite reactions' between the ideologies at the heart of both the mythologies and the realities of the scientific revolution.
- Robert Markley: Fallen Languages: Crises of representation in Newtonian England, 1660-1740. Ithaca: Cornell University Press, 1993 ISBN 0-8014-2586-3
- This book puts the language of Boyle and the Royal Society under the 'literary theory' microscope. The author claims to find new insights in terms of the transition from Aristotelianism and examining the impact of 'hidden' theological constraints and influences on the key proponents of the scientific revolution.
- Lawrence M. Principe: The Aspiring Adept: Robert Boyle and his alchemical quest .... Princeton, N.J. : Princeton University Press, 1998 ISBN 0-691-01678-X
- Did Boyle really advocate a move away from alchemy to chemistry? Was this the first key move from mysticism to science? Implies that the scientific 'revolution' never occurred, and was a fabrication of biographers.
- Steven Shapin and Simon Schaffer: Leviathan and the Air Pump: Hobbes, Boyle, and the experimental life. Princeton, N.J.: Princeton University Press, 1985 ISBN 0-691-08393-2
- Thomas Hobbes argued in the 1660's that the 'public science' model did not reveal the truth; this book examines the 'first criticisms of the scientific revolution' which may be interesting because they come from come from a 'fellow anti-aristotelian' such as Hobbes.

Anthropology

- Bruno Latour: We Have Never Been Modern; translated by Catherine Porter. New York; London: Harvester Wheatsheaf, 1993 ISBN 0-7450-0682-5 ISBN 0-7450-1321-X (pbk)
- This takes the revolutionary stance presented in Leviathan and the air pump (above) and both develops and challenges it

Thomas Kuhn

Thomas Samuel Kuhn (July 18, 1922 – June 17, 1996) was an American intellectual who wrote extensively on the history of science and developed several important notions in the philosophy of science. Descendant of a Jewish family, Kuhn was born in Cincinnati, Ohio to Samuel L. Kuhn, an industrial engineer, and Minette Stroock Kuhn. He obtained his bachelor's degree in physics from Harvard University in 1943, his master's in 1946 and Ph.D. in 1949, and taught a course in the history of science there from 1948 until 1956 at the suggestion of Harvard president James Conant. After leaving Harvard, Kuhn taught at the University of California, Berkeley in both the philosophy department and the history department, being named Professor of the History of Science in 1961. In 1964 he joined Princeton University as the M. Taylor Pyne Professor of Philosophy and History of Science. In 1979 he joined the Massachusetts Institute of Technology (MIT) as the Laurance S. Rockefeller Professor of Philosophy, remaining there until 1991. He is most famous for his book The Structure of Scientific Revolutions (SSR) (1962) in which he presented the idea that science does not evolve gradually toward truth, but instead undergoes periodic revolutions which he calls "paradigm shifts." The enormous impact of Kuhn's work can be measured in the revolution it brought about even in the vocabulary of the history of science: besides "paradigm shifts," Kuhn raised the word "paradigm" itself from a term used in certain forms of linguistics to its current broader meaning, coined the term "normal science" to refer to the relatively routine, day-to-day work of scientists working within a paradigm, and was largely responsible for the use of the term "scientific revolutions" in the plural, taking place at widely different periods of time in the different disciplines as against a single "Scientific Revolution" in the late Renaissance. Kuhn was named a Guggenheim Fellow in 1954, and in 1982 was awarded the George Sarton Medal in the History of Science. He was also awarded numerous honorary doctorates. He suffered cancer of the bronchial tubes for the last two years of his life and died Monday June 17, 1996. He was survived by his wife Jehane R. Kuhn, his ex-wife Kathryn Muhs Kuhn, and their three children, Sarah, Elizabeth and Nathaniel.

Bibliography

- The Copernican Revolution (Cambridge, MA: Harvard University Press, 1957)
- The Structure of Scientific Revolutions (Chicago: University of Chicago Press, 1962) (ISBN 0226458083)
- The Essential Tension: Selected Studies in Scientific Tradition and Change (1977)
- Black-Body Theory and the Quantum Discontinuity, 1894-1912 (Chicago, 1987) (ISBN 0226458008)
- The Road Since Structure: Philosophical Essays, 1970-1993 (Chicago: University of Chicago Press, 2000) (ISBN 0226457982)

External links

- [http://des.emory.edu/mfp/Kuhnsnap.html Thomas Kuhn] (Biography, Outline of Structure of Scientific Revolutions)
- [http://www.sal.wisc.edu/~sobolpg/kuhn.htm Thomas Kuhn, 73; Devised Science Paradigm] (obituary by Lawrence Van Gelder, New York Times, 19 June 1996)
- [http://www-tech.mit.edu/V116/N28/kuhn.28n.html Thomas S. Kuhn] (obituary, The Tech p9 vol 116 no 28, 26 June 1996)
- [http://plato.stanford.edu/entries/thomas-kuhn/ Thomas Kuhn] at the Stanford Encyclopedia of Philosophy Kuhn, Thomas Kuhn, Thomas Kuhn, Thomas Kuhn, Thomas Kuhn, Thomas Kuhn, Thomas Kuhn, Thomas Kuhn, Thomas ko:토머스 새뮤얼 쿤 ja:トーマス・クーン

History of science

Science is a body of verifiable empirical knowledge, a global community of scholars, and a set of techniques for investigating the universe known as the scientific method. The history of science traces these phenomena and their precursors back in time, all the way to human prehistory. The Scientific Revolution saw the inception of modern scientific methods to guide the evaluation of knowledge. This change is considered to be so fundamental that older inquiries are now known as pre-scientific. Still, many place ancient and medieval natural philosophy clearly within the scope of the history of science. The history of mathematics, history of technology, and history of philosophy are covered in other articles. Mathematics is closely related to, but distinct from science (at least in the modern conception). Technology concerns the creative process of designing useful objects and systems, which differs from the search for empirical truth. Philosophy differs from science in that, while both the natural and the social sciences attempt to base their theories on established fact, philosophy also enquires about other areas of knowledge, notably ethics. In practice, each of these fields is heavily used by the others as an external tool.

Theories and sociology of the history of science

Much of the study of the history of science has been devoted to answering questions about what science is, how it functions, and whether it exhibits large-scale patterns and trends. The sociology of science in particular has focused on the ways in which scientists work, looking closely at the ways in which they "produce" and "construct" scientific knowledge. Since the 1960s, a common trend in the science studies (the study of the sociology and history of science) has been to emphasize the "human component" to scientific knowledge, and to de-emphasize the view that scientific data is self-evident, value-free, and context-free. A major subject of concern and controversy in the philosophy of science has been to inquire about the nature of theory change in science. Three philosophers in particular who represent the primary poles in this debate have been Karl Popper, who argued that scientific knowledge is progressive and cumulative; Thomas Kuhn, who argued that scientific knowledge moves through "paradigm shifts" and is not necessarily progressive; and Paul Feyerabend, who argued that scientific knowledge is not cumulative or progressive, and that there can be no demarcation between science and any other form of investigation. Since the publication of Kuhn's The Structure of Scientific Revolutions in 1962, there has been much debate in the academic community over the meaning and objectivity of "science." Often, but not always, a conflict over the "truth" of science has split along the lines of those in the scientific community and those in the social sciences or humanities (for example, the "Science wars").

Pre-experimental "science"

Science wars In the West, from antiquity up to the time of the Scientific Revolution, inquiry into the workings of the universe was known as natural philosophy, and those engaged in it were known as natural philosophers. This included some fields of study which are no longer considered scientific. Bertrand Russell's History of Philosophy gives a good account of the historical development of (natural) philosophy. In many cases, systematic learning about the natural world was a direct outgrowth of religion, often as a project of a particular religious community. One important feature of "pre-scientific" inquiry (whether in the West or elsewhere) was reluctance to engage in experiment. For example, Aristotle, one of the most prolific natural philosophers of antiquity, made countless observations of nature, especially the habits and attributes of plants and animals. Aristotle focused on categorizing. He also made many observations on the large-scale workings of the universe, which led to the development of a comprehensive theory of physics; see Physics (Aristotle). Yet, until the period of the Scientific Revolution, the utility of experiment was unproven, which means that theories were never empirically tested. Some believed that setting up artificial conditions in an experiment could never produce results that would describe nature as it was in the world around them.

Early cultures

In prehistoric times, advice and knowledge was passed from generation to generation in an oral tradition. The development of writing enabled knowledge to be stored and communicated across generations with much greater fidelity. Combined with the development of agriculture, which allowed for a surplus of food, it became possible for early civilizations to develop, because more time could be devoted to tasks other than survival. Many ancient civilizations collected astronomical information in a systematic manner through simple observation. Though they had no knowledge of the real physical structure of the planets and stars, many theoretical explanations were proposed. Basic facts about human physiology were known in some places, and [[alchemy]] was practiced in several civilizations. Considerable observation of macrobiotic flora and fauna was also performed.

The Middle Ages

With the loss of the [[Western Roman Empire, much of Europe lost contact with the knowledge of the past. While the Byzantine Empire still held learning centers such as Alexandria and Constantinople, Western Europe's knowledge was concentrated in monasteries. Philosophical and scientific teaching of the period was based upon few copies and commentaries of ancient Greek texts that remained in Western Europe.

Islamic science

:See also: Islamic science Islamic scienceMeanwhile, in the Middle East, Greek philosophy was able to find some support by the newly created Arab Caliphate (Empire). With the spread of Islam in the 7th and 8th centuries, a period of Islamic scholarship lasted until the 14th century. This scholarship was aided by several factors. The use of a single language, Arabic, allowed communication without need of a translator. Access to Greek and Roman texts from the Byzantine Empire along with Indian sources of learning provided Islamic scholars a knowledge base to build upon. In addition, there was the Hajj. This annual pilgrimage to Mecca facilitated scholarly collaboration by bringing together people and new ideas from all over the Islamic world. In Islamic versions of early scientific method, ethics played an important role. During this period the concepts of citation and peer review were developed. In mathematics, the Persian scholar Muhammad ibn Musa al-Khwarizmi gave his name to what is now called an algorithm; the term algebra is derived from al-jabr, the beginning of the title of one of his publications. Sabian mathematician Al-Batani (850-929) contributed to astronomy and mathematics and Persian scholar Al-Razi to chemistry. The fruits of these contributions can be seen in Damascus steel (wootz steel), and the Baghdad Battery. Arab alchemy inspired Roger Bacon, and later Isaac Newton. In astronomy, Al-Batani improved the measurements of Hipparchus, preserved in the translation of the Greek Hè Megalè Syntaxis (The great treatise) translated as Almagest. Al-Batani also improved the precision of the measurement of the precession of the earth's axis.

European renaissance in the 12th century

:See also: Renaissance of the 12th century, Scholasticism, Medieval technology Medieval technology An intellectual revitalization of Europe started with the birth of medieval universities in the 12th century. The contact with the Islamic world in Spain and Sicily after the Reconquista and during the Crusades allowed Europeans access to preserved copies of the Ancient Greek and Roman works along with the works of Islamic philosophers, specially Averroes. The European universities aided materially in the translation and propagation of these texts and started a new infrastructure which was needed for scientific communities. At the beginning of the 13th century there were reasonably accurate Latin translations of the main works of almost all the intellectually crucial ancient authors. By then, the natural philosophy contained in these texts began to be extended by notable scholastics such as Robert Grosseteste, Roger Bacon, Albertus Magnus and Duns Scotus. Precursors of the modern scientific method can be seen already in Grosseteste's emphasis on mathematics as a way to understand nature, and in the empirical approach admired by Bacon. The first half of the 14th century saw the scientific work of great thinkers. William of Ockham introduced the principle of parsimony: philosophy should only concern itself with subjects on whom it could achieve real knowledge. This should lead to a decline in fruitless debates and move natural philosophy toward science. Scholars such as Jean Buridan and Nicolas Oresme started to question the received wisdom of Aristotle's mechanics. In particular, Buridan developed the theory of impetus which was a first step towards the modern concept of inertia. inertia, an example of the blend of art and science during the Renaissance]] In 1348, the Black Death and other disasters sealed a sudden end to the previous period of massive philosophic and sientific development. Yet, the rediscovery of ancient texts was improved after the Fall of Constantinople in 1453, when many Byzantine scholars had to seek refuge in the West. Meanwhile, the invention of printing was to have great effect on European society. The facilitated dissemination of the printed word democratized learning and allowed a faster propagation of new ideas. These developments paved the way for the Scientific Revolution, which may also be understood as a resumation of the process of scientific change, halted at the start of the Black Death.

The Scientific Revolution

Scientific Revolution] Modern science in Europe began in a period of great upheaval. The Protestant Reformation, the discovery of the Americas by Christopher Columbus, the Fall of Constantinople, the Spanish Inquisition, but also the re-discovery of Aristotle in the twelfth and thirteenth centuries presaged large social and political changes. Thus, a suitable environment was created in which it became possible to question scientific doctrine, in much the same way that Martin Luther and John Calvin questioned religious doctrine. The works of Ptolemy (astronomy), Galen (medicine), and Aristotle (physics) were found not always to match everyday observations. For example, an arrow flying through the air after leaving a bow contradicts Aristotle's laws of motion, which say that a moving object must be constantly under influence of an external force, as the natural state of earthly objects is to be at rest. Work by Vesalius on human cadavers also found problems with the Galenic view of anatomy. Vesalius The willingness to question previously held truths and search for new answers resulted in a period of major scientific advancements, now known as the Scientific Revolution. The Scientific Revolution is held by most historians to have begun in 1543, when De Revolutionibus, by the Polish astronomer Nicolaus Copernicus, was first printed. The thesis of this book was that the Earth moved around the Sun. The period culminated with the publication of the Philosophiae Naturalis Principia Mathematica in 1687 by Isaac Newton. Other significant scientific advances were made during this time by Galileo Galilei, Edmond Halley, Robert Hooke, Christiaan Huygens, Johannes Kepler, Gottfried Leibniz, and Blaise Pascal. In philosophy, major contributions were made by Francis Bacon, Sir Thomas Browne, René Descartes, and Thomas Hobbes. The basics of scientific method were also developed: the new way of thinking emphasized experimentation and reason over traditional considerations.

Modern science

Thomas Hobbes The Scientific Revolution established science as the preeminent source for the growth of knowledge. During the 19th century, the practice of science became professionalized and institutionalized in ways which would continue through the 20th century, as the role of scientific knowledge grew and became incorporated with many aspects of the functioning of nation-states.

Natural sciences

Physics

The Scientific Revolution is a convenient boundary between ancient thought and classical physics. Nicholas Copernicus revived the heliocentric model of the solar system first devised by Aristarchus . This was followed by the first known model of planetary motion given by Kepler in the early 17th century, which proposed that the planets follow elliptical orbits, with the Sun at one focus of the ellipse. Also, Galileo pioneered the use of experiment to validate physical theories, a key idea in scientific method. Galileo] In 1687, Isaac Newton published the Principia Mathematica, detailing two comprehensive and successful physical theories: Newton's laws of motion, which lead to classical mechanics; and Newton's Law of Gravitation, which describes the fundamental force of gravity. The behavior of electricity and magnetism was studied by Faraday, Ohm, and others during the early 19th century. These studies led to the unification of the two phenomena into a single theory of electromagnetism, by Maxwell (known as Maxwell's equations). Maxwell's equations] The beginning of the 20th century brought the start of a revolution in physics. The long-held theories of Newton were shown not to be correct in all circumstances. Beginning in 1900, Max Planck, Albert Einstein, Niels Bohr and others developed quantum theories to explain various anomalous experimental results, by introducing discrete energy levels. Not only did quantum mechanics show that the laws of motion did not hold on small scales, but even more disturbingly, the theory of general relativity, proposed by Einstein in 1915, showed that the fixed background of spacetime, on which both Newtonian mechanics and special relativity depended, could not exist. In 1925, Werner Heisenberg and Erwin Schrödinger formulated quantum mechanics, which explained the preceding quantum theories. The observation by Edwin Hubble in 1929 that the speed at which galaxies recede positively correlates with their distance, led to the understanding that the universe is expanding, and the formulation of the Big Bang theory by George Gamow. George Gamow" in physics.]] Further developments took place during World War II, which led to the practical application of radar and the development and use of the atomic bomb. Though the process had begun with the invention of the cyclotron by Ernest O. Lawrence in the 1930s, physics in the postwar period entered into a phase of what historians have called "Big Science", requiring massive machines, budgets, and laboratories in order to test their theories and move into new frontiers. The primary patron of physics became state governments, who recognized that the support of "basic" research could often lead to technologies useful to both military and industrial applications. Currently, general relativity and quantum mechanics are inconsistent with each other, and efforts are underway to unify the two.

Chemistry

Big Science] The history of chemistry begins with the distinction of chemistry from alchemy by Robert Boyle in his work The Skeptical Chymist (1661). It can also be dated to Antoine Lavoisier's discovery of oxygen and the law of conservation of mass, which refuted phlogiston theory. Proof that all matter is made of atoms, which are the smallest indestructible part of matter, was provided by John Dalton in 1803. He also formulated the law of mass relationships. In 1869, Dmitry Mendeleyev composed his periodic table of elements on the basis of Dalton's discoveries. The synthesis of urea by Friedrich Wöhler opened a new research field in chemistry, and by the end of the 19th century, scientists were able to synthesize hundreds of organic compounds. The later part of the nineteenth century saw the exploitation of the Earth's petrochemicals, after the exhaustion of the oil supply from whaling. By the twentieth century, systematic production of refined materials provided a ready supply of products which provided not only energy, but also synthetic materials for clothing, medicine, and everyday disposable resources. The twentieth century also saw the integration of physics and chemistry, with chemical properties explained as the result of the electronic structure of the atom; Linus Pauling's book on The Nature of the Chemical Bond used the principles of quantum mechanics to deduce bond angles in ever-more complicated molecules, culminating in the physical modelling of DNA, or (in the words of Francis Crick) the secret of life. In the same year, the Miller-Urey experiment demonstrated in a simulation of primordial processes, that basic constituents of DNA, simple amino acids, could themselves be built up from simpler molecules.

Geology

Chinese polymath Shen Kua (1031 - 1095) was the first to formulate hypotheses for the process of land formation. Based on his observation of fossils in a geological stratum in a mountain hundreds of miles from the ocean, he deduced that the land was formed by erosion of the mountains and by deposition of silt. deposition and continental drift illustrated on relief globe]] Theophrastus' work on rocks Peri lithōn remained authoritative for millennia: its interpretation of fossils was not overturned until after the Scientific Revolution. During the 1700s Jean-Etienne Guettard and Nicolas Desmarest hiked central France and recorded their observations on geological maps; Guettard recorded the first observation of the volcanic origins of this part of France. James Hutton recorded his Theory of the Earth in 1788, which would later be refered to as Uniformitarianism. In 1811, Georges Cuvier and Alexandre Brongniart published their explanation of the antiquity of the Earth, inspired by Cuvier's discovery of fossil elephant bones in Paris. They formulated the principle of stratigraphic succession of the layers of the earth. Charles Lyell's Principles of Geology reiterated Hutton's Uniformitarianism, which influenced Charles Darwin. In the 20th century, the main development has been the theory of plate tectonics in the 1960s. Plate tectonic theory (which revolutionized The theory the Earth sciences) arose out of two separate geological observations: seafloor spreading and continental drift.

Astronomy

Advances in astronomy and in optical systems in the 19th century resulted in the first observation of an asteroid (Ceres) in 1801, and the discovery of Neptune in 1846. In the 1840s, the first galaxies outside our solar system were observed by (William Parsons). George Gamow, Ralph Alpher, and Robert Hermann had calculated that there should be evidence for a Big Bang in the background temperature of the universe. In 1964, Arno Penzias and Robert Wilson discovered a 3 kelvin background hiss in their Bell Labs radiotelescope, which was evidence for this hypothesis, and formed the basis for a number of results that helped determine the age of the universe. Supernova SN1987A was observed by astronomers on Earth both visually, and in a triumph for neutrino astronomy, by the solar neutrino detectors at Kamiokande. But the solar neutrino flux was a fraction of its theoretically-expected value. This discrepancy forced a change in some values in the standard model for particle physics.

Biology, medicine, and genetics

particle physics In 1847, Hungarian physician Ignác Fülöp Semmelweis dramatically reduced the occurrency of puerperal fever by the simple experiment of requiring physicians to wash their hands before attending to women in childbirth. This discovery predated the germ theory of disease. However, Semmelweis' findings were not appreciated by his contemporaries and came into use only with discoveries by British surgeon Joseph Lister, who in 1865 proved the principles of antisepsis. Lister's work was based on the important findings by French biologist Louis Pasteur. Pasteur was able to link microorganisms with disease, revolutionizing medicine. He also devised one of the most important methods in preventive medicine, when in 1880 he produced a vaccine against rabies. Pasteur invented the process of pasteurization, to help prevent the spread of disease through milk and other foods. Perhaps the most prominent and far-reaching theory in all of science has been the theory of evolution by natural selection put forward by the British naturalist Charles Darwin in his On the Origin of Species in 1859. Darwin's theory proposed that all differences in animals were formed by natural processes over long periods of time, and that even humans were simply evolved organisms. Implications of evolution on fields outside of pure science have led to both opposition and support from different parts of society, and profoundly influenced the popular understanding of "man's place in the universe". In the early 20th century, the study of heredity became a major investigation after the rediscovery in 1900 of the laws of inheritance developed by the Austrian monk Gregor Mendel in 1866. Mendel's laws provided the beginnings of the study of genetics, which became a major field of research for both scientific and industrial research. By 1953, James Watson and Francis Crick clarified the basic structure of DNA, the genetic material for expressing life in all its forms. In the late 20th century, the possibilities of genetic engineering became practical for the first time, and a massive international effort began in 1990 to map out an entire human genome (the Human Genome Project) has been touted as potentially having large medical benefits.

Ecology

Human Genome Project, NASA ]] The famous Earthrise picture, taken in 1968 by the astronauts of Apollo 8, was important in creating awareness of the finiteness of Earth, and the limits of its natural resources. The interconnection and interpendence of each component ecosystem may imply that human beings should not overexploit Earth's resources, without regard for its main ecosystems (air, water, ground, plants and animals). This change of sensitivity to ecological issues has now been well established in Western civilization. Still, industrialized deforestation has occurred in the exploitation of the forests of Southeast Asia and the Amazon rainforest. It may be hypothesized that other vital and free goods (such as air) will, one day, be subject to price.

Social sciences

Successful use of the scientific method in the physical sciences led to the same methodology being adapted to better understand the many fields of human endeavor. From this effort the social sciences have been developed.

Political science

:Main article: History of political science One of the basic requirements for a scientific community is the existence and approval of a political sponsor; in England, the Royal Society operates under the aegis of the monarchy; in the US, the National Academy of Sciences was founded by Act of Congress; etc. Otherwise, when the basic elements of knowledge were being formulated, the political rulers of the respective communities could choose to arbitrarily either support or disallow the nascent scientific communities. For example, Alhazen had to feign madness to avoid execution. The polymath Shen Kuo lost political support, and could not continue his studies until he came up with discoveries that showed his worth to the political rulers. The admiral Zheng He could not continue his voyages of exploration after the emperors withdrew their support. Another famous example was the suppression of the work of Galileo, and before him, Giordano Bruno, burned at the stake, for his statements on cosmology; by the twentieth century, Galileo would be pardoned.

Linguistics

Historical linguistics emerged as an independent field of study at the end of the 18th century. Sir William Jones proposed that Sanskrit, Persian, Greek, Latin, Gothic, and Celtic languages all shared a common base. After Jones, an effort to catalog all languages of the world was made throughout the 19th century| and into the 20th century. Publication of Ferdinand de Saussure's Cours de linguistique générale spawned the development of descriptive linguistics. Descriptive linguistics, and the related structuralism movement caused linguistics to focus on how language changes over time, instead of just describing the differences between languages. Noam Chomsky further diversified linguistics with the development of generative linguistics in the 1950s. His effort is based upon a mathematical model of language that allows for the description and prediction of valid semantics. Additional specialties such as sociolinguistics, cognitive linguistics, and computational linguistics have emerged from collaboration between linguistics and other disciplines.

Economics

computational linguistics The basis for classical economics forms Adam Smith's An Inquiry into the Nature and Causes of the Wealth of Nations, published in 1776. Smith criticized mercantilism, advocating a system of free trade with division of labour. He postulated an "Invisible Hand" that large economic systems could be self-regulating through a process of enlightened self-interest. Karl Marx developed an alternative economical system, called Marxian economics. Marxian economics is based on the labor theory of value and assumes the value of good to be based on the amount of labor required to produce it. Under this assumption, capitalism was based on employeers not paying the full value of workers labor to create profit. The Austrian school responded to Marxian economics by viewing entrepreneurship as driving force of economic development. This replaced the labor theory of value by a system of supply and demand. In the 1920s, John Maynard Keynes prompted a division between microeconomics and macroeconomics. Under Keynesian economics macroeconomic trends can overwhelm economic choices made by individuals. Governments should promote aggregate demand for goods as a means to encourage economic expansion. Following World War II, Milton Friedman created the concept of monetarism. Monetarism focuses on using the supply and demand of money as a method for controlling economic activity. In the 1970s, monetarism has adapted into supply-side economics which advocates reducing taxes as a means to increase the amount of money available for economic expansion. Other modern schools of economic thought are New Classical economics and New Keynesian economics. New Classical economics was developed in the 1970s, emphasizing solid microeconomics as the basis for macroeconomic growth. New Keynesian economics was created partially in response to New Classical economics, and deals with how inefficiencies in the market create a need for control by a central bank or government.

Psychology

New Keynesian economics The end of the 19th century marks the start of psychology as a scientific enterprise. The year 1879 is commonly seen as the start of psychology as an independent field of study. In that year Wilhelm Wundt founded the first laboratory dedicated exclusively to psychological research (in Leipzig). Other important early contributors to the field include Hermann Ebbinghaus (a pioneer in memory studies), Ivan Pavlov (who discovered classical conditioning), and Sigmund Freud. Freud's influence has been enormous, though more as cultural icon than a force in scientific psychology. Freud's basic theories postulated the existence in humans of various unconscious and instinctive "drives", and that the "self" existed as a perpetual battle between the desires and demands of the internal id, ego, and superego. The 20th century saw a rejection of Freud's theories as being too unscientific, and a reaction against Edward Titchener's atomistic approach of the mind. This led to the formulation of behaviorism by John B. Watson, which was popularized by B.F. Skinner. Behaviorism proposed epistemologically limiting psychological study to overt behavior, since that could be reliably measured. Scientific knowledge of the "mind" was considered too metaphysical, hence impossible to achieve. The final decades of the 20th century have seen the rise of a new interdisciplinary approach to studying human psychology, known collectively as cognitive science. Cognitive science again considers the mind as a subject for investigation, using the tools of evolutionary psychology, linguistics, computer science, philosophy, and neurobiology. This new form of investigation has proposed that a wide understanding of the human mind is possible, and that such an understanding may be applied to other research domains, such as artificial intelligence.

Sociology

artificial intelligence.]] Ibn Khaldun is regarded as the founder of modern sociology. As a scientific discipline, sociology emerged in the early 19th century as the academic response to the modernization of the world. Among many early sociologists (e.g., Émile Durkheim), the aim of sociology was in structuralism, understanding the cohesion of social groups, and developing an "antidote" to social disintegration. Max Weber was concerned with the modernization of society through the concept of rationalization, which he believed would trap individuals in an "iron cage" of rational thought. Some sociologists, including Georg Simmel and W. E. B. Du Bois, utilized more microsociological, qualitative analyses. This microlevel approach played an important role in American sociology, with the theories of George Herbert Mead and his student Herbert Blumer resulting in the creation of the symbolic interactionism approach to sociology. American sociology in the 1940s and 1950s was dominated largely by Talcott Parsons, who argued that aspects of society that promoted structural integration were therefore "functional". This structural functionalism approach was questionedin the 1960s, when sociologists came to see this approach as merely a justification for inequalities present in the status quo. In reaction, conflict theory was developed, which was based in part on the philosophies of Karl Marx. Conflict theorists saw society as an arena in which different groups compete for control over resources. Symbolic interactionism also came to be regarded as central to sociological thinking. Erving Goffman saw social interactions as a stage performance, with individuals preparing "backstage" and attempting to control their audience through impression management. While these theories are currently the prominent in sociological thought, other approaches exist, including feminist theory, post-structuralism, rational choice theory, and postmodernism.

Anthropology

Anthropology can best be understood as an outgrowth of the Age of Enlightenment. It was during this period that Europeans attempted systematically to study human behavior. Traditions of jurisprudence, history, philology and sociology developed during this time and informed the development of the social sciences of which anthropology was a part. At the same time, the romantic reaction to the Enlightenment produced thinkers such as Johann Gottfried Herder and later Wilhelm Dilthey whose work formed the basis for the culture concept which is central to the discipline. Traditionally, much of the history of the subject was based on colonial encounters between Europe and the rest of the world, and much of 18th- and 19th-century anthropology is now classed as forms of scientific racism. During the late 19th-century, battles over the "study of man" took place between those of an "anthropological" persuasion (relying on anthropometrical techniques) and those of an "ethnological" persuasion (looking at cultures and traditions), and these distinctions became part of the later divide between physical anthropology and cultural anthropology, the latter ushered in by the students of Franz Boas. In the mid-20th century, much of the methodologies of earlier anthropological and ethnographical study were reevaluated with an eye towards research ethics, while at the same time the scope of investigation has broadened far beyond the traditional study of "primitive cultures" (scientific practice itself is often an arena of anthropological study).

Emerging disciplines

During the 20th century, a number of interdisciplinary scientific fields have emerged. Three examples will be given here: Communication studies combines animal communication, information theory, marketing, public relations, telecommunications and other forms of communication. Computer science, built upon a foundation of theoretical linguistics, discrete mathematics, and electrical engineering, studies the nature and limits of computation. Subfields include computability, computational complexity, database design, computer networking, artificial intelligence, and the design of computer hardware. Computer science provides much of the theoretical basis for software engineering. Materials science has its roots in metallurgy, minerology, and crystallography. It combines chemistry, physics, and several engineering disciplines. The field studies metals, ceramics, plastics, semiconductors, and composite materials.

Notes

Alpher, Herman, and Gamow. Nature 162,774 (1948). [http://nobelprize.org/physics/laureates/1978/wilson-lecture.pdf Wilson's 1978 Nobel lecture] [http://www.nature.com/genomics/human/watson-crick/ James D. Watson and Francis H. Crick. "Letters to Nature: Molecular structure of Nucleic Acid." Nature 171, 737–738 (1953).] [http://cwp.library.ucla.edu/Phase2/Wu,_Chien_Shiung@841234567.html C.S. Wu's contribution to the overthrow of the conservation of parity – see also the CWP, below]

References

- Thomas S. Kuhn (1996). The Structure of Scientific Revolutions (3rd ed.). University of Chicago Press. ISBN 0226458075
- Howard Margolis (2002). It Started with Copernicus. New York: McGraw-Hill. ISBN 0-07-138507-X
- Joseph Needham. Science and Civilisation in China. Multiple volumes (1954–2004).
- Bertrand Russell (1945). A History of Western Philosophy: And Its Connection with Political and Social Circumstances from the Earliest Times to the Present Day. New York: Simon and Schuster.
- Leonard C. Bruno (1989), The Landmarks of Science. ISBN 0-8160-2137-6
- John L. Heilbron, ed., The Oxford companion to the history of modern science (New York: Oxford University Press, 2003).

External links

- [http://www.worldwideschool.org/library/catalogs/bysubject-sci-history.html A History of Science, Vols 1–4], online text
- [http://ocw.mit.edu/OcwWeb/Science--Technology--and-Society/STS-002Toward-the-Scientific-RevolutionFall2003/CourseHome/index.htm MIT STS.002 – Toward the Scientific Revolution]. From MIT OpenCourseWare, class materials for the history of science up to and including Isaac Newton.
- [http://ocw.mit.edu/OcwWeb/Science--Technology--and-Society/STS-042JEinstein--Oppenheimer--Feynman--Physics-in-the-20th-CenturyFall2002/CourseHome/index.htm MIT STS.042 – Einstein, Oppenheimer, Feynman: Physics in the 20th Century]. Class materials for the history of physics in the 20th century.
- [http://cwp.library.ucla.edu/ Contributions of 20th century Women to Physics ("CWP")]
- [http://nobelprize.org/ The official site of the Nobel Foundation]. Features biographies and info on Nobel laureates

Galileo Galilei

Galileo Galilei (Pisa, February 15 1564 – Arcetri, January 8 1642), was an Italian physicist, astronomer, and philosopher who is closely associated with the scientific revolution. His achievements include improvements to the telescope, a variety of astronomical observations, the first law of motion and the second law of motion, and effective support for Copernicanism. He has been referred to as the "father of modern astronomy," as the "father of modern physics," and as "father of science." His experimental work is widely considered complementary to the writings of Francis Bacon in establishing the modern scientific method. Galileo's career coincided with that of Johannes Kepler. The work of Galileo is considered to be a significant break from that of Aristotle. In addition, his conflict with the Roman Catholic Church is taken as a major early example of the conflict of authority and freedom of thought, particularly with science, in Western society.

Galileo's Family & Early Careers

Galileo was born in Pisa, in the Tuscan region of Italy, the son of Vincenzo Galilei, a mathematician and musician born in Florence in 1520, and Giulia Ammannati, born in Pescia and married in 1563. Galileo was their first child. Although a devout Catholic, Galileo fathered three children out of wedlock. All were the children of Galileo and Marina Gamba. Because of their illegitimate birth, both girls were sent to the convent of San Matteo in Arcetri at early ages.
- Virginia (b. 1600) who took the name Maria Celeste upon entering a convent. Galileo's eldest child, the most beloved, and inherited her father's sharp mind. She died in 1634 on April second. She is buried with Galileo at the Basilica di Santa Croce di Firenze.
- Livia (b. 1601) took the name Suor Arcangela. Was sickly for most of her life at the convent.
- Vincenzio (b. 1606) was later legitimized and married Sestilia Bocchineri He was home schooled at a very young age. After that he attended the University of Pisa, but was forced to cease his study there for financial reasons. However, he was offered a position on its faculty in 1589 and taught mathematics. Soon after, he moved to the University of Padua, and served on its faculty teaching geometry, mechanics, and astronomy until 1610. During this time he explored science and made many landmark discoveries.

Experimental science

In the pantheon of the scientific revolution, Galileo takes a high position because of his pioneering use of quantitative experiments with results analyzed mathematically. There was no tradition of such methods in European thought at that time; the great experimentalist who immediately preceded Galileo, William Gilbert, did not use a quantitative approach. However, Galileo's father, Vincenzo Galilei, had performed experiments in which he discovered what may be the oldest known non-linear relation in physics, between the tension and the pitch of a stretched string. Galileo also contributed to the rejection of blind allegiance to authority (like the Church) or other thinkers (such as Aristotle) in matters of science and to the separation of science from philosophy or religion. These are the primary justifications for his description as the "father of science." In the 20th century some authorities challenged the reality of Galileo's experiments, in particular the distinguished French historian of science Alexandre Koyré. The experiments reported in Two New Sciences to determine the law of acceleration of falling bodies, for instance, required accurate measurements of time, which appeared to be impossible with the technology of the 1600s. According to Koyré, the law was arrived at deductively, and the experiments were merely illustrative thought experiments. Later research, however, has validated the experiments. The experiments on falling bodies (actually rolling balls) were replicated using the methods described by Galileo (Settle, 1961), and the precision of the results was consistent with Galileo's report. Later research into Galileo's unpublished working papers from as early as 1604 clearly showed the reality of the experiments and even indicated the particular results that led to the time-squared law (Drake, 1973).

Astronomy

Contributions

Although the popular idea of Galileo inventing the telescope is inaccurate, he was one of the first people to use the telescope to observe the sky, and for a time was one of very few people able to make a good enough telescope for the purpose. Based on sketchy descriptions of telescopes invented in the Netherlands in 1608, Galileo made one with about 8x magnification, and then made improved models up to about 20x. On August 25, 1609, he demonstrated his first telescope to Venetian lawmakers. His work on the device also made for a profitable sideline with merchants who found it useful for their shipping businesses. He published his initial telescopic astronomical observations in March 1610 in a short treatise entitled Sidereus Nuncius (Sidereal Messenger). Sidereus Nuncius. This observation upset the notion that all celestial bodies must revolve around the Earth. Galileo published a full description in Sidereus Nuncius in March 1610.]] On January 7, 1610 Galileo discovered three of Jupiter's four largest satellites (moons): Io, Europa, and Callisto. Ganymede he discovered four nights later. He determined that these moons were orbiting the planet since they would appear and disappear; something he attributed to their movement behind Jupiter. He made additional observations of them in 1620. Later astronomers overruled Galileo's naming of these objects, changing his Medicean stars to Galilean satellites. The demonstration that a planet had smaller planets orbiting it was problematic for the orderly, comprehensive picture of the geocentric model of the universe, in which everything circled around the Earth. Galileo noted that Venus exhibited a full set of phases like the Moon. The heliocentric model of the solar system developed by Copernicus predicted that all phases would be visible since the orbit of Venus around the Sun would cause its illuminated hemisphere to face the Earth when it was on the opposite side of the Sun and to face away from the Earth when it was on the Earth-side of the Sun. By contrast, the geocentric model of Ptolemy predicted that only crescent and new phases would be seen, since Venus was thought to remain between the Sun and Earth during its orbit around the Earth. Galileo's observation of the phases of Venus proved that Venus orbited the Sun and lent support to (but did not prove) the heliocentric model. Galileo was one of the first Europeans to observe sunspots, although there is evidence that Chinese astronomers had done so before. The very existence of sunspots showed another difficulty with the unchanging perfection of the heavens as assumed in the older philosophy. And the annual variations in their motions, first noticed by Francesco Sizzi, presented great difficulties for either the geocentric system or that of Tycho Brahe. A dispute over priority in the discovery of sunspots led to a long and bitter feud with Christoph Scheiner; in fact, there can be little doubt that both of them were beaten by David Fabricius and his son Johannes. He was the first to report lunar mountains and craters, whose existence he deduced from the patterns of light and shadow on the Moon's surface. He even estimated the mountains' heights from these observations. This led him to the conclusion that the Moon was "rough and uneven, and just like the surface of the Earth itself", and not a perfect sphere as Aristotle had claimed. Galileo observed the Milky Way, previously believed to be nebulous, and found it to be a multitude of stars, packed so densely that they appeared to be clouds from Earth. He also located many other stars too distant to be visible with the naked eye. Galileo observed the planet Neptune in 1612, but did not realize that it was a planet and took no particular notice of it. It appears in his notebooks as one of many unremarkable dim stars.

Modern claims of scientific errors and misconduct

Although Galileo is generally considered one of the first modern scientists, as evidenced by his position in the sunspot controversy, he is often said to have arrogantly considered himself to be the sole-propietor of the discoveries in astronomy. Furthermore, he never accepted Kepler's elliptical orbits for the planets, holding to the circular orbits of Copernicus, which still employed epicycles to account for irregularities in planetary motions. Concerning his theory on tides, Galileo attributed them to momentum despite his great knowledge of the ideas of relative motion and Kepler's better theories using the Moon as the cause. (Neither of these great scientists, however, had a workable physical theory of tides; this had to wait for the work of Newton) Galileo stated in his Dialogue that, if the Earth spins on its axis and is traveling at a certain speed around the Sun, parts of the Earth must travel "faster" at night and "slower" during the day. This, of course, is true in the Sun's frame of reference; but it is by no means adequate to explain the tides. Many commentators consider that Galileo developed this position simply to justify his own opinion because the theory was not based on any real scientific observations because if his theory was correct, there would be only one high tide per day and it would happen at noon. The fact that there are two daily high tides at Venice instead of one, and that they travel around the clock, Galileo and his contemporaries knew, but he dismissed as due to several secondary causes, such as the shape of the sea, its depth, and other things. Against the imputation that Galileo was guilty of some kind of deceit in making these arguments one may take the position of Albert Einstein, as one who had done original work in physics, that Galileo developed his "fascinating arguments" and accepted them too uncritically out of a desire for a physical proof of the motion of the Earth (Einstein, 1952)

Physics

Galileo's theoretical and experimental work on the motions of bodies, along with the largely independent work of Kepler and René Descartes, was a precursor of the Classical mechanics developed by Sir Isaac Newton. He was a pioneer, at least in the European tradition, in performing rigorous experiments and insisting on a mathematical description of the laws of nature. One of the most famous stories about Galileo is that he dropped balls of different masses from the Leaning Tower of Pisa to demonstrate that their time of descent was independent of their mass (excluding the limited effect of air resistance). This was contrary to what Aristotle had taught: that heavy objects fall faster than lighter ones, in direct proportion to weight. Though the story of the tower first appeared in a biography by Galileo's pupil Vincenzo Viviani, it is not now generally accepted as true. However, Galileo did perform experiments involving rolling balls down inclined planes, which proved the same thing: falling or rolling objects (rolling is a slower version of falling, as long as the distribution of mass in the objects is the same) are accelerated independently of their mass. He determined the correct mathematical law for acceleration: the total distance covered, starting from rest, is proportional to the square of the time (This law is regarded as a predecessor to the many later scientific laws expressed in mathematical form.). He also concluded that objects retain their velocity unless a force -- often friction -- acts upon them, refuting the accepted Aristotelian hypothesis that objects "naturally" slow down and stop unless a force acts upon them. Galileo's Principle of Inertia stated: "A body moving on a level surface will continue in the same direction at constant speed unless disturbed." This principle was incorporated into Newton's laws of motion (1st law). Newton's laws of motion Galileo also noted that a pendulum's swings always take the same amount of time, independently of the amplitude. The story goes that he came to this conclusion by watching the swings of the bronze chandelier in the cathedral of Pisa, using his pulse to time it. While Galileo believed this equality of period to be exact, it is only an approximation appropriate to small amplitudes. It is good enough to regulate a clock, however, as Galileo may have been the first to realize. (See Technology below) In the early 1600s, Galileo and an assistant tried to measure the speed of light. They stood on different hilltops, each holding a shuttered lantern. Galileo would open his shutter, and, as soon as his assistant saw the flash, he would open his shutter. At a distance of less than a mile, Galileo could detect no delay in the round-trip time greater than when he and the assistant were only a few yards apart. While he could reach no conclusion on whether light propagated instantaneously, he recognized that the distance between the hilltops was perhaps too small for a good measurement. Galileo is lesser known for, yet still credited with being one of the first to understand sound frequency. After scraping a chisel at different speeds, he linked the pitch of sound to the spacing of the chisel's skips (frequency). In his 1632 Dialogue Galileo presented a physical theory to account for tides, based on the motion of the Earth. If correct, this would have been a strong argument for the reality of the Earth's motion. (The original title for the book, in fact, described it as a dialogue on the tides; the reference to tides was removed by order of the Inquisition.) His theory gave the first insight into the importance of the shapes of ocean basins in the size and timing of tides; he correctly accounted, for instance, for the negligible tides halfway along the Adriatic Sea compared to those at the ends. As a general account of the cause of tides, however, his theory was a failure. Kepler and others correctly associated the Moon with an influence over the tides, based on empirical data; a proper physical theory of the tides, however, was not available until Newton. Galileo also put forward the basic principle of relativity, that the laws of physics are the same in any system that is moving at a constant speed in a straight line, regardless of its particular speed or direction. Hence, there is no absolute motion or absolute rest. This principle provided the basic framework for Newton's laws of motion and Einstein's theory of relativity.

Mathematics

While Galileo's application of mathematics to experimental physics was innovative, his mathematical methods were the standard ones of the day. The analyses and proofs relied heavily on the Eudoxian theory of proportion, as set forth in the fifth book of Euclid's Elements. This theory had become available only a century before, thanks to accurate translations by Tartaglia and others; but by the end of Galileo's life it was being superseded by the algebraic methods of Descartes, which a modern finds incomparably easier to follow. Galileo produced one piece of original and even prophetic work in mathematics: Galileo's paradox, which shows that there are as many perfect squares as there are whole numbers, even though most numbers are not perfect squares. Such seeming contradictions were brought under control 250 years later in the work of Georg Cantor.

Technology

Galileo made a few contributions to what we now call technology as distinct from pure physics, and suggested others. This is not the same distinction as made by Aristotle, who would have considered all Galileo's physics as techne or useful knowledge, as opposed to episteme, or philosophical investigation into the causes of things. In 1595–1598, Galileo devised and improved a "Geometric and Military Compass" suitable for use by gunners and surveyors. This expanded on earlier instruments designed by Niccolo Tartaglia and Guidobaldo del Monte. For gunners, it offered, in addition to a new and safer way of elevating cannons accurately, a way of quickly computing the charge of gunpowder for cannonballs of different sizes and materials. As a geometric instrument, it enabled the construction of any regular polygon, computation of the area of any polygon or circular sector, and a variety of other calculations. About 1606–1607 (or possibly earlier), Galileo made a thermometer, using the expansion and contraction of air in a bulb to move water in an attached tube. In 1609, Galileo was among the first to use a refracting telescope as an instrument to observe stars, planets or moons. In 1610, he used a telescope as a compound microscope, and he made improved microscopes in 1623 and after. This appears to be the first clearly documented use of the compound microscope. In 1612, having determined the orbital periods of Jupiter's satellites, Galileo proposed that with sufficiently accurate knowledge of their orbits one could use their positions as a universal clock, and this would make possible the determination of longitude. He worked on this problem from time to time during the remainder of his life; but the practical problems were severe. The method was first successfully applied by Giovanni Domenico Cassini in 1681 and was later used extensively for land surveys; for navigation, the first practical method was the chronometer of John Harrison. In his last year, when totally blind, he designed an escapement mechanism for a pendulum clock. The first fully operational pendulum clock was made by Christiaan Huygens in the 1650s. He created sketches of various inventions, such as a candle and mirror combination to reflect light throughout a building, an automatic tomato picker, a pocket comb that doubled as an eating utensil, and what appears to be a ballpoint pen. ballpoint pen

Church controversy

:Main article: Trial of Galileo. Not long after Galileo began publishing his astronomical work in The Starry Messenger, his Copernican ideas came under attack as a possible heresy, violating the Biblical picture of the Earth as the center of the universe (as well as the accepted philosophical teachings of the time). By 1616 the attacks seemed to Galileo to have become dangerous, and he went to Rome to try to persuade the Church authorities not to ban the new teachings. The mission was a failure: in the end, Cardinal Bellarmine, acting on orders from the Pope, delivered him an order not hold or defend the idea that the Earth moves and the Sun stands still at the center. For the next several years Galileo stayed well away from the controversy. Toward 1630, however, he revived his project of writing a book on the subject, encouraged by the election of Pope Urban VIII. The book, Dialogue Concerning the Two Chief World Systems, was published in 1632, with formal authorization from the Inquisition; there is dispute, however, concerning this license. Galileo was ordered to Rome to stand trial on suspicion of heresy in 1633. The sentence of the Inquisition was in three essential parts:
- Galileo was required to recant his heliocentric ideas, which were condemned as "formally heretical";.
- He was ordered imprisoned; the sentence was later commuted to house arrest.
- His offending Dialogue was banned; and in an action not announced at the trial, publication of any of his works was forbidden, including any he might write in the future. After a period with the friendly Archbishop Piccolomini in Siena, Galileo was allowed to return to his villa at Arcetri near Florence, where he spent the remainder of his life under house arrest.

Galileo's writings

Arcetri
- Two New Sciences 1638 Lowys Elzevir (Louis Elsevier) Leiden (in Italian, Discorsi e Dimostrazioni Matematiche, intorno á due nuoue scienze Leida, Appresso gli Elsevirii 1638)
- Dialogue Concerning the Two Chief World Systems 1632 (in Italian, Dialogo dei due massimi sistemi del mondo)
- The Starry Messenger 1610 Venice (in Latin, Sidereus Nuncius)
- Letter to Grand Duchess Christina

Writings on Galileo

- Galileo Galilei, an opera by Philip Glass
- Galileo a play by Bertolt Brecht

References

- Drake, Stillman (1953). Dialogue Concerning the Two Chief World Systems. Berkeley: University of California Press.
- Drake, Stillman (1957). Discoveries and Opinions of Galileo. New York: Doubleday & Company. ISBN 0-385-09239-3
- Drake, Stillman (1973). "Galileo's Discovery of the Law of Free Fall". Scientific American v. 228, #5, pp. 84-92.
- Drake, Stillman (1978). Galileo At Work. Chicago: University of Chicago Press. ISBN 0-226-16226-5
- Einstein, Albert (1952). Foreword to (Dr