Brief History of Modern Science

1. Brief History of Modern Science • Discovery - A new method of acquiring knowledge was invented by a series of European thinkers from 1500 to 1700. Among these thinkers are Copernicus, Galileo, Descartes, Kepler, and Newton • Definition of Science- A special method and knowledge executed by practitioners of science called scientists.

4. Aristotelian Science Theory of Matter Matter stuff out of which things are made In sublunary world (below the moon) there are four elements or essences: earth, water, air, and fire. These four elements never found pure always mixed. Heavy things made out of earth Light things made mix of water,air, and fire

5. Aristotelian Science • Above sun, planets are stars imbedded in the crystalline sphere • The crystalline sphere made out of pure quintessence ( 5th essence) • Different laws pertain the sublunary world than to the world above the moon

6. Archimedes (287-212 BCE ) Sicilian geometrician who calculated an accurate value for pp, demonstrated the relationship between the volume of spheres and cylinders, discovered methods for determining the center of gravity of plane figures, and provided a foundation for the science of hydrostatics. Archimedes also invented many ingenious machines, including a pump for raising water, effective levers and compound pulleys, and a mechanical planetarium. He died defending Syracuse against a Roman seige during the second Punic war.

7. Ptolemy & Epicycles more accurate measurement required more epicycles

8. Thomas Aquinas (1224-1274 ) • Although matters of such importance should be accepted on the basis of divine revelation alone, Aquinas held, it is at least possible (and perhaps even desirable) in some circumstances to achieve genuine knowledge of them by means of the rigorous application of human reason. As embodied souls ( hylomorphic composites ), human beings naturally rely on sensory information for their knowledge of the world. Reading hint: Although the rigidly formal structure of the Summa articles can be rather confusing to a modern reader, the central portion beginning with the words, " I answer that ..." is always a direct statement of Aquinas's own position.

9. Roger Bacon • Bacon, Roger (1214-1292 )English philosopher who translated many Aristotelean treatises from Arabic into Latin. Although passionately interested in alchemy and magic, Roger defended reliance upon mathematics and experimental methods for the improvement of human knowledge generally and theological understanding in particular in the Opus Maius (Greater Work ) (1267) { at Amazon.com } and On Experimental Science (1268). His novel educational doctrines were supposed to violate the condemnation of 1277 , and much of Roger's later work, including the Compendium Studii Theologiae (1292) was suppressed.

10. Roger Bacon Against authority of… Church State Commonly held opinion Obstacles to truth: Frail and unsuitable authority Long-held custom Uninstructed popular opinion Concealment of ignorance in apparent wisdom

11. Roger Bacon Bacon’s advice: To study Natural Philosophy, use; “External experience, aided by instruments, and made precise by mathematics.”

12. Roger Bacon: “The result of all true philosophy is to arrive at a knowledge of the creator through knowledge of the created world” “He who wishes to rejoice without doubt in regard to the truths underlying phenomena must know how to devote himself to experiment. For authors write many statements, and people believe them through (deductive) reasoning, which they formulate without experience. Their reasoning is wholly false” (Opus Majus)

13. William of Ockham, • Ockham, William of (1285-1349 )English philosopher who defended the logic, physics, and metaphysics of Aristotle in Summa Logicae (The Whole of Logic ) (1328) vol. 1 { at Amazon.com } and vol. 2 { at Amazon.com } and the Dialogus . An extreme nominalist , Ockham held that general terms are signs that indefinitely signify discrete (though similar) particulars. Ockham is best known for his statement of the law of parsimony as the ontological principle often called Ockham's Razor : " Frustra fit per plura quod potest fieri per pauciora " ["It is pointless to do with more what can be done with less"]. Thus, according to Ockham, we ought never to postulate the reality of any entity unless it is logically necessary to do so.

14. William of Ockham Ockham’s Razor: “What can be accounted for by fewer assumptions in explained in vain by more.” His philosophy of science: “Nothing is assumed as evident unless it is known per se or is evident by experience, or is proved by authority of scripture.”

15. Paracelsus (Phillippus Aureolus Theophrastus Bombastus von Hohenheim) ( 1493-1541 ) • Swiss chemist and physician. Rejecting the ancient reliance on concern for bodily "humours," Paracelsus transformed the practice of medicine by employing careful observation and experimentation. Although his chemical knowledge was rudimentary by modern standards, Paracelsus envisioned using pharmaceutical methods for treating disease and something like inoculation for preventing it.

16. Scientific Development From 1543 to 1789 • 1543: Nicolas Copernicus (1473-1543) publishes De Revolutionibus Orbium Coelestium, which argues that the Sun is the center of the Solar System. • 1543: Andrea Vesalius (1514-1564) publishes Concerning the Structure of the Human Body, the first modern anatomical text. • 1600: William Gilbert (1540-1603) publishes Concerning the Magnet. • 1605: Francis Bacon (1561-1626) publishes Advancement of Learning. • 1609: Astronomia Novais published by Johannes Kepler (1571-1630), in which he presented his first two Laws of Planetary Motion. • 1610: Galileo Galilei (1564-1642) publishes Sidereal Messenger, describing his observations using the telescope. • 1619: Kepler publishes his Third Law inHarmonia Mundi.

17. Scientific Development From 1543 to 1789 *1628: William Harvey (1578-1657) publishes On the Motion of the Heart and Blood in Animals, in which he proves that the heart circulates blood throughout the body. *1632: Galileo publishes Concerning the Two Chief World Systems, in which he compares the Copernican and Ptolemaic solar systems. *1637: Rene Descartes publishes his Discourse on Method, in which he lays the foundation for modern philosophy. *1644-9: Pierre Gassendi (1592-1655), in a series of works, revives the traditions of Epicureanism and Skepticism. *1660: Robert Boyle (1627-1691) publishes New Experiments Physico-Mechanical Touching the Spring of the Air, in which he states his laws of gases. *1662: The Royal Society of London is founded. `

18. Scientific Development From 1543 to 1789 *1666: The French Academy of Science is founded. *1677: Anton von Leeuwenhoek (1632-1723), using a microscope, discovers male spermatoza. *1678: Christian Huygens (1629-1695) proposes the wave theory of light. *1687: Isaac Newton (1642-1727) publishes his Principia Mathematica. *1704: Isaac Newton publishes his Optics. *1735: Carolus Linnaeus publishes his Systema Naturae, which establishes the science of taxonomy. *1789: Antoine Lavoisier publishes his treatise on chemistry, laying the foundation for the modern theory of chemical elements.

19. Copernicus b. 1473 Poland • Polish astronomer who developed the theory that the earth is a moving planet. In Copernicus's time, most astronomers accepted the theory the Greek astronomer Ptolemy had formulated nearly 1,400 years earlier. • Some astronomers before Ptolemy had suggested that the earth did in fact move. Copernicus decided that the simplest and most systematic explanation of heavenly motion required that every planet, including the earth, revolve around the sun. The earth also had to spin around its axis once every day. The earth's motion affects what people see in the heavens, so real motions must be separated from apparent ones. • Copernicus skillfully applied this idea in his masterpiece, On the Revolutions of the Heavenly Spheres (1543). In this book, he demonstrated how the earth's motion could be used to explain the movements of other heavenly bodies. Copernicus could not prove his theory, but his explanation of heavenly motion was mathematically strong and was less complicated than Ptolemy's theory. By the early 1600's, such astronomers as Galileo in Italy and Johannes Kepler in Germany began to develop the physics that would prove Copernicus' theory correct.

20. Nikolai Copernicus Wrote: “On the Revolution of Celestial Orbs” His philosophy of Science: “True assumptions must save the appearances.”

22. Tycho Brahe b. 1546 • Danish astronomer. Brahe developed a systematic approach for observing the planets and stars. He stressed the importance of making such observations on a regular basis. The telescope had not yet been invented, and so Brahe used his eyesight and such instruments as astrolabes and quadrants to estimate the positions of celestial objects. His observations were far more precise than those of any earlier astronomer. • Brahe's observations of planetary motion revealed that the tables then in use to predict the positions of the planets were inaccurate. His sighting of a supernova (type of exploding star) in 1572 helped disprove the ancient idea that no change could occur in the heavens beyond the orbit of the moon. • Like many astronomers of his time, Brahe refused to accept the Copernican theory of the solar system. According to this theory, the earth and the other planets move around the sun. Brahe reasoned that if the earth revolved around the sun, he should have been able to measure changes in the positions of the stars resulting from the earth's movement. He did not realize that such changes were too small for his instruments to detect. However, Brahe's observational data later enabled Johannes Kepler, a German astronomer and mathematician, to confirm the Copernican theory. • Brahe was born in Knudstrup (then a Danish city but now in Sweden), near Malmo. As a member of the nobility, he attended universities in Denmark, Germany, and Switzerland. Brahe built an elaborate observatory on the island of Hven (now called Ven), where he made many of his observations.

23. Tycho Brahe b. 1546 • Danish astronomer. Brahe developed a systematic approach for observing the planets and stars. He stressed the importance of making such observations on a regular basis. The telescope had not yet been invented, and so Brahe used his eyesight and such instruments as astrolabes and quadrants to estimate the positions of celestial objects. His observations were far more precise than those of any earlier astronomer. • Brahe's observations of planetary motion revealed that the tables then in use to predict the positions of the planets were inaccurate. His sighting of a supernova (type of exploding star) in 1572 helped disprove the ancient idea that no change could occur in the heavens beyond the orbit of the moon.

24. Tycho Brahe (1546-1601)

25. Johannes Kepler b. 1571 • Discovered three laws of planetary motion. • Newton later used Kepler's three laws to arrive at the principle of universal gravitation • Kepler's laws are: (1) Every planet follows an oval-shaped path, or orbit, around the sun, called an ellipse. The sun is located at one focus of the elliptical orbit. (2) An imaginary line from the center of the sun to the center of a planet sweeps out the same area in a given time. This means that planets move faster when they are closer to the sun. (3) The time taken by a planet to make one complete trip around the sun is its period. The squares of the periods of two planets are proportional to the cubes of their mean distances from the sun. • Kepler formed an association with Tycho Brahe, which shaped the rest of his life. His most significant discoveries trying to find an orbit to fit all Brahe's observations of the planet Mars. Earlier astronomers thought a planet's orbit was a circle or a combination of circles. However, Kepler could not find a circular arrangement to agree with Brahe's observations. He realized that the orbit could not be circular and resorted to an ellipse in his calculations. The ellipse worked, and Kepler destroyed a belief that was more than 2,000 years old. • Kepler was the first astronomer to openly uphold the theories of the Polish astronomer Nicolaus Copernicus.

26. Johannes Kepler b. 1571 • Kepler formed an association with Tycho Brahe, which shaped the rest of his life. His most significant discoveries trying to find an orbit to fit all Brahe's observations of the planet Mars. Earlier astronomers thought a planet's orbit was a circle or a combination of circles. However, Kepler could not find a circular arrangement to agree with Brahe's observations. He realized that the orbit could not be circular and resorted to an ellipse in his calculations. The ellipse worked, and Kepler destroyed a belief that was more than 2,000 years old. • Kepler was the first astronomer to openly uphold the theories of the Polish astronomer Nicolaus Copernicus.

27. Johannes Kepler b. 1571 FIRST LAW • The orbits of the planets are ellipses, with the Sun at one focus of the ellipse.

28. Johannes Kepler b. 1571 SECOND LAW • The line joining the planet to the Sun sweeps out equal areas in equal times as the planet travels around the el

29. Johannes Kepler b. 1571 THIRD LAW • The ratio of the squares of the revolutionary periods for two planets is equal to the ratio of the cubes of their semi-major axes: • T^2/R^3 = constant for all planets

30. Gilbert, William (1540-1603), • Gilbert, William (1540-1603), an English doctor and scientist, was the first person to use the word electricity. He has been called the "Galileo of Magnetism" because of his celebrated book De Magnete, which he published in 1600. It was concerned with the properties of magnetism, with electricity, and with the use of compasses in navigation. • Gilbert's most important discoveries in the field of magnetism were the laws of attraction and repulsion, magnetic dip, and the properties of loadstones. Gilbert based his findings on observation and practical experiments. This practice differed greatly from that of most of the scientists of his time, who developed only abstract theories, unsupported by experiments. • Gilbert was born in Colchester, in Essex, England, and was educated at St. John's College, Cambridge. He was physician to Queen Elizabeth I and attended her during her last illness. Gilbert died on Nov. 30, 1603.

31. William Harvey (1578-1657) • An English physician who became famous for his discovery of how blood circulates in mammals, including human beings. He described his discovery in An Anatomical Study of the Motion of the Heart and of the Blood in Animals (1628). This work became the basis for all modern research on the heart and blood vessels.

32. Galileo Galilei

34. Pendulum • The Simple Pendulum • If a pendulum of mass m attached to a string of length L is displaced by an angle from the vertical, it experiences a net restoring force due to gravity: • In this small angle approximation, the amplitude of the pendulum has no effect on the period. This is what makes pendulums such good time keepers. As they inevitably lose energy due to frictional forces, their amplitude decreases, but the period remains constant.

36. GALILEO GALILEI1610 Published “The Starry Messenger”‘The Bible was written to show us how to go to heaven, not how the heavens go”“In discussions of physical problems we ought to begin not from the authority of scriptural passages, but from the sense-experiences and necessary demonstrations.”“For the Holy Bible and the phenomena of nature proceed alike from the divine Word, the former as the dictate of the Holy Spirit and the latter as the observant executor of God’s commands.”

37. GALILEO (cont.)“To ban Copernicus now that his doctrine is daily reinforced by many new observations would seem in my judgment to be a contravention of truth, and an attempt to hide and supress her the more as she revealed herself the more clearly and plainly…And to prohibit the whole science would be but to censure a hundred passages of holy scripture which teaches us that the glory and greatness of Almighty God are marvelously discerned in all his works and divinely read in the open book of heaven.”1632 “Dialogue of the two Chief World Systems

38. Rene Descartes 1596-1650 • Rene Descartes was one of the founders of modern philosophy. In this painting, Descartes conducts a scientific experiment for Queen Christina of Sweden shortly before his death in 1650.

39. Descartes 1596 - 1650 French philosopher, mathematician, and scientist. He is often called the father of modern philosophy. Descartes invented analytic geometry and developed a detailed account of the physical universe in terms of matter and motion. “I think, therefore I am.” Wrote “Discourse on Method.” “The need to experiment is an expression of the failure of the ideal” Concerning Galileo: “Without having considered the first causes of nature, he has looked only for the reasons for certain particular effects, and that thus he has built without foundation.”

40. Bacon, Francis (1561-1626) Bacon believed the mind could attain truth if it followed the inductive method of investigation. He developed four steps of doing so: (1) listing all known cases in which a phenomenon occurs; (2) listing similar cases where the phenomenon does not occur; (3) listing the cases in which the phenomenon occurs in differing degrees; and (4) examination of the three lists. These steps would lead to the cause of a phenomenon. Bacon suggested the use of preliminary hypotheses (assumptions) to aid scientific investigation. His treatment of hypothesis is still a subject of study. Bacon also wrote an unfinished romance called New Atlantis (published in 1627, after his death). The book describes an imaginary island where the inhabitants dedicate themselves to the study of science.

41. Francis Bacon “Nature, to be commanded, must be obeyed.” Wrote “Novum Organum” “The end of our foundation is the knowledge of causes, and the secret motions of things, and the enlarging of the bounds of human empire, to the affecting of all things possible.” “Knowledge ought to bear fruit in work, that science ought to be applicable to industry, that men ought to organize themselves as a sacred duty to improve and transform the conditions of life.” “I am fitted for nothing so well as the study of truth.”

42. Robert Boyle (1627-1691) • He helped establish the experimental method in chemistry and physics. • Boyle is best known for his experiments on gases that led to the formulation of Boyle's law. Boyle also helped improve the air pump, and with it he investigated the nature of vacuums. • Boyle disproved the theory that air, earth, fire, and water were the basic elements of all matter. Boyle argued that all basic physical properties were due to the motion of atoms, which he called "corpuscles." • Boyle was a founding member of the Royal Society of London, the first publicly recognized scientific organizations.

43. Robert Boyle (1627-1691)

44. ROBERT BOYLEWrote “The Excellence of Theology or The Preeminence of the Study of Divinity Above That of Natural Philosophy”Wrote “The Skeptical Chymist”Scientist should “Set themselves diligently to make experiments and collect observations, without being overtoward to establish principles and axioms.”Theories are never final, but should be thought of as “the best we have, but capable of improvement.”

45. Boyle (cont.) • We assent to experience, even when its information seems contrary to reason. • Objects have color by virtue of “ a certain disposition of the superficial particles which are capable of refracting and reflecting light” (ie. color is a secondary property)

46. Robert Hooke • The Science of Nature has been already too long made only a work of the brain and the fancy. It is now high time that it should return to the plainness and soundness of observations on material and obvious things.

48. Sir Isaac Newton, 1642-1727 Mathematician, Philosopher, Alchemist, Deist and Scientist

49. Isaac Newton 1642 - 1727 • Explained motion of planets and moon • Proposed law of universal gravitation • Explained tides • Assumed laws on Earth were same as in the heavens • Discovered light composed of different colors • Invented reflector telescope • Invented calculus • Wrote “Principia” 1687 • Directed English Mint

50. SIR ISAAC NEWTON“Whence is it that nature does nothing in vain; and whence arises all that order and beauty which we see in the world?”The best and safest method of philosophizing seems to be, first to inquire diligently into the properties of things, and to establish those properties by experiences and then to proceed more slowly to hypothesis for the explanation of them. For the hypothesis should be employed only in explaining the properties of things, but should not be assumed in determining them.1687 Published “Principia”