Scientific Revolution III
Descartes, Newton, and the Mechanical Universe

  1. Rene Descartes (1596-1650)

    1. French mathematician

    2. Proposes a mechanical universe

      1. Universe governed by laws of mechanics and impacts

      2. Movement of celestial bodies controlled by whirlpools of aetherial matter

      3. Saw mechanics also in physiology and medicine

    3. Main point of scientific discussion in 17th century Europe will be on the correctness of Descartes

  2. The Scientific Environment of the 17th Century

    1. Geographic center moves north, particularly to Netherlands and England

      1. Protestant, and generally tolerant for the age

      2. Church structures weaker than in Catholic countries

      3. Mercantile, with great interest in navigation and new exploitable technologies

    2. Numerous advances in math and science, concentrated in Netherlands and England

      1. Descartes, although French, worked in the Netherlands

      2. Newton, of course, was English

      3. Anton van Leeuwenhoek  (Duth, 1632-1723) pioneers microscopic studies, but meaning of his discoveries not clear for a century

      4. William Harvey (English, 1578-1657) discovers circulation of blood in 1618

    3. Growing belief in social, commercial utility of science

      1. Renaissance magic, Hermeticism, alchemy all argued for the social utility of the study of nature

      2. Various thinkers began to promote the idea that the study of nature could uncover tools for power for governments

      3. Philip II of Spain (1526-1598) and Charles II of England (1630-1685) both established alchemy laboratories

      4. Francis Bacon (1561-1626)

        1. Argued that useful discoveries could come from systematic investigation

        2. Envisioned a scientific utopia in which "Dowry men" would be assigned to search out useful knowledge

        3. Said that true knowledge was empirically knowledge

        4. Laid out philosophical basis for scientific method - deductive logic, in which theories are built and tested on empirical observation

      5. Bacon and Descartes both argued that humans should become masters and possessors of nature

    4. Science as an Institution

      1. Particularly in England, new institutions spring up to advance the study of nature

        1. Royal College of Physicians, 1518

        2. Royal Society of London, 1662 - begins publishing Philosophical Transactions, oldest scientific journal in continuous publication

        3. Royal Observatory at Greenwich, 1675

        4. Royally funded chairs in science and mathematics at Oxford (1621) and Cambridge (1663)

      2. Paris Academy of the Sciences, 1666

      3. Scientific academies also appear in Russia, Prussia, and Sweeden

  3. Isaac Newton (1642-1727)

    1. A Profound Legacy

      1. With laws of motion and universal gravitation, unites the celestial and terrestrial spheres under one set of laws

      2. Invents (along with Leibniz) calculus

      3. Fundamental work on optics

      4. Provides a research agenda for the future, particularly in astronomy, mechanics, and optics

    2. Newton the Icon

      1. For the Enlightenment and the Industrial Revolution, he was the epitome of the rational scientist

        1. Alexander Pope (1688-1744) wrote

          • Nature, and Nature's Laws lay hid in Night
            God said, Let Newton be! and All was Light

      2. In his lifetime, his career (he was eventually knighted) showed the changing social position of the scientists

      3. In the 20th century, discussion of his emotional problems and revelations about his study or religion and the occult present a more complex image

    3. Beginnings

      1. Born to a modest background, but connections to some wealth on his mother's side

      2. These connections make it possible for him to attend Cambridge

      3. In 1666, has a number of key insights on gravity, optics, and calculus that paved the way for his life's work, though he told no one

      4. Becomes Lucasian Chair of Mathematics at Cambridge in 1669, at 26

      5. Publishes first paper in Philosophical Transactions in 1672

        1. Groundbreaking work on optics - showed that colors coming from a prism were a property of light (not of the prism)

        2. Gets him elected to the Royal Academy

        3. This work overturned work by Aristotle and Descartes, and it produced strong criticism

        4. Led him to build the first reflecting telescope, now called a Newtonian telescope

        5. In face of criticism, Newton retreated to Cambridge, works privately on theological question for rest of 1670s, early 1680s

          1. although he keeps it to himself, becomes increasingly fanatical and unorthodox in his religion

          2. Essentially adopts a form of Arianism and Gnosticism

    4. The Principia

      1. Prodded by a question in 1684 from Edmond Halley (of comet fame), returned to work on celestial mechanics

      2. The Principia Mathematica Philosophia Naturalis (Mathematical Priniples of Natural History) published by Royal Academy in 1687

      3. Primarily a mathematical and geometric text, it begins in the preface with three axioms, Newton's Laws of Motion

        1. Inertia - bodies at rest tend to stay at rest, bodies in motion tend to stay in motion - unless acted on by an outside force

        2. Force is measured by change in motion (eventually, this will be expressed as f=ma)

        3. For every action, there is an equal and opposite reaction

      4. Further lays out the techniques of calculus (which is tricky, since his audience would never have seen calculus)

      5. Gravity

        1. Law of Universal Gravitation

          1. Shows that force governing falling bodies (worked out largely by Galileo) and force governing the orbit of the Moon were the same thing

          2. Gravity as a Universal Law of Nature

        2. Shows that this force, gravity, varies with the inverse square of distance, from which we can derive Kepler's Laws of Planetary Motion

        3. Thus Kelper's and Galileo's work can both be expressed as extensions of Newton's mechanics

      6. Hydromechanics and aerodynamics

        1. Describes the motion of bodies through a medium, as a way to dismiss Descartes' whirlpools

        2. As an aside, mentions that this could be useful to boat builders

    5. God the Clockmaker

      1. Newton believed that God could be known through His creations

      2. In 1713 edition of Principia Proposes God the Clockmaker - God as the designer of a mechanical universe founded on natural laws

      3. This will become an important image for Enlightenment thinkers

    6. Later Career and Social Climb

      1. In 1693, suffered some kind of mental breakdown, perhaps severe depression, retreats once again

      2. However, in the Glorious Revolution, his staunch anti-Catholicism led him to public support William and Mary and overthrow of James II

      3. Leads to him becoming first warden (1696) and then master (1699) of the Royal Mint, where he remained until death

        1. Demonstrates how scientists were becoming civil servants, valuable experts for the bureaucracy

        2. Government, not the universities, serve as a principle center of development in lat 17th, early 18th century Europe

      4. Becomes President of the Royal Academy in 1703, holds that position till death

        1.  Uses position to try to quash Leibniz's claim to origination of calculus

        2. Ironically, modern mathematics uses Leibniz's notation as opposed to Newton's more cumbersome system

      5. Knighted in 1705