Building the Modern Mind - the Scientific Revolution

  1. Paradigms and Paradigm Shifts

    1. The Scientific Revolution is an example of a paradigm shift

    2. Paradigm

      1. A basic framework of ideas for understanding the world around us

      2. A model for interpreting, organizing, and classifying  information

      3. Context for all thinking

      4. Often unconscious acceptance of a perceived reality

      5. Paradigms determine which questions can be asked and which can not

      6. There is not one paradigm - we all work with several, that guide our thinking about many topics

    3. Paradigm Shift

      1. This occurs when one paradigm collapses and is replaced with another

      2. This generally happens when the old paradigm encounters significant problems or information it can not solve or explain

  2. Ptolemy and Aristotle - The pre-Scientific Revolution paradigm for scientific knowledge

    1. The basic scientific paradigm of ancient and medieval Europe depended primarily on two men - Aristotle and Ptolemy

      1. Aristotle - Greek philosopher, 384-322 BC - established fundamentals of logic

      2. Ptolemy - Greek astronomer, 87 -150 AD - developed a system for predicting movement of planets based on a geocentric (Earth-centered) universe

    2. Features of the Ptolemaic/Aristotelian paradigm

      1. Earth is at center of the universe

      2. The heavens are perfect (hence, everything in the heavens is a perfect circle or a sphere)

      3. Since Earth is clearly imperfect, it is very different from the heavens, and vice versa

      4. Personal observation can be fully trusted (We know the Sun goes around the Earth because that's what it looks like it does)

      5. Ancient thinkers are the best source of knowledge (particularly the Greeks, Romans, and the Bible)

      6. Some aspects of the universe are inherently mysterious, known only to God

  3. Breaking down the Aristotelian/Ptolemaic paradigm

    1. Old paradigm begins to disintegrate because of astronomy

      1. Ptolemy had created a very complex system for explaining and predicting motions of planets in the sky

      2. These worked well for centuries, but by the 1400s, his system had become increasingly unworkable and less reliable

    2. Nicolaus Copernicus, Poland, mathematician, and astronomer (1473-1543)

      1. Proposed in his book, On the Revolution of Heavenly Spheres (1543), that the problems with Ptolemy could be solved by putting Sun at center - heliocentric universe

      2. Still mostly in old paradigm - kept planets moving in perfect circles, got his idea from ancient texts

      3. Unfortunately, his system did a worse job of predicting motion of planets than Ptolemy

    3. Galileo Galilei--Italy (1564-1642) astronomer

      1. Believed Copernicus was right, set out to prove it

      2. Used telescope to show Moon was not a perfect sphere (mountains and craters), that not everything circled the Earth (Moons of Jupiter)

      3. By discovering Jupiter's four largest moons, showed that ancients did not now everything about the heavens

      4. Also did experiments that disproved Aristotle's claim that light objects fell slower than heavier objects

    4. Johannes Kepler, German astronomer, mathematician, 1571-1630

      1. Led a very hard luck life

      2. Inherited the astronomical observations of Europe's best astronomer, Tycho Brahe of Denmark (1546-1601)

      3. Showed that motion of planets could be perfectly predicted if we assumed that traveled around the Sun in ellipses, not circles

      4. Developed mathematical formulas to describe the motion of the planets - Kepler's Laws of Planetary Motion

      5. Thus showed two things

        1. The ancients were wrong about the heavens being made up of perfect circles and spheres

        2. It was possible to develop mathematical formula to describe the workings of the universe

    5. Isaac Newton--England (1642-1727) physicist, mathematician

      1. Gained fame for work in optics

      2. Invented calculus (Gottfried Wilhelm von Leibniz also did at same time - today we use Leibniz's notation system, not Newton's)

      3. Publishes Principia in 1687 (Full title=Philosophiae naturalis principia mathematica)

        1. Primarily concerned about gravity, motion of planets

        2. Demonstrated that gravity in all places, here on Earth as well as in space, could be described with simple mathematical formulas

        3. This gives us the idea of a universal natural law - that there are laws of science that apply everywhere, at all times and places

    6. Implications of the Universal Natural Laws (UNL)

      1. If the same laws apply everywhere, including the heavens, then Earth and the heavens are the same

      2. Also, if there are UNLs about gravity, there are probably UNLs for everything else

      3. In this time period, people began to think of UNLs as being like gears in a clock. If we can understand all the gears, we can understand all the universe, and potentially control it

      4. In the past, that kind of knowledge belonged, in Western thought, only to God

      5. Now inductive reasoning could find these laws

        1. uniform observations are made and tested

        2. these observations must be empirical - that is based on the concrete world we can detect with our senses

        3. natural laws can then be inferred if predictable, repeatable patterns emerge from these observations

  4. The New Paradigm

    1. Sun is at the center of the universe (or course, this is later changed - Sun is out on the fringes of the galaxy, and there are billions of galaxies)

    2. The heavens are not perfect - everything in the space is not a perfect sphere or circle

    3. Earth is not different from the heavens - the rules here are the same as they are everywhere

    4. Personal observation is potentially untrustworthy - your senses can fool you

    5. Ancient thinkers did not know everything - it is possible to learn new things that they did not know

      1. Scientific method (hypothesis, experimentation, verification, developing principles from experimental results) becomes key to new knowledge

      2. Formally developed by Francis Bacon (1521-1626, England) but practiced by many, including Galileo

    6. The universe is place we can fully understand and predict, and thus potentially control, because of the existence of universal natural laws

    7. Much of universe can be described mathematically