The Scientific Revolution: Background and Overview Unit 3 - Day 1

Science as We Know It - The Scientific Method 1.Define the question 2.Gather information and resources (observe) 3.Form hypothesis 4.Perform experiment and collect data 5.Analyze data 6.Interpret data and draw conclusions that serve as a starting point for new hypothesis 7.Publish results 8.Retest (frequently done by other scientists)

A key concept – epistemology  Among many other things the scientific revolution in the 17 th and 18 th centuries represented a profound shift in prevailing epistemologies.  Question: What is epistemology? Epistemology- the study/science of knowledge Central Questions: 1.How do we know truth (i.e. about the natural world)? 2.Can we know truth? 3.How certain can we be?

Epistemology – Two Ways of Knowing Authority vs. Reason Authority – Someone smarter than you tells you what is true. Reason – You figure out what is true based on your own ability to think logically.

The Smartest Guy of All (If You’re a Christian in the Sixteenth Century)

Epistemology – Two Ways of Reasoning Deduction vs. Induction General Principle or Law Individual Examples DEDUCTIONINDUCTION

Epistemology – Two Ways of Reasoning Deduction Begins with a general principle and reasons to particulars (individual examples) Type of reasoning most commonly associated with geometric proofs Example: Circles are figures in which every point is equidistant from a central point. (general principle) Figure A is a figure in which every point is equidistant from a central point. Therefore Figure A is a circle (particular example) Figure A

Epistemology – Two Ways of Reasoning Induction Begins with observation of individual examples and reasons to form general principles about their relationships Type of reasoning most commonly associated with experimentation Example: Lots of people have seen swans (particular examples) All the swans ever observed are white. No one has ever seen a non-white sway Therefore it seems probable that all swans are white. (general principle)

Epistemology – Two Kinds of Reasoning Induction vs. Deduction – Advantages and Disadvantages  Deduction  Advantage: If all the terms are perfectly defined produces absolute certainty  Disadvantage: Difficult to find circumstances in which all terms and principles can be defined perfectly  Induction  Advantage: Relatively easy to do – just observe the world  Disadvantage: Can never be absolutely certain one has observed ALL particulars

The Scientific Method 1.Define the question 2.Gather information and resources (observe) 3.Form hypothesis 4.Perform experiment and collect data 5.Analyze data 6.Interpret data and draw conclusions that serve as a starting point for new hypothesis 7.Publish results 8.Retest (frequently done by other scientists)

Aristotle – Another Pretty Smart Guy

The Aristotelian Cosmos The World according to Aristotle – Spheres of the Planets and the Fixed Stars

The Aristotelian Cosmos The World according to Aristotle – Spheres of Earth, Water, Air and Fire

Aristotelian Physics Universe divided up at the sphere of the moon: Below the sphere of the moon (sublunar) physics-  Things naturally move in straight lines (rectilinear motion)  Objects composed of compounds of four elements: Earth, Water, Air, Fire  Elements naturally move toward their place in the universe  Earth moves down  Fire moves up  Water and Air in between  Aristotle occasionally describes the reasons for natural motion in “animistic terms”  Why does a piece of chalk fall? – because the earth in it “desires” to be at the center of the universe  By definition earth is “heavy” – it wants to fall down; fire is “light” – it wants to go up

Aristotelian Physics Universe divided up at the sphere of the moon: Above the sphere of the moon (celestial) physics-  Things naturally move circularly (circular motion)  Objects composed purely of an element found only in the heavens – Quintessence (Fifth Element)  By definition, things composed of Quintessence – stars planets, sun, moon, etc “want” to move in a circle around the earth.

Aristotelian Cosmology  Why is Aristotle’s Cosmology So Brilliant?  Explains several things at once Explains celestial phenomena – why sun, planets, moon, stars rise and set in the sky Explains terrestrial phenomena – why things fall, why fire rises, why gasses bubble up through liquids More subtly – explains why there is an obvious difference between the celestial realm and the terrestrial – why things on earth move up and down when things in the heavens move around in circles; why the heavens remain constant and unchanging while things on earth change all the time

Christian/Aristotelian Cosmology In the Middle Ages, Christian philosophers, theologians, and poets found ways of making Aristotle’s Cosmology fit into their understanding of the way the world worked. This further reinforced the authority of Aristotle in Europe in the sixteenth century. Right: An illustration of the universe from an early printed edition of Dante’s Divine Comedy.