Science and reason. HI174 lecture 3 October 23, 2017

Transcription

1 Science and reason HI174 lecture 3 October 23, 2017

2 No man s knowledge can go beyond his experience John Locke EMPIRIC, a quack who prescribes at random, without being at all acquainted with the principles of the art Enc. Brit the imperceptible nuances from the most complex animal to the basest mineral Georges Buffon in less than a hundred years there will not be three geometers in Europe Denis Diderot It is not, therefore, reason, which is the guide of life, but custom David Hume

3 There is nothing in the mind that is not first in the senses credence must be given to observation rather than to theory, and to theory only insofar as it agrees with what is observed Top: medieval scholastic maxim Bottom: quote from Aristotle, Generation of Animals, 4 th century BC

4 More experience Anticipations = collected from a few instances, and those for the most part of familiar occurrence Interpretations = gathered here and there from very various and widely dispersed facts -- New Organon (1620)

5 Frontispiece to Francis Bacon, The Great Instauration (including his New Organon) (1620) many shall run to and fro, and knowledge shall be increased - Book of Daniel, 12:4

6 Better instances Nothing duly investigated, nothing verified, nothing counted, weighed, or measured, is to be found in natural history. [traditional natural history] contains the variety of natural species only, and not experiments of the mechanical arts. For even as in the business of life a man's disposition and the secret workings of his mind and affections are better discovered when he is in trouble than at other times, so likewise the secrets of nature reveal themselves more readily under the vexations of art than when they go their own way

7 1. History of the Heavenly Bodies; or Astronomical History 2. History of the Configuration of the Heaven 9. History of the Blue Expanse, of Twilight, of Mock-Suns, Mock-Moons, Haloes, various colors of the Sun 29. History of Gems; as the Diamond, the Ruby, etc. 35. Chemical History of Vegetables. 46. History of Excrements; Spittle, Urine, Sweats, Stools, Hair of the Head, Hairs of the Body, Whitlows, Nails, and the like. 90. Miscellaneous History concerning the care of the body as of Barbers, Perfumers, etc. 95. History of manufactures of Feathers. 98. History of Leather-making, Tanning, and the arts thereto belonging. From Catalogue of Particular Natural Histories by Titles, in Bacon s Preparative Toward Natural and Experimental History (1620)

8 Tis of great use to the sailor to know the length of his line, though he cannot with it fathom all the depths of the ocean. Tis well he knows, that it is long enough to reach the bottom, at such places, as are necessary to direct his voyage, and caution him against running upon shoals, that may ruin him. Our business here is not to know all things, but those which concern our conduct -- John Locke, An Essay Concerning Human Understanding, 1690

9 sunlight board 1 board 2 paper screen surface 1 surface 2 Newton s Experimentum Crucis (crucial experiment), from his 1672 paper in the Phil. Trans.

10 'Nature and Nature's laws lay hid in night: God said, Let Newton be! and all was light -- Alexander Pope

11 The two-prism experiment Rainbows Transparent liquids Natural colours Light is a mixture of rays of different colours and refrangibilities

12 The two-prism experiment Rainbows Transparent liquids Natural colours Light is a mixture of rays of different colours and refrangibilities What are the rays made of? Are they like waves, or particles? Why do rays bend at the surface of a prism?

13 this union of mathematics and physics can only be made for a very small number of subjects that lack nearly all physical properties - Georges Buffon, Premier discours, Histoire naturelle (1749) [mathematics] usually assumes bodies to be more regular and more perfect than they really are - Charles Dufay, member of Paris Acadmey of Sciences, 1726 in less than a hundred years there will not be three geometers in Europe - Denis Diderot, co-author of the Encyclopédie

14 Munroe: You can t take the square root of your feelings, you can t differentiate your emotions 18c scientists: you can t take the square root of an acid, or of electricity, or of magnetism. It was only in the last third of the 18c that this attitude started to change. Only then that one could say Randall Munroe, XKCD

15 The physicist who does not measure only plays F. K. Achard, 1782 Horace-Bénédict Saussure, Essais sur l hygrométrie (1783)

16 this union of mathematics and physics can only be made for a very small number of subjects that lack nearly all physical properties - Georges Buffon, Premier discours, Histoire naturelle (1749) [mathematics] usually assumes bodies to be more regular and more perfect than they really are - Charles Dufay, member of Paris Acadmey of Sciences, 1726 in less than a hundred years there will not be three geometers in Europe - Denis Diderot, co-author of the Encyclopédie

17 1. Mathematics 2. History Coulomb s law Force between two charged particles = a constant x charge on first particle x charge on second particle 3. Classification divided by 4. Disciplines 5. Institutions the square of the distance between the particles Torsion balance of Charles-Augustin de Coulomb, Mémoires of the Paris Academy of Science, 1785 Coulomb trained at Ecole royale de genie de Mézières, est

18 Risks of ENP [The RSL s] purpose was, to heap up a mixt Mass of Experiments, without digesting them into any perfect model whatever they have recorded, they have done it, not as compleat Schemes of opinions, but as bare unfinished Histories -- Sprat, History of the RSL (1667) there was a party arising in the Society, that were for rejecting all kinds of useful knowledge except ranking and filing of shells, insects, fishes, birds, etc., under their several species and classes; and this they termed Natural History, and Investigating Nature -- William Molyneux (1686)

19 Horace-Benedict de Saussure climbing Mont Blanc, 1787 (18 th -century illustration)

20 We perceive things through our ideas (Locke) a blue chair idea of a blue chair the mind s eye observing its idea of a blue chair

21 Ideas do not resemble their causes (Galileo, Descartes, Locke). a blue chair idea of a blue chair the mind observing its idea of a blue chair

22 so how can we know anything about the causes of our ideas (Bishop Berkeley)?? idea of a blue chair the mind perceiving its idea of a blue chair

23 perhaps ordinary objects just are our ideas (Berkeley again) idea of a blue chair the mind perceiving its idea of a blue chair Treatise Concerning the Principles of Human Knowledge (1710)

24 Change over time (Bacon to Locke, Dufay to Coulomb) Different disciplines (astronomy v chemistry) Different institutions (RSL and RAS) Slipperiness of ideas (Locke to Kant)