Lecture 5.2 Theory of Mathematics and Mechanics
Read for Mechanics: 6.5; 6.6; 6.7; 6.11
Read for Optics: 7.1; 7.4
Read for Astrology: 4.4; 4.6; 4.7
I. Theory of Mathematics
a) Platonists
theory of Forms
Forms are unique, unchanging, immaterial, objects of
knowledge
they are opposed to multiple objects of sense
perception, changing and material
mathematical entities are in between
they are unchanging, immaterial
objects of knowledge
but they are multiple and
manipulable
b) Aristotelians
substance is material
mathematics is the study of the abstracted quantity
of material substance
Aristotle’s favorite example:
snub nose is curvature in nose
flesh
curvative is shape abstracted
from matter
II. Mixed Sciences and Axiomatics
Aristotle recognized various levels of abstraction in “pure and applied
mathematics”
e.g. general mathematics, geometry, optics,
iridology, material physics
Almagest, Euclid’s Optics, etc. are geometrical
studies of nature
Dispute between Aristotle and Plato important for Galileo and Descartes
G and D. side with Plato: the physics is mathematical
and against Aristotle: physical things have
physical, not mathematical properties
-still it is a somewhat bogus question
III. Mechanics
technology, science and economic development
slavery
aristocratic cooption for intellectual elites
kingly patronage for military purposes
[we didn't cover this material in class; it won't be on the exam BUT IT
IS SO COOL
Mechanical Problems cited by Aristotle and Pappus (Mathematical
Collection, VIII. 1-5)
-to find the force necessary to draw a weight up an
inclined plane at a given angle
Heron discusses a study of friction and inclined
planes (GS 6.11 pp. 168-9)
-given a wheel with x cogs, find the diameter of a
second wheel with y cogs which will engage with it
Archimedes’ Equilibrium of Planes
method of determine the inverse proportional law for
balance
difference between dynamic and static methods
(compare the mechanical method Archimedes used for determining the
relative size of a triangle inscribed in a parabola (GS pp. 29-30)
see Plane Equilibrium (GS 6.5 p.156-7)
On Floating Bodies treated as application of
equilibrium]
Heron (writing AD 55-68)
from preface on Pneumatics: “We are further led to
write this work from the consideration that it is fitting that the
treatment of this subject should correspond with the method given by us
in our treatise, in four books, on water-clocks. For, by the union of
air, earth, fire and water, and the concurrence of three, or four,
elementary principles, various combinations are effected, some of which
supply the most pressing wants of human life, while others produce
amazement and alarm.”
on the ataraxia brought on by possessing war engines.