Announcements
•Exam 1 is next time. It will cover
Chapters 1 – 5. Sample questions are
posted. The exam will consist of 15
multiple choice questions and 3 essay
questions. Open book so be sure to
bring yours.
•Don’t forget the 1st Project
presentations are two weeks from
Thursday. A written paper and oral
presentation is required
Rene
Descartes
1596 – 1650
I think, therefore,
I am
Not an astronomer but a
philosopher/mathematician.
Like Plato, though, his
philosophy influences
astronomical thought.
Born in La
Haye near
Tours in
southern
France
His father was a
Councilor in Parliament
and an intellectual so he
was raised an
environment conducive
to learning and
education
He studied at the Jesuit
College in La Fleche and
then Canon Law at Poitiers
17th Century painting of
the Jesuit College at
La Fleche
The modern day
University of Poitiers
In 1628 he moved to Holland
where he stayed until 1649,
moving frequently
Dordrecht (1628), Franeker (1629), Amsterdam (1629-30),
Leiden (1630), Amsterdam (1630-2), Deventer (1632-4),
Amsterdam (1634-5), Utrecht (1635-6), Leiden (1636),
Egmond (1636-8), Santpoort (1638-1640), Leiden (1640-1),
Endegeest (a castle near Oegstgeest) (1641-3), and finally
for an extended time in Egmond-Binnen (1643-9).
Most of his
major works
were published
while he was in
Holland
Discourse on The
Methods was first
published in 1637
His Principles of Philosophy was
published in 1644
The universe of Descartes was
filled with an aether
Matter filled the
universe. It was
only through
motion that
“objects” had form
His work was of sufficient
importance to geometry that we call
the coordinate system Cartesian
In 1649 he is invited to Stockholm
by Queen Christina
He dies in Stockholm on
February 11, 1650
His tomb is at
the Church of
Saint Germain
des Pres, Paris
The stage is
now set for
the rise of
Newtonianism
William Gilbert proposed the Earth
was a huge magnet
Published in 1600, On
The Magnetic was a
treatise on magnetism
English intellectuals of the early
1600’s gathered at Gresham College
Check out the Gresham College website
In 1660 the
Greshamites
form the
Royal
Society
The Philosophical
Transactions of the Royal
Society have been
published since 1665 and
are available online
Robert Hooke is the Curator of
Experiments for the Royal Society
Known as London’s
Leonardo because of
his involvement in the
rebuilding of London
after the great fire of
1666. His experiments
on the pendulum gave
rise to Hooke’s Law.
Check out the official
Robert Hooke website
Hooke attempted to prove that
Earth moved
An Attempt to Prove the Motion of the Earth by
Observations
Made by:
Robert Hooke
Fellow of the Royal Society. *Senec. Nat. Qu. lib. I. cap.
30. `Nè miremur tam tardè erui quæ tam altè jacent.
Wether the Earth move or stand still hath been a Problem, that since
Copernicus revived it, hath much exercised the Wits our best modern
Astronomers and Philosophers, amongst which notwithstanding there
hath not been any one who hath found out a certain manifestation either
of the one or the other Doctrine. The more knowing and judicious have for
many plausible reasons adhered to the Copernican Hypothesis: But the
generality of others, either out of ignorance or prejudice, have rejected it
as a most extravagant opinion.
A major result of this work was the idea of mutual attraction
Hooke postulates an attractive
force between the Sun and planets
that diminishes with distance
He never showed
it was an inverse
square law, just
an inverse law of
some sort.
In a series of letters, Hooke spurred
Newton into thinking about Gravity
Hooke’s “discussions” with Newton became somewhat
critical of Newton’s ideas. As a result, Newton despised
Hooke and eventually tries to erase all traces of him
from the Royal Society records