Transcript Day 06

Announcements
•Exam 1 will cover Chapters 1, 2, 3, 4 & 5.
Sample questions have been posted.
Format will be 15 MC’s (3 points each) and
3 essays (18 points each) from a list of 5.
Open Book!
•For Tuesday read Chapter 5.
With the invention of the printing
press in 1450, astronomy texts
flourished
Regiomontanus’ Epitome
of the Almagest published
in 1496
Sacrobosco’s
Sphaera Mundi
published in 1472
Peuerbach’s
Theoricae Novae
Planetarum first
published in 1474
The scientific community of the late
1400’s and early 1500’s was ripe for
challenging the ideas of the Greeks
Aristotle’s explanation of
projectile motion was both
absurd and clearly wrong. If this
was wrong, what of the rest of
Aristotle’s Physics?
What everyone hated was
Ptolemy’s Equant
Nicolaus Copernicus
February 19, 1473 – May 24, 1543
Educated in Krakow, he studied
astronomy from Sacrobosco’s text
He doesn’t receive a
degree here, though
And mathematics from
Euclid’s Elements
In 1495 his uncle arranges for
him to become a Canon of the
church in Frombork
He gets a leave of absence to
study canon law in Bologna
He also conducted astronomical observations with
Domenico Maria de Novara at the Specola. He doesn’t
receive a degree but returns to Frombork in 1501
He also studied medicine at the
University of Padua
He doesn’t finish, though. The program of study is three
years and he is only granted two years leave from his
position in Frombork
He finally receives a degree in
Canon Law around 1504
After finishing, he goes to
live with his uncle (the
bishop of Warmia) and is
the attending physician
when he falls ill in 1507 and
eventually returns to
Frombork in 1510
The university that finally grants him a degree is the
University of Ferrara which is near Venice
In 1515 he publishes his first
writings on a heliocentric universe
Commentariolus is an
early outline of the
heliocentric model. It is
only a few pages long
and doesn’t go into the
mathematics
In 1539 Georg Joachim Rheticus
visits and convinces him to
publish the full works
Rheticus is a mathematician
and brings several math
books to show the quality of
printing available in Germany
De Revolutionibus Orbium
Coelestium
First published in 1543
Andreas Osiander added a
foreword to De Revolutionibus
To the Reader
Concerning the Hypotheses of this Work
There have already been widespread reports about the novel
hypotheses of this work, which declares that the earth moves whereas
the sun is at rest in the center of the universe. Hence certain scholars, I
have no doubt, are deeply offended and believe that the liberal arts,
which were established long ago on a sound basis, should not be
thrown into confusion. But if these men are willing to examine the
matter closely, they will find that the author of this work has done
nothing blameworthy. For it is the duty of an astronomer to compose the
history of the celestial motions through careful and expert study. Then
he must conceive and devise the causes of these motions or
hypotheses about them. Since he cannot in any way attain to the true
causes, he will adopt whatever suppositions enable the motions to be
computed correctly from the principles of geometry for the future as well
as for the past. The present author has performed both these duties
excellently. For these hypotheses need not be true nor even probable.
On the contrary, if they provide a calculus consistent with the
observations, that alone is enough.…
Like Ptolemy’s Almagest, De
Revolutionibus described how to
calculate the positions of planets
Watch Museo Galileo Copernican System video
The numbers weren’t much better
than Ptolemy’s
Origanus used Copernicus’ method to calculate the position
of Mars (dashed line). Compare it to the calculation using
Kepler’s laws
The Copernican revolution would
change the way we view our place
in the universe
Conversation With God by Jan Matejko in 1872