PHY1033C/HIS3931/IDH 3931 : Discovering Physics:
The Universe and Humanity’s Place in It
Fall 2015
Prof. Peter Hirschfeld, Physics
Announcements
• HW 2 due Sept. 22 (use Almagest passage in
syllabus)
• Lab 2 today 2nd hour
• Reading: Gregory, Chapter 3, pp. 45-51
• http://www1.umn.edu/ships/galileo/library/c
usa3.pdf Sections 156-166 (pp.89-95) (tough!)
• Osiander’s foreword and Copernicus’ preface
Last time
• Concept of acceleration (see slides on web)
• Mathematical contributions of Mertonian/Parisian scholar
• Exploration of the globe: from Ptolemy to da Gama
Clicker quickies
acceleration is defined to be
a. the rate of change of the position of an object
b. the rate of change of velocity of an object
c. the speed of an object multiplied by time
d. the speed of an object divided by distance
e. the displacement of an object divided by time
Clicker quickies
Reading: Wertheim discusses the “mathematical harmonies”
of the Pythagoreans, which they thought were related to
a. the ratios of the sizes of planetary orbits
b. The ratios of the frequencies of musical notes
c. the ratios of the speeds of the planets
d. natural mathematical affinities of the soul
e. all of the above
Expansion of humanity’s
understanding of the globe, cont’d
• da Gama has shown you can go around Africa to get to India
• One would like to go further, to China and the spice Islands
(Moluccas), but it’s far
• Can you go west and get to India/China?
Cristobal Colon (Christopher Columbus)
•
•
•
•
sometimes called the world’s greatest politician:
When he left, he didn’t know where he was going
When he arrived, he didn’t know where he was
He messed up the lives of everyone he encountered
Did it all on someone else’s money
Now that India had been reached by sea,
was there another route to the East?
Columbus
studied
Ptolemy’s
Read had
Paolo
Toscanelli
–
Distance
Reduced
Began
from
trying
distance
Africa
to
to
persuade
to
China
3500
not
miles
great
After
rejection,
turned
to
Spain
Geography
and
Marcomiles
Polo’s Travels
distance
= 5000
Portuguese in 1480s
UsedLeft
dead
forreckoning,
Canary the
Islands
not
celestial
August,
1492
Columbus
underreported
distances
he navigation
calculated
to the crew
Gold ornaments the of inhabitants of the islands
convinced him he had reached islands off China
Others became convinced
Inspired
that
what
by
thethese
voyages
of Columbus,
One
Other
who
voyages
used
to the
words
east
coast
was the
of South
Columbus had revealed was
he
visited
a new
the
world
Gulf and
the
eastern
Italian
America
geographer
convinced
Amerigo
him
that
Vespucci
this territory
coast
of the U.S.
in a continent
voyage of 1497
represented
a new
map of
of the
150716th century
The world at theWorld
beginning
Waldseemüller
was a differentMartin
place from
what it had been
The goals were the same as they had been in the East – spices, gold, and Christians
Ironically as theIn
Before
world
became
Copernicus
new,stumbled
there
Europeans
was upon
another
looked
world
backwards
shaking
regain
lost wisdom
the process
they
a new
vision
of to
theevent
cosmos
In 1505
he signed
on at 24
to athe
20-ship
Expected
resistance
from
Sultanfleet
From the lesser Portuguese nobility
the kingofcommissioned
take over
Egypt and theto
Indian
rajahsspice trade
Ferdinand Magellan
(~1480-1521)
Cannanore
Malacca
Back
inwas
Portugal
he fell
outhis
ofactions
favor
at
Was notFrustrated
able
Magellan
to
persuade
by
the
rejections,
promoted
the king
tofor
he
search
turned
forto
shorter
the
incourt
these
king
route
ofcampaigns
Spain
to the Spice Islands
Magellan claimed to have learned about the existence of
18-year
old Emperor
Charles
I found
the idea
intriguing
But after
He also
being
reported
disappointed
a geographer’s
with
Columbus,
conclusion
theabout
king’s
the
advisors
Treaty
were
of Tordesailles
against it
a pass from a document in the Portuguese archives
A first
fleet
of
5 ships
set
September
20,
with
Magellan
command
The
location
offarther
theoff
supposed
passsouth
was
just
the
of
river
Magellan
pushed
and
farther
– he
was
caught
ina in
awide
bind
Other
4 ships
had
Spanish
captains
who
did
not
trust
the
Portuguese
admiral
But
the
farther
south
he
went,
the1519
more
hismouth
hopes
waned
Three
Heships
knewarrived
he could
in the
not Philippines
beto
Magellan
determined
farintake
from
thethe
the
spring
Spice
offor
1521
Islands
land
Spain
Since those left behind in Malacca were later captured
When the Victoria
into port
Spain
there
were but 18 crew left
Thenstumbled
cargo of spices
did in
pay
for the
voyage
these were the only survivors of the original 265
Ecclesiastical debate about humanity’s
central position in cosmos
…or, do extraterrestrials exist?
“It is in the highest degree unlikely
that this earth and sky are the only
ones to have been created.”
For Lucretius the world resulted
from the collision of accidental,
random, and purposeless
Lucretius (99-55 B.C.E.)
Roman poet, philosopher atoms, producing the earth, sea, sky,
and the races of living creatures.
De rerum natura
(from Epicurus 341-270 BCE)
Aristotelian idea of “natural place” implies
one must reject plurality of worlds
But God could have made many worlds
Singularity of life here does not impugn
God’s omnipotence
Thomas Aquinas
Italian, 1224-1275
Nevertheless Thomas was misunderstood and
Proposition 34 of the Condemnations of 1277 referred to his teachings:
one could not advocate
“That the First Cause cannot make other worlds.”
Content of condemnations of 1277 – directed at U. Paris
Edict of Pope John XXI condemned the propagation of Aristotelian “errors”, e.g.
9. "That there was no first man, nor will there be a last; on the contrary, there
always was and always will be generation of man from man.“
34. “That the First Cause cannot make other worlds”
49. "That God could not move the heavens with rectilinear motion; and the reason is
that a vacuum would remain.“
87. "That the world is eternal as to all the species contained in it; and that time
is eternal, as are motion, matter, agent, and recipient”
After 1277
Two possibilities emerge for Christian theology
Earth the only world
Plurality of worlds
Condemnations of 1277
Before 1277
Epicurean plurality of worlds rejected by Christian theologians
“Life, as it exists on earth in the form
of men, animals and plants, is to be
found, let us suppose, in a higher
form in the solar and stellar regions.
Rather than think that so many stars
and parts of the heavens are
uninhabited and that this earth of
ours alone is peopled - and that with
beings, perhaps of an inferior type we will suppose that in every region
there are inhabitants, differing in
nature by rank and all owing their
origin to God, who is the centre
and circumference of all stellar
regions.”
From On Learned Ignorance, 1440
Nicholas of Cusa
(1401-1464)
+
“If it be inquired whether men exist on that [other] world, and
whether they have sinned as Adam sinned, I answer no, for they
would not exist in sin and did not spring from Adam . . . . As to
the question whether Christ by dying on this earth could redeem
the inhabitants of another world, I answer that he is able to do this
even if the worlds were infinite, but it would not be fitting for
Him to go unto another world that he must die again.”
William Vorilong,
French 1390 – 1463
+
“If there are globes in the heaven
similar to our earth, do we vie with
them over who occupies a better
portion of the universe? For if their
globes are nobler, we are not the
noblest of rational creatures. Then
how can all things be made for man’s
sake?”
from Kepler’s Conversation with
Galileo’s Sidereal Messenger,1610
Johannes Kepler
“The earth is home of the special
creature and for his sake the
universe and world have been
made.”
from The Epitome of Copernican
Astronomy, Bks IV-V, 1620-21
“I do not see at all that the mystery
of the Incarnation, and all the other
advantages that God has brought
forth for man, obstruct him from
having brought forth an infinity of
other very great advantages for an
infinity of other creatures.”
Was not automatically saying that
this had occurred, only that it
might have.
Rene Descartes
Letter to Chanut, 1647
+
Fixed stars may be centers
of other systems like ours.
General Scholium, Opticks
“If all places to which we
have access are filled with
living creatures, why should
all these immense spaces
of the heavens above the
clouds be incapable of
inhabitants?”
+
Population
Mercury
Venus
Mars
Vesta
Juno
Ceres
Pallas
Jupiter
Saturn
Saturn's outer ring
Inner ring
Edges of the rings
Uranus
The Moon
Jupiter's satellites
Saturn's satellites
Uranus's satellites
Total
8,960,000,000
53,500,000,000
15,500,000,000
64,000,000
1,786,000,000
2,319,962,400
4,000,000,000
6,967,520,000,000
5,488,000,000,000
8,141,963,826,080
1,077,568,800,000
4,200,000,000
26,673,000,000
55,417,824,000
47,500,992,000
21,891,974,404,480
Thomas Dick, Celestial Scenery, 1837
NB population of Earth in 1840 was 1,000,000,000
Question for discussion:
Did the Church’s suppression of Aristotle’s
teachings help or hurt the progress
of science?