Announcements
•Exam 1 is one week from today. Covers
Chapters 1 – 5. Sample questions are
posted. Exam will consist of 15 multiple
choice questions and 3 essay questions.
•Don’t forget the 1st Project presentations
are three weeks from today.
•1st Quarter Observing Night Monday
night. Set-up starts at 6:45pm. Meet here
at that time
After Tycho’s death, Kepler is
appointed Astronomer Royal
Kepler explains his astronomy to Rudolph II
A legal battle
between Tycho’s
family and
Rudolph II keeps
the data in limbo
Kepler basically steals the
data until ownership is
eventually sorted out. Kepler
credits Tycho in the
Rudolphine Tables
With the data in hand,
Kepler begins his “war on
Mars”
The
calculations
were
extremely
tedious
Kepler’s 2nd Law was actually his first
Although he didn’t have the details worked out, he
knew that planets travel fastest when closest to the
Sun and slowest when farthest away before he knew
the shape of the orbit.
Eventually he
comes up with
his 1st Law of
Planetary motion
He publishes his first
two laws in 1609
rd
3
His
Law
took another
10 years to
develop
Harmony of the Worlds is
first published in 1619
His last
publication is
the
Rudolphine
Tables in 1627
As seemed fitting for his troubled
life, his grave was destroyed within
a few years of his death
This is the house he lived in
briefly in Regensburg. He
had returned to try and
collect on an old debt when
he took ill and died. He was
buried in the cemetery of
the local protestant church.
Within five years the church
is destroyed and his grave
is erased.
Galileo Galilei
1564 – 1642
Born in Pisa, his family moved to
Florence when he was 8
At 17 he begins study at the
University of Pisa
Originally he studies medicine but is unhappy with it
so he changes to mathematics. In 1589 he is
appointed chair of mathematics at the university
In 1592 he moves to the University
of Padua to teach math, geometry
and astronomy
While at Padua he performs
numerous physics experiments
Early on he is not yet a committed
Copernican but he isn’t happy with
Ptolemy either
Vs
He considers Tycho’s model a bastardization
of Ptolemy and not worth bothering with
In the summer of 1609 he hears
about a new invention: the telescope
Invented by Hans Lippershey of Zeeland in 1608,
word quickly spread across Europe to Galileo
After making
refinements
to the
design,
Galileo turns
his
telescope to
the heavens
His first major
discovery
concerned the
planet Jupiter
Over a week long period
in January 1610 he makes
observations that prove
the existence of four
moons orbiting Jupiter.
His observations of the moon
showed it to have topography
similar to Earth
He publishes his first observations
in the Starry Messenger
Published in March 1610. He
calls the moons of Jupiter
the Medicean stars after his
patrons
Simon Marius claimed to
have observed the moons
before Galileo but didn’t
publish his findings until after
Starry Messenger came out
His next significant observations
are of the Sun
By tracking sunspots
across the face of the
Sun he deduces the
rotation of the Sun.
While he does make
observations and
sketches, his studies
of the Sun are not as
detailed as other
observers of the time.
Another observation that supports
his new Copernican views was the
phases of Venus
He observes the rings of Saturn but
never understands what they are
He first observes it in July 1610. By 1612 the rings were
edge-on and became invisible only to reappear by 1616
In December
1614 Father
Tommaso
Caccini preaches
against the
Copernican view
The sermon is directly
aimed at Galileo and is
meant to incite ferment
against the Copernicans
In 1615 Galileo is called to Rome
to defend his views before
Cardinal Bellarmine
In 1616 the Church formally bans
De Revolutionibus
Cardinal Bellarmine
explicitly warns Galileo
not to hold or espouse the
Copernican view.
Galileo publishes more
observations in The Assayer in
1623
He also attacks other
astronomers that still hold
to the Ptolemaic view.
In 1623 Galileo’s friend, Cardinal
Barberini, becomes Pope Urban VIII
Emboldened by
discussions with
Pope Urban VIII,
Galileo defies
the Inquisition
and publishes
Dialogues in
1632
By late 1632, Dialogues is banned
and Galileo is put on trial
By June 1633 he is found guilty
and sentenced to prison. After
recanting his views, his sentence is
commuted to house arrest
While under
house arrest, he
finally publishes
the results of his
physics
experiments
Discourses and Mathematical
Demonstrations Relating to Two
New Sciences lays the foundation
for kinematics and dynamics
He dies while still under house
arrest, on January 8, 1642
If you have time…