#9
#10
The Scientific Revolution began with the European
re-discovery of Aristotle in the 12th and 13th centuries.
The earliest followers were burned at the stake as
heretics because they went against church teachings.
Over time, teachings are combined with church
doctrine to form a watered – down science.
In the Middle Ages, scientists were
mostly concerned with alchemy –
standard chemistry problems
Roger Bacon – most important
scientist of this time.
Invented gunpowder
Came up with experimental
science
Despite this progress, people believed
the center of truth and existence was
God.
The Scientific Revolution gains momentum during the
Renaissance with the works of Leonardo da Vinci in the
middle of the 15th century, and Nicolaus Copernicus in
the 16th century.
“Here, right here, in the eye, here forms, here colors,
right here the character of every part and everything
of the universe are concentrated to a single point.
How marvelous that point is! In this small space the
universe can be completely reproduced and
rearranged in its entire vastness!” (da Vinci)
Da Vinci is saying humans can see the universe in the
same way as God can encompass the universe. This is a
huge shift in the European thought! Now people were
willing to extend their views to new things –science.
Arabic Numerals
During the Middle Ages, Europeans switched from Roman to
Arabic numerals. This is very important for the Scientific
Revolution.
Without this system, Copernicus could not have made his
mathematical calculations,
Arabic numerals use a place number system consisting of ten
numerals – when these are used up, a new number is added.
Allows for fast calculations.
Try to multiply: MDMCXLVII BY CCCLXXII without
converting to Arabic Numerals
AS THE WORLD TURNS
Geocentric
Heliocentric
Old Geocentric Theory
Official view of the Catholic Church
Geocentric: Earth-centered
Sun rises
Sun sets
Earth seems still
Geocentric Theory
Proof:
Earth seems stationary
Sun seems to move across the sky
Bible quotes
Blind acceptance of Greek teachings
Man views himself as focus of the universe
Teachings of Aristotle – 300 BCE
World is made up of 5 elements:
Earth, air, water, fire and Quintessence
Earth does not rotate.
Teachings of Aristotle
Clear, round, domes hold
planets and stars.
Laws of Motion:
Things move by
weight or violent force
Ptolemy 150 CE (Greek)
Agrees with Aristotle
Used math and Geometry to “prove” the
Geocentric Theory
Problems:
•Planets must travel in loop orbits
•Does not fit calendar
•Math is forced
NEW HELIOCENTRIC THEORY
The theory is introduced by Copernicus (1473 –
1543) a Polish astronomer and mathematician
Goal: Fix the problems of Ptolemy (Calendar
and math)
Make the sun the
center and the
math works!
HELIOCENTRIC THEORY
Sun is the center of the
universe.
The earth revolves around the
sun and it rotates
Problem: It goes against the
teachings Aristotle and
“common sense”
On the Revolutions of the Celestial Spheres,
the book written by Copernicus is not
published until after his death
Tycho Brahe (Danish
mathematician)
Takes measurements for
over 20 years
Really supported Aristotlewanted to prove
Copernicus wrong
Provides the mathematical
evidence that Copernicus
is correct.
Leaves his work to
assistant Johannes
Kepler
Johannes Kepler (1571 – 1630) German
The Proof: Used Brahe’s measurements –
made one adjustment, and the math worked
perfectly!
Laws:
Planets travel in an Ellipse
Planets travel slow then
fast
Figure distance from sun by
how long it takes to revolve
around sun. T² = ka³
Galileo Tells The World
Galileo (1564 – 1642) Italian
Always liked proving
Aristotle wrong
On Motion:
Things fall at an equal rate
Objects tend to stay in motion
First Telescope
Sees Venus, moon, and 4 moons of
Jupiter
Visual proof Copernicus is correct
Galileo tries to convince the
church – told to be quiet
Wrote The Dialogs – 3 guys
talking (Galileo, Copernicus,
and Ptolemy). Used the
book to prove his point, but
says Ptolemy is correct
Wrath of Catholic Church:
Defensive of Criticism – Galileo put on trial
Found Guilty of heresy – going against the
Pope
Sentenced to house arrest until his death
Never figured
out gravity.
The final piece – Gravity!
Sir Isaac Newton 1642 – 1727
(England)
Explains orbit of planets:
Gravity and Inertia
Created Calculus to help
explain
Finalized the Laws Of Motion
Law #1 Objects in motion tend to stay in motion, objects at
rest tend to stay at rest. (Unless acted upon by another
force)
Law #2 Change in
motion is proportional to
force
Law #3 For each action
there is an equal and
opposite reaction
Law of Gravity: All objects have a natural attraction
that varies with mass and distance