the birth of modern astronomy renaissance: from the ancients and beyond
TRANSCRIPT
The Birth of Modern The Birth of Modern AstronomyAstronomy
Renaissance: From the Renaissance: From the ancients and beyondancients and beyond
RenaissanceRenaissance• The Renaissance is marked by the The Renaissance is marked by the
rediscovery of the knowledge of the rediscovery of the knowledge of the ancient Greeks and Romans as well ancient Greeks and Romans as well as continuation of the progress of as continuation of the progress of scientific discovery.scientific discovery.
• However, it is also a time turbulence However, it is also a time turbulence in the religious sphere. Freedom of in the religious sphere. Freedom of expression is strongly curbed at expression is strongly curbed at times.times.
RenaissanceRenaissance• Great ExcitementGreat Excitement
• Columbus sails in 1492Columbus sails in 1492
• Da Vinci and MichelangeloDa Vinci and Michelangelo
• The Catholic church is questioned by The Catholic church is questioned by Martin Luther and the beginning of Martin Luther and the beginning of ProtestantismProtestantism
• The nature of the world came into The nature of the world came into question.question.
Nicolas Copernicus
Nicolas Copernicus• 1473 to 1543• He was a canon in
the Catholic Church• Good mathematician• Physician• Well Educated• In Rome for the 1500
Jubilee
Nicolas CopernicusHe wrote a book in1514 outlining his basic arguments for the Heliocentric universe.He only allowedfriends to read it anddid not put his nameon it.
Copernicus’ Axioms1. There is no one center in the universe.2. The Earth’s center is not the center of the universe.3. The center of the universe is near the Sun.4. The distance from the Earth to the Sun is
imperceptible compared with the distance to the stars.
5. The rotation of the Earth accounts for the apparent daily rotation of the stars.
6. The apparent annual cycle of movements of the Sun is caused by the Earth revolving around it.
7. The apparent retrograde motion of the planets is caused by the motion of the Earth from which one observes.
Nicolas CopernicusPtolemy Copernicus
Copernicus still believed inPerfect circular orbits
Copernicus• Since he knew that
his book De Revoltionibus would be considered heresy, Copernicus had it published by a friend after his death.
• He also pointed out gaps in Ptolemy’s model .
Copernicus• Despite the improvement
in the model of the
universe, he still believed
in the idea of perfect
circular orbits.• This made his predictions no more accurate than
Ptolemy’s and led to doubts about his theory.• Although the Church condemned the book, the
damage was already done and the world was opened to new was of thinking about the world.
Christopher Clavius• 1538 to 1612• Astronomer for Pope Leo X.• Clavius determined that the
Julian Calendar was adding 3 days too many over a period of 385 years.
• This caused the date of Easter to slip against the calendar.
• That’s a bad thing!!
Christopher Clavius• Clavius made (2) proposals:
1. The day following Wednesday October 4th 1582 should be called Thursday October 15th 1582
2. Leap years occur in all years divisible by 4 but in years ending in “00” must be divisible by 400 to called a leap year.
– 1600, 2000 yes– 1700, 1800, 1900, 2100 No
Pope Gregory X is credited for instituting the newCalendar and today it is known as the
Gregorian Calendar.
Tycho Brahe• 1546 to 1601• Tycho studied medicine, law,
mathematics, astronomy, and politics.
• A supernova seen in 1572 turned his attentions toward astronomy permanently.
• He constructed observatories at Hven
• After closing Hven due to the political environment, he became the Imperial Mathematician to the Holy Roman Empire in Prague.
Tycho Brahe• Tycho was a great maker
of astronomical instruments.
• He was able to measure the positions of hundreds of stars to within 4’.
• Because he found great errors in the Alphonsine tables he decided to create his own Rudolphine Tables
• He measured the positions of the planets to within 2’.
Tycho Brahe• Tycho had devised
his own unique model of the universe where the moon and the sun revolved around the Earth but all of the planets went around the Sun.
• He hoped to use his data tables to prove his hypothesis
Tycho Brahe• Kepler applied to work at
Tycho’s observatory.• Tycho recognized his
talents quickly and set him to work on the Rudolphine tables with the purpose of finding the laws of planetary motion.
• Unfortunately Tycho died less than two years later, before Kepler worked out his first two laws. (1601)
Giordono Bruno• 1548 to 1600• He was an ordained priest
by the Catholic Church.• He believed in many
heretical ideas.• Here are just a few:
– He believed that there was no center to our universe
– the universe was infinite.– He believed other stars
were suns– He believed in atoms
Giordono Bruno• He believed in atoms• Because of his views, he
was persecuted by many different churches and peoples.
• Ultimately he went back to face trial in the Vatican.
• The trial lasted 7 years before he was found guilty and sentenced
Giordono Bruno
Giordono Bruno
Giordano Bruno
• Giordano Bruno was publicly burned at the stake on Feb 17th, 1600.
• This was the year of the Jubilee celebration.
• Bruno was easily 200 years ahead of his time.
Galileo Galilei• 1564 to 1642• Very talented
mathematician• Excellent
experimenter and astronomer
• Originally trained in medicine but never completed the degree
Galileo Galilei
Galileo Galilei• Strong believer in the
Copernican system.• Understood that an object
that is dropped will fall straight down, not left behind because of the Earth’s rotation!
• Used a telescope to look at the heavens and made improvements in quality and magnification.
Galileo GalileiDiscoveries
• Venus has phases that shows it orbits the Sun.• The Moon is covered with mountains, valleys, and
craters (Imperfect).• The Sun is covered with spots (Imperfect) that come
and go and the rotation is measured.• Jupiter has moons that clearly do not orbit the Earth.• He also found that the innermost moon was fastest
and they moved slower as they became farther away (just as Copernicus’ system)
• Saturn is not round (rings)• The Milky Way is the result of a larger number of stars
that are too faint too be seen by the eye.
Galileo Galilei• Galileo wrote a book
in Italian about the new evidence for the Copernican system.
• He ultimately faced the Inquisition and was force to renounce the Copernican system
Galileo Galilei• He was sentenced to
house arrest for the last ten years of his life.
• During that time he wrote his most complete argument for the Copernican system.
Johannes Kepler• 1571 to 1630• Kepler showed great
mathematical talent as a youth
• Studied at the University of Tubingen (in modern Germany)
• Became a professor at Graz
Johannes Kepler• Kepler was a member
of the Lutheran Orthodox church and even considered being ordained as a priest until his astronomy teacher convinced him to become a professor of mathematics
• Kepler had issues with his church much like Galileo.
Johannes Kepler• Kepler’s open minded
beliefs caused doubts among the clergy
• In 1612 he was excommunicated despite his position as the Imperial Mathematician (he replaced Tycho Brahae
• The ban was never lifted
Johannes Kepler• Kepler’s first
cosmological model was based on solid geometric shapes and met with good agreement of the orbits. 1596
• When Tycho Brahae received Kepler’s book Mysterium Cosmographicum he immediately hired Kepler!
Johannes Kepler• Tycho set Kepler on
the task of solving Mars’ orbit.
• Kepler used Tycho’s massive amount of planetary data to work out the three Laws of Planetary motion.
• The first two laws came quickly but the third took almost 10 years to complete
Johannes Kepler• At the core of Kepler’s
work is the undying belief in the Copernican Helio- centric system
• Kepler’s 1st Law – The orbits of the
planets are ellipse with the sun at one foci of the ellipse
Johannes Kepler
Johannes Kepler• Kepler’s 2nd Law• Planets sweep out
an equal area in equal time.
• This address the issue of planets moving at different speeds depending on what part of their orbit they were in and the systematic change in brightness
Johannes Kepler• Kepler’s 3rd Law• The square of the period
of a planet is proportional to the cube of its average distance from the Sun.
• T2 = k·r3
• This law took almost ten years to formulate and allows near perfect predictions of planet locations
Johannes Kepler• Kepler’s other scientific
contributions include error analysis, optics, Algorithms proof, early steps toward calculus, astronomical tables, astrology.
• He defended his mother in a witchcraft trial where she was later acquitted
Isaac Newton• 1643 to 1727• Born and raised on a
farm, Newton was relatively useless as a farm hand.
• He showed great promise in school and later attended Trinity college in London where he graduated with a degree in math in 1665
Isaac Newton• The college was shut
down for two years due to the plague so Newton returned home to the farm.
• Here he formulated some of his greatest achievements.
• These include:
Isaac Newton• The Law of Universal
Gravitation• Invention of Calculus• 3 Laws of Motion• Optical
advancements• Nature of light and the
spectrum
Isaac Newton• 3 Laws of Motion
1. All objects resist changes in their state of motion unless acted on by an outside net force (law of inertia)
Isaac Newton• 3 Laws of Motion
2. If an object is acted on by an outside net force, it will accelerate according to the following formula
a=F/m
Isaac Newton• 3 Laws of Motion
3. For every force there exists an equal and opposite force
often called
action-reaction law
Isaac Newton• Law of Universal
Gravitation• Newton’s great
revelation was that the same force that pulls an apple toward the surface of the Earth is the same force that holds the moon in orbit
Isaac NewtonGM1M2
F = ----------------- r2
Newton imagined a cannon fired from high mountain.With enough speed the falling cannon ball would match the curve of the earth and remain at the same height above the surface, returning to the cannon from the other side
Isaac Newton• After returning to
Cambridge University as a professor, He became the Lucasian Professor of Mathematics. 1669
• This position is held by Steven Hawking today
Isaac Newton• Newton was later hired
as the head of the British mint.
• He was in charge of finding and prosecuting counterfeiters
• He often went undercover and ultimately convicted more than 10 counter-feiters who were executed
Isaac Newton• Newton conducted hundreds of
experiments on light and discovered the origin of the spectrum created by prisms
• Newton also
invented the
reflecting
telescope
Isaac Newton• Much of Newton’s life was
filled with controversy.• He fought with many other
scientists and mathematicians over who was the discoverer of various ideas.
• These included Leibnitz (calculus) and Hooke (optics) and several others.
Isaac Newton• Newton is often credited as
the greatest scientist of all time.
• He impacted more areas of science and even invented an entire branch of mathematics called calculus.
• He was knighted among his many honors and served as president of the Royal Society (a scientific watchdog)
• He was ill for the last two years of his life and was buried in Westminster Abbey after his death.
Isaac NewtonFamous Quotes
“If I have seen further it is by standing on the shoulders of giants”
“I do not know what I may appear to the world, but to myself I seem to have been only like a boy playing
on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell
than ordinary, whilst the great ocean of truth lay all undiscovered before me”