Scientists of the Scientific Revolution

Clockwise from top: Kepler, Copernicus, Newton, Galileo, Descartes, and Ptolemy

The “Scientific Revolution”

Science Challenges the Old Ideas

Scientific Revolution” Helio-Centric Theory of the Universe

• Sun at the center of the universe,

with the planets orbiting the sun • Created by Nicholas

Copernicus (1473-1543),

a Polish astronomer

Early scientists

• Made significant contributions in astronomy, physics and math• Began to explain complexities of solar system, limits of physical world• Nicolaus Copernicus, Polish astronomer, among first

Copernicus’ theory

• Idea of earth orbiting sun was not completely new• Copernicus developed detailed mathematical explanation of process• Was first scientist to create complete model of solar system

Copernicus

• Found geocentric theory of movement of sun, moon, planets not accurate• Concluded sun, not earth, near center of solar system• Heliocentric theory, earth revolves around sun

Discoveries in Astronomy, Physics, and Math

Weaknesses of theory

• Mathematical formulas did not predict positions of planets well

• Copernicus did not want to be ridiculed for weaknesses

• Died 1543 after work published, other scientists expanded on ideas

On the Revolutions of the Heavenly Spheres

• Copernicus’ famous book not published until last year of his life

• Knew church would oppose work

• Work contradicted teachings of church

Nicholas Copernicus (1473-1543)

• Polish priest studied in Italy• returns to Poland and works on

Astronomy• writes De Revolutionibus Orbitum

Coelestitum (On the Revolutions of Heavenly Spheres)

• Earth is just another planet with a 24 hour rotation

• retains circular planetary motion (perfection of the sphere).

Copernicus• On the Revolutions of the Heavenly

Spheres.• Proposed a sun-centered view. (helio-

centric)• Universe consisted of 8 spheres. • Planets including earth rotated around the

sun but the moon revolved around the earth.

• Apparent revolution of the sun and stars around the earth was due to the rotation of the earth.

• Did not reject the Ptolemaic vision of the fixed spheres.

• His views did not make a big splash either pro or con, but there was growing dissatisfaction with the Ptolemaic view.

Nicolaus Copernicus(1473-1543)

• Polish astronomer and mathematician

• Introduced to scientific world when he attended the University of Krakow in Poland in 1492

• Appointed as a canon in the cathedral of Frauenburg where he remained for the rest of his life

• Rheticus, a student Copernicus took on in 1539, convinced Copernicus to allow him to publish his works before death

Copernicus’s Scientific Theories:

• Considered the founder of modern science

• Believed that the earth was round and the earth revolved around the sun (contrary to popular belief)– The heliocentric theory was not new, but Copernicus established the

mathematical basis

• To avoid the risk of persecution, excommunication, or imprisonment because his were revolutionary and contrary to church beliefs, Copernicus worked in privacy for more than 30 years; just before his death, friends helped to published his work

• Copernicus’s theory was first taught in several universities in the 1500s and permeated the scientific world by 1600

Copernicus Cont:• “Finally we shall place

the Sun himself at the center of the Universe. All this is suggested by the systematic procession of events and the harmony of the whole Universe, if only we face the facts, as they say, 'with both eyes open’.”- Copernicus

“The earth also is spherical, since it presses upon its center from every direction.”-Copernicus

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Nicolaus CopernicusThe Earth moves, in two ways.• It rotates on an axis (period = 1 day).• It revolves around the sun (period = 1 year).

The Copernican Universe

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The reasons for seasons – the Earth travels around the sun, and its axis of rotation is tilted by 23.5 degrees to the plane of the orbit. In July, the northern hemisphere is getting more sunlight than in January.

The heliocentric model

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The Copernican Model

Giordano Bruno: 1548 – 1600 AD

• Italian monk• Believed Copernicus

was right and that the earth revolved around the sun

• Believed the earth was alive because it moves through space

• Believed the universe is huge and everything is made up of atoms

• He did not do original research; just used reason and speculation.

• Bruno wandered around Europe teaching and writing for a living.

• He returned to Italy and found trouble

Bruno vs the Inquisition

• Bruno had been offered a teaching job in Venice and thought his employer would protect him.

• Instead, Bruno was arrested by the Inquisition for not supporting the Geo-Centric Theory

• After seven years in prison, Bruno was tried as a heretic.

• On February 6, 1600, he was burned at the stake for his scientific ideas.

Tycho Brahe(1546-1601)

• Danish astronomer• Established an observatory

to study heavenly bodies• Accumulated a lot of data

on planetary movements• His tables of astronomical

observation was used by Kepler to prove Copernicus’s

helio-centric hypothesis

Brahe Cont: • Believed that the development of astronomy relied on

accurate observation• Made lots of astronomical observation with the naked

eye• Built and calibrated numerous new instruments

including:• Created a domicile and observatory which he called

Uraniborg

Brahe Cont.

Uraniborg

Instrument to measure angles

Instrument for measuring altitude

Azimuth Quadrant made in 1577.

Brahe, Danish Astronomer• Wrote book proving bright object over Denmark sky was newly visible star• Called it supernova, distant exploding star suddenly visible on earth• Book impressed Denmark’s King Frederick II• Gave Brahe money to build two observatories

• Brahe used observatories

• Developed system to explain planetary movement

• Believed sun revolved around earth

• Other five known planets revolved around sun

Observations

• Hired as Brahe’s assistant to form mathematical theory from measurements of planets

• Published result of measurements of orbit of Mars after Brahe’s death

Kepler, German Mathematician

Brahe and Kepler

Johannes Kepler (1571-1630)

• Student of mathematics and astronomy• studied with Tycho Brahe• tested hypothesis after hypothesis until he

determined that planets move in ellipses• Three Laws of Planetary Motion

1 planets move in ellipses with sun as one focus2 velocity of a planet is not uniform3 equal area of the plane is covered in equal

time by the planets.

Johannes Kepler—(1571-1630)

• Built on the detailed observations of Tycho Brahe.

• Confirmed Copernicus’s heliocentric theory• Worked out the laws that governed planetary

motion.• Discovered that orbits were elliptical, not

circular.• Killed off the Ptolemaic theory of crystalline

spheres and a perfect heaven.• Opens the door to the question of what the

planets and stars are made of and what governs their motion.

Johannes Kepler(1571-1630)

• Used Brahe’s work to successfully prove Copernicus’s helio-centric model mathematically

• However, he disproved Brahe’s claim that planets move in circular motion – found that they move in ellipses

• Discovered that the speed of planets increase as they near the sun and decrease as they go away from it

• Discovered three laws of planetary motion– the planets orbit the sun in elliptical orbits; the sun is at one focus of

the ellipse– An imaginary line drawn from the center of the sun to the center of a

planet will sweep out equal areas in equal intervals of time– The ratio of the squares of the periods of any two planets is equal to he

ratio of the cubes of their average distance from the sun • Worked in optics, discovered two new regular polyhedra,

created the first proof of logarithms, and created a way to find the volume of solids of revolution (which influenced calculus)– Proof of logs based off of the work of Napier and Euclid

Kepler Cont.:

• Very religious (protestant); believed in Intelligent Design, and that God made the Universe according to a mathematical plan – Math was considered a way to find truth, so Kepler

thought that this gave man a way to find and understand the truth of the Universe

• Worked as an aide to Tycho Brahe and continued Brahe’s work and used it in his own work

• Established the idea of observational error

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Johannes Kepler (1571 – 1630) … discovered three empirical laws of planetary motion in the heliocentric solar system

1. Each planet moves on an elliptical orbit.2. The radial vector sweeps out equal areas in equal

times. 3. The square of the period is proportional to the cube

of the radius.

(needed for the CAPA)

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How did Kepler determine the planetary orbits?

Compare the heliocentric model to naked-eye astronomy

The most complete data had been collected over a period of many years by Kepler’s predecessor, Tycho Brahe of Denmark.

The inner planet is Earth; the outer one is Mars. Plot their positions every month. Mars lags behind the Earth so its appearance with respect to the Zodiac is shifting.

Earth

Mars

KEPLER

“And to us Jupiter, like Mars, and in the morning Mercury and Sirius, appeared four-cornered. And one of the diameters running between the corners was blue, the other red, in the middle the body was yellow, and amazingly bright.Account of personal observations...:”

Instrument to show relative distances of planets according to Copernican

System

Kepler’s Solution

Kepler solved main problem of Copernican theory

• Copernicus assumed planets orbited in circle

• Kepler found assumption untrue

• Proved planets orbited in oval pattern, ellipse

• Wanted to prove Copernicus wrong, instead proved heliocentric theory correct

• Kepler’s mathematical solar system model also correct

Galileo Galilei (1564-1642)

• Astronomy– used a telescope, proved the heavens are not perfect (craters on moon)– supported Heliocentric system

• Laws of Motion– dropping weights from the Tower of Pisa– imagined motion without constraint!!!!– Thought of inertia

• Problems with the church– argues for separation of science and theology because we are endowed with

reason– 1633 banned by Church and house arrest– must recant heliocentric system to save neck.

Reactions to Galileo

• Italy and Spain• More freedom in France, England and Holland• University of Padua was under Venice, the most anti-

clerical state in Europe; Copernicus, Galileo and Harvey studied there

• Protestants as hostile as Catholics on Biblical grounds, less state control in Protestant nations and in the end Protestant nations become more liberal than at first.

Galileo Galilei: 1564 – 1642AD

• Italian

• Was a Professor of Mathematics at Pisa University

• Became interested in science after reading the works of Copernicus and Bruno

• These books convinced him that the earth revolved around the sun.

• He also made huge discoveries in physics.

• He proved that a pendulum swings the same time no matter the size.

• He used mathematical rules to explain this; it was the first time math had been used to describe an object in motion.

Galileo• In 1609, he switched

from being a physicist to being an astronomer.

• He heard about the newly-invented telescope and built his own.

• He used it to discover 4 moons of Jupiter and the mountains on the moons.

• These discoveries proved once again that Aristotle’s theories were wrong.

• The moon wasn’t a perfect round ball as the ancient Greeks believed, but had bumps and craters.

Galileo Continued

• Watched as the planets Venus and Saturn travel around the sun

• This proved that the Earth was not the center of the solar system.

• Galileo wrote a book in 1610 about his discoveries

• This is where his trouble with the Catholic Church begins.

Galileo Galilei:• In 1609 Galileo built his own telescope to

observe the night skies • Galileo worked with Kepler who discovered

by using convex lens it would increase the magnification

• Galileo’s telescope developed in 1609, modeled based off other telescopes

• Could magnify three times more than other telescopes; his later telescope magnified twenty times

• He could see the moon, four satellites, a supernova, the phases of Venus, and sunspots

Galileo Galilei (1564-1642)• First European to make

systematic observations of the heavens using a telescope.

• Established that the planets were made of material stuff quite similar to the earth.

• The Starry Messenger. • Publicized the shift in scientific

thinking away from the Ptolemaic view.

Galileo Galileo (1564-1642)

• The Starry Messenger– Published in 1610– Stunned contemporaries and did more to make

Europe aware of the new picture of the universe than the mathematical theories of Copernicus and Kepler

• Galileo, the Church and Inquisition• Dialogue on the Two Chief World Systems:

Ptolemaic & Copernican• Placed under house arrest and during his final

eight years Galileo studied mechanics discovering the principles of inertia & force

Galileo’s Theories

• Brought him into direct conflict with the church• Church leaders pressured him not to support ideas of Copernicus• Dialogue concerning Two Chief World Systems, 1632, showed

support

House Arrest

• Galileo stated would not use Copernican theory in work• Received lenient sentence in return• Pope ordered Galileo under house arrest, where he spent rest of life

Trial

• Pope Urban VII ordered Galileo to Rome to stand trial before Inquisition• Church wanted to stamp out heresy, or dissenting views• Trial held, April 1633

Science and the Church

Galileo and the Church• In 1616, Galileo promised

to give up his ideas. • But he then published a

book making fun of the Catholic’s teaching of the Geo-Centric Theory.

• In his book, he uses a fictional dialogue or conversation to make fun of the Church.

• The character who backed the Church’s views was called Simplicius, which means stupid.

• In 1633 after a series of warnings against his teaching, Galileo was put on trial before the Inquisition

• The charge was heresy with the likely punishment of death

• He was 70 years old at the time

Galileo’s Letter to Castelli

“I am inclined to think that the authority of Holy Scripture is intended to convince men of those truths which are necessary for their salvation, and which being far above man's understanding cannot be made credible by any learning, or any other means than revelation by the Holy Spirit.  But that the same God has endowed us with senses, reason, and understanding, does not permit us to use them, and desires to acquaint us in any other way with such knowledge as we are in a position to acquire for ourselves by means of those faculties, that it seems to me I am not bound to believe, especially concerning those sciences about which the Holy Scriptures contain only small fragments and varying conclusions; and this is precisely the case with astronomy, of which there is so little that the planet are not even all enumerated....”

Galileo and the Church• Some historians

believe Galileo was tortured, because he suffered from weakened muscles in his gut from the stretching rack.

• Others say he was just shown the torture chamber to scare him.

• To save his life, Galileo confessed that the Earth did not go around the sun.

• According to legend, he muttered under his breath: “But it still moves.”

• He was sentenced to life imprisonment and ended up locked in his own home where he went blind and had to give up his scientific work.

Galileo the Heretic• Church found his findings

dangerous. Why?– Removed Humans from the center

of the earth, – Did away with the perfection of

circular orbits and – No longer had God in a fixed place.

• Inquisition condemns this view; he recants under pressure.

• Is placed under house arrest for the last 8 years of he life.

• Attitude of the church crimped further scientific inquiry into the heavens in Italy

Galileo + Church:• While at the University of Padua, Galileo became very much involved with

Copernicus’s heliocentric theory of the universe

• Galileo’s invention of the telescope enabled him to make observations that supported and proved the Copernican theory and encouraged him to publicly support it

• For this and for other letters, works, etc. that criticized the scripture as simply symbolical, Galileo was summoned to Rome where he was tried by the Inquisition in 1633

– They forced him to recant his belief in the Copernican Theories

• In April of 1633 Galileo is interrogated before the Inquisition. He agrees to plead guilty to a lesser charge in exchange for a more lenient sentence.

• Galileo was sentenced to house arrest in Siena

• Only in 1992 did the Church officially admit their mistake with the Galileo Trial

• The Trial caused fear among scientists and encouraged them to keep their findings from the Church and thus from the public

• In February 1632, Galileo published his book, Dialogue Concerning the Two Chief Systems of the World – Ptolemaic and Copernican

Galileo’s Forced StatementI, Galileo, son of the late Vincenzo Galilei, Florentine, aged seventy years, arraigned personally before this tribunal, and kneeling before you, Most Eminent and Reverend Lord Cardinals, Inquisitors-General against heretical depravity throughout the entire Christian commonwealth, having before my eyes and touching with my hands, the Holy Gospels, swear that I have always believed, do believe, and by God's help will in  the future believe, all that is held, preached, and taught by the Holy Catholic and Apostolic Church. But whereas -- after an injunction had been judicially intimated to me by this Holy Office, to the effect that I must altogether abandon the false opinion that the sun is the center of the world and immovable, and that the earth is not the center of the world, and moves, and that I must not hold, defend, or teach in any way whatsoever, verbally or in writing, the said false doctrine, and after it had been notified to me that the said doctrine was contrary to Holy Scripture -- I wrote and printed a book in which I discuss this new doctrine already condemned, and adduce arguments of great cogency in its favor, without presenting any solution of these, and for this reason I have been pronounced by the Holy Office to be vehemently suspected of heresy, that is to say, of having held and believed that the Sun is the center of the world and immovable, and that the earth is not the center and moves: 

Galileo’s Abjuration before the Inquisition, 1633

…because I have been enjoined, by this Holy Office, altogether to abandon the false opinion which maintains that the sun is the center and immovable, and forbidden to hold, defend, or teach, the said false doctrine in any manner… therefore, with a sincere heart and unfeigned faith, I abjure, curse, and detest the said errors and heresies, and generally every other error and sect contrary to the said Holy Church; and I swear that I will never more in future say, or assert anything, verbally nor in writing, which may give rise to a similar suspicion of me; but that if I shall know any heretic, or any one suspected of heresy, I will denounce him to this Holy Office, or to the Inquisitor and Ordinary of the place in which I may be.                                                   

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Galileo’s sketch of the moon as seen from his telescope

A photograph of the moon

“What do you think of the foremost philosophers of this university? In spite of my oft repeated efforts and invitations, they have refused, with the obstinacy of a glutted adder, to look at the planets or Moon or my telescope.” (letter to Kepler)

Galileo

• Scenes from the Trial of Galileo

Replica of Galileo’sTelescope

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Galileo made many specific discoveries in astronomy, through observations by telescope.

The general implications…

● The planets are objects like the Earth – masses – rather than some kind of special heavenly objects. Or, to put it another way, the Earth is just another planet.

● The planets, including Earth, travel around the sun.

● The Universe is a lot bigger than we can see by the naked eye.

These ideas could be dangerous.

Galileo’s conflict with the Church: Can questions about the natural world be settled by the Bible? Or must they be settled by the best empirical and mathematical methods of science?

Are we free to investigate nature, or must we be constrained by religious authority?

The book of God: The history of God and his creation, written in a language for general human comprehension

The book of Nature: The natural world itself, revealing its laws in the phenomena--

--but written in the language of mathematics.

Galileo on science and Scripture:

I think it would be the part of wisdom not to allow any one to apply passages of Scripture in such a way as to force them to support as true any conclusions concerning nature, the contrary of which may afterwards be revealed by the evidence of our senses, or by actual demonstration. Who will set bounds to man's understanding ? Who can assure us that every thing that can be known in the world is known already ?

Galileo on science and Scripture (continued)

. . . I am inclined to think that Holy Scripture is intended to convince men of those truths which are necessary for their salvation, and which being far above man's understanding cannot be made credible by any learning, or by any other means than revelation. But that the same God who has endowed us with senses, reason, and understanding, does not permit us to use them, and desires to acquaint us in another way with such knowledge as we are in a position to acquire for ourselves by means of those faculties— that, it seems to me I am not bound to believe…

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The observed solar system at the time of Newton

SunMercuryVenusEarthMarsJupiterSaturn

(all except Earth are named after Roman gods, because astrology was practiced in ancient Rome)

Three outer planets discovered later…Uranus (1781, Wm Herschel)Neptune (1846 Adams; LeVerrier) Pluto (1930, Tombaugh)

William Herschel: 1782 and Caroline Herschel: 1750 – 1848AD

• Became Britain’s top astronomer

• Discovered the planet Uranus

• Found many types of new stars and comets

• 1783: Found a new type of light called infrared

• His sister, Caroline, helped her brother make the lenses for telescopes and kept his daily records.

• She went on to discover seven comets and to list all the main stars. This became a vital source of information for astronomers.

• She was awarded many medals by the Royal Astronomical Society and the King of Prussia

William and Caroline

Scientific Method

The Scientific Method

• The scientific method is a process whereby scientists observe nature and make hypotheses (educated guesses).

• Scientists then test their hypotheses through experiments.

• A scientist must prove his hypothesis or he cannot claim it is true.

Scientific Method

• During the Scientific Revolution, people were concerned about how they could best understand the physical universe.

• They created the scientific method. The philosopher Francis Bacon was most responsible for this method.

The Scientific Method

• Francis Bacon – Englishman with few scientific credentials– Devised a system or scientific method that was built

on inductive principles• Rene Descartes’ Emphasis on Deduction and

Mathematics – Conversely, Descartes argued for an approach that

emphasized deduction and mathematical logic– He believed that one could start with self-evident

truths, comparable to geometrical axioms, and deduce more complex conclusions

The Scientific Method

• In the course of the Scientific Revolution, attention was also paid to the problem of establishing the correct means to examine and understand the physical realm

• Therefore, the development of a scientific method was crucial to the evolution of science in the modern world

Isaac Newton’s Synthesis of Bacon and Descartes

• Isaac Newton then synthesized these two systems into a simple scientific methodology uniting Bacon’s empiricism with Descartes’ rationalism

• This scientific method began with systematic observations and experiments, which were then used to arrive at general concepts

• New deductions derived from these general concepts could then be tested and verified by precise instruments

• Francis Bacon, experimentation to gain scientific knowledge

• Rene Descartes, reason key

• Believed everything should be doubted until proved by reason

• Relied on math, logic

• Ideas of both continue to influence modern scientific methods

Scientific Method Scholars

• Scientific Method

• Identify problem

• Form hypothesis

• Perform experiments to test hypothesis

• Record results

• Analyze results, form conclusion

New Approach to Investigation

The Scientific Method

Scientific Method• Bacon emphasized

arriving at conclusions about nature using inductive reasoning, or making generalizations from particular observations and experiments organized to test hypotheses.

Scientific Method

• He believed science was to give human kind new discoveries and the power to serve human purposes by conquering “nature in action.”

• The control and domination of nature became an important concern of science and its accompanying technology.

Francis Bacon (1561-1626)

• Proposed INDUCTION– make a lot of observations then generalize rules of

nature - this leads to scientific observation as a method

• Promoted the modern idea of progress because he wanted application of science

• Problem of Induction– there is no logical reason to go argue from any

amount of experience to a general law.

Francis Bacon• Considered the father of scientific

method. • Great Instauration • Wanted human knowledge to be

built on inductive reasoning.– scientific inquiry should proceed from

the specific to the general.– Should make observations and

experiments and draw conclusions based on those observations.

– He called on science to produce practical inventions that would aid business, industry, agriculture and trade.

Francis Bacon: 1561 – 1626 AD

• English• Lawyer who served

Elizabeth I and James I

• In 1621 he was made Lord Chancellor (top lawyer) and then removed for taking bribes

• He then turned his attention to science.

• Wrote a book stating that knowledge about the world should not depend on the ancients like Aristotle

Francis Bacon continued

• He said that scientists should:– Develop own ideas– Build up evidence– Observe– Conduct experiments– Prove if the ideas were true or false

Scientific Method: Francis Bacon

• English professor who believed that ideas based solely on tradition should be discarded completely

• Helped to develop the scientific method • Dedicated to replace and restructure education and

science• Named three “distempers” – diseases, of learning,

eleven errors – “peccant humours”, four “Idols”, three primary mental facilities, etc.

• Was also a lawyer, statesman, essayist, historian, intellectual reformer, and philosopher

Francis Bacon (1561-1626)

• Father of the Scientific Revolution

• The Inductive Method• Emphasis on

practical, useful knowledge

• New attitude toward nature

Bacon Cont.

“No pleasure is comparable to the standing

upon the vantage-ground of truth.”- Of Truth.

“Some books are to be tasted, others to be swallowed, and some few to be chewed and digested.”         

-Of Studies.

THE SCIENTIFIC REVOLUTION

PHILOSOPHICAL THOUGHT

FRANCIS BACON (1561-1626)

Inductive reasoning: working from particular to general conclusions

Empiricism & scientific method

Francis Bacon: 1561-1626

Bacon's Philosophy:Francis Bacon's major contribution to philosophy was his application of induction, rather than the a priori method of medieval scholasticism.

Rene Descartes (1596-1650)

• Significance of Doubt• The Deductive

Method• Spatial relationships

can be expressed in mathematical formulas

• Father of “analytical geometry”

Rene Descartes(1596-1650)

• Great mathematician - showed that any algebraic equation could be plotted on a graph

• In this manner he linked Greek with Hindu and Arabic knowledge

• Also looked at DEDUCTION - go from a theory to the facts

• Only wants what is absolute “Cogito ergo sum” I think therefore I am

• leads to proof of God.

Descartes

• In his Discourse on Method (1637) he asserts that he can rationally be sure of only one thing—his own existence.

• He asserted he would accept only those things his reason said were true.

• Descartes asserted that while he could not doubt the existence of his mind—”I think, therefore I am”—he could doubt the existence of the material world.

Descartes

• He concluded that the material world and the mental world were two different realms.

• He separated mind and matter. • This made matter something inert and

independent of the observer that could be investigated by a detached rationality.

• Descartes has been called the father of modern rationalism.

• This system of thought is based on the idea that reason is the chief source of knowledge.

René Descartes (1596-1650)

• The fundamentally new conception of the universe was bound to have an impact upon the Western view of mankind

• Nowhere is this more apparent than in the works of Rene Descartes whose philosophical system would dominate Western thought until the 20th century

• He set out his philosophical system in his book Discourse on Method

• Descartes decided to set aside all that he had learned and begin again, though one fact above all seemed beyond doubt to him – his own existence, “I think, therefore I am”

Descartes • Rene Descartes (1596-1650)• Father of modern rationalism. • Philosophy: base all beliefs on

logic and observation and abandon all assumptions.

• Basic idea: accept only those things that can be proven through reason.

• Central thesis: distinction between mind and matter, which he saw as fundamentally different. – Cartesian Dualism.

• His books were banned by the Inquisition

“I think, therefore I am”

René Descartes (1596-1650)

• With this emphasis upon the mind, Descartes asserted that we could accept only those things which our reason said were true

• Moreover, from this first postulate Descartes deduced a second principle, the separation of mind & matter

• Matter now became something totally separate and could now be investigated independently by reason

• Additionally, this split would have major implications not just for traditional religious views of the universe, but also how Westerners saw themselves

Rene Descartes

• French philosopher and mathematician• Thought that truth could be found through

reason • Inventor of analytic geometry• Saw mathematics as the perfect model for

clarity and comprehension• Published Discourse on Method in 1637 that

explained his philosophy • Famous for the quote “I think therefore I am”

Descartes Cont.

“Cogito ergo sum”(I think; therefore I am) -Rene Descartes

If you would be a real seeker after truth, it is necessary that at least once in your life you doubt, as far as possible, all things.

-Rene Descartes

THE SCIENTIFIC REVOLUTION

PHILOSOPHICAL THOUGHT

RENÉ DESCARTES (1596-1650)

Geometry: any algebraic formula could be plotted as curve in space

Cartesian Dualism: division of reality into “thinking substance” & “extended substance”

Deductive Reasoning: starting with general assumptions & working downward

Descartes was of the belief that science should be grounded, not in observation and prediction, as Bacon thought, in absolute certainty. He used three principles to describe his philosophy.

Physics

Galileo• At age 19, Galileo discovered the pendulum,

the basis for later clocks• Galileo questioned Aristotelian physics and

performed many of his own experiments, especially with gravity; his work on physics summarized in De Moto

• Most optical telescopes used today derive from the two types of telescopes developed in the 17th century by Galileo and Newton, which amateur and professional astronomers use today

THE SCIENTIFIC REVOLUTION

NEW DIRECTIONS IN ASTRONOMY & PHYSICS

GALILEO GALILEI (1564-1642)

Constructed first telescope

Described motion of bodies on earth

Isaac Newton (1642-1727)

• Possibly the greatest scientist who ever lived - born on the day Galileo died

• math/physics/astronomy• author of Principia Mathematica in

1687– bringing together Galileo’s discoveries

about motion on Earth and Kepler’s discoveries in the heavens

– to do so he had to develop calculus

• explained heavenly motion that was tied to observed motion on Earth.

Isaac Newton

• Provided a synthesis superior to Aristotle

• notion of inertia - only have to explain change

• Three Laws of Motion

Nature and nature’s laws lay hid in nightGod said, “Let Newton be.” and all was light - Pope.

1 Bodies move in straight lines unless impeded (inertia)

2 Every action has an equal and opposite action

3 every body attracts every other body with a force proportional to the distance between

Isaac Newton (1643 - 1727)

-Wrote “Principia Methematica” which contained mathematicalDescriptions of how the world works (up to the speed of light, asEinstein later proves…)

Law 1: Every object continues in its state of rest or of uniform motion in a straight line, unless it is compelled to change that state by forces impressed upon it.  

Law 2: The acceleration of an object is directly proportional to the net force acting on the object, is in the direction of the net force, and is inversely proportional to the mass of the object.  

Law 3: Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first.

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To explain the motion of the planets, Newton developed three ideas:

1. The laws of motion2. The theory of universal gravitation3. Calculus, a new branch of mathematics

Newton solved the premier scientific problem of his time --- to explain the motion of the planets.

Isaac Newton

“If I have been able to see farther than others it is because I stood on the shoulders of giants.”

--- Newton’s letter to Robert Hooke,perhaps referring to Galileo and Kepler

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Isaac Newton• Mathematical theories explained the

observed motions of the planets. • Considered the greatest scientific

genius until Einstein.• 1684-wrote his major work,

Mathematical Principles of Natural Philosophy

• Theory of gravitation. – Planets bound to the sun by gravitation – Basic force of gravitation and – proved that it explained the motions of

the planets.

Newton’s Beliefs

• 1665: Newton developed calculus

• 1664-1666: Discovered that light is made up of different colors by passing sunlight through a prism

• 1666: Began to develop the theory of gravity

• 1687: Wrote a book on gravity and the laws that make objects move---Principia

Physics: Isaac Newton • English scientist who used the scientific method in science and

mathematics • He was a below average student at the University of Cambridge that

was helped by a tutor who recognized his talent• Newton studied the works of Copernicus and Galileo• In 1665, the plague forced Newton back to rural family farm• There he continued to study and created his theory of gravity• In 1687, Newton published his theories of gravity, etc. in his book

Mathematical Principles of Natural Philosophy aka Principia in which he expanded the theories of Copernicus, Galileo, and Kepler-explained Newton’s theory of universal gravitation-Newton developed calculus in order to prove his theory of gravity

The legend is that Newton saw an apple fall in his garden, thought of it in terms of an attractive gravitational force towards the earth, and realized the same force might extend as far as the moon.

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Newton’s Theory of Universal GravitationNewton and the Apple

(The apple never fell on his head, but sometimes a stupid person will say that, trying to be funny.)

Newton asked good questions the key to his success.

Observing Earth’s gravity acting on an apple, and seeing the moon, Newton asked whether the Earth’s gravity extends as far as the moon.

Newton Cont.

Original copy of Newton’s Principia

Replica of Newton’s Refracting telescope

“To explain all nature is too difficult a task for any one man or even for any one age. `Tis much better to do a little with certainty, and leave the rest for others that come after you, than to explain all things.” - Newton

“...from the same principles, I now demonstrate the frame of the System of the World”Principia Mathematica. Hypotheses non fingo.

“I feign no hypotheses”Principia Mathematica.

If I have seen further it is by standing on the shoulders of giants.

Isaac Newton, Letter to Robert Hooke, February 5, 1675

Newton’s Findings

Newton developed calculus, new kind of math

• Used calculus to predict effects of gravity

• German philosopher Gottfried von Leibniz also developed calculus at same time

• Each accused the other of plagiarism

• Historians believe it was simple case of independent discovery

Isaac Newton and Universal Physics

• The implications of Newton’s law were enormous for he demonstrated with one universal law, mathematically proved, that all motion in the universe, from the movements of the planets to an apple falling off a tree, could be explained

• This Newtonian synthesis created a new cosmology in which the world was largely seen in mechanistic terms

• Would remain the dominant cosmology until Einstein’s concept of relativity

Michael Faraday: 1791 – 1867AD

• English• Attended the lectures

at the Royal Institution

• 1825: discovered benzene when looking at the ingredients of oil from a dead whale

• Did experiments with electricity

• In 1831, Faraday discovered electromagnetic induction, the principle behind the electric transformer and generator.

• discovery was crucial in allowing electricity to be transformed from a curiosity into a powerful new technology.

• During the remainder of the decade he worked on developing his ideas about electricity.

• He was partly responsible for coining many familiar words including 'electrode', 'cathode' and 'ion'

Michael Faraday

Henry Cavendish

• Experimented with electricity

• Tested the electric current by giving himself shocks and noting the pain he felt

• In 1747, Henry Cavendish started measuring the conductivity (the ability to carry an electrical current) of different materials and published his results.

Henry Cavendish• Cavendish had the ability to make a seemingly limited

study give far-reaching results. • An example is his study of the origin of the ability of

some fish to give an electric shock. He made up imitation fish of leather and wood soaked in salt water, with pewter (tin) attachments representing the organs of the fish that produced the effect.

• By using Leyden jars (glass jars insulated with tinfoil) to charge the imitation organs, he was able to show that the results were entirely consistent with the fish's ability to produce electricity.

• This investigation was among the earliest in which the conductivity of aqueous (in water) solutions was studied.

Anatomy and Medicine

History of Medicine

• Renaissance (1400 - 1800)– The invention of the printing press - ideas could be spread

quickly and cheaply.– The revival of classical learning - scholars went back to the

original Greek and Roman texts. These reminded scientists to observe nature closely and make theories that explained the world.

– The Church was criticized for the first time - people challenged old ideas and established authorities. In the Reformation the Catholic Church lost its hold over many countries, as well as universities and education. People became less willing to accept the Church's rulings about issues such as dissection.

– Voyages of exploration - people traveled more and had greater contact with other societies. New ideas and attitudes were brought into Europe. New drugs were introduced, such as quinine, which could be used against malaria.

Leonardo Da Vinci (1452 to 1519)

Artists in Renaissance period interested in human form, so studied anatomy.

Da Vinci made hundreds of anatomically correct drawings.

He dissected bodies in secret.

Just as astronomers moved away from the works of ancient Greeks, other scientists used the scientific method to acquire new knowledge and make great discoveries in the fields of Biology and Chemistry.

• European Middle Ages doctors relied on Greek, Galen

• Galen’s works inaccurate

• Flemish doctor Andreas Vesalius became known for work in anatomy

Biology• Used bodies of

executed criminals for dissection

• Hired artists to produce accurate drawings

• On the Workings of the Human Body, 1543

Vesalius

• English physician, early 1600s

• Observed, explained workings of human heart

• Described blood, circulatory system functions

William Harvey

Discoveries in Biology and Chemistry

Robert Hooke

• English physician, inventor

• Used early microscope to describe appearance of plants at microscopic level

• Credited with creating the term cell

Antony van Leeuwenhoek

• Dutch scientist, 1600s

• Used interest in developing magnifying lens to invent microscope

• First to describe appearance of bacteria, red blood cells, yeast, other microorganisms

Scientific Revolution: Paracelsus: Philippus Aureolus Theophrastus

Bombastus von Hohenheim• 1493 to 1541 AD• Swiss• One of the first to

challenge the ideas of Galen

• Said that people could only learn by experience

• So when he became a teacher, he burned the books of Galen

• He was the first to realize that poisoning could causes diseases like breathing metal vapors

• He was the first to think of chemicals as medicine

• Unfortunately his favorite medicine was mercury, so he actually poisoned the people he was trying to heal

Paracelsus (1493-1541)• Rejected the work of both

Aristotle and Galen• Replace the traditional system

with a new chemical philosophy based upon a new understanding of nature derived from fresh observation & experiment

• Believed disease was caused by chemical imbalance in the organs which could be solved by chemical remedies

• Although chemical remedies had been used, Paracelsus and his followers differed by giving careful attention to the proper dosages of their chemically prepared metals & materials

Andreas Vesalius: 1514 - 1564

• Belgian

• Proved Galen wrong by stealing bodies and dissecting them

• Grave-robbing for corpses became common

Andreas Vesalius (1514 to 1564)

Barber surgeon (combination barber, dentist, doctor).

Got special permission from the Pope to dissect criminals.

First scientist to understand human anatomy.

Wrote the first accurate book on human anatomy – Fabrica.

Shortage of cadavers

• In England and Scotland, medical schools began to open.

• No one donated bodies to science – churchgoers believed in literal rising from grave, so dissection spoiled chances of resurrection.

• Became a tradition to rely on executed prisoners, even up to 18th and 19th centuries.

Serious Crimes

• The added punishment of being dissected after death was considered another deterrent from crime.

• Ex. – Steal a pig: you were hung• Kill a person: you were

hung and dissected• Anatomists were often associated

with executioners.

• Because they needed body parts, anatomists at medical school bought odd things.

• A man could sell the leg of his son if it had to be amputated

Grave Robbing

• Some medical students raided grave yards; some professors did also.

• In certain Scottish schools in 1700s, you could trade a corpse for your tuition.

Resurrectionists• By 1828 in London, body snatchers

(or resurrectionists) provided the medical schools with corpses.

• Not a crime; a dead body could not be owned or stolen.

• (Anatomy studies were only conducted from October to May to avoid stench of decomposition.)

• Wealthy people chose to be buried in iron cages, some covered in concrete.

• Also churches built “dead houses” which were locked and guarded.

The Body in the Scientific Revolution

A New Doctor – A New BodyAndreas Vesalius (1514-1564)

• Dutch-born Physician• Taught medicine at University of Padua (Italy)

• 1543 –Publishes new textbook on anatomy, On the Workings of the Human Body • Same year Copernicus publishes On the Revolutions of the Heavenly Spheres

•Textbook attacks many of the established theories of Aristotle and Galen on the basis of Vesalius’s own dissections. • Book is illustrated with detailed printed images.

Andreas Vesalius:(1514-64)

• Belgian anatomist and physician whose work help correct many of the misconceptions of the time

• Dissected actual human bodies, in a belief that Galen’s work was inaccurate because it was based on animals

• Published his finding in 1543 in On The Structure of the Human Body

• wrote De Humani Corporis Fabrica (On the Structure of the Human Body) – seven volumes on the structure of the human body which he illustrated himself

– These were the most accurate and comprehensive anatomical texts at the time

Appointed as physician to the Holy Roman Emperor Charles V.

• Images from Vesalius’s

book

Vesalius

Andreas Vesalius

• The new anatomy of the sixteenth century was based on the work of Andreas Vesalius.

• He reported his results from dissecting human bodies as a professor of surgery at the University of Padua, presenting an accurate view of the individual organs and general structure of the human body.

• He erroneously believed that the body had two kinds of blood

Andreas Vesalius (1514-1564)

• His studies corrected Galen in relation to anatomy - believed practical research as the best way for understanding human anatomy

• 1543 published On the Fabric of the Human Body– Based upon his lectures at Padua– Deviated from traditional practice by personally dissecting a

body to illustrate what he was discussing• Through his “hands-on” approach, Vesalius rectified

some of Galen’s more glaring errors• For example, the belief that the great blood vessels

originated from the liver, but he still clung to Galen’s belief about the ebb & flow of two kinds of blood in the veins and arteries

The Body in the Scientific Revolution

An anatomy lesson from the title page of Vesalius’s book.

Giovanni Morgagni: 1682 – 1771AD

• Italian

• Studied the effects of disease on the body’s insides

• Published a big book listing the effects of diseases on the body’s organs

• Proved the ancient doctors wrong and that death was caused by damage to organs and not by humours

William Harvey:• English Physician• Also disproved many of Galen’s hypotheses• discovered the circulation of blood, the function of valves in

the heart• Worked with small animals and with humans• Published his observations in Exercitatio Anatornica de Moto

Cordis et Sanguinis in Animalibus aka De Moto Cordis• Discovered the lack of circulation to the lungs in the fetal

stage and therefore that lungs were collapsed and inactive in this phase

• Largely influenced by the mechanical philosophy in his work with the flow of blood

• First doctor to use quantitative and observational methods in his experiments

• Very skeptical of spontaneous generation; proposed that all animals originated from an egg

“[The heart] is the household divinity which, discharging its function, nourishes, cherishes, quickens the whole body, and is indeed the foundation of life, the source of all action” - Harvey

Harvey

William Harvey

• He also showed that the same blood runs through veins and arteries and that the blood makes a complete circuit through the body.

• Harvey’s work was based on close observation and experiment.

William Harvey and the Human Blood System

• It was only with the discoveries of William Harvey that this belief was corrected

• Through his research & observations, Harvey demonstrated that the heart, not the liver, was the beginning point of circulation of blood in the body, that the same blood flows in both veins and arteries, and most important, blood makes a complete circuit as it passes through the body

The Body in the Scientific Revolution

From Observation to Experimentation

William Harvey’s experiments to demonstrate the circulation of blood (1628).

This illustrates an experiment to show that blood in the veins only flows toward the heart because of valves that stop blood from flowing back away from it.

Edward Jenner: 1749 - 1823• Developed the first vaccination in 1796

• It was to treat smallpox.

• His vaccine used smallpox pus from the less deadly disease cowpox.

• by 1800 most were using it. Jenner was awarded £30 000 by Parliament to enable him to continue carrying out his tests.

• Deaths from smallpox plummeted and vaccination spread through Europe and North America.

• Jenner worked in a rural community and most of his patients were farmers or worked on farms with cattle.

• In the 18th century smallpox was a very common disease and was a major cause of death.

• The main treatment was by a method which had brought success to a Dutch physiologist Jan Ingenhaus and was brought to England in 1721 from Turkey by Lady Mary Wortly Montague.

• This method involved inoculating healthy people with substances from the pustules of those who had a mild case of the disease, but this often had fatal results

• In 1788 an epidemic of smallpox hit Gloucestershire and during this outbreak Jenner observed that those of his patients who worked with cattle and had come in contact with the much milder disease called cowpox never came down with smallpox. Jenner needed a way of showing that his theory actually worked.

• Jenner was given the opportunity on the 14 May 1796, when a young milkmaid called Sarah Nelmes came to see him with sores on her hands like blisters.

• Jenner identified that she had caught cowpox from the cows she handled each day.

• Jenner now had the opportunity to obtain the material try out his theories. He carefully extracted some liquid from her sores and then took some liquid from the sores of a patient with mild smallpox.

• Jenner believed that if he could inject someone with cowpox, the germs from the cowpox would make the body able to defend itself against the dangerous smallpox germs which he would inject later.

• Jenner approached a local farmer called Phipps and asked him if he could inoculate his son James against smallpox.

• He explained to the farmer that if his theory was correct, James would never contract smallpox. Surprisingly, the farmer agreed.

• Jenner made two small cuts on James's left arm.

• He then poured the liquid from Sarah's cowpox sores into the open wounds which he bandaged.

• James went down with cowpox but was not very ill.

• Six weeks later when James had recovered, Jenner vaccinated him again, this time with the smallpox virus.

• This was an extremely dangerous experiment. If James lived Jenner would have found a way of preventing smallpox. If James developed smallpox and died he would be a murderer.

History of Medicine 1800s

• Florence Nightingale (1820 - 1910)– In 1854 Florence Nightingale took 38 women to Turkey to nurse

wounded and sick British soldiers in the Crimean War. This was the first time the government had allowed women to do this.

– She suffered from PTSD (Post Traumatic Stress Disorder) for the rest of her life. She became not only the first modern war nurse and nurse commander but its first documented psychological casualty.

– She publishes a small booklet titled "Notes on Nursing." It is very popular. It is expanded and published again in 1860 and in 1861 with special section on taking care of babies. This book sold millions all over the world: the only money she ever earned in her life was her royalties from this book.

– This book establishes the foundation for the nursing profession

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History of Medicine 1800s• Louis Pasteur (1822 - 1881)

– He proved that air contains living organisms (bacteria)– That these microbes can produce putrefaction– That these microbes could be killed by the heating of the

liquid they were in - sterilization by high temperature -> Pasteurization

– He proved that the old idea that diseases start out of nothing (spontaneous generation) was inaccurate and that micro-organisms cause disease.

– Demonstrates the presence of bacteria in air and explains how disease can be transmitted by airborne route.

Louis Pasteur: 1822 – 1895AD

• French• Developed the theory

that the bacteria we call germs caused disease and not bad smells

• Found out how to preserve wine by heating it to kill germs---pasteurization

• Found the causes of anthrax and cholera

• Discovered how to weaken germs by heating them up until they are damaged and can no longer multiply

• He used this to develop vaccinations for rabies

Biology

Robert Hooke: • Discovered the cell – cork tissue using a newly invented

microscope; called them cells because they reminded him of the cells of a monastery

• Published his book Micrographia in 1665• Created the compound microscope and illumination system

– Used it to observe such organisms as insects, sponges, bryozoans, foraminifera, bird feathers, etc.

• Observed fossils under the microscope and noted the similarities between petrified wood and real wood and created the theory that fossils are forms of animals

• Published two years after his death, Hooke’s Discourse of Earthquakes in which he explained that fossils found in inland regions are a result of times when that land was under water

Cork Seen Through Microscope

Hooke:

Objects the Hooke

observed under the microscopeHooke’s compound

microscope

“1 The truth is, the science of Nature has been already too long made only a work of the brain and the fancy: It is now high time that it should return to the plainness and soundness of observations on material and obvious things. “ - Hooke

Antony van Leeuwenhoek:(1632-1723)

• Inspired to take up microscopy by Hooke’s Micrographia

• Made over 500 microscopes, but only ten have survived to this day

• Leeuwenhoek was very skillful at grinding lenses and was able to use this skill to magnify objects over 200 times

• Hired an illustrator to create drawing of what he saw under his microscopes

• In 1673, Leeuwenhoek began to write letters to the Royal Society of London in which he described his findings under the microscopes – he would correspond with this organization for the next fifty years; his letters were collected and printed in the Philosophical Transactions of the Royal Society

• Observed lake water and discovered numerous types of algae and other small organisms

• Observed plaque from human teeth – the first known observation of living bacteria

• Leeuwenhoek observed animal and plant tissues, mineral crystals, and fossils

Leeuwenhoek:

• “. . . my work, which I've done for a long time, was not pursued in order to gain the praise I now enjoy, but chiefly from a craving after knowledge, which I notice resides in me more than in most other men. And therewithal, whenever I found out anything remarkable, I have thought it my duty to put down my discovery on paper, so that all ingenious people might be informed thereof. “ - Leeuwenhoek

Daphnia, small organism that Leeuwenhoek found in lake water

Example of Leeuwenhoek’s microscopes

Maria Merian: 1647 – 1717AD

• Dutch• Studied plants and

animals• Wrote a book of

drawings of insects in various stages of development

• Went to Surinam in South America to study insects

• Fell ill with malaria and her health was never strong again

• Her book on Surinam insects was published in 1705AD

• First time European scientists were able to see South American insects

Carl Linnaeus

• Linnaeus was born in 1707, the son of a Lutheran clergyman, at Rashult in Sweden.

• He began to study medicine at the University of Lund in 1727, transferring to the university of Uppsala the following year.

• Linnaeus headed an expedition to Lapland in 1732, travelling 4,600 miles and crossing the Scandinavian Peninsula by foot to the Arctic Ocean.

• On the journey he discovered a hundred botanical species.

• In 1734, he mounted another expedition to central Sweden.

• He finished his medical degree at the University of Hardewijk in Holland in 1735, then going to the University of Leiden for further studies.

• That year, he published Systema Naturae, his classification of plants based on their sexual parts

Carl Linnaeus

• His method of binomial nomenclature using genus and species names was further expounded when he published Fundmenta Botanica and Classes plantarum.

• This system used the flower and the number and arrangements of its sexual organs of stamens and pistils to group plants into twenty-four classes which in turn are divided into orders, genera and

species.

• In his publications, Linnaeus provided a concise, usable survey of all the world's plants and animals as then known, about 7,700 species of plants and 4,400 species of animals.

• These works helped to establish and standardize the consistent binomial nomenclature for species which he introduced on a world scale for plants in 1753, and for animals in 1758, and which is used today.

Carl Linnaeus• His Species Plantarum 10th edition,

volume 1(1758), have accordingly been accepted by international agreement as the official starting points for botanical and zoological nomenclature.

• Scientific names published before then have no validity unless adopted by Linnaeus or by later authors.

• This confers a high scientific importance on the specimens used by Linnaeus for their preparation, many of which are in his personal collections now treasured by the Linnean Society.

• Twenty-three of Linnaeus' students themselves became professors and this spread his methods widely, as did his extensive correspondence with leading naturalists all over Europe.

• In the mid-1700s, the Swedish biologist, Carolus Linnaeus, shortened the long descriptive terms for each organism to a binomial system, using only the genus (group) and species (individual kind) name. For example, the two oaks shown below belong to the genus Quercus (always italicized or underlined) for oaks, and phellos or rubra (always in lower case italics or underlined), for the willow or red oak

Charles Darwin: 1809 – 1882 AD

• British• Studied medicine and

to be a priest for the Anglican Church

• Spent most of his time collecting beetles and butterflies

• Went on a scientific expedition on the Beagle voyage

• From his observations, he developed the theory of evolution.

• Famous Evidence: the tortoises of the Galapagos Islands in the Pacific

“I have called this principle, by which each slight variation, if useful, is

preserved, by the term Natural Selection.”- CHARLES DARWIN

• Darwin was the British naturalist who became famous for his theories of evolution and natural selection.

• Like several scientists before him, Darwin believed all the life on earth evolved (developed gradually) over millions of years from a few common ancestors.

• From 1831 to 1836 Darwin served as naturalist aboard the H.M.S. Beagle on a British science expedition around the world.

•

• In South America Darwin found fossils of extinct animals that were similar to modern species.

• On the Galapagos Islands in the Pacific Ocean he noticed many variations among plants and animals of the same general type as those in South America.

• The expedition visited places around the world, and Darwin studied plants and animals everywhere he went, collecting specimens for further study.

• Upon his return to London Darwin conducted thorough research of his notes and specimens.

• Out of this study grew several related theories:

• one, evolution did occur; • two, evolutionary change was

gradual, requiring thousands to millions of years;

• three, the primary mechanism for evolution was a process called natural selection;

• and four, the millions of species alive today arose from a single original life form through a branching process called “speciation.”

• Darwin's theory of evolutionary selection holds that variation within species occurs randomly and that the survival or extinction of each organism is determined by that organism's ability to adapt to its environment.

• He set these theories forth in his book called, On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life (1859) or “The Origin of Species” for short.

• Darwin's work had a tremendous impact on religious thought.

• Many people strongly opposed the idea of evolution because it conflicted with their religious convictions.

• Darwin avoided talking about the theological and sociological aspects of his work, but other writers used his theories to support their own theories about society.

• Darwin was a reserved, thorough, hard working scholar who concerned himself with the feelings and emotions not only of his family, but friends and peers as well.

• It has been supposed that Darwin renounced evolution on his deathbed. Shortly after his death, temperance campaigner and evangelist Lady Elizabeth Hope claimed she visited Darwin at his deathbed, and witnessed the renunciation.

• Her story was printed in a Boston newspaper and subsequently spread. Lady Hope's story was refuted by Darwin's daughter Henrietta who stated, “I was present at his deathbed ... He never recanted any of his scientific views, either then or earlier.”

Charles Darwin

• Many people felt Darwin’s ideas clashed with the Bible’s story of Genesis

• Debate 1860 in Oxford: the Bishop of Oxford made a speech attacking Darwin

• Thomas Huxley defended Darwin’s ideas

• Unfortunately, people missed the important point of Darwin’s work that he said young animals inherit their features from their parents but he did not have the evidence for it

Darwin’s Theory of Evolution Challenged Christian Ideas

The value of human beings: made in God’s image just another animal

The purpose of human beings: part of God’s Plan accidental without purpose

The eternal future of human beings: eternal soul this life only

Varied Responses to Darwin

• The Science vs Religion Battle over-simplifies responses to Darwin

• Many Christians welcomed and supported Darwin’s ideas from the start

Varied Responses to Darwin1. Some Christians abandoned their faith

a. Industrialisation and Urbanisation had done much already to cut people’s links with the churches

b. Some became Humanists; some supported Social Darwinism

2. Some Christians rejected evolution – interpreted Genesis literally; USA Bible Belt; Monkey Trials

3. Many Christians welcomed and supported evolution from the start, reinterpreting their Christian message

Some Used Evolution as a Basis for Living: Social Darwinism

• Some used Darwin's theory of evolution and survival of the fittest to guide human society

• Competition weeds out the weak

• Charity, benefits or aid wrongly allow weak to survive

Criticism:• Misapplied DESCRIPTIVE biological theories • Became a PRESCRIPTIVE guide to how we should behave

History of Medicine 1800s• Gregor Mendel (1822 - 1884)

– Augustinian monk who taught natural science to high school students

– Studied the theories of heredity based on his experiments with pea plants during seven years-> basic laws of inheritance

– His work was so brilliant and unprecedented at the time it appeared that it took thirty-four years for the rest of the scientific community to catch up to it. He set the stage for the discovery of genes and DNA.

– Mendel was the first person to trace the characteristics of successive generations of a living thing

– From his studies, Mendel derived certain basic laws of heredity:• hereditary factors do not combine, but are passed intact• each member of the parental generation transmits only half of its

hereditary factors to each offspring (with certain factors "dominant" over others)

• different offspring of the same parents receive different sets of hereditary factors.

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Gregor Mendel: 1822 – 1884 AD

• Austrian• Monk• Mendel realized that

the parent plants were passing on their features to their seedlings in the form of chemical messages in the pollen---genes

• Mendel’s pea plants for two genes for growing

• GS—grow short• GT---grow tall• But only one set of genes is

switched on• By counting the different

types of pea plant in each crop, Mendel found that plants carried the genes to Grow Short and Grow Tall always grew tall.

Mendel

• The only plants that grew short were those with the gene Grow Short and Grow Short.

• This was a dramatic discovery because it showed how genes work and some genes override each other.

• Mendel grew 28,000 pea plants.

• He studied their height, flower color, and five other characteristics.

• From his work, we get a new branch of biology called genetics.

History of Medicine 1800s

• Joseph Lister (1827 - 1912) – A Professor of Surgery at Glasgow University, he was very aware that

many people survived the trauma of an operation but died afterwards of what was known as ‘ward fever’

– Work on ward cleanliness and the link between germs and good post-operative health had already been studied by a Hungarian doctor called Ignaz Semmelweiss. He argued that if a doctor went from one patient to another after doing surgery, that doctor would pass on to the next visited patient a potentially life threatening disease.

– He insisted that those doctors who worked for him wash their hands in calcium chloride after an operation and before visiting a new patient -> Introduces antiseptic surgery

– At the time, it was not known that the infections were caused by bacteria

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History of Medicine 1800s

• Robert Koch (1843 - 1910)– Koch was a German doctor, influenced by Pasteur's work. In 1872, he began

research into the microbes affecting animals and people. – The first animal disease that Koch investigated was anthrax. Koch found out

that the anthrax microbe produced spores that lived for a long time after an animal had died. He also proved that these spores could then develop into the anthrax germ and could infect other animals.

– Koch also devised a method of proving which germ caused an infection: Koch Postulates

– He perfected the technique of growing pure cultures of germs using a mix of potatoes and gelatine. This was a solid enough substance to allow for the germs to be studied better.

– In 1882 he identified the bacteria causing tuberculosis (TB). – In 1883, he identified the bacteria causing cholera.– By 1900, twenty-one germs that caused diseases had been identified in just

21 years

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Chemistry

• French chemist, 1700s

• Developed methods for precise measurements

• Discovered law of Conservation of Mass, proved matter could not be created, destroyed

• Recognized, named oxygen, introduced metric system, invented first periodic table

Antoine-Laurent Lavoisier• Father of modern chemistry

• First to define element

• The Sceptical Chemist, 1661, described matter as cluster of tiny particles (now called atoms)

• Changes in matter occurred when clusters rearranged

• Boyle’s law - temperature, volume, pressure affect gases

Robert Boyle

Chemistry

Robert Boyle

• The work of Robert Boyle in chemistry was also based on close observation and experiment.

Robert Boyle: 1627 – 1691AD• Irish chemist• Inspired by Bacon• First to prove that

alchemy did not work• However, he still thought

that gold was a compound and could be made if you mixed the right elements.

• Wrote a new book suggesting a theory about chemicals but did not have the proof to support it

• Boyle suggested that some basic chemicals could not be divided up into any other basic kinds.

• These were called elements and each element was a type of atom.

• Other more complex chemical mixtures were called compounds.

Robert Boyle(1627-1691)

• Through careful experimentation, Boyle established chemistry as a pure science

• experiments using a vacuum Discovered “Boyle’s Law” : the idea that the volume of gas

varies inversely with pressure Studied the physical nature of air, through numerous Supported corpuscularism: a form of atomism which discussed

reality and change in terms of particles and their motion Boyle thought that chemical experiments would be able to show

the truth of corpuscularism Made use of Hooke’s microscope Used an air pump to prove that sound travels through air Completed numerous experiments on air by burning a candle in a

closed air pump

Boyle Cont.

• Spent time at Oxford during the English Civil Wars, where he worked with a group experimenting– The group was committed to the New Philosophy, which

emphasized observation and experiment as having equal importance to logical thinking in scientific discovery and comprehension

– Foreshadowed the Royal Society, founded in 1660– Here, Boyle came in contact with numerous philosophical

writings including those of Gassendi and Descartes All of Boyle’s writing were published in English and

in Latin translations

Boyle

• Boyle’s work encouraged scientists to mix chemicals in a more scientific way

• He founded a brand new science---chemistry!

BOYLE

Boyle’s first air pump Boyle’s New Experiments and ObservationsTouching Cold - 1683

Boyle and Lavoisier

• He formulated Boyle’s Law about gases—the volume of a gas varies with the pressure exerted on it.

• In the eighteenth century Antoine Lavoisier, the founder of modern chemistry, invented a system of naming the chemical elements.

Antoine Lavoisier 1743 – 1794 AD

• French• Member of the French

Academy of Sciences• Worked on a report on

the Paris water supply• In 1772, he found that

all chemicals could exist as a gas, a liquid, and a solid depending on how hot they were.

• In the 1772, Lavoisier found that oxygen is needed for both rusting and burning. He discovered the process called oxidation.

• He also showed that water is made up of oxygen and hydrogen.

Lavoisier

• Insisted that all the chemicals he used should be carefully weighed and accurate records should be made of all his experiments.

• Chemists had not always done this in the past.

• This made it possible for the experiments to be duplicated and verified.

Antoine Lavoisier(1743-1794)• French chemist

• Through scientific experiments found that materials do not give off phlogiston when burned and that in fact they consume oxygen

– Realized that oxygen is also responsible for acidity, which explains why he called it oxygen (Greek for acid-former)

– Showed that organisms disassemble and reassemble air in the same way that something does when it burns

• Considered the father of modern chemistry

• Lighted the streets of Paris

• Through experiment proved that the transmutation of water is impossible

• Established the Law of Conservation of Mass which states that matter can never be created or destroyed; it can only change form

• Using the experiments of John Priestly, Lavoisier showed that air is made of two parts; However, he tried to take the credit

– One part was oxygen and the other he called azote (Greek for no life)

Lavoisier Cont. • Discovered Cavendish’s inflammable gas which he called hydrogen,

Greek for water-former

• Invented a system of chemical nomenclature which he explained in his book Methods of Chemical Nomenclature (1787)

• Created the first modern chemical textbook, Elementary Treatise of Chemistry, 1789, which presented new theories, Law of Conservation of Mass, denial of the existence of phlogiston, and a list of elements

• Believed that the real existence of atoms was philosophically impossible

• Used a calorimeter to estimate the amount of heat created per unit of carbon dioxide created through combustion

• Believed the radical theory – that radicals when functioning as one group in a reaction would combine with oxygen

• Believed all acids containing oxygen

• Lavoisier was beheaded during the French Revolution

Lavoisier• "I have tried...to arrive at the truth by linking up facts; to suppress as much

as possible the use of reasoning, which is often an unreliable instrument which deceives us, in order to follow as much as possible the torch of observation and of experiment." - Lavoisier

Lavoisier working in his Laboratory

Marie Lavoisier:

• Married to Antoine Lavoisier at the age of 13

• Translated English and Latin essays and books for her husband, Antoine Lavoisier

• Condensed articles for him

• Illustrated, edited, and published his work

• Studied chemistry and learned English during her teenage years

• Often argued whether she was an aide to Antoine or a large influence on his work as a contributor who has gained no credit

• Following her husband’s death, Marie ran a scientific salon

Marie Lavoisier

Marie’s drawing of a gazometer

in Antoine’s Elementary

Treatise of Chemistry

Marie with Antoine

Joseph Priestley(1733-1804)

• English chemist and clergyman• Conducted experiments on the properties of air • Studied carbon dioxide; this led to his invention of carbonated

beverages• Examined air emitting from numerous substances• Isolated and characterized eight gases, including oxygen • Contributed to the understanding of photosynthesis and

respiration• Continually argued with Lavoisier over how to interpret the

results of experiments of gases – Priestley used phlogiston – hypothetical principle of flammability that

was thought to give metals their characteristics of luster and ductility; widely used to explain combustion, etc.

• Completed experiments with candles, plants, and mice in air pumps

• The "goodness" of air, a measure of its respirability, interested Priestley. In 1771 he noted the restoration of "injured" or depleted air by green plants. He wrote,

• The injury which is continually done to the atmosphere by the respiration of such a large number of animals...is, in part at least, repaired by the vegetable creation. (5)

• This balance between animal and plant kingdoms is particularly relevant to our present environmental concerns over global warming and rainforest destruction.

• Joseph Priestley simplified experimental techniques for the preparation and collection of gases.

• his pneumatic trough of 1772 was an admirable apparatus. Gases soluble in water, previously difficult to collect, were collected successfully over mercury.

• in Wiltshire, England, on August 1, 1774 Priestley focused sunlight through a lens in order to heat a sample of mercuric oxide (red calx).

• The resulting gas supported the burning of a candle with a vigorous flame, was essentially insoluble in water, and accommodated a mouse under glass for some time. In Priestley's own words,

• I have discovered an air five or six times as good as common air. (5)

Priestley Cont. • Religion:

– Educated to be a minister in churches opposing the Church of England

– Spent much of his life as a preacher or teacher Supported both the French and American Revolutions Emigrated to the United States after a mob attacked and

destroyed his house and laboratory in 1791 Planned to create a model community with his sons, but

this never materialized Influenced and encouraged to study by Ben Franklin

Caused Priestley to work with electricity

• Among his accomplishments during his years in Birmingham were the publication of the first part of Letters to a Philosophical Unbeliever, an attempt to defend natural religion against the skepticism of David Hume; a History of the Corruptions of Christianity, a direct attack on the central tenets of orthodox religion, particularly the doctrine of the Trinity; and a History of the Early Opinions Concerning Jesus Christ, where he set out to prove that the doctrine of the Trinity was not according to Scripture.

• These three works catalyzed storms of controversy. Priestley was attacked in pamphlets and periodicals, denounced in pulpits and in the House of Commons, and considered as an agent of the Devil because of his unorthodox views. Under the Test and Corporation Acts in England, the Dissenter was deprived of the rights of citizenship, and , by law, the Unitarian was not even tolerated.

• When the French Revolution broke out, the sympathies of the Dissenters lay with those who were struggling under the yoke of corruption, tyranny and oppression. Two years later, festivities were planned to celebrate the auspicious event. On the 11th of July, 1791 a local newspaper printed an advertisement for a dinner to be held at a leading hotel on July 14,

• to commemorate the auspicious day (Bastille Day) which witnessed the Emancipation of Twenty-six Millions of People from the yoke of Despotism . . .(1)

• The dinner was attended by eighty one men and ended without incident.

• Dr. Priestley had declined to attend, to the disappointment of the crowd that had gathered to demonstrate their contrary views to Priestley's revolutionary and heretical writings.

• By evening, the crowd reconvened and, fueled by liquor, sacked and burned the New Meetinghouse where Priestley preached.

• The Old Meetinghouse was sacked and burned, too. • Warned of the murderous multitude, Priestley and his wife left Fairhill,

with nothing more than the clothes we happened to have on. They did not realize the magnitude of the danger they were in and stopped at a friend's house a mile away.

• There they received information that the mob was now at their house looking for them. They moved again a little farther away but not far enough for Priestley to be spared the sight of the holocaust that engulfed his home, his laboratory and especially his library which contained precious manuscripts of works, some of which were as yet unpublished.

• Priestley fled to London and was never to return to Birmingham. He moved to Tottenham and then to Hackney. During the following months, Priestley was verbally attacked in the House of Commons, burned in effigy, portrayed in caricatures, denounced in pulpits and subjected to threatening letters.

• Priestley had by now become an honorary citizen of France which was at war with England.

• He was snubbed by the Royal Society and was forced to resign his membership when several of his colleagues turned against him.

• His sons were unable to find work in the area and decided to emigrate to America. He and his wife decided to join them. They sailed from Gravesend on the Samson on April 7, 1794, two weeks after Priestley's 61st birthday.

• While the Priestleys were on their journey to America, Laviosier met his death at the guillotine in the Place de la Revolution.

• The Priestleys landed in New York and proceeded to the capital, Philadelphia. He refused the offer of a chair in chemistry at the University of Pennsylvania, choosing instead to join his son, Joseph, and friend, Thomas Cooper, who were establishing a colony for English Dissenters in central Pennsylvania.

• He moved 130 miles to the north and settled in the small town of Northumberland on the banks of the Susquehanna River. Within the year, the youngest Priestley son, Harry, died, as did Joseph's wife. Priestley remained active, writing, preaching and experimenting in his newly established laboratory, but the old fire and cheerfulness were gone.

• Michael Faraday, Address delivered at the Commemoration of the Centenary of the Birth of Dr Priestley (1833)

• Dr. Priestley had that freedom of mind, and that independence of dogma and of preconceived notions, by which men are so often bowed down and carried forward from fallacy to fallacy, their eyes not being opened to see what that fallacy is. I am very anxious at this time to exhort you all, - as I trust you all are pursuers of science, - to attend to these things; for DR Priestley made his great discoveries mainly in consequence of his having a mind which could be easily moved from what it had held to the reception of new thoughts and notions; and I will venture to say that all his discoveries followed from the facility with which he could leave a preconceived idea.

Priestley

Examples of Priestley’s equipment

“Could we have entered into the mind of Sir Isaac Newton, and have traced all the steps by which he produced his great works, we might see nothing very extraordinary in the process.” -Priestley

Henry Cavendish: 1731 – 1810 AD

• British• Was worth over one

hundred million pounds• Son of a Lord and the

grandson of the Duke of Devonshire

• Spent most of his life doing science experiments at home alone

• He discovered a whole range of new gasses

• In 1776 he added acid to marble and the gas that was given off was called fixed air.

• He then dripped acid onto iron, and another gas was given off. It seemed that this gas was lighter than air and burnt so easily, so he called it “fire air.”---What we know now as hydrogen.

Cavendish

• Cavendish was so shy that he never told anyone about his discoveries.

• It was not until 100 years later when James Clerk Maxwell came across his notebooks.

Karl Scheele: 1742 – 1786 AD

• Swedish• Was a druggist’s

assistant• Made a series of

discoveries in the 1770s and 1780s

• He discovered five elements: chlorine, barium, manganese, moylbdenum, and nitrogen.

• He also discovered a green dye made up of copper and poisonous arsenic.

• He found out how to extract phosphorus from animal bones instead of urine.

• He claimed Priestly and Lavoisier stole his discovery of oxygen.

Effects of Scientific Revolution

Effects of Revolution

• Social impact– rich get richer– not much immediate direct change for peasants – widens intellectual gap

• effect on navigation, map making and artillery • Science has innumerable social effects over time:

new guns, bigger armies, more taxes, social discontent – guns lead to European colonialism (more accurate

cannon fire)

• new way of observing the world.

Church and Science

• Increasing tension between science/rationality and religion/faith.

• Most of the key scientist were religious men who did not try to take God out of the equation.

• Many people, though, believed that new rationality/science took God out of the equation. This was seen as frightening by many.– Response by the Church: ban books and to label certain

scientific ideas heresy.– Response by others was to try to redraw the philosophical

connection between science and religion.

The church feared reason as an enemy of faith, but eventually began to embrace some of the achievements of the Scientific Revolution.

As science assumed greater significance, the question of the role of the Roman Catholic Church in a changing culture became important. While the church opposed the views of many scientists, it benefited from new discoveries that made Renaissance art and architecture possible.

• Church most powerful institution in Europe, Middle Ages

• Primary resource for knowledge, learning

• Cathedral schools, universities trained people to run the church

Science and the Church

Effects of the Scientific Revolution:Science and Society

• Most scientists did not want to challenge role of Christianity

• Church explained world through inspiration, revealed truth

• Science explained world through logical reasoning

Conflicts

Effects of the Scientific Revolution

• Laws discovered by human reason

• “De-Spiritualized” and de-mystified the Universe

• Mechanical View of the Universe

• Deistic View of God

--God as the cosmic capitalist

Effects of the Scientific Revolution

• View of nature as a machine• Nature as matter in motion governed by

unchanging laws• Knowledge of these laws => ability to use

nature (Bacon)• God as a watchmaker (impersonal)• A whole new world

– Telescope: the heavens– Microscope: the previously unseen.

The Spread of Scientific Knowledge

• In the seventeenth century, scientific learning and investigation increased at a dramatic pace. Fueled by :– printing press– Scientific method became the standard – Scientific communities developed to critically

examine the findings of others – Establishment of major universities– Patronage of scientists and scientific societies

Effects of the Scientific Revolution

• Rise of the “Scientific Community”

--Royal Society of London (1662)

--Academy of Royal Sciences (1666)

• The modern scientific method

• A universe ordered according to natural laws

Scientific Societies

• Scientific Societies arose in Italy, France and England during the 1600s.

• All put emphasis on scientific research.• French society (French Royal Society) received

generous state aid, while the English Royal Society developed largely without governmental help.

• Early on they were focused on practical applications of science, but soon moved to more theoretical pursuits.

• Observatories constructed in both France and England.

The Enlightenment• The heart of the Enlightenment is the application of

reason to all aspects of life. • Applied scientific method to other aspects of the human

condition. • “The Age of Reason” People were encouraged to

shake off the thinking of the past and the superstition of religiously-based answers.

• Was a search for the natural laws that governed human interaction

• Culmination of four intellectual developments – popularization of science– skepticism about religion– knowledge about cultures outside of Europe– the work of Newton and Locke.

Path to Enlightenment• Popularization of Science

– In the 17th century authors popularized the work on top scientists by “translating” it into language that average intelligent people could understand.

– Theories of Copernicus, Galileo and Newton became widely known

– Bernard de Fontenelle.• Religious Skepticism

– Reformation disputes caused growing cynicism toward structured religion.

– Scientific discoveries led some to believe that answers could be found outside of the blind faith of the church.

• Travel Reports– Books and articles written by people who had been to other

lands also began to lead people to question the assumption that the way things had been done in Europe for the last 500 years was the best way.

Locke and Newton

• Newton’s world-view based on an orderly rational universe based on natural laws had a profound impact on intellectuals

• Increasingly thinkers began to search for ways to apply natural laws to other things. Such as?

• Locke developed a theory of knowledge based on the idea that all people are born blank slates—tabula rasa.– Everything that people know and believe is based on

experience and exposure.– Can create better people by providing a better

environment. – Improve society so that there is a better environment

for shaping people.