Discoveries of 20th Century

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Discoveries of 20th Century

• 1900 Quantum nature of energy
• 1903 First motorized airplane flew
• Special theory of relativity published
• 1907Radiometric dating finds earth 2.2 billion
  years old
• Ehrlich finds cure for syphilis
• 1912 Leavitt discovers Cepheid's period and
  luminosity
• 1912 Wegener proposes continental drift

• 1913 Leavitt discovers
• 1913Bohr describes atomic structure
• 1915 General theory of relativity
• 1922 Banting and Best isolate insulin
• 1924 Hubble identifies new galaxy
• 1926 Television developed
• 1927 Big bang theory introduced
• 1927 Heisenberg state uncertainty principle

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Discoveries of 20th Century

• 1928 Fleming discovers penicillin
• 1929 Hubble finds universe expanding
• 1931 Lawrence invents cyclotron
• 1935 Nylon invented
• 1942 Fermi creates 1st controlled nuclear
  reaction
• 1945 ENIAC built
• 1945 Atomic bomb detonated

• 1947 Libby introduces C14 dating
• 1947 Transistor invented
• 1953 Salk polio vaccine
• 1953 Miller makes amino acids in laboratory
• 1953 Mid-Atlantic rift discovered
• 1953 Watson and Crick describe DNA
• 1954 First kidney transplant
• 1959 Leaky finds early hominid

3
Discoveries of 20th Century

• 1960 Hess propose sea-floor spreading
• 1965 Penzias and Wilson observe cosmic background
  microwave radiation
• 1967 Pulsars discovered
• 1969 Apollo lands on moon
• 1971 First commercial microprocessor introduced
• 1974 Johanson finds 3.2 million year old Lucy
• 1975 Personal computer launched
• 1976 Cosmic string theory introduced

• 1977 found near deep ocean vents
• 1980 Alvarez finds evidence for dinosaur killing
  asteroid
• 1992 World wide Web
• 1992 The risk of carbon dioxide buildup and
  global warming is recognised.
• 1992 The first 'xenotransplant' from one type of
  animal to another involving genetically
  engineered tissue (liver) is carried out
  successfully.

4
Discoveries of 21st Century

• 1997 Dolly the sheep is born. She has been
  produced by Ian Wilmut and his team at the Roslin
  Institute near Edinburgh
• 2000 World Wide Web estimated to cover 1 billion
  pages.
• As homework the student list other discoveries
  during the past 4 years

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Brief History of Modern Science

• Discovery - A new method of acquiring knowledge
  was invented by a series of European thinkers
  from 1550 to 1700. Among these thinkers are
  Galileo, Descartes, Kepler, and Newton
• Definition of Science- A special method and
  knowledge executed by practitioners of science
  called scientists.

6
Meaning of Science

• Science is practiced by specially trained people
  with a specific world view. Scientists try to be
  objective, non-sentimental, unemotional, honest,
  and unbiased
• Scientists work in laboratories where conditions
  are carefully controlled.
• Scientists report their findings in peer-reviewed
  journals to other scientists
• Scientists do not claim more than what they can
  prove

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External World

• Science deals with things or objects in the
  external world. External world is anything that
  can be measured and described in mathematical
  terms
• The external world the scientist believes follows
  rules of mathematics.
• The external world contains solar systems,
  galaxies, quanta, quarks, quasars, four forces,
  six lepton, six lepton and six hadrons

8
Science Language

• Scientists describe the results of controlled
  experiments in a specialized language and/or in
  mathematics.
• Is the external world understandable because our
  brains conform to the external world or because
  the external world is essentially mathematical in
  nature as is the human mind?

9
Philosophical Foundations of Science Originated
in the 17th century

• Science removed animism as a physical
  explanation. Greek philosophers thought movement
  was a sign of life. Planets were moved by
  angels. Newtons 1st law of motion changed this
  attitude.
• Science changed mans position from the center of
  the universe to its periphery. Mans place in
  the universe was seen as minor.
• Scientific achievement revived human pride in
  place of an obsession with sin.

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Archimedes (287-212 BCE )

• Sicilian geometrician who calculated an accurate
  value for p, demonstrated the relationship
  between the volume of spheres and cylinders,
  discovered methods for determining the center of
  gravity of plane figures, and provided a
  foundation for the science of hydrostatics.
  Archimedes also invented many ingenious machines,
  including a pump for raising water, effective
  levers and compound pulleys, and a mechanical
  planetarium. He died defending Syracuse against a
  Roman siege during the second Punic war.

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Aristotelian Science

• Theory of Matter
• Matter stuff out of which things are made
• In sublunary world (below the moon) there
• are four elements or essences
• earth, water, air, and fire.
• These four elements never found pure always
  mixed.
• Heavy things made out of earth
• Light things made mix of water,air, and fire

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Aristotelian Science

• Above sun, planets are stars imbedded in the
  crystalline sphere
• The crystalline sphere made out of pure
  quintessence ( 5th essence)
• Different laws pertain the sublunary world than
  to the world above the moon

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Aristotelian Science

• Motion
• Natural state of all sublunary things is rest
• All objects seek rest
• Earth, Air, and water seek down for rest
• Fire seek rest upward
• Bodies seek the grave, the souls seek heaven

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Aristotelian Science

• Motion
• Two kinds of motion -- violent and natural
• Things move because theyre pulled or pushed
• Sun, planets, and stars move in uniform,
  circular motion
• Circles are ideal and circular motion is an
  aspect of quintessence.
• Earth is at center of Universe

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Aristotelian Science

• Violent Motion
• A projectile exhibits violent motion
• Question why does an object keep moving after
  leaving the bow or hand?
• Answer air moves from the front of the object to
  the back and pushes the object along.

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Aristotelian Science Violent Motion
19
Ptolemy Epicycles
more accurate measurement required more epicycles
20
Roger Bacon

• Bacon, Roger (1214-1292 )English philosopher who
  translated many Aristotelian treatises from
  Arabic into Latin. Although passionately
  interested in alchemy and magic, Roger defended
  reliance upon mathematics and experimental
  methods for the improvement of human knowledge
  generally and theological understanding in
  particular in the Opus Maius (Greater Work )
  (1267) at Amazon.com and On Experimental
  Science (1268). His novel educational doctrines
  were supposed to violate the condemnation of 1277
  , and much of Roger's later work, including the
  Compendium Studii Theologiae (1292) was
  suppressed.

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Deductive and Inductive Reasoning

• A deductive argument is one in which it is
  claimed that it is impossible for the premises to
  be true but the conclusion false. Thus, the
  conclusion follows necessarily from the premises
  and inferences. In this way, it is supposed to be
  a definitive proof of the truth of the claim
  (conclusion). Here is an example
• 1. All men are mortal. (premise)
• 2. Socrates was a man. (premise)
• 3. Socrates was mortal. (conclusion)
• As you can see, if the premises are true (and
  they are), then it simply isn't possible for the
  conclusion to be false.
• An inductive argument is one in which the
  premises are supposed to support the conclusion
  in such a way that if the premises are true, it
  is improbable that the conclusion would be false.
  Thus, the conclusion follows probably from the
  premises and inferences. Here is an example
• 1. Socrates was Greek. (premise)
• 2. Most Greeks eat fish. (premise)
• 3. Socrates probably ate fish. (conclusion)

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Deductive and Inductive Reasoning

• inductive
• The meerkat is closely related to the suricat
• The suricat thrives on beetle larvae
• Therefore, probably the meerkat thrives on beetle
  larvae

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Deductive and Inductive Reasoning

• deductive
• The meekat is a member of the mongoose family
• All members of the mongoose family are carnivores
• Therefore, it necessarily follows that the
  meerkat is a carnivore

mongoose
cobra
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Inductive Mathematical Reasoning

• Find a General Rule for the Number series 0, 2,
  8, 18, 32, 50, 72..
• Explain the Fibonacci Series 1, 2, 3, 5, 8, 13,
  21, 34,
• Stable Atomic Nuclei have the following number of
  nucleons (proton and neutrons)
• 2, 8, 20, 28, 50, 82, 126, What is the next
  member in the series?

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Logical Fallacieshttp//www.intrepidsoftware.com/
fallacy/toc.php 

• Novelty, Appeal to
• No True Scotsman
• Numbers, Appeal to
• Money, Appeal to
• Oversimplification and Exaggeration
• Pity, Appeal to (Argumentum ad Misercordiam)
• Poisoning the Well
• Poverty, Appeal to
• Presumption
• Quantifier Fallacy
• Quoting out of Context
• Reification / Hypostatization
• Fallacies of Relevance (index)
• Scope Fallacy
• Suppressed Evidence
• Tradition, Appeal to
• Tu Quoque (two wrongs don't make a right
• Genetic Fallacy
• Illicit Observation

• Abusive ad hominem
• Accent
• Ambiguity (index)
• Amphiboly
• Age, Appeal to
• Authority, Appeals to (4 types)
• Authority, Legitimate Appeal to
• Ad Hominem (5 types)
• Begging the Question
• Circumstantial ad hominem
• Complex Question
• Composition
• Correlation vs. Causation
• Division
• Emotion and Desire, Appeals to (5 types)
• Equivocation
• Unqualified Authority, Appeal to
• False Dilemma
• Flatter, Appeal to

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Logical Fallacies

• Straw Man
• Definition
• The author attacks an argument which is different
  from, and
• usually weaker than, the opposition's best
  argument.
• Examples
• (i) People who opposed the Charlottown Accord
  probably just
• wanted Quebec to separate. But we want Quebec to
  stay in
• Canada.
• (ii) We should have conscription. People don't
  want to enter
• the military because they find it an
  inconvenience. But they
• should realize that there are more important
  things than
• convenience.
• Proof
• Show that the opposition's argument has been
• misrepresented by showing that the opposition has
  a stronger
• argument. Describe the stronger argument.

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Logical Fallacies

• Definition
• The truth of the conclusion is assumed by the
  premises.
• Often, the conclusion is simply restated in the
  premises in a
• slightly different form. In more difficult cases,
  the premise is
• a consequence of the conclusion.
• Examples
• (i) Since I'm not lying, it follows that I'm
  telling the truth.
• (ii) We know that God exists, since the Bible
  says God exists.
• What the Bible says must be true, since God wrote
  it and
• God never lies. (Here, we must agree that God
  exists in order
• to believe that God wrote the Bible.)
• Proof
• Show that in order to believe that the premises
  are true we
• must already agree that the conclusion is true.

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Logical Fallacies

• Coincidental Correlation
• (post hoc ergo propter hoc )
• Definition
• The name in Latin means "after this therefore
  because of this".
• This describes the fallacy. An author commits the
  fallacy when
• it is assumed that because one thing follows
  another that the
• one thing was caused by the other.
• Examples
• (i) Immigration to Alberta from Ontario
  increased. Soon
• after, the welfare rolls increased. Therefore,
  the increased
• immigration caused the increased welfare rolls.
• (ii) I took EZ-No-Cold, and two days later, my
  cold
• disappeared.
• Proof
• Show that the correlation is coincidental by
  showing that (i)
• the effect would have occurred even if the cause
  did not
• occur, or (ii) that the effect was caused by
  something other
• than the suggested cause.

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Thomas Aquinas (1224-1274 )

• Although matters of such importance should be
  accepted on the basis of divine revelation alone,
  Aquinas held, it is at least possible (and
  perhaps even desirable) in some circumstances to
  achieve genuine knowledge of them by means of the
  rigorous application of human reason. As embodied
  souls
• (hylomorphic composites), human beings naturally
  rely on sensory information for their knowledge
  of the world. Reading hint Although the rigidly
  formal structure of the Summa articles can be
  rather confusing to a modern reader, the central
  portion beginning with the words, " I answer that
  ..." is always a direct statement of Aquinas's
  own position.

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William of Ockham,

• William of Ockham
• (1285-1349 )English philosopher who defended the
  logic, physics, and metaphysics of Aristotle in
  Summa Logicae (The Whole of Logic ) (1328) vol. 1
  at Amazon.com and vol. 2 at Amazon.com
  and the Dialogus . An extreme nominalist , Ockham
  held that general terms are signs that
  indefinitely signify discrete (though similar)
  particulars. Ockham is best known for his
  statement of the law of parsimony as the
  ontological principle often called Ockham's Razor
  " Frustra fit per plura quod potest fieri per
  pauciora " "It is pointless to do with more what
  can be done with less". Thus, according to
  Ockham, we ought never to postulate the reality
  of any entity unless it is logically necessary to
  do so.

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Paracelsus (Phillippus Aureolus Theophrastus
Bombastus von Hohenheim) ( 1493-1541 )

• Swiss chemist and physician. Rejecting the
  ancient reliance on concern for bodily "humours,"
  Paracelsus transformed the practice of medicine
  by employing careful observation and
  experimentation. Although his chemical knowledge
  was rudimentary by modern standards, Paracelsus
  envisioned using pharmaceutical methods for
  treating disease and something like inoculation
  for preventing it.

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Scientific Development From 1543 to 1789

• 1543 Nicolas Copernicus (1473-1543) publishes
  De Revolutionibus Orbium Coelestium, which argues
  that the Sun is the center of the Solar System.
• 1543 Andrea Vesalius (1514-1564) publishes
  Concerning the Structure of the Human Body, the
  first modern anatomical text.
• 1600 William Gilbert (1540-1603) publishes
  Concerning the Magnet.
• 1605 Francis Bacon (1561-1626) publishes
  Advancement of Learning.
• 1609 Astronomia Nova is published by Johannes
  Kepler (1571-1630), in which he presented his
  first two Laws of Planetary Motion.
• 1610 Galileo Galilei (1564-1642) publishes
  Sidereal Messenger, describing his observations
  using the telescope.
• 1619 Kepler publishes his Third Law in Harmonia
  Mundi.
• 1628 William Harvey (1578-1657) publishes On
  the Motion of the Heart and Blood in Animals, in
  which he proves that the heart circulates blood
  throughout the body.
• 1632 Galileo publishes Concerning the Two Chief
  World Systems, in which he compares the
  Copernican and Ptolemaic solar systems.
• 1637 Rene Descartes publishes his Discourse on
  Method, in which he lays the foundation for
  modern philosophy.
• 1644-9 Pierre Gassendi (1592-1655), in a series
  of works, revives the traditions of Epicureanism
  and Skepticism.
• 1660 Robert Boyle (1627-1691) publishes New
  Experiments Physico-Mechanical Touching the
  Spring of the Air, in which he states his laws of
  gases.
• 1662 The Royal Society of London is founded.
• 1666 The French Academy of Science is founded.
• 1677 Anton von Leeuwenhoek (1632-1723), using a
  microscope, discovers male spermatoza.
• 1678 Christian Huygens (1629-1695) proposes the
  wave theory of light.
• 1687 Isaac Newton (1642-1727) publishes his
  Principia Mathematica.
• 1704 Isaac Newton publishes his Optics.
• 1735 Carolus Linnaeus publishes his Systema
  Naturae, which establishes the science of
  taxonomy.

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Scientific Development From 1543 to 1789

• 1543 Nicolas Copernicus (1473-1543) publishes De
  Revolutionibus Orbium Coelestium, which argues
  that the Sun is the center of the Solar System.
• 1543 Andrea Vesalius (1514-1564) publishes
  Concerning the Structure of the Human Body, the
  first modern anatomical text.
• 1600 William Gilbert (1540-1603) publishes
  Concerning the Magnet.
• 1605 Francis Bacon (1561-1626) publishes
  Advancement of Learning.
• 1609 Astronomia Nova is published by Johannes
  Kepler (1571-1630), in which he presented his
  first two Laws of Planetary Motion.
• 1610 Galileo Galilei (1564-1642) publishes
  Sidereal Messenger, describing his observations
  using the telescope.
• 1619 Kepler publishes his Third Law in Harmonia
  Mundi.

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Scientific Development From 1543 to 1789
1628 William Harvey (1578-1657) publishes On
the Motion of the Heart and Blood in Animals, in
which he proves that the heart circulates blood
throughout the body. 1632 Galileo publishes
Concerning the Two Chief World Systems, in which
he compares the Copernican and Ptolemaic solar
systems. 1637 Rene Descartes publishes his
Discourse on Method, in which he lays the
foundation for modern philosophy. 1644-9
Pierre Gassendi (1592-1655), in a series of
works, revives the traditions of Epicureanism and
Skepticism. 1660 Robert Boyle (1627-1691)
publishes New Experiments Physico-Mechanical
Touching the Spring of the Air, in which he
states his laws of gases. 1662 The Royal
Society of London is founded.

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Scientific Development From 1543 to 1789

• 1666 The French Academy of Science is founded.
• 1677 Anton von Leeuwenhoek (1632-1723), using a
  microscope, discovers male spermatoza.
• 1678 Christian Huygens (1629-1695) proposes the
  wave theory of light.
• 1687 Isaac Newton (1642-1727) publishes his
  Principia Mathematica.
• 1704 Isaac Newton publishes his Optics.
• 1735 Carolus Linnaeus publishes his Systema
  Naturae, which establishes the science of
  taxonomy.
• 1789 Antoine Lavoisier publishes his treatise
  on chemistry, laying the foundation for the
  modern theory of chemical elements.

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Copernicus b. 1473 Poland

• Polish astronomer who developed the theory that
  the earth is a moving planet. In Copernicus's
  time, most astronomers accepted the theory the
  Greek astronomer Ptolemy had formulated nearly
  1,400 years earlier.
• Some astronomers before Ptolemy had suggested
  that the earth did in fact move. Copernicus
  decided that the simplest and most systematic
  explanation of heavenly motion required that
  every planet, including the earth, revolve around
  the sun. The earth also had to spin around its
  axis once every day. The earth's motion affects
  what people see in the heavens, so real motions
  must be separated from apparent ones.
• Copernicus skillfully applied this idea in his
  masterpiece, On the Revolutions of the Heavenly
  Spheres (1543). In this book, he demonstrated how
  the earth's motion could be used to explain the
  movements of other heavenly bodies. Copernicus
  could not prove his theory, but his explanation
  of heavenly motion was mathematically strong and
  was less complicated than Ptolemy's theory. By
  the early 1600's, such astronomers as Galileo in
  Italy and Johannes Kepler in Germany began to
  develop the physics that would prove Copernicus'
  theory correct.

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Tycho Brahe b. 1546

• Danish astronomer. Brahe developed a systematic
  approach for observing the planets and stars. He
  stressed the importance of making such
  observations on a regular basis. The telescope
  had not yet been invented, and so Brahe used his
  eyesight and such instruments as astrolabes and
  quadrants to estimate the positions of celestial
  objects. His observations were far more precise
  than those of any earlier astronomer.
• Brahe's observations of planetary motion revealed
  that the tables then in use to predict the
  positions of the planets were inaccurate. His
  sighting of a supernova (type of exploding star)
  in 1572 helped disprove the ancient idea that no
  change could occur in the heavens beyond the
  orbit of the moon.
• Like many astronomers of his time, Brahe refused
  to accept the Copernican theory of the solar
  system. According to this theory, the earth and
  the other planets move around the sun. Brahe
  reasoned that if the earth revolved around the
  sun, he should have been able to measure changes
  in the positions of the stars resulting from the
  earth's movement. He did not realize that such
  changes were too small for his instruments to
  detect. However, Brahe's observational data later
  enabled Johannes Kepler, a German astronomer and
  mathematician, to confirm the Copernican theory.
• Brahe was born in Knudstrup (then a Danish city
  but now in Sweden), near Malmo. As a member of
  the nobility, he attended universities in
  Denmark, Germany, and Switzerland. Brahe built an
  elaborate observatory on the island of Hven (now
  called Ven), where he made many of his
  observations.

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Tycho Brahe b. 1546

• Danish astronomer. Brahe developed a systematic
  approach for observing the planets and stars. He
  stressed the importance of making such
  observations on a regular basis. The telescope
  had not yet been invented, and so Brahe used his
  eyesight and such instruments as astrolabes and
  quadrants to estimate the positions of celestial
  objects. His observations were far more precise
  than those of any earlier astronomer.
• Brahe's observations of planetary motion revealed
  that the tables then in use to predict the
  positions of the planets were inaccurate. His
  sighting of a supernova (type of exploding star)
  in 1572 helped disprove the ancient idea that no
  change could occur in the heavens beyond the
  orbit of the moon.

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Tycho Brahe b. 1546

• Like many astronomers of his time, Brahe refused
  to accept the Copernican theory of the solar
  system. According to this theory, the earth and
  the other planets move around the sun. Brahe
  reasoned that if the earth revolved around the
  sun, he should have been able to measure changes
  in the positions of the stars resulting from the
  earth's movement. He did not realize that such
  changes were too small for his instruments to
  detect. However, Brahe's observational data later
  enabled Johannes Kepler, a German astronomer and
  mathematician, to confirm the Copernican theory.
• Brahe was born in Knudstrup (then a Danish city
  but now in Sweden), near Malmo. As a member of
  the nobility, he attended universities in
  Denmark, Germany, and Switzerland. Brahe built an
  elaborate observatory on the island of Hven (now
  called Ven), where he made many of his
  observations.

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Tycho Brahe (1546-1601)
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Johannes Kepler b. 1571

• Discovered three laws of planetary motion.
• Newton later used Kepler's three laws to arrive
  at the principle of universal gravitation
• Kepler's laws are
• (1) Every planet follows an oval-shaped path, or
  orbit, around the sun, called an ellipse. The sun
  is located at one focus of the elliptical orbit.
• (2) An imaginary line from the center of the sun
  to the center of a planet sweeps out the same
  area in a given time. This means that planets
  move faster when they are closer to the sun.
• (3) The time taken by a planet to make one
  complete trip around the sun is its period. The
  squares of the periods of two planets are
  proportional to the cubes of their mean distances
  from the sun.
• Kepler formed an association with Tycho Brahe,
  which shaped the rest of his life.
• His most significant discoveries were trying to
  find an orbit to fit all Brahe's observations of
  the planet Mars. Earlier astronomers thought a
  planet's orbit was a circle or a combination of
  circles. However, Kepler could not find a
  circular arrangement to agree with Brahe's
  observations. He realized that the orbit could
  not be circular and resorted to an ellipse in his
  calculations. The ellipse worked, and Kepler
  destroyed a belief that was more than 2,000 years
  old.
• Kepler was the first astronomer to openly uphold
  the theories of the Polish astronomer Nicolaus
  Copernicus.

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Johannes Kepler b. 1571

• Discovered three laws of planetary motion.
• Newton later used Kepler's three laws to arrive
  at the principle of universal gravitation
• Kepler's laws are
• (1) Every planet follows an oval-shaped path, or
  orbit, around the sun, called an ellipse. The sun
  is located at one focus of the elliptical orbit.
• (2) An imaginary line from the center of the sun
  to the center of a planet sweeps out the same
  area in a given time. This means that planets
  move faster when they are closer to the sun.
• (3) The time taken by a planet to make one
  complete trip around the sun is its period. The
  squares of the periods of two planets are
  proportional to the cubes of their mean distances
  from the sun.

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Johannes Kepler b. 1571

• Kepler formed an association with Tycho Brahe,
  which shaped the rest of his life.
• His most significant discoveries trying to find
  an orbit to fit all Brahe's observations of the
  planet Mars. Earlier astronomers thought a
  planet's orbit was a circle or a combination of
  circles. However, Kepler could not find a
  circular arrangement to agree with Brahe's
  observations. He realized that the orbit could
  not be circular and resorted to an ellipse in his
  calculations. The ellipse worked, and Kepler
  destroyed a belief that was more than 2,000 years
  old.
• Kepler was the first astronomer to openly uphold
  the theories of the Polish astronomer Nicolaus
  Copernicus.

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Johannes Kepler b. 1571

• FIRST LAW
• The orbits of the planets are ellipses, with the
  Sun at one focus of the ellipse.

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Johannes Kepler b. 1571

• SECOND LAW
• The line joining the planet to the Sun sweeps out
  equal areas in equal times as the planet travels
  around the el

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Johannes Kepler b. 1571

• THIRD LAW
• The ratio of the squares of the revolutionary
  periods for two planets is equal to the ratio of
  the cubes of their semi-major axes

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Gilbert, William (1540-1603),

• Gilbert, William (1540-1603), an English doctor
  and scientist, was the first person to use the
  word electricity. He has been called the "Galileo
  of Magnetism" because of his celebrated book De
  Magnete, which he published in 1600. It was
  concerned with the properties of magnetism, with
  electricity, and with the use of compasses in
  navigation.
• Gilbert's most important discoveries in the field
  of magnetism were the laws of attraction and
  repulsion, magnetic dip, and the properties of
  loadstones. Gilbert based his findings on
  observation and practical experiments. This
  practice differed greatly from that of most of
  the scientists of his time, who developed only
  abstract theories, unsupported by experiments.
• Gilbert was born in Colchester, in Essex,
  England, and was educated at St. John's College,
  Cambridge. He was physician to Queen Elizabeth I
  and attended her during her last illness. Gilbert
  died on Nov. 30, 1603.

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William Harvey (1578-1657)

• An English physician who became famous for his
  discovery of how blood circulates in mammals,
  including human beings. He described his
  discovery in An Anatomical Study of the Motion of
  the Heart and of the Blood in Animals (1628).
  This work became the basis for all modern
  research on the heart and blood vessels.

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Robert Boyle (1627-1691)

• An Irish scientist considered the founder of
  modern chemistry. He helped establish the
  experimental method in chemistry and physics.
• Boyle is best known for his experiments on gases
  that led to the formulation of Boyle's law (see
  GAS (Gas laws)). This law says the volume of a
  gas at constant temperature varies inversely to
  the pressure applied to the gas. Boyle also
  helped improve the air pump, and with it he
  investigated the nature of vacuums.
• Boyle introduced many new methods for determining
  the identity and chemical composition of
  substances. He disproved the theory that air,
  earth, fire, and water were the basic elements of
  all matter. Boyle argued that all basic physical
  properties were due to the motion of atoms, which
  he called "corpuscles."
• Boyle lived in England for most of his life. He
  was a founding member of the Royal Society of
  London, one of the world's foremost scientific
  organizations. Boyle described his experiments in
  many books. He was born at Lismore Castle,
  Ireland.

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Robert Boyle (1627-1691)
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Antoine Lavoisier 1743 - 1794

• French chemist who, through a conscious
  revolution, became the father of modern
  chemistry. As a student, he stated "I am young
  and avid for glory." He was educated in a radical
  tradition, a friend of Condillac and read
  Maquois's dictionary. He won a prize on lighting
  the streets of Paris, and designed a new method
  for preparing saltpeter. He also married a young,
  beautiful 13-year-old girl named Marie-Anne, who
  translated from English for him and illustrated
  his books. Lavoisier demonstrated with careful
  measurements that transmutation of water to earth
  was not possible, but that the sediment observed
  from boiling water came from the container. He
  burnt phosphorus and sulfur in air, and proved
  that the products weighed more than he original.
  Nevertheless, the weight gained was lost from the
  air. Thus he established the Law of Conservation
  of Mass.

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Galileo Galilei 1564 - 1657

• Italian astronomer and physicist, has been
  called the founder of modern experimental
  science. Galileo made the first effective use of
  the refracting telescope to discover important
  new facts about astronomy. He also discovered the
  law of falling bodies as well as the law of the
  pendulum. Galileo designed a variety of
  scientific instruments. He also developed and
  improved the refracting telescope, though he did
  not invent it.

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Galileo Galilei
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Astronomy and Kinematics

• In 1610 Galileo made observations of sunspots and
  of Venus, noting that the planet progresses
  through phases similar to those of the moon. This
  fact confirmed his doubts about Ptolemaic
  astronomy and deepened his conviction of the
  truth of Copernicus' theory that the earth and
  planets revolve around the sun. Publication of
  these findings, starting in 1610, brought him
  wide renown.

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Astronomy and Kinematics

• Galileo also pursued research on
  motion-especially the motion of freely falling
  bodies. The problem, as he saw it, was that the
  Aristotelian theory of motion, which referred all
  motion to a stationary earth at the center of the
  universe, made it impossible to believe the earth
  actually moves. Galileo went to work to develop a
  theory of motion consistent with a moving earth.

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Astronomy and Kinematics

• Among the most important results of this search
  were the law of the pendulum and the law of
  freely falling bodies. Galileo observed that
  pendulums of equal length swing at the same rate
  whether their arcs are large or small. Modern
  measuring instruments show that the rate is
  actually somewhat greater if the arc is large.
  Galileo's law of falling bodies states that all
  objects fall at the same speed, regardless of
  their mass and that, as they fall, the speed of
  their descent increases uniformly.

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Galileo and Inertia

• http//id.mind.net/zona/mstm/physics/mechanics/fo
  rces/galileo/galileoInertia.html

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Pendulum

• The Italian physicist Galileo discovered
  the laws of the pendulum. He noticed that a
  hanging lamp would swing with an almost constant
  period, whether the arc was large or small. He
  believed that a pendulum could regulate the
  movements of clocks. The Dutch scientist
  Christiaan Huygens patented the first pendulum
  clock in 1657. Galileo's observations are still
  correct as long as the pendulum's swing is small.
  But modern measuring instruments have shown that
  the period of a pendulum increases when it has a
  large swing.

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Pendulum

• The Simple Pendulum
• If a pendulum of mass m attached to a string of
  length L is displaced by an angle from the
  vertical, it experiences a net restoring force
  due to gravity
• In this small angle approximation, the amplitude
  of the pendulum has no effect on the period. This
  is what makes pendulums such good time keepers.
  As they inevitably lose energy due to frictional
  forces, their amplitude decreases, but the period
  remains constant.

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Pendulum
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Descartes 1596 - 1650

• French philosopher, mathematician, and scientist.
  He is often called the father of modern
  philosophy. Descartes invented analytic geometry
  and developed a detailed account of the physical
  universe in terms of matter and motion. He was a
  pioneer in the attempt to formulate simple,
  universal laws of motion that govern all physical
  change.

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Rene Descartes

• Rene Descartes was one of the founders of modern
  philosophy. In this painting, Descartes conducts
  a scientific experiment for Queen Christina of
  Sweden shortly before his death in 1650.
• Detail of Rene Descartes Conducts a Demonstration
  Before Queen Christina of Sweden (about 1700) oil
  on canvas by Dumesnil (The Art Archive)

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Bacon, Francis (1561-1626)

• English philosopher, essayist, jurist, and
  statesman. He was one of the earliest and most
  influential supporters of empirical
  (experimental) science and helped develop the
  scientific method of solving problems.
• Bacon believed all previous claims to knowledge,
  particularly of medieval science, were doubtful
  because they were based on poor logic. He
  believed the mind makes hasty generalizations,
  which prevent the attainment of knowledge. But he
  also believed that the mind could discover truths
  that would enable humanity to conquer disease,
  poverty, and war by gaining power over nature. To
  discover truths, the human mind must rid itself
  of four prejudices. Bacon called these prejudices
  Idols of the Mind.
• Bacon believed the mind could attain truth if it
  followed the inductive method of investigation.
  He developed four steps of doing so (1) listing
  all known cases in which a phenomenon occurs (2)
  listing similar cases where the phenomenon does
  not occur (3) listing the cases in which the
  phenomenon occurs in differing degrees and (4)
  examination of the three lists. These steps would
  lead to the cause of a phenomenon.
• Bacon suggested the use of preliminary hypotheses
  (assumptions) to aid scientific investigation.
  His treatment of hypothesis is still a subject of
  study. Bacon also wrote an unfinished romance
  called New Atlantis (published in 1627, after his
  death). The book describes an imaginary island
  where the inhabitants dedicate themselves to the
  study of science.

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Isaac Newton 1642 - 1727

• Proposed three laws of mechanics
• 1. Inertia - A body continues to move in a
  straight line unless acted upon by a force
• 2. F ma Acceleration is proportional
  to the applied force. As long as the force is
  applied the velocity increases.
• 3. For every action there is a reaction
• Explained motion of planets and moon
• Proposed law of universal gravitation
• Explained tides
• Assumed laws on Earth were same as in the heavens
• Discovered light composed of different color
• Invented reflector telescope

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Newtons Rules of Reasoning

• Use no more hypothesis than needed a restatement
  of Ockhams Razor
• Apply same cause to same effect
• Properties on earth are same as properties (laws)
  in other parts of universe
• Offer hypotheses supported only by experiment
• we are to look upon propositions inferred by
  general induction from phenomena as accurately or
  very nearly true, not withstanding any contrary
  hypothesis that may be imagined till such time as
  other phenomena occur by which they may either
  be made more accurate or liable to exception

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Maxwell, James Clerk (1831-1879)

• Scottish scientist, one of the greatest
  mathematicians and physicists of the 1800's is
  best known for his research on electricity and
  magnetism and for his kinetic theory of gases.
  This theory explains the properties of a gas in
  terms of the behavior of its molecules. Maxwell
  also investigated color vision, elasticity,
  optics, Saturn's rings, and thermodynamics, a
  branch of physics that deals with heat and work.
• Maxwell based his work on electricity and
  magnetism on the discoveries of the English
  physicist Michael Faraday. In 1864, Maxwell
  combined his ideas with those of Faraday and
  certain other scientists and formed a
  mathematical theory that describes the
  relationship between electric and magnetic
  fields. Both these fields exert forces on
  electrically charged objects. Maxwell showed that
  waves in combined electric and magnetic fields,
  called electromagnetic waves, travel at the speed
  of light. In fact, Maxwell argued that light
  itself consists of electromagnetic waves. In the
  late 1880's, the German physicist Heinrich R.
  Hertz conducted experiments that confirmed
  Maxwell's theory.
• Maxwell's equations indicate that light moves at
  a particular speed, represented by the letter c.
  The value of c is now known to be 186,282 miles
  (299,792 kilometers) per second. Maxwell assumed
  that c was the speed of light relative to the
  ether. According to this assumption, light would
  travel faster or slower than c in an inertial
  frame moving relative to the ether.

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Michelson and Morley

• During the 1800's, physicists tried
  unsuccessfully to measure the speed of the earth
  relative to the ether. According to classical
  physics, the ether was motionless. In the early
  1880's, Hendrik A. Lorentz, a Dutch physicist,
  explained the failure of these experiments by
  assuming that the ether was partially dragged
  along as the earth moved through it. Two American
  physicists, Albert A. Michelson and Edward W.
  Morley, developed an instrument that made far
  more precise measurements than earlier devices.
  Their experiments helped destroy the ether
  theory. In 1887, Michelson and Morley
  demonstrated that the earth's movement around the
  sun had no effect on the speed of light. Their
  finding could be understood only by assuming that
  the ether near the surface of the earth moved at
  the same speed as the earth. However, this
  assumption contradicted the results of many other
  experiments.

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Michael Faraday, b. Sept. 22, 1791 d. Aug. 25,
1867

• The English chemist and physicist Michael
  Faraday, b. Sept. 22, 1791, d. Aug. 25, 1867, is
  known for his pioneering experiments in
  electricity and magnetism. Many consider him the
  greatest experimentalist who ever lived. Several
  concepts that he derived directly from
  experiments, such as lines of magnetic force,
  have become common ideas in modern physics.

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JAMES CLERK MAXWELL 1831-1879

• James Clerk Maxwell was one of the greatest
  scientists who have ever lived. To him we owe the
  most significant discovery of our age - the
  theory of electromagnetism. He is rightly
  acclaimed as the father of modern physics. He
  also made fundamental contributions to
  mathematics, astronomy and engineering.

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Albert Einstein (1879-1955),

• Was one of the greatest scientists of all time.
  He is best known for his theory of relativity,
  which he first advanced when he was only 26. He
  also made many other contributions to science.
• Relativity. Einstein's relativity theory
  revolutionized scientific thought with new
  conceptions of time, space, mass, motion, and
  gravitation. He treated matter and energy as
  exchangeable, not distinct. In so doing, he laid
  the basis for controlling the release of energy
  from the atom.
• Thus, Einstein was one of the fathers of the
  nuclear age. Einstein's famous equation, E equals
  m times c-squared (energy equals mass times the
  velocity of light squared), became a foundation
  stone in the development of nuclear energy.
  Einstein developed his theory through deep
  philosophical thought and through complex
  mathematical reasoning. The great scientist was
  once reported to have said that only a dozen
  people in the world could understand his theory.
  However, Einstein always denied this report.

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Principles of Relativity

• Einstein introduced a new principle, the special
  principle of relativity. This principle has two
  parts (1) There is no ether, and the speed of
  light is the same for all observers, whatever
  their relative motion. (2) The laws of nature are
  the same in all inertial frames, where the laws
  are understood to include those described by
  Maxwell.

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