Hellenistic natural philosophy
Download
1 / 19

Hellenistic Natural Philosophy - PowerPoint PPT Presentation


  • 154 Views
  • Updated On :

Hellenistic Natural Philosophy. The Hellenistic World Schools and Education Four Major Philosophies Mathematics Astronomy. Pre Alexander: Hellenic. Post Alexander: Hellenistic. Alexander the Great (356 – 323 BCE). Alexandria: the new cultural capital. Ptolemy’s Kingdom: Egypt.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Hellenistic Natural Philosophy' - zaza


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Hellenistic natural philosophy l.jpg
Hellenistic Natural Philosophy

  • The Hellenistic World

  • Schools and Education

  • Four Major Philosophies

  • Mathematics

  • Astronomy

Pre Alexander: Hellenic

Post Alexander: Hellenistic

Alexander the Great (356 – 323 BCE)


Slide2 l.jpg

Alexandria: the

new cultural capital

Ptolemy’s

Kingdom:

Egypt


Ii schools and education l.jpg
II. Schools and Education

A. Elementary education: the gymnasium

B. Sophists

1. Itinerant (travelling) teachers

2. Democracy demands educated citizenry

3. Sophists expand teaching subjects to include all

knowledge


C academy and lyceum l.jpg
C. Academy and Lyceum

1. Academy (388 – 83 BCE; 410 – 560 CE)

2. Lyceum (335 – 86 (?))


Questions l.jpg
Questions

  • Why is the Greek world after Alexander called “Hellenistic”?

  • After Alexander’s conquests living in Greece is like living in Hell

  • In tribute to Alexander’s wife, Helen

  • There was a mix of cultures from the countries Alexander conquered

  • Hellena in Egypt became the new cultural capital of Greece

  • Which of the following relates to why the Sophists were so popular?

  • They taught young girls how to become politicians

  • The Greeks valued all knowledge

  • The Greeks were very competitive

  • The Greeks rejected the authority of the gods

  • More than one of the answers above is possible

  • Which of the following is correct about events that occurred after

  • Alexander’s death?

  • Athens remained the cultural center of Greece

  • The Greek empire was stabilized into a single unit

  • Alexander’s general competed for prestige


Iii four major philosophies l.jpg
III. Four Major Philosophies

A. Platonic and Aristotelian

B. Epicureanism: ethics most important

1. Happiness (in moderation)

  • the way to happiness: eliminate fear of unknown and

  • supernatural through natural philosophy

2. Atomists (with some modification)

  • denial of

    • ruling mind

    • divine providence

    • destiny

    • life after death

    • final causes (purpose)

  • determinism

Epicurus (341 – 270)

  • all is according to Chance


Iii four major philosophies7 l.jpg

4. The Cosmos: Eternal cycle of expansion and contraction

III. Four Major Philosophies

C. Stoicism

1. Compared to Epicureans

  • Ethics number one

  • Happiness is the goal

2. Different from Epicureans

  • Achieve happiness by living in harmony with Nature

  • Cosmos is an organic being not mechanistic

  • Purpose exists

  • Divine rationality creates determinism

3. Pneuma (literally: breath)

  • Mix of air and fire

  • Three forms of pneuma

Zeno of Citium (334 – 262 )

1. Hexis: binds matter together

2. Physis: vital principle of plants and animals

3. Psyche: soul (organizing principle)

  • expansion: cosmos consumed in fire

  • contraction: cosmos reborn


Questions8 l.jpg
Questions

  • Which of the following philosophies taught that the Stuff was atoms?

  • Epicureanism

  • Stoicism

  • Both Epicureanism and Stoicism

  • Which of the following philosophies believed that the goal of life was

  • happiness?

  • Epicureanism

  • Stoicism

  • Both Epicureanism and Stoicism

  • Which of the following philosophies was atheistic?

  • Epicureanism

  • Stoicism

  • Both Epicureanism and Stoicism


Iv mathematics l.jpg
IV. Mathematics

A. Application of mathematics to nature

1. Pythagoras: ultimate reality is numbers (geometric)

2. Plato: 4 elements reducible to geometry

3. Aristotle: there is a difference between Nature and numbers

  • Natural things are sensible and changeable

  • Geometry only one property of natural thing; also weight, color, etc.

B. Greek math emphasizes geometry

1. Reason: problem with irrational numbers

  • Square with sides of 1

  • Diagonal = √ 2

= 1.4142135623730950488016887240297 …

2. Euclid (325 – 270 BCE)

father of mathematics (geometry)


3 archimedes 287 212 l.jpg
3. Archimedes (287 – 212)

  • Method of exhaustion

  • Principle of the lever

Eureka!

  • Water screw

  • Archimedes principle


Questions11 l.jpg
Questions

  • Which of the following Greeks was least interested in applying math to

  • Natural phenomena?

  • Plato

  • Archimedes

  • Pythagoras

  • Aristotle

  • What did the Greeks have against pure math (as opposed to geometry)?

  • Pure math had not yet been invented

  • They believed it played a minor role as simply one of many parts of form

  • They had problems with the aesthetics of irrational numbers

  • Their number system did not allow for complex calculations

  • An object floats in water when the weight of the water the object displaces

  • is equal to the weight of the object.

  • is less than the weight of the object.

  • is more than the weight of the object.


V astronomy l.jpg
V. Astronomy

A. Final Cause

1. Observation and mapping of stars - astrology

2. Creating an accurate calendar

  • solar year (365.24 days) and lunar month (29.5 days) don’t match

  • 12 – 30 day months short by 5 days

  • Metonic calendar (425 BCE)

    • 19 solar years = 235 lunar months (off by 2 hours)

    • 12 years of 12 months followed by 7 years of 13 months

  • still in use: NASA and Hebrew calendar

B. Plato and Eudoxus

1. Shift to planetary concentration

2. 2 sphere model

3. Ultimate goal to simplify

4. Aristotle further develops model and

claims physical reality


V astronomy13 l.jpg
V. Astronomy

C. Heliocentric universe

Aristarchus (310 – 230 BCE)

  • Problem: it didn’t work

1. No stellar parallax observed (link)

2. Not common sense

3. Against authority and religion


D size of the earth l.jpg
D. Size of the Earth

Eratosthenes (276 – 194)


E ptolemy 85 165 ce l.jpg
E. Ptolemy (85 – 165 CE)

Flat Earth Myth

  • Geographer

  • Astrologer

  • Astronomer


Ptolemy s geocentric models l.jpg
Ptolemy's geocentric models

Problem: how to reconcile circular (simplest) motion with

erratic movement of planets (sun and moon included).

1. Simple circular motion doesn’t work to explain anything

2. Eccentric model: works well enough for sun and moon

3. Epicycle on deferent model for other planets

  • epicycle = small circle

  • deferent = large circle

  • Problem: not accurate enough to predict movement

  • or locations of planets


Ptolemy s geocentric models17 l.jpg

Ptolemy's geocentric models

4. Equant model

  • Earth off center

  • Planet orbits around central point (not Earth)

  • Planet sweeps out equal angles in equal times from a reference point (equant point) inside the circle.

  • Problem: still doesn’t work! Doh!

5. Solution!

  • Eccentric + (Deferent + epicycle) + Equant =

  • Physical Reality (almost!)

  • Simplicity?

  • The model of the Universe until 17th Century


Questions18 l.jpg
Questions

  • Which of the following was NOT a problem for Aristarchus’s heliocentric model of the universe?

  • Stellar parallax

  • Common sense

  • Retrograde motion of the planets

  • Accepted authority on the nature of the universe

  • Which of Ptolemy’s models worked well enough to explain the movement of

  • the sun?

  • Equant

  • Epicycle on deferent

  • Eccentric

  • A combination of equant and eccentric

  • Which of Ptolemy’s models worked well enough as a model of the universe?

  • Equant

  • Epicycle on deferent

  • Eccentric

  • A combination of equant, eccentric, and epicycle


ad