Aristotelian , ptolemy and the greek tradition

Thales of miletus

6th century BCE - proposed that water is the fundamental substance of all things and is considered one of the first philosophers in Western history.

Ionian concept

refers to the philosophical and scientific ideas originating from the ionian region of Greece that emphasized natural explanations for phenomena, moving away from mythological interpretations.

Pythagoras

6th century BCE pythagoreanism was the concept that the universe was based on numbers, proportions geometry, and ratios. The pythagoras developed a cosmology that divided the universe into 3 spheres.

The Terrestrial sphere

“Uranos” - also called the sublunar realm. The least divine part of the universe, included earth and everything around it - air , the oceans, mountains and all living things and was thought to be subject to change and decay.

the celestial sphere

“cosmos” - beyond the earth are the cosmos, the sphere where the stars, plantes and other celestial bodies move. The celestial sphere is the realm of stars and planets beyond Earth, considered more perfect and orderly than the sublunar realm, where celestial bodies move in predictable patterns.

the divine sphere

“ olympian realm” - sphere of the gods , after the mountains , where ancient greeks believed gods lived.

the celestial fire

The element that was considered to be the purest and most divine form of matter in the Aristotelian cosmology, associated with the heavens and the divine. the heart of the universe representing th essence of the universe.

Aristarchos of samos

Jump to future - 3rd century An ancient Greek astronomer who proposed an early heliocentric model of the universe, suggesting that the Earth revolves around the Sun. this idea predated capernicus by nearly 1,800 years

heraclitus of Ephesus

6th century BCE His view - “ everything flows change is constant” the world is in a constant state of change and flux Famous quote- you cannot step into the same river twice, you are as changed as the river and only the continuity of throught gives the illusion of constancy

parmenides of Elea

6th-5th century BCE his view - being is the only true reality , change is an illusion reality is unchanging and eternal. what exists must always exist and it cannot change , come or cease to be.

Zeno of Elea

5th century BCE- student of parmenides , his paradox was created to support parmenides ideas - change and motion are illusions

zeno paradox

zeno’s paradox about the turtle and achilleus in a race

Socratic Era

5th century BCE refers to the period in Ancient Greek philosophy marked by the influence of the philosopher socrates - everything before socrates is referred to as pre socratic and everything after is referred to as post socratic

socrates

an ancient greek philosopher in the 5th century BCE believed in selfless dedication to the truth- teacher of plato

socratic method

a form of argumentative dialogue that stimulates critical thinking and ideas in order to achieve a deeper understanding

idealism

Socrates believed that ideal forms were accessible to the human intellect because humans possess a soul that connects them to the realm of perfection. Through this connection, he argued, we inherently hold knowledge within ourselves, which can be uncovered or revealed through introspection and inquiry. - plato also believed in idealism

plato

5th century BCE entering 4th century BCE he was a student of socrates. founded his academy in the 4th century BCE his primary works are: 28 dialogues, and the republic. Mostly he believed in the same ideas as socrates and everything we know about socrates is from plato’s works

The allegory of the cave

this theory is from Plato book the republic : people are like prisoners in a dark cave who, from childhood , see only a strange kind of shadow play. because the prisoners have no other reference , the shadows are taken to be reality.

the four elements

The 4 elements are a classical concept from ancient philosophy and science, particularly in Ancient Greek thought. They represent the fundamental components of the natural world. The elements have been used by ancient greek philosophers to make sense of matter and the world.

Platonic solids

a special class of three dimensional geometric shapes that are highly symmetrical. they were named after plato , who associated them with the classical elements in his philosophy

Aristotle

4th century BCE - he was a student of Plato and teacher of alexander the great. founded his school of philosophy and research “ the lyceum” in Athens.

Aristotle’s idea

• did not reject all of plato’s philosophy , he shared the belief in the necessity of logic and some aspect of platonic idealism.

• He was far more interested in the material world - although he agreed with plato that th world was impure and our senses fallible, he argued that they were all we had

• our intellect could only be applied to what we observe of the world around us

• he set out to create a complete system of natural philosophy.

Aristotle system

a complete system of natural philosophy created by Aristotle. This system had two main purposes 1. to provide a complete description of natural objects. 2. to verify knowledge that would satisfy the demands of proof necessary to convince people who lived in a society.

Aristotle physics

1. four elements & all material objects in the terrestrial realm were composed of these four elements. ( the superficial distinction between objects was the result of different proportions and quantities of the elements)

2. matter also seemed to have four qualities which Aristotle identified as HOT/COOL and WET/DRY. ( these were always presented as pairs hot/dry , cool/wet, hot/dry, cool/dry)

3. four causes (how a thing came to be) formal- the plan of model

   material - the stuff used to create the object

   Efficient - the agent that caused the object to come into being

   Final- the purpose or necessary condition that led to the objects creation

natural motion

the movement of objects to their natural place, eg heavy objects fall and fire rises

( Earth and water move down - towards the centre of the universe and Air and fire move up away from the centre)

violent motion

occurs when an external force is applied to an object, eg pushing. Aristotle believed that violent motion stops when external force is removed.

The syllogism

Aristotles system of logic with the major, minor premise, and the conclusion

geocentric cosmos

• all motion in the heavens is uniform circular motion - planets move in perfect circles

• objects in the heavens are made from perfect material , and cannot change thier intrinsic properties ( eg brightness)

• earth is an the centre of the universe and everything revolves around it.

Aristotle astronomy 4th century BCE

believed in the geocentric view and also accepted the pythagorean idea that all matter in the celestial realm was perfect .

Roman era

Roman rise to empire - 3rd century BCE. Roman empire dominated Greece

Roman position on natural philosophy

the study of nature for the romans oriented more towards practicality than philosophical speculation

Ptolemy

2nd century BCE - was both Greek and Roman lived in Alexandria. Supported the geocentric view

what did he do?

• created a mathematical model that combined Aristotelian cosmology with observation

• provided comprehensive tools including tables and directions to move accurate observation

• produced material on astrology , astronomy, and geography.

  Legacy: his methods of astronomical calculation shaped the western view of the heavens for more than 1,000 years, even though copernicus opend a bridge to helicentrism Ptolmic view was not surpassed until the beggining of the 17th century CE in the era of Tycho Brahe and Galileo.

what did ptolemy want to do

He wanted to refine and expand upon the geocentric model of the universe that originated with earlier greek philosophers and astronomers ( ex Aristotle )

the problems 1. retrograde motion

An apparent phenomenon in which a planet seems to move backwards ( east to west) in the sky for a period of time before resuming its normal prograde motion ( west to east) this is observed with the naked eye and was a key challenge for early astronomers to explain.

varying speed

a number of planets seemed to move at different speeds in different parts of their orbits

dimmer & brightness

planets appeared to get dimmer and brighter over time

bigger picture

these combined problems of motion and time seemed to contradict the axiom of the perfect circular & unchanging nature of the heavens

Ptolemy solution

introduced geometric ‘fixes” that allowed for a mechanization of the process of mapping the movement of the celestial bodies these fixes were the eccentric , the epicycle , and the equant

the eccentric

A circle whose centre is slightly away from the earth. In this system, the planets would still move in a circle but the centre of the circle was not the earth - this fixed the varying speeds problem

Epicycle

A small circle attached to one of the concentric spheres - this fixes the problem of Retrograde motion - why planets seem to move backwards

Equant

A point equidistant from the circle’s centre on the opposite side from the earth.

Innovation

the process of creating and implementing new ideas, methods, or value.

Renovation

Expanding on something that already exists.

Ptolmy’s works

Geographica - work for the terrestrial realm

the Almagest -work for the celestial realm