1 / 20

Evolution of Cosmologies

Evolution of Cosmologies. From Mythic to Mathematical. Natural Cycles begat Explanations. Over time, people notice patterns and cycles in the sky. The cycles of sunrise and sunset, lunar phases, seasonal motions of the stars,

Download Presentation

Evolution of Cosmologies

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.


Presentation Transcript

  1. Evolution of Cosmologies From Mythic to Mathematical

  2. Natural Cycles begat Explanations • Over time, people notice patterns and cycles in the sky. • The cycles of sunrise and sunset, • lunar phases, • seasonal motions of the stars, • These cycles were likely known by everyone (in contrast to today!) • Different cultures had different explanations for these observed motions. With a growing awareness of self and a need to feel connected to the cosmos, individual cultures began to project their personality onto the celestial canopy. Certain patterns of stars took on special importance as they were endowed with human or animal characteristics.

  3. Natural Cycles and Seasonal Weather • Over time, a statistical association between weather and the positions of stars became apparent. • This leads to building very large scale calendars (Pyramids, Stonehenge, etc) as a means of known when seasonal change is coming (flooding, time to plant crops, etc)

  4. Components of The Mythic Universe • Demons  represent our innate fears (of the unknown?) • Gods  a source of comfort and exist to combat Demons • Male/Female polarization  evil demons often Male; benevolent gods are Female • Cosmic Womb  primal female gives birth to the Universe

  5. Cosmic Womb • This is an original idea • the entire Universe was created in a single event • Also suggests a connection between organic and inorganic material as all were created in the same place • Note that in this model, man and nature are inseparable

  6. The Mythic Universe • Contains a great number of parameters (e.g. demons and gods) • Is highly qualitative/behaviorist in nature (no math) • Is not a peaceful, harmonious place, but rather a place of fierce and feuding Gods that ultimately produces a cataclysm that leads to re-birth. • Is shaped by the whims of the gods and appears not to have much order

  7. Fundamental Forces • Starting around 600 BC the Greeks developed this sense: All the world can be understood as an interaction between 4 primal elements: Air, Earth Fire and Water.

  8. Air, Earth, Fire and Water • Table of Elements  ordering the Cosmos and removing the Chaos • However, given their hierarchical nature, various Greek philosophers attempted to make one of these elements more fundamental than the others. • Thales  water • for there must be some natural substance, either one or more than one, from which the other things come-into-being, while it is preserved -- Thales • Anaximenes  Air (stars are fires in the sky  fire now subservient to Air)

  9. More World Views • Anaximander thought of the primal elements as opposites in conflict (e.g. Fire vs Water, Air vs Earth) • Anaximenes had a different conception: the primal elements are not opposed, but different stages of a continuum. • Air is most important because other elements “condense out of it”. • Air is the nearest to an immaterial thing; for since we are generated in the flow of air, it is necessary that it should be infinite and abundant, because it is never exhausted.

  10. Alternate Viewpoint • Democritus (500 BC)  The Universe consists of atoms and the Void; all else is opinion and illusion • The Atomists argue that visible change in the Universe is a consequence of RANDOM rearrangement of atoms interacting in an infinite void. • This provides and answer to Parmenides who claims it impossible for “something to come from nothing” • In the atomist view, new stuff randomly comes into “being” in the Kosmos all of the time, but all of this stuff is impermanent as is everything that is observed currently.

  11. Alternate Viewpoint • This alternate viewpoint was not culturally acceptable to the strong Greek desire for logic and order and hence the idea was essentially dismissed (but still recorded) • The atomist view point also requires there to be a void – which according to Aristotle and followers, is a logical impossibility • In the atomist view The Universe runs by itself  there is no order  no need for physical laws  just like Max Planck says 2500 years later

  12. Cause and Effect Now we have CAUSE and EFFECT and the first hints of the physical nature of the Universe. The question is whether the CAUSE is due to human behavior or to the natural physics of nature. It is often difficult, through observations alone, to distinguish between these alternatives. If Nature functions by a set of ordered and rational physical laws, then does it not make sense to structure society so it too is "governed" by a set of rational laws? After all, science says …

  13. Cause and Effect • Is generally viewed as linear in either the vertical (events are isolated) or horizontal (there is a linear chain of events). The third option is not, historically, ever considered (emergent behavior)

  14. Thales • Scientific thought was the discovery of nature • natural phenomena we see around us are explicable in terms of matter interacting by natural laws, and are not the results of arbitrary acts by gods.  • Thales’ theory of earthquakes  the (presumed flat) earth is actually floating on a vast ocean, and disturbances in that ocean occasionally cause the earth to shake or even crack, just as they would a large boat. 

  15. Water is the Primary Principle

  16. Creation Ideas/Cosmology • Thales suggested that in the beginning there was only water, so somehow everything else emerged from it • Anaximander supposed that initially there was a boundless chaos, and the universe grew into this boundless space. • Anaximenes suggested that originally there was only air and the liquids and solids we see around us were formed by condensation.  • This means a simple initial state develops into our world using physical processes and not the micromanaging by Gods

  17. Parmenides of Elea(c. 490 B.C.) • Only two states: Being (Eon) and Non-being • Both states are permanent • Change is an illusion – this is the essence of a long debate on whether or not change exists • The senses can’t be trusted; truth comes through reason alone – many decipher his hard to read prose as saying this in his “The Way of Turth” poem

  18. Heraclitus (c. 500 B.C.) • Change is the only permanent thing, given structure by logos (logic) • “You can’t step in the same river twice” • Senses can be trusted if interpreted correctly • World made from fire (symbol of change)

  19. Leucippus of Abdera (c. 425 B.C.) • Materials can be divided until a primal, uncuttable particle is reached: “ATOMOS” • Atoms move through a void space (not according to Aristotle later in about 100 years) • Motion caused by a primeval vortex (like the Prime Mover)

  20. Order, order, order, • Above all, Air Earth Fire and Water are arranged in some order to create the World. Many different philosophies change component order, but order is always preserved

More Related