Cosmology and the Origin of Life

Fine Tuning the Cosmos: Identifying its essential Ingredients

600 BC Greeks start to dissect the world into component pieces:

ORIGINAL IDEA ALERT:
• All the world can be understood as an interaction between 4 primal elements (variation on the earlier theme)

• Air, Earth, Fire, Water

Now we have CAUSE and EFFECT and the first hints of the physical nature of the Universe.

Next step is to have a contest to see which of the four elements is really the most important (in modern cosmology we call this contest - Grand Unified Theory):

• Thales Water: world floats in primordial sea
• Anaximander World works through intermingled opposites (light and dark, up and down)
• Anaximenes Air is ultimate: stars are fires in the sky

An Alternative to the idea that something is most important:

500 BC:

Democritus: The Universe consists of atoms and the Void; all else is opinion and illusion

Collisions between atoms formed the Universe

The Universe runs by Itself

ORIGINAL IDEA ALERT

Quantum Mechanics has just been expressed. That is, the universe can exist without anyone in it

Now comes geometry and the concepts of perfection. Culturally this seems like a natural harmonious meld with the Cosmos:

Pythagoras Geometry!

• Earth is a sphere (which is a perfect figure)
• Planetary Motion is governed by geometric laws
• Geometry begets Harmony

Aristotle introduces the Two Sphere Universe. This is a FINITE Universe that you can now draw the Universe on a piece of paper!

We have come a long way from the world view that everything had a common origin (e.g. the Cosmic Womb in the Mythic Universe):

Now the Universe has a hierarchy and their are RULERS. Some elements are more important than others. Some things have dominion over other things.

To top it off: The Earth lies at the Center of the Two Sphere Universe and everything revolves around it Huge Cultural Bias.

Furthermore, Aristotle tells us that the Universe is perfect and unchanging.

Clearly, imagination has now vanished. We have a deterministic model of the Universe (e.g. two spheres) and we think that all is figured out!

Now all is in harmony, the earth is at the center of the universe and the cosmos revolves around us in perfect contentment

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Okay, our task is to now remove the earth from the center of the Universe and come up with something more sensible:

Elements of the Universe at this time (Aristotle):

• Geocentric Cosmology
• Stars and planets on perfect crystalline spheres
• Universe is perfect and Changeless

Problems:

• observed transient phenomena (comets, novae, variable stars) attributed to disturbances in the upper atmosphere of the earth

• Aristotelian model makes a definite prediction all planets and stars should move in the same direction . But Mars was known at that time to sometimes move in the opposite direction for a brief period of time (this is known as retrograde motion)

• So Ptolemy builds an incredible complicated machine to preserve the geocentric model and account for retrograde motion ( like this )

• The correct explanation for retrograde motion
  • Java Applet for Retrograde Motion
  • Applet Showing the Relative orbits or Earth and Mars

• This model stood for 1500 years before anybody asked this relevant question

Back to the Original Idea Alert:

Cardinal Nicholas of Cusa (15th Century) through a lot about cosmology and came up with the following;

• Every direction is relative
• The Universe has its center everywhere
  The above two means there can be no UNIQUE place in the Universe
• The Earth may not be stationary
• Wherever one stood in the Universe, the same pattern of stars would be strewn out before them (homogeneity)

Thus for the first time we see the ideas of relativity, homogeneity and non-uniqueness expressed.

Copernicus embraces the non-uniqueness idea and then asks why should the earth be at the center - lets put the SUN there

This is the First Heliocentric Cosmology

Evolving Models of the Solar System and The Scientific Method:

Galileo sees a mini solar system around Jupiter

Tycho searches for stellar parallax sees none Aarogant rejection of Copernicun Model

Tycho publishes data Kepler makes Geometrical Model

• Summary of Kepler's Laws

• Animated summary of Kepler's Laws

Kepler's laws are only empirical they have no dynamical basis. Therefore, they would appear to be magic as they have no physical explanation (yet). (see page 16 in the book).

Newton invents gravity, calculus but forgets about the speed of light

Einstein invents causality and gravity as curved spacetime

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