Historical views of Earth's place in the universe (helicocentric and geocentric).
1000 b.c.e.– Greeks distinguish stars and planets– Stars rotate around a fixed point– Planēs: “wanderer”
– What was the Sun? • A burning bowl of oil(A ball of red hot iron)
Draw and describe Eratosthenes' calculations and significance.
What is Ptolemy's model for a geocentric universe? What is the most important thing Ptolemy was able to do that got people to believe the geocentric model?
Know the contribution for the helocentric model by Galileo, Newton and Foucault and pendulum.
They made this machine that they noticed the ball would swing at different angles at different types which the swing helped them determin which way out Earth rotated.
How old is the universe?
• Big Bang Theory
– 13.7 billion years ago
– Explosion of matter from a single point
– Evidence for the theory
• Unsolved mysteries
– Where did matter come from?
– Multiple cycles of expansion and collapse
What is the Big Bang Theory? and is it flawed?
• When did the expanding begin?
– All of the mass and energy in the Universe was packed into a single small point
– 13.7 Ga it exploded and has been expanding ever since
• A rapid cascade of events.
– Protons and neutrons formed within 1 second.
– Hydrogen atoms formed within 3 minutes.
– Hydrogen fused to form new light elements (He, Be, Li, B) via big bang nucleosynthesis
After Big Bang
With expansion and cooling...
– Hydrogen forms H2
- The fuel of stars
– Molecules coalesced into gaseous nebulae
What are the characteristis of our solar system and how it formed?
• Heavier elements– From stellar nucleosynthesis.
• The mass of a star governs its element production.
Large mass stars burn more rapidly, are short lived, and create heavier elements up to Iron.
Small Mass stars burn slowly, burn slowly, live longer, create lower elements up to carbon.
• A 3rd, 4th or nth generation nebula forms 4.56 Ga• The nebula condenses into an accretion disc
• Particles coalesce to form planetesimals and stars
Know the characteristics of Earth's interior and its significance.
• Our Place
– Earth is one of nine planets in the solar system
– The solar system is on an arm of the Milky Way galaxy
– Our Sun is one of 300 billion stars in this galaxy
• Small planetoid collides with Earth• Debris forms a ring around the Earth • The debris coalesces and forms the Moon
Have an idea of what geologic age is.
Multiple mass, extinctions, 90% of Earth's history is void of complex life, stable oxigenation. 1 billion years ago.
• Earth is 4.5 billion years old
– Stable oxygenation 1 billion years ago
• Life evolves
– Positions on watch
– Primitive: 3-4 million years ago
– Modern: 90,000 years ago
Definition of mineral.
A mineral is a naturally occurring inorganic solid element or compound, with a definite chemical composition and a repetitive internal crystal structure.
~ Atoms in a mineral are specifically ordered.
~A solid with disordered atoms is called a glass.
~Crystalline structure based on atomic patterns.
What is important about a crystal lattice in a mineral? Are we able to identify crystal structure by a sample in our hand?
~ Ordered atoms in crystals form a 3-D lattice
~ Lattices are patterns that repeat in 3 dimensions
~ This internal pattern controls mineral properties• Crystalshape • Symmetry
~No it can not be fully seen by the Human eye.
~Instrumentation allows us to “see” atoms • A beam of electrons passes through material • Atoms scatter electrons, which pass between them • A shadow on the detector indicates a row of atoms • This principle drives theelectron microscope
~X-Ray Diffraction (XRD) probes crystal lattices
~Unique lattice spacing is used to ID minerals
What is a polymorph?
A polymorph is one or two or more minerals with an identical chemical composition but with different arrangements of atoms. Example, diamond and graphite.
~Same composition but different crystal structure
~Polymorphs reveal the importance of bond type
~Diamond and graphite are carbon polymorphs• Diamond–Strongcovalentbonds;hardestmineral • Graphite – Weak Van der Waals bonds; softest mineral
What is a nucleation point and what happens at it?
A nucleation point is a pit in a rock or mineral which becomes filled with a carbonite. When these two meet it forms a fissing at the surface. Example, HCL and calcite.
Luster - vitreous, waxy-greasy, pearly, satiny, earthy/dull, and porcelaneous.