What do they have in common Account for




























- Slides: 28

What do they have in common?

Account for the difference

The Big Bang Theory “Cosmic Egg”

Outward Explosion M a t t e r STARS & ELEMENTS G a s e s

Supernovas sent matter/gasses into space?

Is the universe still expanding outward? Or will it slow, stop and fall in upon itself to repeat the cycle?


The Protoplanet Hypothesis A. K. A: “Nebular or Stellar Cloud Theory” Rotates Disc shaped cloud of dust particles

B A Rotating cloud of dust and gas gathers due to gravitational forces. Rotating mass contracts and flattens with most of the mass in the center. D C Star ignites to form the sun. Gases blown to outer planets. Planets form by the accretion of stony and iron meteorites as well as ice particles.

“Accretion”


The sun also accreted, pulling in most of the mass. Increased pressure and temperature caused thermonuclear fusion Sun = source of energy for all life on earth.

Ignition of the sun = T. Tauri Wind (blast wave) Lighter elements Denser elements Lighter elements

Oxygen, Silicon, metallic elements Denser Hydrogen, Helium, Methane Less Dense

How did Earth evolve as a planet? From this… To this! 4. 6 Billion Years Old


Early Earth is hot, hot!!! “DIFFERENTIATION” Heat Sources?

HEAT

1. High velocity collisions with Planetesimals Energy of motion converts to heat “ACCRETION”

2. Compression of planet under its own weight Heat is generated by this compression

3. Decay of radioactive elements Eg. Uranium, Plutonium Has persisted for millions of years = Heat

Internal Sources of Energy Three Sources of the Earth’s Internal Energy (Heat) 1. Impacts of asteroids 2. Decay of radioactive elements 3. Gravitational contraction

Interior of Earth 2000 C. (well beyond melting point of Iron) Silicon Sodium Iron Nickle Aluminum Potassium Differentiation occurs - Heavier elements settle to center - Lighter elements form crust & mantle


Earth’s Structure/layers Form

Cooling Crust = Continents & Oceans

Volcanic Action = Earth’s Atmosphere Water Vapor Carbon Dioxide Nitrogen

ASSIGNMENTS 1. CH 1 & 2 Vocab Notes 2. Contour/Side Profile Worksheet