Geology 101 Outline of Current Lecture Science of Earth Development of Geology Magnitude of Geologic Time Nature of Scientific Inquiry Structure of the Universe Hierarchic Structure Evolution of Earth Red Shift and Doppler Effect Lecture 1 Geology 101 Chapter 1 Science of the Earth o Geology study of the Earth Addresses questions and practical problems o Physical and Historical o Physical Geology materials and processes o Historical Geology understand the origin and development of Earth Earth and Development People o Most people live in cities Resources important focus in geology Geologic processes hazards rock cycle plate tectonics floods sea levels rising earthquakes and volcanoes o How we study geology Field observations Lab experiments Theories o Fundamental Principles Theory of plate tectonics Concept of Earth system Development of Geology o Aristotle believed rocks were made from stars influence and that earthquakes were made from crowded air underground o Catastrophism Ussher Referenced bible Landscapes were shaped primarily from catastrophes o Sudden events Geology 101 Magnitude of Geologic Time Nature of Scientific Inquiry o Assumption world is consistent and predictable o Hypothesis Testable Tentative explanation o Theory Well tested widely accepted best explains o Scientific Method Question Data observations Results shared Structure of Universe o Heliocentric Earth moves Sun center All planets orbit sun Renaissance 15th century Hierarchic Structure o Sun medium sized star solar system o Sun 300 billion stars milkway galaxy o 100 billion galaxies universe o Distance measured in light verse distance light travels in one earth year Sun is 8 3 light minutes from us Edge of visible universe 13 billion light years away Evolution of Earth o Hubble 1920s Geology 101 Observations light of the galaxies displayed red shifts relative to light nearby Doppler Effect o All distant galaxies moving rapidly away from Earth Formation began 13 7 billion years ago Initially subatomic particles formed o As it cooled hydrogen and helium formed Condensed into stars o Nuclear fusion within stars Hydrogen nuclei convert to helium nuclei releasing radiant energy Thermal reactions make all elements up to 26 iron Rest are created during the explosive death of a star 8X or more massive than our sun o Supernova exploding star produces elements heavier than iron o Planetesimals to Protoplanets Solar system 4 6 billion years ago from solar nebula Solar nebula o Large rotating cloud of instellular dust and gas Contracted most mass goes to center to create protosun Remaining formed the flattened rotating disk o Gradually cooled and condensed Repeated collisions Protoplanets o Composition Determined by proximity to protosun Temperatures are higher when they are closer o Inner planets composed of materials with higher melting points Colder when further away o Ice CO2 Ammonia NH4 Repeated collision and accretion Solar system forms o Nebular theory proposes bodies of solar systems evolved from enormous rotating clouds Super Nova external influence causes supernova to become protosun during collapse gravitational energy is converted into thermal energy o The whole universe is expanding Size is not fixed Red Shift and Doppler Effect o Basis for Big Bang Theory of universe formation o Apply to different types of waves Sound Geology 101 Light Stationary same pitch Toward higher pitch Away lower pitch Blue high frequency Red low frequency We only see red Red away Blue toward