(II) A beam of light in air strikes a slab of glass (n = 1.56)and is partially reflected and partially refracted. Determinethe angle of incidence if the angle of reflection is twice theangle of refraction.
print out labs from ilearn Slide 1: Introduction to geology and geologic time 2 Earth formed 4.5 Ga (billion years ago) Big bang 13.7 3 Structure of the earth o Everything is related o Outside of the earth (crust) is mostly silica and oxygen Two types of crust (oceanic and continental) o Beneath the crust is the mantel Silicates, magnesium and iron As going to the center there are different chemicals and elements o Core Mostly iron Some nickel Dense metals Chemistry of the earth changes from less dense to more dense going in 4 Mechanical layers o Lithosphere is the crust and upper mantle o Asthenosphere is the upper mantle Every time you feel an earthquake its those two layers operating together Slide o Lithosphere- plates o Asthenosphere- slushy Slide Plate tectonics: o Manner in which plates move around on the earth, as a result of radioactive decay in the core, giving off heat, making the mantle go through upwelling, pushing the lithosphere around the asthenosphere We are standing on a ridged plate, and every time it moves it is a reaction between the litho and asthenosphere Slide Wasn’t until the 60’s that plate tectonics was accepted Slide We live on the ring of fire Slide Tectonic boundaries: o Divergent move away from each other (divergent movie, she was divergent and moved away from her family) Spreading centers o Convergent- plates are colliding Subduction zone- when ocean crust [destroyed] goes into land (underneath) Continent-continent- mountains [neither is destroyed; just keep building up] o Transform- sliding past one another [san Andrea’s] Slide All oceanic crust older than 180 million years old has be subducted under continental crust This means that the oldest continental crust is about 4.1 billion years old Slide Because of plate tectonics the earth has had many different configurations Slide 250 mya (million years ago) there was Pangea slide Paleozoic; Mesozoic; Cenozoic 245, 135, 65 slide rock types o igneous- cooled magma or lava o Sedimentary- form when rock forms from hardened sediments o Metamorphic- rocks altered b heat or chemical reactions Slide Typically fossils are found and preserved in sedimentary rock Slide Steno- father of understanding geological record of sedimentary rocks o Laws: Original horizontality: all strata are deposited horizontally Sediments get laid down horizontally Lateral continuity: continuous lateral layers Was first horizontal then due to erosion there are pieces gone but across there will be the same layer on the other side Superposition: oldest rocks are on the bottom, youngest are on the top (top were deposited last) Slide Time 1- horizontal deposited 2. Tectonics force uplifting and deformation 3. Magma introduced cutting across 4. Slide relative and absolute dating Slide dating; o relative ordering (dating relative to other sediments) o absolute measure of time (this is a million years old- specific dating) Slide fossils occur in distinct intervals Slide absolute dating- radioactive dating o certain isotopes are radioactive [unstable] [carbon 14] o the minute lava becomes rock, there is no more input or output o in it all the unstable isotopes, overtime they are still trying to become stable unstable [parent]-> new element formed after going through radioactive decay [daughter] time needed for half of parent to decay = half life half life is element dependent Slide decay is predictable but spontaneous [popcorn] o putting it in you don’t know which will pop first, but you know when pulling them out they will be popped RATE of decay is constant Geo-003/Bio-010 Headlines in the History of Life ” Instructor: Mary Droser Before the headlines -Building the Tool Box: The Fossil Record Geology 5 Billions of years ago 4 3 2 1 Today 4.5 billion years Origin of the Earth 5 Billions of years ago 4 3 2 1 Today 3.5 billion years First evidence of life Fossil filamentous bacteria nearly 3.5 billion years old. This is one of the oldest fossils known. -Origins of Life & the first ~3 billionyears -Origins of Life & the first ~3 billionyears Time Today Modern Oxygen No oxygen F M E L r i E a i f t t k n c a v o y e r s e s t l B e n s s a o k e e a o f w f t f m o o e s NatureLyonsandothers, 2014, 5 Billions of years ago 4 3 2 1 Today 565 million years First multicellular animals () 5 Billions of years ago 4 3 2 1 Today 545 million years Cambrian Explosion 5 Billions of years ago 4 3 2 1 Today 545 million years Cambrian Explosion 5 Billions of years ago 4 3 2 1 Today 425 million years Invasion of Land 5 4 3 2 1 Billions of years ago Today 345 million years Amniotic Egg Evolution of the amniotic egg expanded the success of vertebrates on land 5 Billions of years ago 4 3 2 1 Today 250 million years Permo-Triassic Mass Extinction Although nearly 96% of marine species go extinct, the ultimate cause is still debated. 5 Billions of years ago 4 3 2 1 Today 65 million years Dinosaurs go extinct How do we know Paleontology :study of ancient life through the fossil record Integrative/Interdisciplinary field utilizing Biology & Geology, as well as Oceanography,Atmospheric Science, Chemistry, etc. The Fossil Record demonstrates direct evidence of evolution and extinction of life on this planet. Why Bother 1)Resources– fossil fuel , coal: Why Bother 1)Resources 2)Climate Change: Why Bother 1)Resources 2)Climate Change 3)Biodiversity Crisis: Extinctions Why Bother 1)Resources 2)Climate Change 3)Biodiversity Crisis 4)Astrobiology:Life on other planets Why Bother 1)Resources 2)Climate Change 3)Biodiversity Crisis 4)Astrobiology 5)Evolution vs. Creationism How Do We Do This Science: “a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe” Science is both a body of knowledge and a process. In school, science may sometimes seem like a collection of isolated and static facts listed in a textbook, but that is only a small part of the story. Just as importantly, science is also a process of discovery that allows us to link isolated facts into coherent and comprehensive understanding of the natural world. Science is not just a tidy package of knowledge. Science is not just a step-by-step approach to discovery. Science is more like a mystery inviting anyone who is interested to become a detective and joinin the fun. How Do We Do This Science: “standardized method for discovering information about na”ure Method: -Make Observation How Do We Do This Science: “standardized method for discovering information about nat”re Method: -Make Observation -Form Question: Collect Data How Do We Do This Science: “standardized method for discovering information about nat”re Method: -Make Observation -Form Question:Collect Data -Hypothesize: “educatedguess” How Do We Do This Science: “standardized method for discovering information about natu”e Method: -Make Observation -Form Question:Collect Data -Hypothesize: “educated guess” -Experiment: Test Hypothesis: Collect More Data How Do We Do This Science: “standardized method for discovering information about natu”e Method: -Make Observation -Form Question:Collect Data -Hypothesize: “educated guess” -Experiment: est Hypothesis: Collect More Data -Analyze Data: Draw Conclusions… **Starting Point for New Hypothesis** How Do We Do This -Hypothesis: logical, testable idea/explanationfor an observed phenomenon. How Do We Do This Important Concepts in formulating Hypotheses 1) Parsimony: The simplest LOGICAL explanation is the best. 2) Replicability:All experiments/tests/results must be replicable **Other parties must be able to conduct the same tests and get the same results** Intro to Geology: