Earth and Life Science Reviewer Lessons 1-8 PDF
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Summary
This document reviews theories of the universe's origin, including the Big Bang theory, Steady State theory, String theory, and M-Theory. It also summarizes the origin of the solar system and Earth, and explains different processes within these areas.
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Earth and Life Science Reviewer: Lessons 1-8 Lesson 1: The Universe and the Solar System Beginning of the Universe: ○ The universe contains all matter and energy, including galaxies, stars, and dust. The study of these cosmic structures is known as cosmology....
Earth and Life Science Reviewer: Lessons 1-8 Lesson 1: The Universe and the Solar System Beginning of the Universe: ○ The universe contains all matter and energy, including galaxies, stars, and dust. The study of these cosmic structures is known as cosmology. ○ Cosmologists are scientists who study the origin, evolution, and structure of the universe. Creation Myths: ○ Different cultures have creation stories: Biblical Genesis: God created the world in six days (approximately 4004 BCE according to Bishop Ussher). Tagalog Mythology: Life began with the first man and woman emerging from a bamboo shoot. Theories on the Origin of the Universe: 1. Big Bang Theory - Overview: This is the most widely accepted explanation for how the universe began. - Key Points: ○ The universe started as a singularity—an infinitely small, hot, and dense point—about 13.8 billion years ago. ○ It began to expand rapidly in a massive explosion, which is what we call the Big Bang. ○ As the universe expanded, it cooled down, allowing particles to form. Eventually, these particles combined to create atoms (primarily hydrogen and helium). ○ Over millions of years, these atoms came together to form stars, galaxies, and other cosmic structures. - Evidence: ○ Cosmic Microwave Background Radiation: A faint glow left over from the Big Bang that fills the universe, detected as a uniform background radiation. ○ Redshift of Galaxies: Observations show that galaxies are moving away from us, indicating that the universe is still expanding. This is measured through the redshift of light. 2. Steady State Theory - Overview: This theory suggests that the universe has always existed in a similar state and is continuously creating new matter. - Key Points: ○ The universe is expanding, but as it does, new matter is created to fill the gaps, keeping the overall density constant. ○ There is no beginning or end to the universe; it has always existed. - Key Proponents: This theory was notably promoted by Fred Hoyle, Thomas Gold, and Hermann Bondi in 1948. - Criticism: This theory lost favor as evidence supporting the Big Bang, such as cosmic microwave background radiation, emerged. 3. String Theory - Overview: A theoretical framework that attempts to reconcile quantum mechanics and general relativity. - Key Points: ○ Proposes that the fundamental particles we know (like electrons and quarks) are not point-like dots but rather tiny, vibrating strings. ○ The vibrations of these strings determine the properties of particles, such as their mass and charge. ○ String theory requires additional dimensions beyond the four we experience (three spatial dimensions and time), suggesting there may be up to 11 dimensions. - Importance: It’s a candidate for a theory of everything, aiming to explain all physical phenomena, including the origins of the universe. 4. M-Theory - Overview: An extension of string theory that incorporates multiple dimensions and proposes a more unified framework. - Key Points: ○ Developed in the 1990s, primarily through the work of Edward Witten. ○ Suggests that different versions of string theory are actually different aspects of a single underlying theory. ○ Includes the concept of branes, which are multi-dimensional objects where strings can end. - Implications: M-theory has the potential to describe the universe and its origins in a more complete way, including insights into black holes and the early universe. Theories on the Origin of the Solar System: ○ Descartes’ Vortex Theory (17th century): Suggested that planets formed from swirling cosmic fluids. ○ Buffon’s Collision Theory (18th century): Proposed that planets formed from debris after a collision with a comet. ○ Kant-Laplace’s Nebular Theory (1796): Suggested the solar system formed from a rotating cloud of gas and dust. ○ Tidal Theory (19th century): Proposed that gravitational interactions with nearby stars pulled material away from the sun to form planets. ○ Solar Nebular Theory (20th century): The most widely accepted theory describing the solar system's formation from a solar nebula. Key Terms: Astronomy: The scientific study of celestial bodies and the universe as a whole. Redshift: A phenomenon observed in light from distant galaxies, indicating that the universe is expanding. Important Figures: Edwin Hubble: Demonstrated that the universe is expanding, leading to the formulation of Hubble's Law in the 1920s. Albert Einstein: His theory of general relativity (1915) revolutionized our understanding of gravity and cosmology. Lesson 2: Earth and Earth Systems Earth's Layers: ○ Core: Inner Core: Solid, mainly composed of iron and nickel; extremely hot (about 6,000°C). Outer Core: Liquid layer responsible for generating Earth’s magnetic field. ○ Mantle: Thick layer between the core and crust. Upper Mantle: Rigid; part of the lithosphere. Lower Mantle: Plastic; allows for convection currents that drive tectonic plate movements. ○ Crust: The thin outer layer of the Earth where life exists. Oceanic Crust: Dense and thinner (5-10 km). Continental Crust: Thicker and less dense (30-50 km). Subsystems of Earth: ○ Lithosphere: The rigid outer layer, including the crust and upper mantle. ○ Atmosphere: The layer of gasses surrounding Earth, essential for weather and climate. ○ Hydrosphere: All water on Earth, including oceans, rivers, and lakes. ○ Biosphere: The zone of life, where living organisms interact with their environment. Discontinuities: Boundaries between different layers of the Earth: ○ Mohorovičić Discontinuity (Moho): Discovered by Andrija Mohorovičić in 1909; boundary between the crust and mantle. ○ Gutenberg Discontinuity: Between the mantle and outer core. ○ Lehmann Discontinuity: Between the outer core and inner core. Important Processes: Differentiation: The process by which Earth’s layers formed due to varying densities of materials (heavy materials sank, while lighter ones rose). Seismic Waves: P-Waves (Primary waves): Longitudinal waves that travel through solids and liquids; they are the fastest seismic waves. S-Waves (Secondary waves): Transverse waves that can only travel through solids; they arrive after P-waves during an earthquake. Lesson 3: Rocks and Minerals Minerals: 1. Naturally occurring, inorganic solids with a specific chemical composition and crystalline structure. Key Properties: 1. Color: The visible hue of the mineral. 2. Streak: The color of the powdered form of the mineral, which can differ from the color of the whole mineral. 3. Luster: The way light reflects off the mineral's surface (metallic vs. non-metallic). 4. Hardness: A mineral’s resistance to scratching, measured using Mohs hardness scale (from talc, 1, to diamond, 10). 5. Cleavage: The tendency to break along flat surfaces. 6. Specific Gravity: Density compared to water. Types of Rocks: 1. Igneous Rocks: Formed from cooled magma or lava. Intrusive (Plutonic): Formed inside the Earth with larger crystals (e.g., granite). Extrusive (Volcanic): Formed on the surface with smaller crystals (e.g., basalt). 2. Sedimentary Rocks: Formed from particles of other rocks and organic material. Clastic: Made from broken fragments of other rocks (e.g., sandstone). Chemical: Formed from dissolved minerals precipitating out of water (e.g., limestone). Organic: Formed from the remains of plants and animals (e.g., coal). 3. Metamorphic Rocks: Formed from existing rocks transformed by heat, pressure, and chemical processes (e.g., schist, marble). Rock Cycle: A continuous process describing the transformation of rocks through igneous, sedimentary, and metamorphic forms, driven by Earth's internal heat and surface processes. Mineral Identification: Techniques such as acid tests for calcite or hardness tests using the Mohs scale are essential for mineral identification in geology Lesson 4: Exogenic Processes Exogenic Processes: Geological processes that occur at or near the Earth's surface, shaping landscapes through: Key Processes: Weathering Definition: Weathering is the process that breaks down rocks into smaller pieces through physical, chemical, or biological means. It plays a critical role in soil formation and the landscape's evolution. Types of Weathering 1. Physical Weathering (Mechanical Weathering) ○ Definition: The breaking down of rocks into smaller pieces without changing their chemical composition. ○ Key Processes: Frost Wedging: Occurs when water seeps into cracks in rocks. When temperatures drop, the water freezes and expands, causing the rock to crack further. Common in regions with freeze-thaw cycles (e.g., mountainous areas). Insolation Weathering: Caused by extreme temperature changes, where rocks expand during the day when heated and contract at night when cooled. This repeated cycle leads to the cracking and breaking of rocks. Pressure Release (Unloading): Rocks formed under pressure (e.g., plutonic rocks) expand and fracture when the overlying material is removed (e.g., through erosion). This process often creates large dome-shaped rock formations. Biological Weathering: Involves the breaking down of rocks through the action of plants and animals. For example, plant roots can grow into cracks in rocks, exerting pressure and causing fractures. Animals, like burrowing rodents, can also contribute by disturbing the soil and rocks. 2. Chemical Weathering ○ Definition: The alteration of the mineral composition of rocks through chemical reactions. ○ Key Processes: Oxidation: Occurs when minerals (especially those containing iron) react with oxygen, leading to rust formation. This process weakens the rock structure and changes its color. Carbonation: The reaction of carbon dioxide with water to form carbonic acid, which dissolves limestone and other carbonate rocks. This process is responsible for the formation of caves and karst landscapes. Hydrolysis: A reaction where water reacts with minerals to form new minerals and soluble salts. For example, feldspar in granite weathers to form clay minerals. Dissolution: The process in which soluble minerals (e.g., salt, gypsum) dissolve in water, leading to the breakdown of rock structures. Importance of Weathering Soil Formation: Weathering contributes to the formation of soil by breaking down rocks and releasing nutrients, which are essential for plant growth. Landscape Shaping: It alters the landscape, creating features like valleys, hills, and sedimentary layers. Nutrient Cycling: Weathering plays a vital role in the nutrient cycle, making essential minerals available to living organisms. ○ Erosion: The removal and transportation of weathered materials by agents such as water, wind, and ice. ○ Mass Wasting: Movement of rock debris down slopes due to gravity (e.g., landslides, mudflows). ○ Deposition: Accumulation of eroded materials, forming features like deltas (formed when a river slows as it meets a larger body of water) and alluvial fans. Soil Formation: Weathering contributes to soil formation by breaking down rocks into smaller particles, which combine with organic matter to create fertile soil. Importance of Erosion: While erosion shapes landscapes, it can also lead to negative impacts like loss of topsoil and habitat destruction. Lesson 5: Endogenic Processes Endogenic Processes: Processes originating from within the Earth, leading to geological changes. Key Processes: ○ Volcanism: The eruption of magma onto the surface, forming volcanoes. ○ Tectonics: Movement of the Earth's lithospheric plates. Plate Boundaries: ○ Convergent Boundaries: Plates collide, forming mountains or causing subduction (e.g., Himalayas). ○ Divergent Boundaries: Plates move apart, creating new crust (e.g., Mid-Atlantic Ridge). ○ Transform Boundaries: Plates slide past one another, causing earthquakes (e.g., San Andreas Fault). Types of Volcanoes: Shield Volcanoes: Broad and gently sloping, formed by low-viscosity lava (e.g., Mauna Loa). Stratovolcanoes: Steep and conical, composed of alternating layers of lava flow and tephra (e.g., Mount St. Helens). Cinder Cone Volcanoes: Smallest type, formed from volcanic ash and small lava fragments (e.g., Paricutin). Seismic Activity: Earthquake Focus: The point where an earthquake originates (hypocenter). Epicenter: The point on the Earth's surface directly above the focus. Lesson 6: History of the Earth Laws of Stratigraphy: Techniques for determining the relative ages of rock layers. ○ Law of Superposition- This law states that younger rock layers are atop the older layers (Nicolaus Steno, 1669). ○ Law of Original Horizontality: Sedimentary rocks are deposited horizontally (Steno). ○ Law of Cross-Cutting Relationships: A rock or fault that cuts through another is younger (Steno). ○ Law of Included Fragments: Rock fragments within another rock are older than the surrounding rock. ○ Law of Faunal Succession: Fossils succeed each other in a predictable manner, allowing for dating of rock layers (William Smith, 1796). Fossils: Remains of ancient life that provide information about Earth's history. Mold Fossil: Definition: A mold fossil is an imprint of an organism left in rock. Cast Fossil: Definition: A cast fossil is a replica of an organism created when minerals fill a mold fossil. Carbon Fossil: Definition: Carbon fossils are thin layers of carbon left behind when an organism decays. Petrified Fossil: Definition: Petrified fossils occur when organic material turns into stone. Trace Fossil: Definition: Trace fossils are evidence of an organism’s activity rather than the organism itself. True Form Fossil: Definition: True form fossils are the actual remains of an organism. Geologic Time Scale: A timeline that organizes Earth's history based on the presence and evolution of life forms. Dating Methods: Relative Dating: Does not provide exact ages but allows for ranking events or rocks. Absolute Dating: Uses radioactive isotopes to determine the exact age of rocks (e.g., radiocarbon dating for organic material). Major Geological Events: Mass Extinctions: Significant loss of biodiversity over a relatively short time (e.g., the Permian-Triassic extinction, approximately 252 million years ago). Lesson 7: Geologic, Natural, Marine Coastal Hazards, and Mitigation Hazards: Dangerous events or conditions that can cause harm to people, property, and the environment. ○ Natural Hazards: Caused by natural processes (e.g., earthquakes, floods). ○ Man-Made Hazards: Result from human activities (e.g., industrial spills). Types of Hazards: ○ Geologic Hazards: Earthquakes and volcanic eruptions. Earthquakes: Sudden shaking of the ground caused by the release of energy from faults. Magnitude: Amount of energy released, measured on the Richter or moment magnitude scale. Intensity: Strength of shaking as felt by people, measured using the Modified Mercalli Intensity scale. ○ Hydrometeorological Hazards: Floods, droughts, hurricanes, and typhoons. Floods: Can be caused by heavy rains, poor drainage, or melting snow Typhoons and Hurricanes: Strong storms characterized by high winds and heavy rain. Effects of Hazards: ○ Hazards can lead to loss of life, property damage, and environmental degradation. For instance, Typhoon Yolanda (Haiyan) in 2013 caused catastrophic destruction in the Philippines, with thousands dead and widespread devastation. Disaster Risk Reduction: ○ Mitigation Strategies: Include land-use planning, building codes, and public education to reduce the impact of hazards. Examples of Natural Hazards: ○ Tsunamis: Often caused by underwater earthquakes or volcanic eruptions; they can travel across entire ocean basins. ○ Landslides: Can occur suddenly after heavy rains or earthquakes, leading to rapid movement of soil and rock. Volcanic Activity Overview: Volcanic activity includes eruptions and other geological processes that can pose threats to human life and the environment. Volcanic eruptions can range from mild to catastrophic and often lead to earthquakes. Types of Volcanic Hazards 1. Effusive Eruption: ○ Description: Occurs when magma flows out gently from a volcano, resulting in lava flows. ○ Impact: Generally less explosive but can still cover large areas with lava. 2. Explosive Eruption: ○ Description: Characterized by violent eruptions that blast ash, gas, and volcanic rock into the air. ○ Impact: Can produce dangerous ash clouds and pyroclastic flows, posing serious risks to life and property. 3. Pyroclastic Flow/Surges: ○ Description: Fast-moving currents of hot gas and volcanic matter that flow down the sides of a volcano. ○ Impact: Extremely dangerous due to high temperature (up to 1,000 °C) and speed, capable of destroying everything in their path. 4. Tephra Fall: ○ Description: Solid volcanic material (ash, pumice, etc.) that is ejected into the atmosphere and falls back to Earth. ○ Impact: Can cover large areas, damaging crops, infrastructure, and health due to inhalation of fine ash. 5. Possible Area Earthquake: ○ Description: Earthquakes can occur due to volcanic activity as magma moves within the Earth. ○ Impact: May cause ground shaking and damage to structures. 6. Possible Tsunami: ○ Description: If a volcanic eruption occurs underwater or causes a landslide into the sea, it can generate tsunamis. ○ Impact: Tsunamis can inundate coastal areas, causing widespread destruction. 7. Landslide: ○ Description: Volcanic eruptions can destabilize slopes, leading to landslides. ○ Impact: Can bury communities and alter landscapes. 8. Lahar and Lava Flow: ○ Lahar: A volcanic mudflow composed of water, ash, and debris that flows down river valleys. Impact: Can be very destructive, burying everything in its path. ○ Lava Flow: The movement of molten rock from a volcano. Impact: Can destroy property and alter landforms. Hydrometeorological Hazards Overview: Hydrometeorological hazards are extreme weather events caused by meteorological and climatic factors. They can lead to significant damage and loss of life. Types of Hydrometeorological Hazards 1. Floods: ○ Description: Occur when water overflows onto normally dry land, often caused by heavy rainfall or melting snow. ○ Causes: Poor drainage, low-lying areas, and rapid urbanization. ○ Impact: Can destroy homes, infrastructure, and crops. 2. Flash Floods: ○ Description: Sudden floods that occur within minutes to hours of heavy rain or rapid snowmelt. ○ Impact: Extremely dangerous and can result in loss of life and property. 3. River Floods: ○ Description: Flooding that occurs when rivers overflow due to prolonged heavy rain. ○ Impact: Affects communities near riverbanks, leading to evacuation and damage. 4. Urban Floods: ○ Description: Floods that occur in cities where land has been paved over, reducing absorption of rainwater. ○ Impact: Can disrupt transportation, damage infrastructure, and pose health risks. 5. Coastal Floods: ○ Description: Flooding associated with coastal storms, including hurricanes and typhoons. ○ Impact: Can lead to storm surges that inundate coastal communities. 6. Drought: ○ Description: A prolonged period of below-average precipitation leading to water shortages. ○ Causes: Lack of rainfall, high temperatures, and climate patterns like El Niño. ○ Impact: Affects agriculture, drinking water supplies, and can lead to famine. 7. Cyclones: ○ Description: Also known as tropical cyclones or hurricanes, they are strong storms with rotating winds. ○ Impact: Can cause heavy rain, strong winds, and storm surges, leading to widespread damage. 8. Tornadoes: ○ Description: Violently rotating columns of air extending from a thunderstorm to the ground. ○ Impact: Can cause localized destruction with high wind speeds, damaging buildings and infrastructure. 9. La Niña and El Niño: ○ Description: Climate patterns in the Pacific Ocean that influence global weather. ○ La Niña: Leads to cooler ocean temperatures and can cause wetter conditions in some regions. ○ El Niño: Leads to warmer ocean temperatures and can cause droughts and warmer conditions in other regions. Coastal Processes Coastal areas are dynamic regions where land meets the sea. They are subject to various natural processes, including erosion, transportation, deposition, and submersion. 1. Definitions: ○ Coast: The area where land meets the sea. ○ Shoreline: The exact line where the ocean meets the land. ○ Waves: Movements of water caused by the wind, which carry energy and materials. 2. Common Coastal Hazards: ○ Coastal Erosion: The wearing away of land by the action of waves. ○ Submersion: The gradual rise of sea levels, causing the land to be submerged. ○ Storm Surges: Sudden rises in sea level due to storms, leading to flooding in coastal areas. ○ Saltwater Intrusion: The movement of saltwater into freshwater aquifers, often caused by rising sea levels or excessive groundwater withdrawal. Deposition Definition: Deposition is the process where eroded materials are dropped or settled in a new location, creating landforms. This happens when the energy of the transporting medium (water, wind, or ice) decreases. 1. How It Works: ○ When waves lose energy, they can no longer carry sediments, leading to deposition. ○ This process creates various coastal landforms, such as beaches, sandbars, and deltas. 2. Types of Coastal Depositional Features: ○ Beaches: Accumulations of sand and gravel along the shore where waves deposit materials. ○ Sandbars: Long, narrow deposits of sand that form parallel to the shoreline, often exposed at low tide. ○ Deltas: Formed at the mouth of rivers where sediment is deposited as the river slows down when entering a larger body of water. 3. Factors Influencing Deposition: ○ Wave Energy: Strong waves carry more sediment and can lead to more significant erosion, while weaker waves allow for deposition. ○ Current Direction: Longshore currents can transport sediments along the coastline, influencing where deposition occurs. ○ Human Activities: Construction and coastal management (like jetties and groins) can alter natural deposition patterns. Lesson 8: Introduction to Life Theories on the Origin of Life: ○ Panspermia Theory: Life's building blocks (e.g., amino acids) arrived on Earth via meteors. ○ Divine Creation Theory: Life was created by a supernatural being, with different cultures having unique accounts. ○ Nonliving Matter Origin: Life arose from chemical reactions among organic compounds, demonstrated by the Miller-Urey Experiment (1953), which simulated early Earth conditions to produce organic compounds. Evolution of Life: ○ Life began with simple organic compounds evolving into complex biomolecules, eventually forming the first cells. ○ Early life forms thrived in extreme environments, such as hydrothermal vents, through processes like chemosynthesis (bacteria using chemicals for energy). Characteristics of Life: ○ Cellular Organization: All living organisms are composed of cells. ○ Metabolism: The total of all biochemical processes that occur within an organism. ○ Homeostasis: The ability to maintain a stable internal environment despite external changes. ○ Reproduction and Heredity: Ability to produce offspring and pass on genetic information (DNA). Unifying Themes in Biology: ○ Levels of Organization: Structure from cells to ecosystems (e.g., CELL → TISSUE → ORGAN → ORGAN SYSTEM → ORGANISM → POPULATION → COMMUNITY → ECOSYSTEM). ○ Flow of Energy: Energy transfer from producers to consumers in ecosystems (illustrated using energy pyramids). ○ Interaction: Organisms interact with their environment and each other, exemplified by nutrient cycles. ○ Structure and Function: The design of body parts correlates with their function (e.g., finch beak shapes and feeding habits). ○ Evolution: The core theme explaining the diversity of life and the common ancestry among organisms. Key Biological Concepts: ○ Biogenesis vs. Abiogenesis: Biogenesis refers to life arising from pre-existing life, while abiogenesis refers to life arising from non-living matter. ○ Natural Selection: Proposed by Charles Darwin in the 19th century, this is the process by which organisms better adapted to their environment tend to survive and reproduce. Cell Theory: ○ All living organisms are composed of cells, and all cells arise from pre-existing cells. This principle is foundational to biology. Biological Classification: ○ Organisms are classified into domains and kingdoms: Domains: Bacteria, Archaea, Eukarya. Kingdoms: Include plants, animals, fungi, and protists within the domain Eukarya..