The Origin and Structure of Earth PDF

Unit 1 The Origin and Structure of Earth LESSON 1: The Origin of the Universe Learning Competency: ✓ describe the historical development of theories that explain the origin of the Universe (S11/12E...

Unit 1 The Origin and Structure of Earth LESSON 1: The Origin of the Universe Learning Competency: ✓ describe the historical development of theories that explain the origin of the Universe (S11/12ES- Ia-b-1) Objectives: At the end of the lesson, the learners will be able to: a. state the different hypothesis that preceded the Big Bang Theory of the Origin of the Universe; b. explain the concept of red-shift and how it used as proof of an expanding universe; c. discuss the Big Bang Theory and the evidences supporting the theory; and d. formulate understanding of how life on earth started.  Have you ever wondered how the universe began? Don’t worry. You are not alone. Most people seek to find the answer to this question. The good thing is scientists are working hard to find accurate answers to these questions. There are various theories trying to explain the origin of the universe. Differentiate hypothesis and theory. Recall doppler effect and redshift galaxy. Theories are what we call tried-and-tested hypotheses. Although, not as concrete and standalone as law, theories have provided the scientific world with a good start with explaining natural phenomena. ORIGIN OF THE UNIVERSDE Non-scientific Thought Ancient Egyptians believed in many gods and myths which narrate that the world arose from an infinite sea at the first rising of the sun. In India, there is the narrative that gods sacrificed Purusha, the primal man whose head, feet, eyes, and mind became the sky, earth, sun, and moon respectively.  The monotheistic religions of Judaism, Christianity, and Islam claim that a supreme being created the universe, including man and other living organisms. Ancient Theory Greek philosopher Democritus believed in an atomic universe. Together with his teacher Leucippus, they held that the universe was composed of very small, indivisible, and indestructible atoms. The famous Greek philosophers Ptolemy proposed a geocentric universe where Earth stayed motionless in the heavens, and everythingrevolved around it. This would later contradict astronomer Nicolaus Copernicus’ view in 1543 with his theory of heliocentrism. After a decade, Isaac Newton refined the Copernicus model and introduced the law of universal gravitation which extended the laws of classical physics in Earth to that of the universe. Back then, the universe was considered static and unchanging. This idea was not questioned until Albert Einstein published his final theory in general relativity. Modern Theories on the Origin of the Universe Steady State Theory Proposed by astronomers Fred Hoyle, Thomas Gold, and Hermann Bondi. The steady state theory is another theory that tries to explain the origin of the universe. As opposed to the big bang, this theory states that the universe has no beginning and no end. Predicted a universe that expanded but did not change its density-- matter was inserted into the universe as it expanded in order tomaintain a constant density.  Its predictions led to tests and its eventual rejection with the discovery of the cosmic microwave background. The Big Bang Theory As the currently accepted theory of the origin and evolution of the universe, the Big Bang Theory postulates that 13.8 billion years ago, the universe expanded from a tiny, dense, and hot mass to its present size and much cooler state. The theory rests on two ideas: General Relativity and the Cosmological Principle. In Einstein’s General Theory of Relativity, gravity is thought of as a distortion of space-time and no longer described by a gravitational field in contrast to the Law of Gravity of Isaac Newton. General Relativity explains the peculiarities of the orbit of Mercury and the bending of light by the Sun and has passed rigorous tests. The Cosmological Principle assumes that the universe is homogeneous and isotropic when averaged over large scales. This is consistent with the current large-scale image of the universe. But keep in mind that it is clumpy at smaller scales. Georges Henri Joseph Edouard Lemaître, a Belgian priest, suggested the idea of the expanding universe. He is considered the first proponent of the big bang theory, the universe formed approximately 13.7 billion years ago from a cataclysmic expansion which hurled all matter and created space. What evidence is there to support the Big Bang theory? Major scientific discoveries provide strong support for the Big Bang theory: 1. Expanding Universe - “redshift” Hubble’s discovery in the 1920s of a relationship between a galaxy’s distance from Earth and its speed just as predicted by Einstein’s Theory of General Relativity. Edwin Powell Hubble was an American astronomer who established the Hubble’s law which provided evidence that the universe was not static but expanding. In 1923, Hubble spotted what he thought as a flaring nova star in the M31 nebula or the Andromeda constellation using a Hooker telescope. Hubble carefully studied the photographic plates captured by other astronomers and realized that what he saw was a Cepheid star ― a star that pulsates radially, brightening and dimming periodically. He observed that spectral lines of starlight made to pass through a prism are shifted toward the red part of the electromagnetic spectrum, i.e., toward the band of lower frequency; thus, the inference that the star or galaxy must be moving away from us. 2. The abundance of hydrogen, helium, and lithium. 3.The discovery in the 1960s of cosmic microwave background radiation (CMBR). American astronomers Arno Penzias and Robert Wilson studied cosmic radiation in 1964. They discovered that microwaves with wavelengths of about 7 centimeters were present in space. These waves were referred to as cosmic microwave background (CMB) radiation. CMB radiation is believed to be the thermal energy released when the ionized gases became neutral particles as the early universe cooled down. This radiation served as a “leftover” when the universe was formed. The discovery of this cosmic radiation provided strong evidence that the universe began from the sudden expansion of a singularity, which supported Lemaitre’s study. It can be observed as a strikingly uniform faint glow in the microwave band coming from all directions-blackbody radiation with an average temperature of about 2.7 degrees above absolute zero (fig. 6). Arno Penzias (born 1933) Robert Wilson (born 1941)  LESSON 2: The Origin of the Solar System Learning Competency: ✓ compare the different hypotheses explaining the origin of the Solar System (S11/12ES-Ia-b-2) Objectives: At the end of the lesson, the learners will be able to: a. identify the hypotheses explaining the origin of the solar system; b. differentiate the hypotheses explaining the origin of the solar system; and c. formulate understanding of how life on earth started. The Origin of the Solar System Theories 1. Nebular Hypothesis In the 1700s Emanuel Swedenborg, Immanuel Kant, and Pierre-Simon Laplace independently thought of a rotating gaseous cloud that cools and contracts in the middle to form the sun and the rest into a disc that becomes the planets. This nebular theory failed to  account for the distribution of angular momentum in the solar system. 2. Encounter Hypothesis The encounter theory proposes that the planets were formed from the material ejected from the sun during an encounter with another celestial object. This celestial object could have been another star. According to the encounter hypothesis, about 5 Gya, a rogue star passed close to the sun and stripped hot gases from both the sun and the rogue star. The hot gases continued to  spin in the samedirection as the sun, and coalesced into smaller lumps which formed the planets. It has several forms, Buffon’s (1749) Sun-comet encounter that sent matter to form planet; James Jeans’ (1917) sun-star encounter that would have drawn from the sun matter that would condense to planets, T.C. Chamberlain and F. R. Moulton’s (1904) planetesimal hypothesis involving a star much bigger than the Sun passing by the Sun and draws gaseous filaments from both out which planetisimals were formed. 3. Protoplanet Hypotheses Current Hypothesis -About 4.6 billion years ago, in the Orion arm of the Milky Way galaxy, a slowly rotating gas and dust cloud dominated by hydrogen and helium starts to contract due to gravity. As most of the mass move to the center to eventually become a proto-Sun, the remaining materials form a disc that will eventually become the planets and momentum is transferred outwards. Due to collisions, fragments of dust and solid matter begin sticking to each other to form larger and larger bodies from meter to kilometer in size. These proto-planets are accretions of frozen water, ammonia, methane, silicon, aluminum, iron, and other metals in rock and mineral grains enveloped in hydrogen and helium. High-speed collisions with large objects destroy much of the mantle of Mercury, puts Venus in retrograde rotation. Collision of the Earth with large objects produces the moon. This is supported by the composition of the moon very similar to the Earth's Mantle When the proto-Sun is established as a star, its solar wind blasts hydrogen, helium, and volatiles from the inner planets to beyond Mars to form the gas giants leaving behind a system we know today. LESSON 3: The Life on Earth Learning Competency: ✓ describe the characteristics of Earth that are necessary to support life (S11/12ES-Ia-b-3)1 WEEK Objectives: At the end of the lesson, the learners will be able to: a. identify the characteristics of Earth that are necessary to support life; b. explain the factors that allow planet to support life on Earth; c. expound how the value of stewardship, love and respect promotes in taking care of Earth as a home ; d. compose a poem showing your care for all living and non-living forms on the planet. Geology is the study of the Earth. It is a multi-disciplinary science that aims to understand processes occurring within and on the surface of the planet. Theseprocesses are important in explaining how the planet came to be, the formation materials we acquire from the earth, and preparing for natural phenomena that may pose threat to our survival. Our planet is special and unique. So far this is theonly planet that supports life. But how our planet came to existence is simply morethan just a one-step process.  The Earth is no different from all the other planets revolving around thesun in terms of formation. We have learned that our planet earth started from the collection of dust and other particles drifting in space for some time. As it grows larger, it gains mass enough to pull smaller particles into it. This accumulation or accretion of materials provided heat through impact which became a factor in the formation. PLANET EARTH: Temperature Temperature Influences how quickly atoms & molecules move. Life seems limited to a temperature range of minus 15oC to 115oC. In this range, liquid water can still exist under certain conditions. Heat from the sun is in the form of radiation which enters Earth. As sunlight strikes, some heat is trapped by a layer of gases called the atmosphere. The atmosphere is responsible for the occurrence ofthe greenhouse phenomenon, a natural process which maintainsheat.  Liquid Water Life would not have begun without water. The presence of water allowed the first photosynthetic organisms to thrive. The single- celled organisms would then be involved in the organisms whichare present today. Scientists believe that water on Earth came from two possible sources; (1) water released through volcanism and (2) water that came from the icy meteors of the outer regions of the solar systemthat bombarded Earth. Earth is situated within a habitable zone or the Goldilocks zone -- the distance from a star where liquid water can exist in its liquid form. Atmosphere A vital part of photosynthesis; Photosynthesis ensures the adequate amount and flow of gases on Earth. Any planet devoid of an atmosphere would have an average surface temperature below freezing and would experience unpredictable and extreme weather and climates. It would also have an extreme amount of ultraviolet radiation because there isno atmosphere to absorb it.  LESSON 4: The Earth Systems Learning Competency: ✓ explain that the Earth consists of four subsystems, across whose boundaries matter and energy flow (S11/12ES-Ib-4) Objectives: At the end of the lesson, the learners will be able to: a. define the concept of system; b. recognize the Earth as a system composed of subsystems; c. analyze the interaction of the four Earth subsystems where energy flow that affect Earth life; and d. Improve way of living that can help Earth in maintaining its subsystem. Earth is a closed system. The amount of matter within a closed system is fixed.The resources used can never be regenerated, and the waste produced cannotreally be disposed of. Once used up, the mineral resources are transformed into something else, maintaining the amount of matter within the closed system. Changes within one subsystem eventually cause changes in others. Although Earth is considered a closed system, its four subsystems are open, and matter andenergy can freely transfer between them. Thus, disturbance in one system affects the others. For example, when Mount Pinatubo erupted in 1991, nearly 20 million tons of sulfur dioxide was ejected into the atmosphere. This gas cloud traveled around the world and caused global temperatures to drop temporarily by 0.5 °C. The eruption also dramatically changed the topography of central Luzon. Many people developed silicosis from inhaling the fine volcanic ash. Lahars caused by subsequent typhoons and extreme rainfall buried numerous towns, villages, rice paddies, and sugarcane fields in the region. Earth is composed of four basic subsystems -- geosphere, hydrosphere, atmosphere, and biosphere. It may be important to note that humans are not part of the biosphere and that human lives depend on the interaction of the foursubsystems. Lithosphere Lithosphere refers to solid Earth; Geosphere comes from the Greek word geo which means ground. composed of naturally occurring solid aggregate of minerals, organic material, or natural glass called rocks, and loose particles of rocks that blanket the surface of the Earth called regolith; The lithosphere includes the rocks of the crust and mantle, the metallic liquid outer core, and the solid metallic inner core. Briefly discuss Plate Tectonics as an important process shaping the surface of the Earth. The primary driving mechanism is the Earth's internal heat, such as that in mantle convection  Hydrosphere About 70% of the Earth is covered with liquid water (hydrosphere) and much of it is in the form of ocean water Only 3% of Earth's water is fresh: two-thirds are in the form of ice, and the remaining one- third is present in streams, lakes, and groundwater. the totality of Earth's water, including permanently frozen partscalled cryosphere The oceans are important sinks for CO2 through direct exchange with the atmosphere and indirectly through the weathering of rocks. Heat is absorbed and redistributed on the surface of the Earth through ocean circulation. Atmosphere The atmosphere is the thin gaseous layer that envelopes the lithosphere. Its name comes from the Greek word atmos, which means gas. The air in the atmosphere is generally composed of 78% nitrogen, 21% oxygen, 0.9% argon, and the remaining 0.10% is made up of different trace gases; One of the most important processes by which the heat on the Earth's surface is redistributed is through atmospheric circulation. There is also a constant exchange of heat and moisture between the atmosphere and the hydrosphere through the hydrologic cycle. Biosphere Includes all life forms; Most life on Earth exist within a zone less than 220km wide, where interactions between the lithosphere, hydrosphere, and atmosphere create a habitable environment; Organisms interact with other organisms and the physical environment. They form communities called biomes. Biomes exist all over the world. Examples of biomes include deserts, tropical rainforests, swamps, or coral reefs.  Earth Science 11-Module 1 Olivar III, J, et.al. (2016). Exploring Life Through Science , Quezon City: Phonix Publishing House, Inc.. Refran, J, et.al. (2020). Earth Science. Quezon City : Vibal Group Inc., https://www./jctunguia/earth-and-life-science-earth-subsystems https://bit.ly/3Rl5u7w 16 |