EARTH SCI. UNIT 1 LEARNING GUIDE.pdf

Unit 1 The Origin of the Universe and the Solar System Table of Contents Table of Contents 1 Introduction 3 Essent...

Unit 1 The Origin of the Universe and the Solar System Table of Contents Table of Contents 1 Introduction 3 Essential Questions 4 Review 4 Lesson 1.1: Big Bang Theory 5 Objectives 5 Warm-Up 5 Learn about It 7 Key Points 11 Web Links 12 Check Your Understanding 12 Challenge Yourself 13 Lesson 1.2: Steady State Theory and Oscillating Universe Theory 15 Objectives 15 Warm-Up 16 Learn about It 17 Key Points 21 Web Links 21 Check Your Understanding 22 Challenge Yourself 23 Lesson 1.3: Nebular Theory 24 Objectives 24 Warm-Up 24 Learn about It 27 Key Points 31 Web Links 32  Check Your Understanding 32 Challenge Yourself 34 Lesson 1.4: Encounter Theory 35 Objectives 35 Warm-Up 35 Learn about It 36 Key Points 38 Web Links 39 Check Your Understanding 39 Challenge Yourself 40 Laboratory Activity 41 Performance Task 42 Self Check 44 Key Words 44 Wrap Up 46 Photo Credits 46 References 47 2  Lesson 1.2: Steady State Theory and Oscillating Universe Theory Objectives In this lesson, you should be able to: explain the origin and the fate of the universe according to steady state theory and oscillating universe theory; identify different proponents of the steady state and oscillating universe theory; and enumerate negative implications of steady state and oscillating universe theory. Do you usually go to the grocery store with your mom? If you do, you should have noticed that grocery stores love promos. They usually asked you to buy a thing in packages. For instance, if plastic containers are on sale, it is usually sold in a package of 3 to 5 pieces with varying sizes. At a glance, you know that the bigger size of the plastic containers will be heavier to carry. If you don’t want your packed lunch to add weight on your bag especially if you carry a lot of other things, you will not ask your mom to use the bigger Tupperware for your packed lunch. However, choosing a smaller container means less food can fit inside. This is a problem especially if you want to eat more because you need more energy to accomplish tasks in school. In these situations, you could conclude that mass and volume is directly proportional. As the plastic container increase in volume, it gets heavier as well. How about the container’s density? Does it change as the object increases in size? How could this mass, volume, and density relate to a theory of the origin of the solar system called steady state theory? 13  Learn about It The Steady State Theory 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. Overview of the Steady State Theory The steady state theory suggests that the universe has always been here and will always be present. It also suggests that the universe always looks the same in any time or space, but the universe continuously expands while simultaneously creating matter. During expansion, the density of the universe remains constant; hence, the name steady state. It also explains that the rate of the death of stars is equal to the rate of birth of stars. Hence, as a whole, the universe is not evolving over time. Both the big bang and steady state theory explains that the universe is expanding. However, the difference is that the big bang shows that as the universe expands, the density of matter decreases over time. On the other hand, steady state shows that the universe maintains a constant density as it expands. This means that matter such as stars and galaxies are continuously being added to the universe. Fig. 6 illustrates the primary concept of the steady state theory. Fig. 6. In the steady state theory, matter is constantly created as the universe expands. 14 Proponents of the Steady State Theory The steady state theory was proposed by Hermann Bondi, Thomas Gold, and Fred Hoyle in 1948. These three physicists from Cambridge released the idea of the steady state theory by submitting two papers to Monthly Notices of the Royal Astronomical Society, one from Bondi and Gold, and the other one from Hoyle. Hermann Bondi Thomas Gold Fred Hoyle (1919–2005) (1920–2004) (1915–2001) The steady state idea of Bondi and Gold may have started when they watched a movie together late 1940s. It was a horror movie entitled “Dead of Night” which started and ended in the same way. The circular plot of the movie inspired them to suggest that the universe was dynamic but unchanging. This means that the universe is constantly changing yet remains the same. Some criticism arose since the theory did not explain how matter could be generated out of nothing. 15 Drawbacks of the Steady State Theory The steady state theory was so simple that it was widely accepted even before the proposal of the big bang theory. Other astronomers did not favor this theory since it is not parallel with the law of conservation of energy and mass where energy and matter cannot be created nor destroyed but can only change their form. The discovery of the cosmic microwave background radiation significantly supported the explanations given by the big bang theory and led many scientists to reject the steady state theory in 1965. The steady state theory explained that the cosmic radiation was a result of a supernova. However, after thorough research, it was proven that the radiation is equal in any direction of the universe and could not be a result of many supernovae. The Oscillating Universe Theory Have you ever wondered how many universes are there? Or is our universe the only one? If the oscillating theory holds true, our universe might be the first of the probable series of the universe or nth universe in the series. The oscillating universe theory discusses that the universe is expanding and will contract once all the energy after the big bang has been used up, only to expand again once it approaches the point of singularity (i.e., the beginning of a new universe). It is also referred to as the pulsating theory. Overview of the Oscillating Universe Theory The oscillating universe theory can be described as the combination of the big bang and the big crunch. The big crunch occurs when the universe expands and eventually reverses, then collapses causing the formation of a singularity or the occurrence of another big bang. The oscillating universe theory suggests that once the universe reverses and attains the point of singularity, another universe will be born. This is referred to as the big bounce. 16 Richard Tolman, an American mathematical physicist, and physical chemist theorized that the universe may be first in the cycle, or it could be a result of a previous big bounce event. Proponent of Oscillating Universe Theory Besides being a mathematical physicist and physical chemist, Richard Tolman was someone to look up to when it comes to statistical mechanics. He later became physical chemistry and mathematical physics professor at California Institute of Technology (Caltech). One of his students is Linus Pauling to whom he taught the pre-Schrödinger quantum theory. In the years after Einstein discovered the general relativity, Tolman made essential contributions to theoretical cosmology. In his monograph entitled, “Relativity, Thermodynamics, and Cosmology”, he documented and explained that the universe has zero energy because the positive mass energy and negative gravitational energy cancel each other. His theory on the oscillating universe caught attention to struggles regarding entropy and resulted in its demise. Drawbacks of Oscillating Universe Theory Like the steady state theory, scientists discovered many loopholes in the oscillating universe theory. This theory suggested that the universe would collapse on its own after it reached its full expansion, which would violate some current laws of physics, such as the postulated existence of dark energy. The dark energy is believed to be the driving force of the accelerating expansion of the universe. At present, the postulated end of the universe is by big freeze or heat death. The universe would continuously expand until it reaches a point wherein all its energy dissipates. 20  Key Points The steady state theory suggests that the universe has always been here and will always be present. ○ It was proposed by Hermann Bondi, Thomas Gold, and Fred Hoyle in 1948. The oscillating universe theory discusses that the universe is expanding and will contract once all the energy after the big bang has been used up, only to expand again once it approaches the point of singularity ○ It is also referred to as the pulsating theory. ○ Richard Tolman is the proponent of oscillating universe theory. Web Links For further information, you can check the following web links: Watch this video to study the difference between the big bang theory and steady state theory. Pichael Moon. 2014. ‘Big Bang Theory vs Steady State Theory.’ https://www.youtube.com/watch?v=SuslgoGJdiw&t=21s Watch this video to know more about the steady state theory. The Audiopedia. 2018. ‘What is the Steady State Theory?.’ https://www.youtube.com/watch?v=hsMerhcEcEM 28  Lesson 1.3: Nebular Theory Objectives In this lesson, you should be able to: explain the origin of the solar system according to the nebular theory; describe how planets were formed based on the nebular theory; be familiar with the contribution of the proponent that support the nebular theory; and enumerate the negative implications of the nebular theory. Did you spend most of your childhood playing? It is undeniable that most kids love to play. One of the most common things that kids want to do with their playmates is playing with toy building bricks or molding clay. Most of the time, kids compete with their playmate in building better toy building bricks or clay structure. Both of these situations, building using toy bricks or molding clay, involves creating a larger structure out of the smaller parts. For instance, one toy building brick when combined with other blocks can form a robot or a building. The same is true in molding clay. A small amount of clay can make a certain object when extra clay is added. One theory regarding the origin of the universe also works this way. How can smaller structures become a huge matter such as planets? 29  Learn about It Another theory that explained the origin of the solar system is the nebular theory. From the term itself, "nebula" means cloud. This indicates that stars originate from interstellar gas and dust. The shift from undifferentiated cloud to whole solar system formation complete with planets, moons, and stars takes approximately a hundred million years. Description of the Nebular Theory There are three major steps on how the solar system was formed according to nebular theory. These are cloud collapse, formation of the protoplanetary disk, and growth of planets. Cloud Collapse The origin of the planets and sun in the solar system is a huge cloud of molecular gas and dust. Then, something occurred that made the cloud to collapse. Possible reasons are shockwaves from a supernova or the effect of a passing star. Whatever the reason, the result was a collapse at the center of the cloud due to gravity. As shown in Fig. 8, the collapsing of the cloud makes it spin faster. Fig. 8. Cloud collapse. 210 Have you ever tried to watch a skating competition? One of the tricks of the contestant that amazes people is when they spin so fast without falling. If you are a keen observer, they can only do the trick if they bring in their arms. Extending their arms while attempting to spin fast will result to a failure of the act. As shown in Fig. 9, this is possible because rotational velocity is inversely proportional to radius. Fig. 9. Relationship of radius and rotational velocity. In relation to the nebular theory, the collapsed cloud of interstellar gas and dust results to a smaller radius which means it will spin faster. This resulted to a flattened disk of cloud with a central bulge. Formation of Protoplanetary Disk Metals and silicates could exist near the sun because these compounds have higher boiling points. As a result, terrestrial planets including Mercury, Venus, Earth, and Mars were eventually formed containing a high concentration of these compounds. 211 The terrestrial planets could not grow in huge diameter because of the limited reserve of metallic elements in the solar nebula. Fig. 10. Terrestrial planets. From left to right: Mercury, Venus, Earth, and Mars. Jovian planets composed of Jupiter, Saturn, Uranus, and Neptune are huge planets made up of gases without land surfaces. These planets were formed farther from the sun because the temperature is cool enough for the gases to condense, forming these massive, but low-density planets. Fig. 11. Jovian planets. From left to right: Jupiter, Saturn, Uranus, and Neptune. 212  Fig. 12. The formation of a protoplanetary disk in nebular theory. Growth of Planets As shown in Fig. 13, dust and grains surrounding the sun eventually formed clumps. These clumps then accreted forming planetesimals. Planetesimal is a small celestial body that once collide together, it tends to fuse to form the planets of the solar system. Fig. 13. Growth of planets in the nebular theory. 30 Proponents of the Nebular Theory The nebular theory can be credited to Emanuel Swedenborg, Immanuel Kant, and Pierre-Simon Laplace. Emmanuel Swedenborg Immanuel Kant Pierre-Simon Laplace (1688–172) (1724–1804) (1749–1827) Drawbacks of the Nebular Theory One problem of the nebular theory is that it assumes that dust particles will be attached to each other forming a planet. However, this is not true for Saturn because the particles surrounding it repel each other. Another problem is that it does not follow the law of angular momentum. If it does, the sun should be spinning at a higher rate than the others. Moreover, this theory did not consider Uranus and Venus, which rotates in a clockwise direction. This is opposing to the counterclockwise rotation of other planets. If this theory is correct, all the planets should be moving in the same direction. Key Points Nebula means cloud. This indicates that stars originate from interstellar gas and dust. There are three major steps on how the solar system is formed according to nebular theory. These are cloud collapse, formation of the protoplanetary disk, and growth of planets. 31  Terrestrial planets include Mercury, Venus, Earth, and Mars. These would eventually form closer to the sun. Jovian planets composed of Jupiter, Saturn, Uranus, and Neptune are huge planets made up of gases without land surfaces. These planets were formed farther from the sun. The nebular theory can be credited to Swedenborg, Kant, and Laplace. Web Links For further information, you can check the following web links: Click this link to deepen your knowledge on the nebular theory. OHMS Science Class Videos. 2014. ‘The Nebular Theory.’ https://www.youtube.com/watch?v=PL3YNQK960Y Listen to this short lecture to make the nebular theory clear to you. London Jenks. 2014. ‘Nebular Hypothesis - Formation of the Solar System’ https://www.youtube.com/watch?v=y7eXbIPSYes 32  Lesson 1.4: Encounter Theory Objectives In this lesson, you should be able to: explain the origin of the solar system based on the encounter theory; differentiate the planetesimal and tidal theory; be familiar with the proponents of the planetesimal and tidal theory; and enumerate the negative implications of the planetesimal and tidal theory. Warm-Up Planet Formation Material: electronic gadget with an internet connection Procedure: 1. Click this link to watch a one-minute video clip on how dust traps aid in forming the planets. How does planet formation happen? Tech Insider. 2017. ‘Scientists have found how Planet Formation Occurs.’ https://www.youtube.com/watch?v=aeNixsYTdB4 2. Take down important notes while watching the video. 3. Answer the guide questions below. 33 Guide Questions: 1. What happens when two objects bump into each other too fast? 2. Give at least two characteristics of a dust trap. 3. What is the importance of dust traps? Learn about It 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. The encounter theory has several forms, including the planetesimal theory and the tidal theory. Fig. 14. The encounter theory proposes that the planets formed from the material ejected from the sun during an encounter with another star. The Planetesimal Theory According to the planetesimal theory, a passing star termed as intruding star nearly collided with the protosun. The massive gravitational pull of the intruding star causes the protosun to eject filaments of material. These materials condensed into planetesimals from which the planets were formed through accretion. Unlike the nebular theory which describes Earth starting from molten mass, the planetesimal theory describes Earth starting from a solid mass smaller than its present size. The oceans and the atmosphere were formed on Earth through volcanic activities. 34 Proponents of the Planetesimal Theory The planetesimal theory was proposed by an American geologist, Thomas Chrowder Chamberlin and an American astronomer, Forest Ray Moulton in 1905. Moulton started working with Chamberlin when he took graduate studies in Chicago. As opposed to what Kelvin proposed on the age of Earth, Chamberlin realized that Earth was older. He proposed that accretion of minute solid particles created planets and their moons rather than by gaseous or liquid material condensation. However, Moulton provides mathematical calculations to Chamberlin’s idea making it into a solid theory. Thomas Chrowder Chamberlin Forest Ray Moulton (1843–1928) (1843–1928) Drawbacks of the Planetesimal Theory This theory is no longer accepted today due to the fact that hot material from the sun expands and dissipates rather than contract. In addition, the force from the passing star will pull dust and gases far away from the sun, that they would not be able to form the planets in the solar system. The Tidal Theory The tidal theory explains that the solar system formed as a result of a near collision between a passing star and the sun. However, unlike the planetesimal theory, the tidal theory proposes that the hot gas from the passing star condensed into planets instead of condensing into planetesimals. When the star passed near 35 the sun, the gravitational attraction pulled the mass of dust and gas from the remaining nebula around the sun. The gas particles then condensed into liquid and solid states. The particles clump together to form cosmic bodies of different sizes. These bodies further condensed into planets. Therefore, the interaction from the gravity of the passing star and the sun led to the formation of the planets in the solar system. The materials closer to the sun are denser. This explains the positions of the terrestrial planets near the sun. In contrast, the materials from the passing star are less dense; thus, explaining the positions of the Jovian planets. Proponents of the Tidal Theory The tidal theory was proposed by James Jeans, an English physicist, and astronomer, and Harold Jeffreys, an English mathematician, and astronomer in 1918. Drawbacks of the Tidal Theory One problem of the tidal theory is that the hot material from either star cannot contract. Thus, planets will not form. Key Points The encounter theory proposes that the planets formed from the material ejected from the sun during an encounter with another celestial object. It has several forms, including the planetesimal theory and the tidal theory. The planetesimal theory describes Earth starting from a solid mass smaller than its present size. ○ It was proposed by an American geologist Thomas Chrowder Chamberlin and an American astronomer Forest Ray Moulton. ○ It is no longer accepted today due to the fact that hot material from the sun will expand and dissipate rather than contract. 36  The tidal theory proposes that the hot gas from the passing star condensed into planets instead of condensing into planetesimals. ○ It was proposed by James Jeans, an English physicist, and astronomer, and Harold Jeffreys, an English mathematician, and astronomer. ○ One problem of the tidal theory is that the hot material from either star cannot contract. Thus, planets will not form. Web Links For further information, you can check the following web links: Watch this video to make the difference of the planetesimal theory and nebular theory clear to you. Daniel Gaies. 2014. ‘Planetesimal Theory versus Nebular Theory’ https://www.youtube.com/watch?v=12PkSkgo_mU View this video to help you visualize what is the planetesimal theory talking about Rose Ann Antonio. 2013. ‘Planetesimal Theory’ https://www.youtube.com/watch?v=Ct-BMiK7NSE 37