AEFUNAI HPS 106 Lecture Notes PDF

GOOD MORNING www.google.com/universe AEFUNAI HPS 106: HISTORY AND PHILOSOPHY OF SCIENCE MODULE 1:MAN AND HIS COSMIC ENVIRONMENT/NATURAL RESOURCES INSTRUCTOR: PROF. A.C. EKWE JULY 2024  GROUND RULES!! Be on Time Come Prepared to...

GOOD MORNING www.google.com/universe AEFUNAI HPS 106: HISTORY AND PHILOSOPHY OF SCIENCE MODULE 1:MAN AND HIS COSMIC ENVIRONMENT/NATURAL RESOURCES INSTRUCTOR: PROF. A.C. EKWE JULY 2024  GROUND RULES!! Be on Time Come Prepared to Learn Respect Yourself and Others NO PHONE CALLS Join good study groups  INTENDED LEARNING OUTCOMES  When you complete this module and all the in and out-of-class activities, you will Use concept maps to explain the Cosmos (Universe) Use well labelled diagrams to explain the solar system Use lucid examples to demonstrate why the Earth is a unique planet. Use clear and well labelled diagrams to show the layers of the Earth’s Atmosphere and the major subdivisions of the Earth Teach others  LEARNING AND TEACHING METHODS The course will be delivered through a combination of several Student Centered learning techniques: Quescussion Think-pair-shair Buzz groups Brainstorming sessions Minute Papers Role Plays  INSTRUCTIONAL MATERIALS  MULTIMEDIA PROJECTORS  WHITE BOARDS  VIDEO CLIPS  PICTURES  POWERPOINT SLIDES Reading Text Indumati Rao and C. N. R. Rao 2005: Learning Science Part 1: Universe, Solar System, Earth; Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India. 91 pp.  MAN AND HIS COSMIC ENVIRONMENT The cosmic environment is the entire universe in which we live. It includes all things from microscopic particles to the biggest galaxies Man depends on air, heat, water and other natural resources from the entire cosmos, particularly his own earth and the sun for survival. We will try to understand the meaning of universe by taking an imaginary journey through space. Your spaceship is about to blast off into space. Stage One of our Journey: 1.6 million (1.6X106)Kilometers into Space 1.6 million kilometers into Space Earth, Moon, Stars Source: Indumati and Rao , 2006 Earth’s Atmosphere Earth’s Surface  STAGE TWO : 1.6 billion (1.6 X 109) kilometers into space Mercury, Venus, Earth and Mars close to the sun. They look bigger than they actually are Source: Indumati and Rao , 2006  STAGE THREE: 1.6 x 1011 kilometers into space. You can see all the planets. The sun looks prominent and the earth looks small. You can see the Milky Way clearly. Source: Indumati and Rao , 2006 STAGE FOUR: Far distance into space. The distance from the earth can no longer be measured in… kilometers It has to be measured in light-years ( The distance travelled by light in space in one year) One light-year = 9.41 x 1010 kilometres  STAGE FIVE: 16 light years into space Earth’s Atmosphere The Milky Way dominates your view. The sun and the planets look tiny. You can see some stars which are close to the sun shining brightly Source: Indumati and Rao , 2006  STAGE SIX: 1.6 million light-years into intergalactic space Our sun is just a speck. It is almost lost in the group of millions of other stars. You can see many new clusters of stars that you cannot see from the Earth. Source: Indumati and Rao , 2006 STAGE SEVEN: FAR DISTANCE INTO INTERGALACTIC SPACE Your view may look like this galaxies stars Intergalactic dust Source: Indumati and Rao , 2006 All things from microscopic particles to the biggest galaxies are part of the universe. All Space, including All Stars intergalactic dust The Planets UNIVERSE (COSMOS)  How was the universe formed? Astronomers postulated that a fiery explosion, now called the “Big Bang” occurred about 15 billion years ago. Immediately after the explosion, the universe expanded rapidly from the size of a pin to about 2,000 times the size of the sun. The elementary particles fused to form hydrogen and helium gas - the life blood of the universe. These particles later formed the galaxies, stars and planets The Big Bang  THE EXPANDING UNIVERSE Towards the end of the 1920’s, Edwin P. Hubble (1889-1953) showed that, the galaxies were moving away from each other and moving in all directions. That is, the universe is expanding all the time in all directions. Edwin P. Hubble is considered to be the founder of extragalactic astronomy – the branch of astronomy that studies the existence of other galaxies. Hubble received many honours for his outstanding contributions to astronomy. The most advanced telescope to study intergalactic world is named after him. Recently, Americans launched the James Webb telescope to study distant galaxies The Hubble telescope  GALAXIES On a cloudless new moon night, we can see a faint band of white light sparkling across the sky. This band consists of millions and millions of stars. The stars appear in groups or clusters. Group or clusters of stars are called galaxies. The white band of stars seen across the sky is the Milky Way galaxy. Our sun is in its outer arm. THE SUN Source: Indumati and Rao , 2006  In addition to stars, galaxies also contain cosmic dust and gases. Sir William Herschel, the famous 18th century astronomer, called them “islands in the sky”. There are millions of galaxies in the universe. Galaxies are millions of light-years apart from each other.There is vast empty space between them.  MILKY WAY GALAXY- OUR HOME IN THE VAST UNIVERSE The Milky Way galaxy contains around 200 billion stars. The stars are too far away from us to be seen individually or by the naked eye. The light from these stars forms a glowing haze in the sky as their light blends with the interstellar dust and gas.  There are millions of galaxies in the universe All the galaxies do not have the same Shape, Spiral shape Elliptical shape Hubble classification Size Number of Stars Source: Indumati and Rao , 2006  CONCEPT MAP OF THE UNIVERSE The Earth Planets Man and other creatures http://prezi.com/dlo6vvbbrh9c/universe-concept-map/  Exploring the Solar System The sun is only one of the millions of stars moving through space. Yet, what makes this average star special? It is the only star known to have a family of its own. Wherever the sun goes in the celestial sky, its family follows it. Source: Indumati and Rao , 2006  How did the solar family begin? There are two theories about the birth of the solar system. THEORY 1 According to an earlier theory, astronomers believed that long ago, a star passed very close to our sun. The star and our sun nearly collided. As a result, large quantities of various materials were thrown off into space. After a long time, these materials formed the planets. The sun held the planets in place. This theory has serious drawbacks. Source: Indumati and Rao , 2006  THEORY 2 1. According to modern astronomy, the solar system was formed from a slowly spinning cloud of gas and dust. 2. Gradually, the cloud began to spin faster and faster. This formed a large spinning disk about the size of the solar system - with a large spinning whirl at the centre and smaller whirls surrounding it at various distances. 3. The huge and heavy centre became hot enough to start the thermonuclear reaction. As a result, the centre began to glow and became our sun. 4. The smaller whirls attracted more and more particles from the cloud of dust and gases and grew in size, forming the planets at varying distances from the Sun Source: Indumati and Rao , 2006  GOD created the Solar system and the Universe In Genesis Chapter 1: 14-19, God created the Sun, Moon, Stars and the entire Universe.  The Planets have two major classes Class one: Inner Planets The four planets – Mercury,Venus, Earth and Mars are closer to the sun. They are called the inner (Terrestrial or Earth-like) planets Class Two: Outer Planets The other four planets - Jupiter, Saturn, Uranus and Neptune are called the outer (Jovian) planets. How about Pluto? Pluto is now a dwarf Planet Source: Indumati and Rao , 2006  Why is Pluto a dwarf Planet? In August 2006, Pluto was categorized as a dwarf planet because it failed some of the criteria outlined by the International Astronomical Union (IAU) for a heavenly body to be called a Planet. Pluto has been downgraded because it does not dominate its neighbourhood. Pluto's large Moon, Charon is about half its size while all the true planets are far larger than their moons. In addition, bodies that dominate their neighbourhoods, "sweep up" asteroids, comets, and other debris, clearing a path along their orbits. By contrast, Pluto's orbit is somewhat untidy and its orbit crossed that of other planets Any clue from the Planets? Let’s ask an Astronomer!!!  Solar family or the solar system Apart from the eight planets, solar family includes Tiny sand-like objects as well as gigantic rocks. Moons. Thousands of asteroids. Millions of meteors. Millions of comets. All the members of the solar system revolve around the sun along their respective paths at varying speeds. Comets Asteroids and Meteors Source: Indumati and Rao , 2006  The Moons The moons are the natural satellites revolving around the planets in the solar system. Except Mercury and Venus, all the other planets have moons. While the Earth and Pluto have one moon each, Uranus has 15, Jupiter 16, and Saturn 18. The size and composition of the moons vary. Some moons are only a few kilometres in diameter, while others are larger than the planet Mercury. While the earth’s moon is rocky, Saturn’s Moon is ~ 50% ice. Satellites, Io, Europa, Ganymede and Callisto of Jupiter are Galilean moons. They were discovered by Galileo in 1610. Lo Europa Ganymede Callisto Source: NASA  Asteroid Belt A ring of space rocks between the orbits of Mars (the last of the inner planets) and Jupiter (the first of the outer planets). Asteroids also orbit the Sun. What are meteors? Meteors are the stony or metallic pieces travelling around the sun. There are billions of meteors in the solar system. When a meteor enters the earth’s atmosphere, it streaks across the sky as a Shooting star. While most of the meteors burn out in the earth’s atmosphere, some big ones land on earth.Those that land on earth are called Meteorites. Comets A comet is an icy small Solar System body(SSSB) that, when close enough to the Sun, displays a visible Coma(a thin, fuzzy, temporary atmosphere) and sometimes also a Tail. Halley’s comet is the most famous comet. It visits the earth once in 76 years. Its most recent visit was in 1986. Source: NASA  Earth - the unique planet In the entire solar system, life as we know it, exists only on earth. This is due, among other factors, to The water cycle. The rock cycle. The carbon dioxide cycle. The oxygen cycle.  Oxygen CO2 Source: Indumati and Rao , 2006 and NASA  Shape of the Earth The Earth is not a perfect sphere. It bulges at the equator and is slightly flattened at the poles. This shape is called an oblate spheroid. Source: Indumati and Rao , 2006  THE SOLAR RAYS AND EARTH’S ATMOSPHERE The sun provides heat and light to all the members of the solar system. But the sun’s radiation includes harmful gamma rays, x-rays and ultraviolet rays. The earth’s atmosphere protects the earth from the harmful gamma rays radiation. The Earth’s Atmosphere is simply defined as the gaseous envelope that surrounds the Earth. There are five layers in the Earth’s Atmosphere namely: Troposphere Stratosphere (The upper layer contains the Ozone layer) Mesosphere Thermosphere/Ionosphere/Magnetosphere Exosphere  http://www.google.com.ng/atm Watch this!!  ROTATION AND REVOLUTION OF THE EARTH Rotation is the spinning of the Earth on its axis. The time for one rotation is 24 hours A revolution occurs as the earth moves around the sun. Time for one revolution = 365 1/4 days Rotation of the Earth causes Day and Night while Revolution brings about the Seasons Let’s see how!!! OTHER FACTS ABOUT ROTATION AND REVOLUTION 1. Does the sun move, or is it stationary in the middle of the solar system? The sun certainly does rotate - it has a rotational period of about 25 days. Not only does the sun rotate, but it also orbits the centre of our galaxy, completing one orbit every 226 million years or so, at a speed of 220 km/s. 2. How about the Moon? Well, the Moon does rotate. In fact, the Moon takes 27.3 days to turn once on its axis. But the Moon also takes 27.3 days to complete one orbit around the Earth. Because the Moon’s rotation time is exactly the same amount of time it takes to complete an orbit, it always presents the same face to the Earth, and one face away.  BRAIN STORM!! 1. The Earth spinning on its axis. Rotation Revolution 2. Going around a larger body. Rotation Revolution Revolution 3. The earth spins once in 24 hours. Rotation Revolution 4. What causes the Earth’s seasons? Rotation Revolution 5. Earth’s yearly trip round the Sun Rotation Revolution 6. The moon going around Earth. Rotation Revolution  THE LAYERS OF THE EARTH The earth has THREE distinct layers: 0 km Upper Crust SiAl The Crust 40 km Lower Crust SiMa Upper Mantle 2900km The Mantle Peridotite Lower Mantle 5200km Outer Core Liquid The Core Inner Core 6400km Solid The Layers Source: Indumati and Rao , 2006 THE PROCESSES THAT OCCUR ON EARTH ARE DRIVEN BY TWO ENGINES EXTERNAL HEAT ENGINE The earth’s external heat engine is driven by the solar energy received by the earth’s surface It is responsible for: Erosion by wind and rain Weathering. Weather and climate Water cycle. Ocean Currents INTERNAL HEAT ENGINE Melts rocks. Throws out magma. Supplies energy to build and move continents around. Pushes up the mountains Drives the plates and trigger earthquakes and other GeoHazards like Tsunami and Landslides  EARTH AS A ROCK FACTORY In this factory, rocks are made and unmade at all times without a break. The raw materials are never in short supply here. There is never any power shut down and the work force never quits. Source: Indumati and Rao , 2006  MAN AND HIS NATURAL RESOURCES TYPES OF NATURAL RESOURCES Renewable resources Renewable resources may be defined as resources that have the potential to be replaced over time by natural processes e.g. Solar energy, Wind energy, Geothermal energy etc Living resources Living resources are important to us because they give us food. Some examples are cattle, blackberries, pork, strawberries, Forests etc. Non renewable resources Nonrenewable resources may be defined as resources whose stock or reserves is limited or fixed. The available supply of nonrenewable resources may be replenished through recycling (e.g. recycling aluminum cans), but the overall supply remains relatively constant.The table below gives several examples of each type of resource e.g. Crude oil, coal, gold, sliver, copper etc.  Group the following into Renewable and Non-renewable resources Gold Silver Copper Limestone Quartz Marble Petroleum Coal Galena Coal Diamond Spharelite Talc  HAVE WE LEARNT ANYTHING?  When you complete this module and all the in and out-of-class activities, you will Use concept maps to explain the Cosmos (Universe) Use well labelled diagrams to explain the solar system Use lucid examples to demonstrate why the Earth is a unique planet. Use clear and well labelled diagrams to show the various layers within the Earth’s Atmosphere and major subdivisions of the Earth Thank you!!!!!