Origin and Structure of the Earth PDF

ORIGIN OF THE UNIVERSE FORMATION OF THE UNIVERSE  The science of cosmology provides several hypotheses explaining the beginning of the universe based on the present physical and chemical properties of the universe. There numerous versions, but the most widely accepted ones are based on c...

ORIGIN OF THE UNIVERSE FORMATION OF THE UNIVERSE  The science of cosmology provides several hypotheses explaining the beginning of the universe based on the present physical and chemical properties of the universe. There numerous versions, but the most widely accepted ones are based on current scientific observations and available evidences that support the claims Among the theories that have been thoroughly investigated and have gained the most support include the big bang theory, the cosmic inflation theory, and the steady state theory.  IF YOU WERE AN ASTRONAUT AND THERE IS ALREADY ADVANCED TECHNOLOGY TO TRAVEL TO DIFFERENT PLANETS, WHICH PLANET WOULD YOU FIRST VISIT? WHAT PLANET IS THE MOST INTERESTING TO YOU? BIG BANG THEORY ▪ Began as a single point, then expanded to grow and is still expanding. ▪ Georges Lemaitre – proposed the theory ▪ US physicist Arno Allan Penzias and radio-astronomer Robert Woodrow Wilson discovered the cosmic microwave background (CMB) COSMIC INFLATION THEORY ▪ Alan Guth and Andrei Linde ▪ Underwent extremely rapid expansion after the Big Bang and has been expanding ever since. ▪ When the universe was just 10-34 of a second or so old — that is, a hundredth of a billionth of a trillionth of a trillionth of a second in age — it experienced an incredible burst of expansion known as inflation, in which space itself expanded faster than the speed of light. STEADY STATE THEORY ▪ Always expanding, but it maintains the same density. ▪ The theory was first put forward in 1948 by British scientists Sir Hermann Bondi, Thomas Gold, and Sir Fred Hoyle. It was further developed by Hoyle. ▪ Sir James Hopwood Jeans was an English physicist and mathematician who was the first to propose that matter is continuously created throughout the universe.  1. Nebular Hypothesis ▪ Immanuel Kant and Pierre-Simon Laplace ▪ A spinning cloud of dust (nebula) flattened into a protoplanetary disk. 2. Planetesimal Theory ORIGIN OF SOLAR ▪ Viktor S. Safronov, Thomas Chrowder Chamberlin, and SYSTEM Forest Ray Moulton ▪ A star collided with the sun that formed planets from accretion of small space bodies (planetesimals). 3. Tidal Theory ▪ James Jeans and Sir Harold Jeffreys ▪ Tidal Forces – Matter was pulled out from the Sun due to a passing massive object. CHARACTERISTICS OF EARTH THAT SUPPORT LIFE 1. It occupies a circumstellar habitable zone. 2. It has available energy-rich sunlight to support life. 3. It has a magnetic field. 4. It has an atmosphere rich in Nitrogen and Oxygen. 5. It has relatively stable climate and temperature. CHARACTERISTICS OF EARTH THAT SUPPORT LIFE 1. Habitable Zone (Goldilocks Zone) The Earth occupies a circumstellar habitable zone which receives the right range of radiant energy so that water stays in liquid form. Water in liquid form is essential for the functioning of biological systems. CHARACTERISTICS OF EARTH THAT SUPPORT LIFE 1. Habitable Zone CHARACTERISTICS OF EARTH THAT SUPPORT LIFE 2. Energy-rich Sunlight Earth is at the right position from the sun that enables it to harness enough amount of sunlight. CHARACTERISTICS OF EARTH THAT SUPPORT LIFE 3. Magnetic Field The magnetic field protects the Earth by shielding it against the sun’s harmful charged particles called Solar Wind. CHARACTERISTICS OF EARTH THAT SUPPORT LIFE 4. Atmosphere Acts as the next layer of protection against the sun’s harmful radiation. Provides chemicals needed for life, such as nitrogen and oxygen. CHARACTERISTICS OF EARTH THAT SUPPORT LIFE 5. Stable Climate and Temperature The relative stability of Earth’s climate and temperature is important for the formation of biological molecules. For living things, it allows them to adapt and evolve gradually.  In what way does Earth’s molten, metallic core help protect Earth’s life forms? CONCEPT Why is Earth’s location in the solar system CHECKS ideal for the development of complex-life forms such as humans? Explain why Earth is just the right size to support life? THE EARTH’S SUBSYSTEM SYSTEMS  A group of interacting, or interdependent, parts that form a complex whole. EARTH’S INTERACTING PARTS  This is a diagrammatic representation— essentially a simple box model—of Earth as a system of interacting parts. Each character represents one of the four major reservoirs (or subsystems), and each arrow represents a flow of materials or energy. EARTH AS A CLOSED SYSTEM  Earth essentially operates as a closed system. Energy reaches Earth from an external source and eventually returns to space as long-wavelength radiation, but the matter within the system is basically fixed. The subsystems within Earth are open systems, freely exchanging matter and energy. THE EARTH’S SUBSYSTEMS  Geosphere  Hydrosphere  Atmosphere  Biosphere THE EARTH’S SUBSYSTEMS  Geosphere It Includes all the soil, rocks, and minerals present in the crust to the core of the Earth. It is divided into three layers namely crust, mantle, and core. THE EARTH’S SUBSYSTEMS  Hydrosphere Includes all the water, ice, and vapor of the Earth. It is comprised of 97% saltwater and 3% freshwater. THE EARTH’S SUBSYSTEMS  Atmosphere Includes all air which envelops the entire Earth. A mixture of different gases. Supports life directly and indirectly. THE EARTH’S SUBSYSTEMS  Biosphere Includes all living things on Earth. It extends to the upper areas of the atmosphere to the deep parts of the oceans. EARTH SUBSYSTEMS  Geosphere - the solid Earth, consisting of the entire planet from the center of the core to the outer crust  Hydrosphere - all of Earth’s water, which circulates among oceans, continents, glaciers, and atmosphere.  Atmosphere - the gaseous layer above the Earth’s surface, mostly nitrogen and oxygen, with smaller amounts of argon, carbon dioxide, and other gases. The atmosphere is held to Earth by gravity and thins rapidly with altitude.  Biosphere - the zone of Earth comprising all forms of life in the sea, on land, and in the air.