It states that at some moment all of space was contained in a single point of very high-density and high-temperature state from which the universe has been expanding in all directions ever since. • Sun was considered young and slowly rotating. In the following section, you will find out how the period, between the 4,600 million years and the present, led to the evolution of life on the surface of the planet. A large number of hypotheses were put forth by different philosophers and scientists regarding the origin of the earth. It talks of a singular huge explosion unimaginable in physical terms. Oceans began to have the contribution of oxygen through the process of photosynthesis. STEADY STATE THEORY. Although it is the most studied planet, it cannot be completely understood in isolation. The study covers looking at landscapes to work out how the earth surface processes, such as air, water and ice, can mould the landscape. This portion of blasted material then continued to orbit the earth and eventually formed into the present moon about 4.44 billion years ago. It was proposed by Forrest R. Moulton and Thomas C. Chamberlin about 1900. Also, the origin of many phenomena like earthquakes, volcanoes, tsunami etc are linked with the structure of earth's interior. From the outermost end of the atmosphere to the centre of the earth, the material that exists is not uniform. There are three stages in the evolution of the present atmosphere. Origin of Earth By- S M Zaki Ahmad 2. The record of life that existed on this planet in different periods is found in rocks in the form of fossils. One of the earlier and popular arguments was by German philosopher Immanuel Kant. The earth was mostly in a volatile state during its primordial stage. It was also suggested that the material forming the moon was separated from what we have at present the depression occupied by the Pacific Ocean. Assumptions 1. In 1796, a mathematician Pierre-Simon Laplace reexamined it. Image of Binary Star Hypothesis - Russell. Earth was hot glowing ball of white hot gases. 7 Theories of Origin of Earth – Part – 2 YouTube Lecture Handouts. The formation of stars is believed to have taken place some 5-6 billion years ago. This tells us that the oceans are as old as 4,000 million years. These small-rounded objects by the process of cohesion develop into what is called planetesimals. Your email address will not be published. ; Modern measurements place this moment at approximately 13.8 billion years ago. Class 11 – Chapter 2 – Origin and Evolution of Earth. EVOLUTION OF THE EARTH . Due to gradual increase in density the temperature inside has increased. The early atmosphere, with hydrogen and helium, is supposed to have been stripped off as a result of the solar winds. Origin of Earth. Notify me of follow-up comments by email. A. I. Oparin (1894-1980) was a Russian Scientist. A large number of hypothesis were put forth by different philosophers and scientists regarding the origin of the earth. 7 Theories of Origin of Earth - Part - 2 . Mathematician Laplace revised it in 1796. Introduction. Explain the purpose of Juno Mission and discuss how it would be useful in understanding about formation of Earth. The chemistry of meteorites and Sun provide constraints on the composition of the bulk of the Earth. Most of them are much larger than the terrestrial planets and have thick atmosphere, mostly of helium and hydrogen. It is now generally accepted that the event of big bang took place 13.7 billion years before the present. This means the scorching ultraviolet rays from the Sun could easily reach the surface of the Earth. Nebula – It is a primordial (primitive) amorphous (without shape) mass of cloud of gas and dust. • The early atmosphere largely contained water vapour, nitrogen, carbon dioxide, methane, ammonia and very little of free oxygen. In 1950, Otto Schmidt in Russia and Carl Weizascar in Germany somewhat revised the ‘nebular hypothesis’, though differing in details. Like the origin of the earth, there have been attempts to explain how the moon was formed. Then suddenly with a bang, the Universe began to expand at an incredible rate and matter, energy, space and time came into being. Origin of magmas : Mantle, onset of partial melting of mantle, processes of partial melting in mantle, mantle-magmas in relation to degree and depth-level of partial melting. These initial density differences gave rise to differences in gravitational forces and it caused the matter to get drawn together. Buffon was the first scientist to give a scientific explanation regarding the origin of the earth and solar system in 1754. Continue your investigation of the moon’s origin. 3. From the surface to deeper depths, the earth’s interior has different zones and each of these contains materials with different characteristics. Earth - Earth - Development of Earth’s structure and composition: The origin of Earth in its present form has long been the subject of intellectual interest, but since the mid-20th century scientists have made particularly significant advances both in concepts and in measurements. This document is highly rated by UPSC … This is far from the present day picture of the earth. The theory failed to explain how the planetesimals had become one planet; Gaseous Tidal Theory. One of the earlier and popular arguments was by German philosopher Immanuel Kant. Bring out the distinctions between the continental drift theory and the plate tectonics theory. It suggests that about 1370 crore (13.7 billion) years ago, all matter and energy in the universe was concentrated into an area smaller than an atom. 1) Laplace, 2) Chamberlain, 3) James Jean , 4) Hoyle, 5) NULL One of the earlier and popular arguments was by German philosopher Immanuel Kant. You can experiment and find what does the expanding universe mean. The rest four are called Jovian or Gas Giant planets. 2. Origin of the Earth: A large number of hypotheses were put forth by different philosophers and scientists regarding the origin of the earth. At this instant, matter, energy, space and time were not existent. Solar system: origin, formation and characteristics of planets, Earth: shape and rotation. Even if the Earth ac- Class 11 – Chapter 2 – Origin and Evolution of Earth. detailed illustrated notes covering entire syllabus, Life Cycle of River YouTube Lecture Handouts, Mountain Building Classification YouTube Lecture Handouts, Mountain Building Theories- YouTube Lecture Handouts: Part 1 to 2, Origin of Earth 3 Theories YouTube Lecture Handouts, Slope Development YouTube Lecture Handouts, Examrace Geography Series (Postal Course), Origin of Earth Next Theories YouTube Lecture Handouts. However, one of the hypotheses namely “Nebular Hypothesis” given by Immanuel Kant and revised by Laplace became more popular.. This started the evolution of the present atmosphere. It can be assumed that life began to evolve sometime 3,800 million years ago. Bowen’s reaction principle : Reaction series and its application to petrogenesis. Particles of gases were compressed together, giving off heat. Mathematician ; Laplace revised it in 1796. It blasted a large part of the earth into space. inanimate matter into living substance. 4.6 billion years ago. (iii) Binary star concept or trihybrid concept (involving more than two heavenly bodies). The following are considered to be the stages in the development of planets : (i) The stars are localised lumps of gas within a nebula. The Big Bang theory attempts to explain to us the origin of universe. One of the earlier and popular arguments was by German philosopher Immanuel Kant. Origin of Earth By- S M Zaki Ahmad 2. Get top class preparation for UGC right from your home: Get detailed illustrated notes covering entire syllabus: point-by-point for high retention. Nebula (Slowly rotating cloud of gas) and the matter was comprised of very cold, solid, and motionless particles. The nebula from which our Solar system is supposed to have been formed, started its collapse and core formation some time 5-5.6 billion years ago and the planets were formed about 4.6 billion years ago.