GEP 111 Introduction to the Natural Environment (PDF)

GEP 111 Introduction to the Natural Environment The Universe IB van Zuydam Department of Geography, Environmental Science and Planning UNISWA (Adapted from Prof. Thomas Schlueter)  The Universe The Universe...

GEP 111 Introduction to the Natural Environment The Universe IB van Zuydam Department of Geography, Environmental Science and Planning UNISWA (Adapted from Prof. Thomas Schlueter)  The Universe The Universe comprises vast expanses of almost empty space, widely separated clouds of gases, dusts and billions of galaxies. A galaxy is a large group of stars held together by their mutual gravitational attraction. The largest galaxy that has been identified is the Milky Way Galaxy, which is disc-shaped and consists of more than two hundred billion stars. It is only one of a billion galaxies that make up the Universe. Our source of information: The Hubble Telescope  Universe and Our Solar System Our solar system is located some 30000 light years (1 light year = 9.5 X 1012 km) from the centre of the Milky way. The origin of our universe is not quite understood, but the Big Bang Theory has been used to explain its formation.  Early Phases of the Universe Gravity altered the composition of the cloud and caused it to be drawn into smaller gas clouds each held together by its own internal gravitational attraction. It is believed that the contraction of these smaller clouds resulted in the generation of heat (up to 11 million degrees centigrades) which caused the thermal fusion that gave births to stars. A series of these stellar fusions resulted in the formation of elements that are heavier than helium.  The Big Bang Theory: Though the Big Bang Theory has been developed and refined over the years, it remains the only theory that fits most of the known facts about the planetary system and has been accepted by the scientific community as an explanation of the origin of the planetary system. According to the Big Bang Theory, some 13 billion years ago, all matter in space was concentrated into one tiny mass sometimes called the „cosmic egg“.  The Cosmic Egg and its Explosion: The formation of the cosmic egg is not understood, but it is believed that the Universe was formed as a result of the explosion of the cosmic egg. This explosion is what is referred to as the Big Bang. The violence of this explosion caused the dense mass of the cosmic egg to be reduced to subatomic particles, which reassembled to form a mixture of hydrogen and helium cloud. Big Bang Theory Spiral Galaxy Galaxies  GALAXIES Some galaxies occur alone or in pairs, or associations known as groups, clusters, and superclusters. Our Milky Way, for instance, is in the Local Group, a galaxy group about 10 million light-years across that also includes the Andromeda galaxy and its satellites. The Local Group and its neighbour galaxy cluster, the Virgo Cluster, both lie within the larger Virgo Supercluster, a concentration of galaxies that stretches about 100 million light- years across. The Virgo Supercluster, in turn, is a limb of Laniakea, an even bigger supercluster of 100,000 galaxies that astronomers defined in 2014. Galaxies in clusters often interact and even merge together Our own Milky Way will merge with the Andromeda galaxy in about 4.5 billion years. Galaxies A Galaxy Seen from the Moon of a Planet Big Bang Big Bang Big Bang Big Bang  Big Bang and CERN These stars eventually exploded as so-called supernovas, spreading their heavy elements throughout the galaxy. The stars and our sun were formed from these supernova stars. In 2008, scientists set up an experiment at the CERN Institute near Geneva in Switzerland that tried to restage what took place during the Big Bang and how the planets were formed. CERN-Large Hadron Collider”? The “Large Hadron Collider”? "Large" refers to its size, approximately 27km in circumference "Hadron" because it accelerates protons or ions, which belong to the group of particles called hadrons "Collider" because the particles form two beams travelling in opposite directions, which are made to collide at four points around the machine CERN complex near Geneva CERN laboratory