Big Bang Theory PDF

Supporting evidences for the Big Bang theory - Galaxies moving away by Edwin Hubble, 1924. The distance between galaxies is increasing with time - CMB, by Arno Penzias and Robert Wilson, 1960. Is speculated to be the remnant energy left from the formation of the universe, the after...

Supporting evidences for the Big Bang theory - Galaxies moving away by Edwin Hubble, 1924. The distance between galaxies is increasing with time - CMB, by Arno Penzias and Robert Wilson, 1960. Is speculated to be the remnant energy left from the formation of the universe, the afterglow - Abundance of light elements, massive amounts of He and H with traces of Li and Be REDSHIFT: - Red shift towards the red end of the spectrum, occurs because light waves are stretched which shows that the Earth and the source are moving away from each other (also known as Doppler shift) What will be the future of the universe? 1. Big Crunch - Expansion will eventually slow down and all matter will contract into singularity, starting another cycle 2. Big Freeze - Based on current observations, might be a possible outcome - Overtime, galaxies will expand in an accelerating rate and stars will die out (acceleration controlled by dark energy) - Universe will be cold and dark, reaching maximum entropy 3. Big Rip - Also might be a possible outcome - Dark energy grows stronger overtime, expanding galaxies and overcoming the gravitational force - It may cause destruction; Atoms and matter comes apart, scattered Steady state theory - Proposition that the universe and density is constant, always existing (Bondi, Gold, and Hoyle, 1948). - The universe doesn’t change its appearance and is homogenous. - Old dying stars get replaced by new stars - The universe never had a beginning and end, it has always existed Inflation theory - Rapid expansion after the Big Bang and explained further its functions - Lasted for a very short time - Uses an inflationary field for the accelerating expansion, the energy left turns into matter and radiation, joining the universe and the stars Flatness - why is the universe flat? Things seem to be curved even though it looks flat. Horizon - Why does the universe look the same in all directions? Spaces in opposite directions are far apart; they could never have contact with each other, which explains the angles of the universe being the same. Regions became closer before expansion Monopole - Why haven't we observed magnetic monopoles (hypothetical particles)? Big bang produces magnetic monopoles and dropped exponentially to undetectable matter during rapid expansion SOLAR SYSTEM Etymology There are many planetary systems like ours in the universe, with planets orbiting a host star. Our planetary system is called "the solar system" because we use the word "solar" to describe things related to our star, after the Latin word for Sun, "solis." Early solar system models Slingshot maneuver - slingshot; gravity assist maneuver, or swing-by is the use of the relative movement (e.g. orbit around the Sun) and gravity of a planet or other astronomical object to alter the path and speed of a spacecraft, typically to save propellant and reduce expense. Rene Discartes - “Vortex Theory” - French philosopher and mathematician - Principa philosophiae (1644) - sun is at the center of a vortex, with rotating invisible matter and swirling planets (leaves in a whirlpool - Every star is a sun, with its vortex, the cosmos are a sea of vortices Georges-Louis Leclerc, Comte de Buffon - “Collision Theory” - French naturalist, mathematician, cosmologist - Proposed that a comet struck the sun into pieces and became planets of the solar system - the Earth was scorching, but gradually it cooled until molten rock turned to dry land and clouds rained down to form oceans - estimated the entire process took over 75,000 years Immanuel Kant - "Nebular Theory” - a German philosopher - published Allgemeine Naturgeschichte und Theorie des Himmels (General Natural History and Theory of the Heavens) - suggested that the gravitational forces in a slowly rotating nebula would gradually flatten it and create within it several denser clouds of gas which would separately compact themselves into distinct spheres, the Sun, and planets Marquis Pierre Simon de Laplace "Solar Nebular Theory" - a French astronomer - the Sun, planets, and their moons began as a whirling cloud of gas - Exposition du système du monde (Exposition of the System of the World) (1796) 1. Collapse - High temp gas ball collapse then heat up and then become disk shape 2. Spinning - Disk spins faster and faster and temp decreased 3. Flattening - Disk become sphere due to rotation, because of fast rotation, some of the fog escape 4. Condensation - Some fog formed the core of the largest mass in the middle, while small part formed around cooling process 5. Accretion - Cores of smaller mass turns into planets, while most remain in a high-temp flare Members of the Solar System Sun - yellow dwarf star - Brings light and warmth - Center of the solar system - Giant ball of glowing gases - Makes lots of energy Solar winds - a continual stream of protons and electrons from the sun’s outermost atmosphere, corona Mercury - rocky crust with craters - closest to the sun - Hot-cold halves - Gray in color - Smallest planet Venus - the hottest planet / “Evening star” - Second planet from the sun - Orange in color - A twin of Earth but with poisonous fog Earth - third planet from the sun - Only planet with liquid water - (possible) Only planet with living things? Mars - red because of iron (iii) oxide dust - Has 2 moons named Phobos and Deimos - Volcanoes and Canyons - Rocks and Sand - Very Thin Atmosphere Jupiter - Largest planet - A giant ball of swirling gas - Has between 80 and 95 moons - Has two very thin rings - Has a large red spot, which is a giant storm - Has the shortest day (10.5 hrs.) Saturn - Has rings that are made up of Frozen gas, ice, and rock - Second Largest Planet - Made mostly of hydrogen and helium Uranus - Looks like it is on its side 90° angle - Very cold and windy - Has Some rings - Blue-green in color (methane) Neptune - Most distant major planet - Two dark spots - Blue in color (methane) - First planet located through mathematical calculations Classification: Terrestrial planets (Mercury, Venus, Earth, Mars) - They are often referred to as the "rocky planets" due to their solid, rocky composition. - Solid, rocky surfaces - High density - Few or no moons - No rings Jovian planets (Jupiter, Saturn, Uranus, Neptune) - “Gas giants” - substantially larger - long orbital periods and numerous satellites - made up mostly of gases (primarily hydrogen & helium) - move quickly in space - have rings and many moons - have a diameter of greater than 48,000 km Other Members of the Solar System Dwarf Planets (Pluto*, Eris, Hauma, Makemake, Ceres) - celestial bodies that orbit the Sun - essentially spherical due to their own gravity, but are not large enough to sweep their orbits - clear of other debris - "cleared the neighborhood" *: PLUTO - Used to be considered a planet - One of Neptune's moons - Gray in color - In August 2006 the International Astronomical Union (IAU) downgraded the status of Pluto to that of a "dwarf planet." Moons. - Diverse in shapes, sizes, and compositions. - Some might have atmospheres and hidden oceans - Most moons likely formed from leftover material around their planets during the solar system's early stages. (protoplanetary disk - matter condensed and clumped together to form moons.) - Some moons may have been captured from elsewhere in space. Asteroids - Sometimes called minor planets - are rocky, airless remnants left over from the early formation of our solar system about 4.6 billion years ago. NEAR - Shoemaker / (Near Earth Asteroid Rendezvous - Shoemaker) - renamed after Eugene Shoemaker - monitors near-Earth asteroids - landed successfully on 21-mile long asteroid Eros on February 12, 2001 Comet - Icy body that releases gases as it orbits the Sun - Dust tail: prominent trail or dust and gases generally. in direction of solar wind but curves toward comet path - Ion tail: trail of plasma streams back from the solar wind - Hydrogen envelope: Invisible, irregular cloud surrounding the coma - Coma: vapor cloud surrounding the nucleus - Nucleus: Solid comet core, may be hidden by coma Source of Comets Oort Cloud (Jan Oort) - cosmographical boundary of the solar system - source of long-period comets Long - period comets - take hundreds of thousands of years to complete a single orbit around the Sun Kuiper Belt (Gerald Kuiper) - hosts short-period comets Short - period comets - orbital periods of less than 200 years - Halley's Comet (76 years) - Encke's Comet (3 years) HISTORY OF THE EARTH EARTH Earth is approximately 4.6 billion years old (4.6 x 109) - Rocks of the crust provide clues to Earth’s past - By analyzing these clues, we can infer events from the past. ROCK - Rocks record geological and evolutionary changes throughout Earth’s history. TIME - Without a time perspective, events have little meaning. UNIFORMATISM - James Hutton - Major assumption in geology - Events in the past occurred the same way that they are occurring today. - “The present is the key to the past”. GEOLOGIC DATING  1) Orovician-Silurian Extinction ○ Around 450m years ago. ○ Massive glaciation and sea level drop (Two extinction events) ○ Affected Brachipods, Trilobites, Graptolites, and Moss Animals 2) Late Devonian Extinction ○ Around 375m years ago ○ Global anoxia and forest evolution ○ Affected Coral-sponge reefs in tropics, fish, and plankton 3) Permian-Triassic Extinction - “The Great Dying” ○ Around 251m years ago ○ Unstable climate, but possibly contributed by asteroid/comet impact ○ Affected all life, mainly marine invertebrates, land plants, plankton, and insects 4) Triassic-Jurassic Extinction ○ Around 200m years ago ○ Volcano eruptions, climate change, and gas hydrate release ○ Affected large amphibians, crurotarsans (except crocodiles), insects, and conodonts 5) Cretaceous-Teritary Extinction ○ Around 65m years ago ○ Asteriod impact at Chicxulub Crater ○ Affected Dinosaurs (except birds), pterosaurs, plesiosaurs, mosasaurs, and ammonoids 6) Present ○ Hasn’t happened yet (Next 100+ years) ○ Most rapid extinction event ○ Possibility caused by human activity Relative Dating - “Youngest to Oldest” - Used to determine if a rock or fossil is younger or older than another. an object/event is younger or older than another object/event from history. qualitative. relative age of the remains. less specific less expensive and time-efficient. It works best for sedimentary rocks having layered arrangement of sediments. STRATIGRAPHY (RELATIVE DATING) Nicolaus Steno - He argued that rock layers are laid down in succession, and that each represents a "slice" of time. PRINCIPLE OF ORIGINAL HORIZONTALITY - Sedimentary layers are deposited in approximately horizontal sheets. - If layers are folded, episodes of deformation must have occurred after rocks formed. - Age of folding is younger than the youngest deformed rock unit. PRINCIPLE OF SUPERPOSITION - Rock layer above is younger than the ones below it. (Oldest on bottom, youngest on top) - May not apply to rocks that have been folded (can get turned upside-down) - It is valid only for the dating of an 'undisturbed' sample of soil or rock. PRINCIPLE OF CROSS-CUTTING RELATIONSHIPS - Any feature (e.g. fault or intrusion) that cuts across rocks is younger than the youngest rock that is cut. - This means igneous intrusions, extrusions, faults and folds are younger than the rock they are in. PRINCIPLE OF INCLUSION - Objects enclosed in a rock must be older than the time of rock formation - Inclusions or fragments in a rock unit are older than the rock itself Absolute Dating - Determines the estimated age of a corresponding ancient rock or fossil. - Numerical dating the age of a rock/object using radiometric techniques. quantitative. helps determine the exact age of the remains. more specific expensive and time-consuming. It works best for igneous and metamorphic rocks. Radioactive decay - occurs when the nuclei of unstable atoms break down, changing the original atoms into atoms of another element. - half-life is the amount of time it takes for half the atoms of a substance to decay into another element - different substances have different half-life’s examples are Uranium 238 and Carbon 14 FOSSILS