NR150 1st Edition Lecture 3 Outline of Last Lecture I Info on Marine Resources II Physical Marine Resources III Energetic Marine Resources IV Biological Marine Resources V Non Extractive Marine Resources Outline of Current Lecture I What is Science and How Does it Work II The Big Bang Theory III Stars IV Galaxies V Our Solar System VI How the Moon Formed VII How Water Vapor and Oceans Formed Current Lecture I What is Science and How Does it Work 1 The systematic process of asking questions about the observable world 2 Step One Systematic process of asking questions 3 Step Two Forming a working hypothesis 4 Hypothesis Speculation about the observable world that can be tested 5 Step Three when a hypothesis is consistently supported by observations or experiments then it is advanced to the status of theory 6 Theories may change as our knowledge and our powers of observation change II The Big Bang Theory 1 all matter was condensed in on tiny place 2 then there was a big bang and the matter started expanding 3 Edwin Hubble a changed our understanding of the universe b confirmed the existence of other galaxies c showed that the universe is expanding d Made a theory called Hubble s Law of Expansion which stated that red shifts are going away from you and blue shifts are coming toward you e with this he proved the universe is expanding 4 Formation of Matter a the universe continued to expand and as it expanded its temperature cooled These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute b the energy of each particle started to decrease III Stars 1 Stars begin as protostars 2 spend 90 of their life time fusing hydrogen into helium 3 this fusion generates the light we see 4 once hydrogen energy is used up the core contracts and forms heavier elements 5 in its final stage iron forms IV Galaxies 1 huge rotating aggregation of stars dust and gas 2 the galaxy we live in is the milky way V Our Galaxy 1 objects composing our solar system condensed about 5 billion years ago from a thin cloud that had been enriched by heavy elements made in exploding stars 2 Accretion the clumping of small masses into larger masses 3 period of accretion latest about 30 50 million years 4 the protosun became the sun 5 Earth s Magnetic Shield a protects earth from incoming solar radiation solar storms etc b pressure began to melt the inside of earth c core is the densest part of earth and is made of iron d because we are rotating and the core is iron the magnetic shield is formed e suns solar storms would just blow away our atmosphere without the shield f the iron core of earth created a magnetic field that shields us from solar storms which is why we have an atmosphere g solar flares go around earth h solar flares the go through the shield at the poles are responsible for the northern lights i when sun spots gets a certain size it gets a number j the more sun spots there are the more active it is VI How the Moon Formed 1 a planetary body somewhat larger than mars smashed into earth and knocked earth of its axis 2 tilted axis is what gives un different seasons 3 if it were straight we would always get the same amount of rays and have no seasons 4 finding water on the moon makes us think it had a little bit of plate tectonics 5 the primary physical property that sorts the earth ocean and atmosphere is density stratification These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute 6 heaviest part of earth is the core 7 young earth was hot and molten VII How Water Vapor and Oceans Formed 1 Water Vapor a sun stripped away earth s first atmosphere b gasses including water vapor released by the process outgassing replaced the atmosphere c greenhouse gasses are necessary for the atmosphere d water vapor condensed into cloud e water droplets form f were probably very hot and evaporated again g boiled back into the cloud h oceans were probably much hotter than they are today i Icy comets may have slammed into earth and melted to give us the water we have 2 Oceans a outgassing b icy comets c probably a combination of both d icy comets probably got water to the moon e Intense bombardment of the early earth by large bodies probably lasted until about 3 8 billion years ago These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute