AST 105 1st Edition Lecture 2Outline of Last Lecture I. Numbersa. Names for Large Powersb. Mass of Electron II. The Largest Object in the Solar (the Sun) a. Characteristics & Composition b. Differential Rotation III. Temperature Scale NamesOutline of Current Lecture (Lecture 2) I. Kelvin and Helmholtza. Kelvin Scaleb. Joules c. Chemical Reactions and the Sun II. Sun’s Atmosphere a. 3 layersb. Surface Features c. Magnetic Fieldsd. Other FeaturesIII. Galileo Kelvin and Helmholtz - Suggested that gravitational collapse produced chemical reactions Gives off energy (heat) - A chemical reaction gives off about 10-19 joules of energy per atom - Joules = Watt x Second- Joules = energy- Watts = power- Second = time - Sun has about 1057 atoms 3.9x1026 watts 10-19 Joules (watts) per second / atoms= 3.9x1045 atoms/second10 57 atoms 3.9x1045atoms/seconds = 3x1011 seconds 10,000 years (as 1 yr=3x107 seconds)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.- Thus, the sun would only burn for 10,000 years if it’s energy was just chemical reactions “But the sun has been around for waaaaay longer than 10,000 years.”- Fossil record on Earth shows life for 3.5 Billion years- Thus, chemical reactions cannot be the source of the suns energyo Kelvin and Helmholtz’s theory that chemical reactions are the source of the suns energy, is false. Kelvin Scale - Absolute temp. scale- 0 kelvin all motion of the particle ceases can never exactly achieve this but can get closeSun’s Atmosphere- Photosphere 5,800 K gives off visible light - Chromosphere 10,000 K gives off ultra violet- Corona Approaches 106 K Gives off mostly X-raysSurface Features of the Sun - Granules are convection cells- Sun spots are dark and cooler spots on the sun’s surface 4500 K 11 year cycle of sun spot activity - a magnetic field is located where the sun spots are- filaments – dark streaks created by arching magnetic field lines- prominences – filaments viewed on edge Magnetic Fields- located where sunspots- can produce a force on a charged particlePicture taken from EducationPortal.com found via Google Image searchGalileo - “first person to really identify sun spots”- First to determine the rotation of the sun (via
View Full Document